xref: /sqlite-3.40.0/src/os_win.c (revision 3e4e697d)
1 /*
2 ** 2004 May 22
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 ******************************************************************************
12 **
13 ** This file contains code that is specific to Windows.
14 */
15 #include "sqliteInt.h"
16 #if SQLITE_OS_WIN               /* This file is used for Windows only */
17 
18 /*
19 ** Include code that is common to all os_*.c files
20 */
21 #include "os_common.h"
22 
23 /*
24 ** Include the header file for the Windows VFS.
25 */
26 #include "os_win.h"
27 
28 /*
29 ** Compiling and using WAL mode requires several APIs that are only
30 ** available in Windows platforms based on the NT kernel.
31 */
32 #if !SQLITE_OS_WINNT && !defined(SQLITE_OMIT_WAL)
33 #  error "WAL mode requires support from the Windows NT kernel, compile\
34  with SQLITE_OMIT_WAL."
35 #endif
36 
37 #if !SQLITE_OS_WINNT && SQLITE_MAX_MMAP_SIZE>0
38 #  error "Memory mapped files require support from the Windows NT kernel,\
39  compile with SQLITE_MAX_MMAP_SIZE=0."
40 #endif
41 
42 /*
43 ** Are most of the Win32 ANSI APIs available (i.e. with certain exceptions
44 ** based on the sub-platform)?
45 */
46 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(SQLITE_WIN32_NO_ANSI)
47 #  define SQLITE_WIN32_HAS_ANSI
48 #endif
49 
50 /*
51 ** Are most of the Win32 Unicode APIs available (i.e. with certain exceptions
52 ** based on the sub-platform)?
53 */
54 #if (SQLITE_OS_WINCE || SQLITE_OS_WINNT || SQLITE_OS_WINRT) && \
55     !defined(SQLITE_WIN32_NO_WIDE)
56 #  define SQLITE_WIN32_HAS_WIDE
57 #endif
58 
59 /*
60 ** Make sure at least one set of Win32 APIs is available.
61 */
62 #if !defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_WIN32_HAS_WIDE)
63 #  error "At least one of SQLITE_WIN32_HAS_ANSI and SQLITE_WIN32_HAS_WIDE\
64  must be defined."
65 #endif
66 
67 /*
68 ** Define the required Windows SDK version constants if they are not
69 ** already available.
70 */
71 #ifndef NTDDI_WIN8
72 #  define NTDDI_WIN8                        0x06020000
73 #endif
74 
75 #ifndef NTDDI_WINBLUE
76 #  define NTDDI_WINBLUE                     0x06030000
77 #endif
78 
79 #ifndef NTDDI_WINTHRESHOLD
80 #  define NTDDI_WINTHRESHOLD                0x06040000
81 #endif
82 
83 /*
84 ** Check to see if the GetVersionEx[AW] functions are deprecated on the
85 ** target system.  GetVersionEx was first deprecated in Win8.1.
86 */
87 #ifndef SQLITE_WIN32_GETVERSIONEX
88 #  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINBLUE
89 #    define SQLITE_WIN32_GETVERSIONEX   0   /* GetVersionEx() is deprecated */
90 #  else
91 #    define SQLITE_WIN32_GETVERSIONEX   1   /* GetVersionEx() is current */
92 #  endif
93 #endif
94 
95 /*
96 ** Check to see if the CreateFileMappingA function is supported on the
97 ** target system.  It is unavailable when using "mincore.lib" on Win10.
98 ** When compiling for Windows 10, always assume "mincore.lib" is in use.
99 */
100 #ifndef SQLITE_WIN32_CREATEFILEMAPPINGA
101 #  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINTHRESHOLD
102 #    define SQLITE_WIN32_CREATEFILEMAPPINGA   0
103 #  else
104 #    define SQLITE_WIN32_CREATEFILEMAPPINGA   1
105 #  endif
106 #endif
107 
108 /*
109 ** This constant should already be defined (in the "WinDef.h" SDK file).
110 */
111 #ifndef MAX_PATH
112 #  define MAX_PATH                      (260)
113 #endif
114 
115 /*
116 ** Maximum pathname length (in chars) for Win32.  This should normally be
117 ** MAX_PATH.
118 */
119 #ifndef SQLITE_WIN32_MAX_PATH_CHARS
120 #  define SQLITE_WIN32_MAX_PATH_CHARS   (MAX_PATH)
121 #endif
122 
123 /*
124 ** This constant should already be defined (in the "WinNT.h" SDK file).
125 */
126 #ifndef UNICODE_STRING_MAX_CHARS
127 #  define UNICODE_STRING_MAX_CHARS      (32767)
128 #endif
129 
130 /*
131 ** Maximum pathname length (in chars) for WinNT.  This should normally be
132 ** UNICODE_STRING_MAX_CHARS.
133 */
134 #ifndef SQLITE_WINNT_MAX_PATH_CHARS
135 #  define SQLITE_WINNT_MAX_PATH_CHARS   (UNICODE_STRING_MAX_CHARS)
136 #endif
137 
138 /*
139 ** Maximum pathname length (in bytes) for Win32.  The MAX_PATH macro is in
140 ** characters, so we allocate 4 bytes per character assuming worst-case of
141 ** 4-bytes-per-character for UTF8.
142 */
143 #ifndef SQLITE_WIN32_MAX_PATH_BYTES
144 #  define SQLITE_WIN32_MAX_PATH_BYTES   (SQLITE_WIN32_MAX_PATH_CHARS*4)
145 #endif
146 
147 /*
148 ** Maximum pathname length (in bytes) for WinNT.  This should normally be
149 ** UNICODE_STRING_MAX_CHARS * sizeof(WCHAR).
150 */
151 #ifndef SQLITE_WINNT_MAX_PATH_BYTES
152 #  define SQLITE_WINNT_MAX_PATH_BYTES   \
153                             (sizeof(WCHAR) * SQLITE_WINNT_MAX_PATH_CHARS)
154 #endif
155 
156 /*
157 ** Maximum error message length (in chars) for WinRT.
158 */
159 #ifndef SQLITE_WIN32_MAX_ERRMSG_CHARS
160 #  define SQLITE_WIN32_MAX_ERRMSG_CHARS (1024)
161 #endif
162 
163 /*
164 ** Returns non-zero if the character should be treated as a directory
165 ** separator.
166 */
167 #ifndef winIsDirSep
168 #  define winIsDirSep(a)                (((a) == '/') || ((a) == '\\'))
169 #endif
170 
171 /*
172 ** This macro is used when a local variable is set to a value that is
173 ** [sometimes] not used by the code (e.g. via conditional compilation).
174 */
175 #ifndef UNUSED_VARIABLE_VALUE
176 #  define UNUSED_VARIABLE_VALUE(x)      (void)(x)
177 #endif
178 
179 /*
180 ** Returns the character that should be used as the directory separator.
181 */
182 #ifndef winGetDirSep
183 #  define winGetDirSep()                '\\'
184 #endif
185 
186 /*
187 ** Do we need to manually define the Win32 file mapping APIs for use with WAL
188 ** mode or memory mapped files (e.g. these APIs are available in the Windows
189 ** CE SDK; however, they are not present in the header file)?
190 */
191 #if SQLITE_WIN32_FILEMAPPING_API && \
192         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
193 /*
194 ** Two of the file mapping APIs are different under WinRT.  Figure out which
195 ** set we need.
196 */
197 #if SQLITE_OS_WINRT
198 WINBASEAPI HANDLE WINAPI CreateFileMappingFromApp(HANDLE, \
199         LPSECURITY_ATTRIBUTES, ULONG, ULONG64, LPCWSTR);
200 
201 WINBASEAPI LPVOID WINAPI MapViewOfFileFromApp(HANDLE, ULONG, ULONG64, SIZE_T);
202 #else
203 #if defined(SQLITE_WIN32_HAS_ANSI)
204 WINBASEAPI HANDLE WINAPI CreateFileMappingA(HANDLE, LPSECURITY_ATTRIBUTES, \
205         DWORD, DWORD, DWORD, LPCSTR);
206 #endif /* defined(SQLITE_WIN32_HAS_ANSI) */
207 
208 #if defined(SQLITE_WIN32_HAS_WIDE)
209 WINBASEAPI HANDLE WINAPI CreateFileMappingW(HANDLE, LPSECURITY_ATTRIBUTES, \
210         DWORD, DWORD, DWORD, LPCWSTR);
211 #endif /* defined(SQLITE_WIN32_HAS_WIDE) */
212 
213 WINBASEAPI LPVOID WINAPI MapViewOfFile(HANDLE, DWORD, DWORD, DWORD, SIZE_T);
214 #endif /* SQLITE_OS_WINRT */
215 
216 /*
217 ** These file mapping APIs are common to both Win32 and WinRT.
218 */
219 
220 WINBASEAPI BOOL WINAPI FlushViewOfFile(LPCVOID, SIZE_T);
221 WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);
222 #endif /* SQLITE_WIN32_FILEMAPPING_API */
223 
224 /*
225 ** Some Microsoft compilers lack this definition.
226 */
227 #ifndef INVALID_FILE_ATTRIBUTES
228 # define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
229 #endif
230 
231 #ifndef FILE_FLAG_MASK
232 # define FILE_FLAG_MASK          (0xFF3C0000)
233 #endif
234 
235 #ifndef FILE_ATTRIBUTE_MASK
236 # define FILE_ATTRIBUTE_MASK     (0x0003FFF7)
237 #endif
238 
239 #ifndef SQLITE_OMIT_WAL
240 /* Forward references to structures used for WAL */
241 typedef struct winShm winShm;           /* A connection to shared-memory */
242 typedef struct winShmNode winShmNode;   /* A region of shared-memory */
243 #endif
244 
245 /*
246 ** WinCE lacks native support for file locking so we have to fake it
247 ** with some code of our own.
248 */
249 #if SQLITE_OS_WINCE
250 typedef struct winceLock {
251   int nReaders;       /* Number of reader locks obtained */
252   BOOL bPending;      /* Indicates a pending lock has been obtained */
253   BOOL bReserved;     /* Indicates a reserved lock has been obtained */
254   BOOL bExclusive;    /* Indicates an exclusive lock has been obtained */
255 } winceLock;
256 #endif
257 
258 /*
259 ** The winFile structure is a subclass of sqlite3_file* specific to the win32
260 ** portability layer.
261 */
262 typedef struct winFile winFile;
263 struct winFile {
264   const sqlite3_io_methods *pMethod; /*** Must be first ***/
265   sqlite3_vfs *pVfs;      /* The VFS used to open this file */
266   HANDLE h;               /* Handle for accessing the file */
267   u8 locktype;            /* Type of lock currently held on this file */
268   short sharedLockByte;   /* Randomly chosen byte used as a shared lock */
269   u8 ctrlFlags;           /* Flags.  See WINFILE_* below */
270   DWORD lastErrno;        /* The Windows errno from the last I/O error */
271 #ifndef SQLITE_OMIT_WAL
272   winShm *pShm;           /* Instance of shared memory on this file */
273 #endif
274   const char *zPath;      /* Full pathname of this file */
275   int szChunk;            /* Chunk size configured by FCNTL_CHUNK_SIZE */
276 #if SQLITE_OS_WINCE
277   LPWSTR zDeleteOnClose;  /* Name of file to delete when closing */
278   HANDLE hMutex;          /* Mutex used to control access to shared lock */
279   HANDLE hShared;         /* Shared memory segment used for locking */
280   winceLock local;        /* Locks obtained by this instance of winFile */
281   winceLock *shared;      /* Global shared lock memory for the file  */
282 #endif
283 #if SQLITE_MAX_MMAP_SIZE>0
284   int nFetchOut;                /* Number of outstanding xFetch references */
285   HANDLE hMap;                  /* Handle for accessing memory mapping */
286   void *pMapRegion;             /* Area memory mapped */
287   sqlite3_int64 mmapSize;       /* Size of mapped region */
288   sqlite3_int64 mmapSizeMax;    /* Configured FCNTL_MMAP_SIZE value */
289 #endif
290 };
291 
292 /*
293 ** The winVfsAppData structure is used for the pAppData member for all of the
294 ** Win32 VFS variants.
295 */
296 typedef struct winVfsAppData winVfsAppData;
297 struct winVfsAppData {
298   const sqlite3_io_methods *pMethod; /* The file I/O methods to use. */
299   void *pAppData;                    /* The extra pAppData, if any. */
300   BOOL bNoLock;                      /* Non-zero if locking is disabled. */
301 };
302 
303 /*
304 ** Allowed values for winFile.ctrlFlags
305 */
306 #define WINFILE_RDONLY          0x02   /* Connection is read only */
307 #define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */
308 #define WINFILE_PSOW            0x10   /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
309 
310 /*
311  * The size of the buffer used by sqlite3_win32_write_debug().
312  */
313 #ifndef SQLITE_WIN32_DBG_BUF_SIZE
314 #  define SQLITE_WIN32_DBG_BUF_SIZE   ((int)(4096-sizeof(DWORD)))
315 #endif
316 
317 /*
318  * If compiled with SQLITE_WIN32_MALLOC on Windows, we will use the
319  * various Win32 API heap functions instead of our own.
320  */
321 #ifdef SQLITE_WIN32_MALLOC
322 
323 /*
324  * If this is non-zero, an isolated heap will be created by the native Win32
325  * allocator subsystem; otherwise, the default process heap will be used.  This
326  * setting has no effect when compiling for WinRT.  By default, this is enabled
327  * and an isolated heap will be created to store all allocated data.
328  *
329  ******************************************************************************
330  * WARNING: It is important to note that when this setting is non-zero and the
331  *          winMemShutdown function is called (e.g. by the sqlite3_shutdown
332  *          function), all data that was allocated using the isolated heap will
333  *          be freed immediately and any attempt to access any of that freed
334  *          data will almost certainly result in an immediate access violation.
335  ******************************************************************************
336  */
337 #ifndef SQLITE_WIN32_HEAP_CREATE
338 #  define SQLITE_WIN32_HEAP_CREATE        (TRUE)
339 #endif
340 
341 /*
342  * This is the maximum possible initial size of the Win32-specific heap, in
343  * bytes.
344  */
345 #ifndef SQLITE_WIN32_HEAP_MAX_INIT_SIZE
346 #  define SQLITE_WIN32_HEAP_MAX_INIT_SIZE (4294967295U)
347 #endif
348 
349 /*
350  * This is the extra space for the initial size of the Win32-specific heap,
351  * in bytes.  This value may be zero.
352  */
353 #ifndef SQLITE_WIN32_HEAP_INIT_EXTRA
354 #  define SQLITE_WIN32_HEAP_INIT_EXTRA  (4194304)
355 #endif
356 
357 /*
358  * Calculate the maximum legal cache size, in pages, based on the maximum
359  * possible initial heap size and the default page size, setting aside the
360  * needed extra space.
361  */
362 #ifndef SQLITE_WIN32_MAX_CACHE_SIZE
363 #  define SQLITE_WIN32_MAX_CACHE_SIZE   (((SQLITE_WIN32_HEAP_MAX_INIT_SIZE) - \
364                                           (SQLITE_WIN32_HEAP_INIT_EXTRA)) / \
365                                          (SQLITE_DEFAULT_PAGE_SIZE))
366 #endif
367 
368 /*
369  * This is cache size used in the calculation of the initial size of the
370  * Win32-specific heap.  It cannot be negative.
371  */
372 #ifndef SQLITE_WIN32_CACHE_SIZE
373 #  if SQLITE_DEFAULT_CACHE_SIZE>=0
374 #    define SQLITE_WIN32_CACHE_SIZE     (SQLITE_DEFAULT_CACHE_SIZE)
375 #  else
376 #    define SQLITE_WIN32_CACHE_SIZE     (-(SQLITE_DEFAULT_CACHE_SIZE))
377 #  endif
378 #endif
379 
380 /*
381  * Make sure that the calculated cache size, in pages, cannot cause the
382  * initial size of the Win32-specific heap to exceed the maximum amount
383  * of memory that can be specified in the call to HeapCreate.
384  */
385 #if SQLITE_WIN32_CACHE_SIZE>SQLITE_WIN32_MAX_CACHE_SIZE
386 #  undef SQLITE_WIN32_CACHE_SIZE
387 #  define SQLITE_WIN32_CACHE_SIZE       (2000)
388 #endif
389 
390 /*
391  * The initial size of the Win32-specific heap.  This value may be zero.
392  */
393 #ifndef SQLITE_WIN32_HEAP_INIT_SIZE
394 #  define SQLITE_WIN32_HEAP_INIT_SIZE   ((SQLITE_WIN32_CACHE_SIZE) * \
395                                          (SQLITE_DEFAULT_PAGE_SIZE) + \
396                                          (SQLITE_WIN32_HEAP_INIT_EXTRA))
397 #endif
398 
399 /*
400  * The maximum size of the Win32-specific heap.  This value may be zero.
401  */
402 #ifndef SQLITE_WIN32_HEAP_MAX_SIZE
403 #  define SQLITE_WIN32_HEAP_MAX_SIZE    (0)
404 #endif
405 
406 /*
407  * The extra flags to use in calls to the Win32 heap APIs.  This value may be
408  * zero for the default behavior.
409  */
410 #ifndef SQLITE_WIN32_HEAP_FLAGS
411 #  define SQLITE_WIN32_HEAP_FLAGS       (0)
412 #endif
413 
414 
415 /*
416 ** The winMemData structure stores information required by the Win32-specific
417 ** sqlite3_mem_methods implementation.
418 */
419 typedef struct winMemData winMemData;
420 struct winMemData {
421 #ifndef NDEBUG
422   u32 magic1;   /* Magic number to detect structure corruption. */
423 #endif
424   HANDLE hHeap; /* The handle to our heap. */
425   BOOL bOwned;  /* Do we own the heap (i.e. destroy it on shutdown)? */
426 #ifndef NDEBUG
427   u32 magic2;   /* Magic number to detect structure corruption. */
428 #endif
429 };
430 
431 #ifndef NDEBUG
432 #define WINMEM_MAGIC1     0x42b2830b
433 #define WINMEM_MAGIC2     0xbd4d7cf4
434 #endif
435 
436 static struct winMemData win_mem_data = {
437 #ifndef NDEBUG
438   WINMEM_MAGIC1,
439 #endif
440   NULL, FALSE
441 #ifndef NDEBUG
442   ,WINMEM_MAGIC2
443 #endif
444 };
445 
446 #ifndef NDEBUG
447 #define winMemAssertMagic1() assert( win_mem_data.magic1==WINMEM_MAGIC1 )
448 #define winMemAssertMagic2() assert( win_mem_data.magic2==WINMEM_MAGIC2 )
449 #define winMemAssertMagic()  winMemAssertMagic1(); winMemAssertMagic2();
450 #else
451 #define winMemAssertMagic()
452 #endif
453 
454 #define winMemGetDataPtr()  &win_mem_data
455 #define winMemGetHeap()     win_mem_data.hHeap
456 #define winMemGetOwned()    win_mem_data.bOwned
457 
458 static void *winMemMalloc(int nBytes);
459 static void winMemFree(void *pPrior);
460 static void *winMemRealloc(void *pPrior, int nBytes);
461 static int winMemSize(void *p);
462 static int winMemRoundup(int n);
463 static int winMemInit(void *pAppData);
464 static void winMemShutdown(void *pAppData);
465 
466 const sqlite3_mem_methods *sqlite3MemGetWin32(void);
467 #endif /* SQLITE_WIN32_MALLOC */
468 
469 /*
470 ** The following variable is (normally) set once and never changes
471 ** thereafter.  It records whether the operating system is Win9x
472 ** or WinNT.
473 **
474 ** 0:   Operating system unknown.
475 ** 1:   Operating system is Win9x.
476 ** 2:   Operating system is WinNT.
477 **
478 ** In order to facilitate testing on a WinNT system, the test fixture
479 ** can manually set this value to 1 to emulate Win98 behavior.
480 */
481 #ifdef SQLITE_TEST
482 LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;
483 #else
484 static LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;
485 #endif
486 
487 #ifndef SYSCALL
488 #  define SYSCALL sqlite3_syscall_ptr
489 #endif
490 
491 /*
492 ** This function is not available on Windows CE or WinRT.
493  */
494 
495 #if SQLITE_OS_WINCE || SQLITE_OS_WINRT
496 #  define osAreFileApisANSI()       1
497 #endif
498 
499 /*
500 ** Many system calls are accessed through pointer-to-functions so that
501 ** they may be overridden at runtime to facilitate fault injection during
502 ** testing and sandboxing.  The following array holds the names and pointers
503 ** to all overrideable system calls.
504 */
505 static struct win_syscall {
506   const char *zName;            /* Name of the system call */
507   sqlite3_syscall_ptr pCurrent; /* Current value of the system call */
508   sqlite3_syscall_ptr pDefault; /* Default value */
509 } aSyscall[] = {
510 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
511   { "AreFileApisANSI",         (SYSCALL)AreFileApisANSI,         0 },
512 #else
513   { "AreFileApisANSI",         (SYSCALL)0,                       0 },
514 #endif
515 
516 #ifndef osAreFileApisANSI
517 #define osAreFileApisANSI ((BOOL(WINAPI*)(VOID))aSyscall[0].pCurrent)
518 #endif
519 
520 #if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)
521   { "CharLowerW",              (SYSCALL)CharLowerW,              0 },
522 #else
523   { "CharLowerW",              (SYSCALL)0,                       0 },
524 #endif
525 
526 #define osCharLowerW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[1].pCurrent)
527 
528 #if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)
529   { "CharUpperW",              (SYSCALL)CharUpperW,              0 },
530 #else
531   { "CharUpperW",              (SYSCALL)0,                       0 },
532 #endif
533 
534 #define osCharUpperW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[2].pCurrent)
535 
536   { "CloseHandle",             (SYSCALL)CloseHandle,             0 },
537 
538 #define osCloseHandle ((BOOL(WINAPI*)(HANDLE))aSyscall[3].pCurrent)
539 
540 #if defined(SQLITE_WIN32_HAS_ANSI)
541   { "CreateFileA",             (SYSCALL)CreateFileA,             0 },
542 #else
543   { "CreateFileA",             (SYSCALL)0,                       0 },
544 #endif
545 
546 #define osCreateFileA ((HANDLE(WINAPI*)(LPCSTR,DWORD,DWORD, \
547         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[4].pCurrent)
548 
549 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
550   { "CreateFileW",             (SYSCALL)CreateFileW,             0 },
551 #else
552   { "CreateFileW",             (SYSCALL)0,                       0 },
553 #endif
554 
555 #define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \
556         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)
557 
558 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
559         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0) && \
560         SQLITE_WIN32_CREATEFILEMAPPINGA
561   { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },
562 #else
563   { "CreateFileMappingA",      (SYSCALL)0,                       0 },
564 #endif
565 
566 #define osCreateFileMappingA ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
567         DWORD,DWORD,DWORD,LPCSTR))aSyscall[6].pCurrent)
568 
569 #if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
570         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
571   { "CreateFileMappingW",      (SYSCALL)CreateFileMappingW,      0 },
572 #else
573   { "CreateFileMappingW",      (SYSCALL)0,                       0 },
574 #endif
575 
576 #define osCreateFileMappingW ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
577         DWORD,DWORD,DWORD,LPCWSTR))aSyscall[7].pCurrent)
578 
579 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
580   { "CreateMutexW",            (SYSCALL)CreateMutexW,            0 },
581 #else
582   { "CreateMutexW",            (SYSCALL)0,                       0 },
583 #endif
584 
585 #define osCreateMutexW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,BOOL, \
586         LPCWSTR))aSyscall[8].pCurrent)
587 
588 #if defined(SQLITE_WIN32_HAS_ANSI)
589   { "DeleteFileA",             (SYSCALL)DeleteFileA,             0 },
590 #else
591   { "DeleteFileA",             (SYSCALL)0,                       0 },
592 #endif
593 
594 #define osDeleteFileA ((BOOL(WINAPI*)(LPCSTR))aSyscall[9].pCurrent)
595 
596 #if defined(SQLITE_WIN32_HAS_WIDE)
597   { "DeleteFileW",             (SYSCALL)DeleteFileW,             0 },
598 #else
599   { "DeleteFileW",             (SYSCALL)0,                       0 },
600 #endif
601 
602 #define osDeleteFileW ((BOOL(WINAPI*)(LPCWSTR))aSyscall[10].pCurrent)
603 
604 #if SQLITE_OS_WINCE
605   { "FileTimeToLocalFileTime", (SYSCALL)FileTimeToLocalFileTime, 0 },
606 #else
607   { "FileTimeToLocalFileTime", (SYSCALL)0,                       0 },
608 #endif
609 
610 #define osFileTimeToLocalFileTime ((BOOL(WINAPI*)(CONST FILETIME*, \
611         LPFILETIME))aSyscall[11].pCurrent)
612 
613 #if SQLITE_OS_WINCE
614   { "FileTimeToSystemTime",    (SYSCALL)FileTimeToSystemTime,    0 },
615 #else
616   { "FileTimeToSystemTime",    (SYSCALL)0,                       0 },
617 #endif
618 
619 #define osFileTimeToSystemTime ((BOOL(WINAPI*)(CONST FILETIME*, \
620         LPSYSTEMTIME))aSyscall[12].pCurrent)
621 
622   { "FlushFileBuffers",        (SYSCALL)FlushFileBuffers,        0 },
623 
624 #define osFlushFileBuffers ((BOOL(WINAPI*)(HANDLE))aSyscall[13].pCurrent)
625 
626 #if defined(SQLITE_WIN32_HAS_ANSI)
627   { "FormatMessageA",          (SYSCALL)FormatMessageA,          0 },
628 #else
629   { "FormatMessageA",          (SYSCALL)0,                       0 },
630 #endif
631 
632 #define osFormatMessageA ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPSTR, \
633         DWORD,va_list*))aSyscall[14].pCurrent)
634 
635 #if defined(SQLITE_WIN32_HAS_WIDE)
636   { "FormatMessageW",          (SYSCALL)FormatMessageW,          0 },
637 #else
638   { "FormatMessageW",          (SYSCALL)0,                       0 },
639 #endif
640 
641 #define osFormatMessageW ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPWSTR, \
642         DWORD,va_list*))aSyscall[15].pCurrent)
643 
644 #if !defined(SQLITE_OMIT_LOAD_EXTENSION)
645   { "FreeLibrary",             (SYSCALL)FreeLibrary,             0 },
646 #else
647   { "FreeLibrary",             (SYSCALL)0,                       0 },
648 #endif
649 
650 #define osFreeLibrary ((BOOL(WINAPI*)(HMODULE))aSyscall[16].pCurrent)
651 
652   { "GetCurrentProcessId",     (SYSCALL)GetCurrentProcessId,     0 },
653 
654 #define osGetCurrentProcessId ((DWORD(WINAPI*)(VOID))aSyscall[17].pCurrent)
655 
656 #if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)
657   { "GetDiskFreeSpaceA",       (SYSCALL)GetDiskFreeSpaceA,       0 },
658 #else
659   { "GetDiskFreeSpaceA",       (SYSCALL)0,                       0 },
660 #endif
661 
662 #define osGetDiskFreeSpaceA ((BOOL(WINAPI*)(LPCSTR,LPDWORD,LPDWORD,LPDWORD, \
663         LPDWORD))aSyscall[18].pCurrent)
664 
665 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
666   { "GetDiskFreeSpaceW",       (SYSCALL)GetDiskFreeSpaceW,       0 },
667 #else
668   { "GetDiskFreeSpaceW",       (SYSCALL)0,                       0 },
669 #endif
670 
671 #define osGetDiskFreeSpaceW ((BOOL(WINAPI*)(LPCWSTR,LPDWORD,LPDWORD,LPDWORD, \
672         LPDWORD))aSyscall[19].pCurrent)
673 
674 #if defined(SQLITE_WIN32_HAS_ANSI)
675   { "GetFileAttributesA",      (SYSCALL)GetFileAttributesA,      0 },
676 #else
677   { "GetFileAttributesA",      (SYSCALL)0,                       0 },
678 #endif
679 
680 #define osGetFileAttributesA ((DWORD(WINAPI*)(LPCSTR))aSyscall[20].pCurrent)
681 
682 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
683   { "GetFileAttributesW",      (SYSCALL)GetFileAttributesW,      0 },
684 #else
685   { "GetFileAttributesW",      (SYSCALL)0,                       0 },
686 #endif
687 
688 #define osGetFileAttributesW ((DWORD(WINAPI*)(LPCWSTR))aSyscall[21].pCurrent)
689 
690 #if defined(SQLITE_WIN32_HAS_WIDE)
691   { "GetFileAttributesExW",    (SYSCALL)GetFileAttributesExW,    0 },
692 #else
693   { "GetFileAttributesExW",    (SYSCALL)0,                       0 },
694 #endif
695 
696 #define osGetFileAttributesExW ((BOOL(WINAPI*)(LPCWSTR,GET_FILEEX_INFO_LEVELS, \
697         LPVOID))aSyscall[22].pCurrent)
698 
699 #if !SQLITE_OS_WINRT
700   { "GetFileSize",             (SYSCALL)GetFileSize,             0 },
701 #else
702   { "GetFileSize",             (SYSCALL)0,                       0 },
703 #endif
704 
705 #define osGetFileSize ((DWORD(WINAPI*)(HANDLE,LPDWORD))aSyscall[23].pCurrent)
706 
707 #if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)
708   { "GetFullPathNameA",        (SYSCALL)GetFullPathNameA,        0 },
709 #else
710   { "GetFullPathNameA",        (SYSCALL)0,                       0 },
711 #endif
712 
713 #define osGetFullPathNameA ((DWORD(WINAPI*)(LPCSTR,DWORD,LPSTR, \
714         LPSTR*))aSyscall[24].pCurrent)
715 
716 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
717   { "GetFullPathNameW",        (SYSCALL)GetFullPathNameW,        0 },
718 #else
719   { "GetFullPathNameW",        (SYSCALL)0,                       0 },
720 #endif
721 
722 #define osGetFullPathNameW ((DWORD(WINAPI*)(LPCWSTR,DWORD,LPWSTR, \
723         LPWSTR*))aSyscall[25].pCurrent)
724 
725   { "GetLastError",            (SYSCALL)GetLastError,            0 },
726 
727 #define osGetLastError ((DWORD(WINAPI*)(VOID))aSyscall[26].pCurrent)
728 
729 #if !defined(SQLITE_OMIT_LOAD_EXTENSION)
730 #if SQLITE_OS_WINCE
731   /* The GetProcAddressA() routine is only available on Windows CE. */
732   { "GetProcAddressA",         (SYSCALL)GetProcAddressA,         0 },
733 #else
734   /* All other Windows platforms expect GetProcAddress() to take
735   ** an ANSI string regardless of the _UNICODE setting */
736   { "GetProcAddressA",         (SYSCALL)GetProcAddress,          0 },
737 #endif
738 #else
739   { "GetProcAddressA",         (SYSCALL)0,                       0 },
740 #endif
741 
742 #define osGetProcAddressA ((FARPROC(WINAPI*)(HMODULE, \
743         LPCSTR))aSyscall[27].pCurrent)
744 
745 #if !SQLITE_OS_WINRT
746   { "GetSystemInfo",           (SYSCALL)GetSystemInfo,           0 },
747 #else
748   { "GetSystemInfo",           (SYSCALL)0,                       0 },
749 #endif
750 
751 #define osGetSystemInfo ((VOID(WINAPI*)(LPSYSTEM_INFO))aSyscall[28].pCurrent)
752 
753   { "GetSystemTime",           (SYSCALL)GetSystemTime,           0 },
754 
755 #define osGetSystemTime ((VOID(WINAPI*)(LPSYSTEMTIME))aSyscall[29].pCurrent)
756 
757 #if !SQLITE_OS_WINCE
758   { "GetSystemTimeAsFileTime", (SYSCALL)GetSystemTimeAsFileTime, 0 },
759 #else
760   { "GetSystemTimeAsFileTime", (SYSCALL)0,                       0 },
761 #endif
762 
763 #define osGetSystemTimeAsFileTime ((VOID(WINAPI*)( \
764         LPFILETIME))aSyscall[30].pCurrent)
765 
766 #if defined(SQLITE_WIN32_HAS_ANSI)
767   { "GetTempPathA",            (SYSCALL)GetTempPathA,            0 },
768 #else
769   { "GetTempPathA",            (SYSCALL)0,                       0 },
770 #endif
771 
772 #define osGetTempPathA ((DWORD(WINAPI*)(DWORD,LPSTR))aSyscall[31].pCurrent)
773 
774 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
775   { "GetTempPathW",            (SYSCALL)GetTempPathW,            0 },
776 #else
777   { "GetTempPathW",            (SYSCALL)0,                       0 },
778 #endif
779 
780 #define osGetTempPathW ((DWORD(WINAPI*)(DWORD,LPWSTR))aSyscall[32].pCurrent)
781 
782 #if !SQLITE_OS_WINRT
783   { "GetTickCount",            (SYSCALL)GetTickCount,            0 },
784 #else
785   { "GetTickCount",            (SYSCALL)0,                       0 },
786 #endif
787 
788 #define osGetTickCount ((DWORD(WINAPI*)(VOID))aSyscall[33].pCurrent)
789 
790 #if defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_GETVERSIONEX
791   { "GetVersionExA",           (SYSCALL)GetVersionExA,           0 },
792 #else
793   { "GetVersionExA",           (SYSCALL)0,                       0 },
794 #endif
795 
796 #define osGetVersionExA ((BOOL(WINAPI*)( \
797         LPOSVERSIONINFOA))aSyscall[34].pCurrent)
798 
799 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
800         SQLITE_WIN32_GETVERSIONEX
801   { "GetVersionExW",           (SYSCALL)GetVersionExW,           0 },
802 #else
803   { "GetVersionExW",           (SYSCALL)0,                       0 },
804 #endif
805 
806 #define osGetVersionExW ((BOOL(WINAPI*)( \
807         LPOSVERSIONINFOW))aSyscall[35].pCurrent)
808 
809   { "HeapAlloc",               (SYSCALL)HeapAlloc,               0 },
810 
811 #define osHeapAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD, \
812         SIZE_T))aSyscall[36].pCurrent)
813 
814 #if !SQLITE_OS_WINRT
815   { "HeapCreate",              (SYSCALL)HeapCreate,              0 },
816 #else
817   { "HeapCreate",              (SYSCALL)0,                       0 },
818 #endif
819 
820 #define osHeapCreate ((HANDLE(WINAPI*)(DWORD,SIZE_T, \
821         SIZE_T))aSyscall[37].pCurrent)
822 
823 #if !SQLITE_OS_WINRT
824   { "HeapDestroy",             (SYSCALL)HeapDestroy,             0 },
825 #else
826   { "HeapDestroy",             (SYSCALL)0,                       0 },
827 #endif
828 
829 #define osHeapDestroy ((BOOL(WINAPI*)(HANDLE))aSyscall[38].pCurrent)
830 
831   { "HeapFree",                (SYSCALL)HeapFree,                0 },
832 
833 #define osHeapFree ((BOOL(WINAPI*)(HANDLE,DWORD,LPVOID))aSyscall[39].pCurrent)
834 
835   { "HeapReAlloc",             (SYSCALL)HeapReAlloc,             0 },
836 
837 #define osHeapReAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD,LPVOID, \
838         SIZE_T))aSyscall[40].pCurrent)
839 
840   { "HeapSize",                (SYSCALL)HeapSize,                0 },
841 
842 #define osHeapSize ((SIZE_T(WINAPI*)(HANDLE,DWORD, \
843         LPCVOID))aSyscall[41].pCurrent)
844 
845 #if !SQLITE_OS_WINRT
846   { "HeapValidate",            (SYSCALL)HeapValidate,            0 },
847 #else
848   { "HeapValidate",            (SYSCALL)0,                       0 },
849 #endif
850 
851 #define osHeapValidate ((BOOL(WINAPI*)(HANDLE,DWORD, \
852         LPCVOID))aSyscall[42].pCurrent)
853 
854 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
855   { "HeapCompact",             (SYSCALL)HeapCompact,             0 },
856 #else
857   { "HeapCompact",             (SYSCALL)0,                       0 },
858 #endif
859 
860 #define osHeapCompact ((UINT(WINAPI*)(HANDLE,DWORD))aSyscall[43].pCurrent)
861 
862 #if defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
863   { "LoadLibraryA",            (SYSCALL)LoadLibraryA,            0 },
864 #else
865   { "LoadLibraryA",            (SYSCALL)0,                       0 },
866 #endif
867 
868 #define osLoadLibraryA ((HMODULE(WINAPI*)(LPCSTR))aSyscall[44].pCurrent)
869 
870 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
871         !defined(SQLITE_OMIT_LOAD_EXTENSION)
872   { "LoadLibraryW",            (SYSCALL)LoadLibraryW,            0 },
873 #else
874   { "LoadLibraryW",            (SYSCALL)0,                       0 },
875 #endif
876 
877 #define osLoadLibraryW ((HMODULE(WINAPI*)(LPCWSTR))aSyscall[45].pCurrent)
878 
879 #if !SQLITE_OS_WINRT
880   { "LocalFree",               (SYSCALL)LocalFree,               0 },
881 #else
882   { "LocalFree",               (SYSCALL)0,                       0 },
883 #endif
884 
885 #define osLocalFree ((HLOCAL(WINAPI*)(HLOCAL))aSyscall[46].pCurrent)
886 
887 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
888   { "LockFile",                (SYSCALL)LockFile,                0 },
889 #else
890   { "LockFile",                (SYSCALL)0,                       0 },
891 #endif
892 
893 #ifndef osLockFile
894 #define osLockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
895         DWORD))aSyscall[47].pCurrent)
896 #endif
897 
898 #if !SQLITE_OS_WINCE
899   { "LockFileEx",              (SYSCALL)LockFileEx,              0 },
900 #else
901   { "LockFileEx",              (SYSCALL)0,                       0 },
902 #endif
903 
904 #ifndef osLockFileEx
905 #define osLockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD,DWORD, \
906         LPOVERLAPPED))aSyscall[48].pCurrent)
907 #endif
908 
909 #if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && \
910         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
911   { "MapViewOfFile",           (SYSCALL)MapViewOfFile,           0 },
912 #else
913   { "MapViewOfFile",           (SYSCALL)0,                       0 },
914 #endif
915 
916 #define osMapViewOfFile ((LPVOID(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
917         SIZE_T))aSyscall[49].pCurrent)
918 
919   { "MultiByteToWideChar",     (SYSCALL)MultiByteToWideChar,     0 },
920 
921 #define osMultiByteToWideChar ((int(WINAPI*)(UINT,DWORD,LPCSTR,int,LPWSTR, \
922         int))aSyscall[50].pCurrent)
923 
924   { "QueryPerformanceCounter", (SYSCALL)QueryPerformanceCounter, 0 },
925 
926 #define osQueryPerformanceCounter ((BOOL(WINAPI*)( \
927         LARGE_INTEGER*))aSyscall[51].pCurrent)
928 
929   { "ReadFile",                (SYSCALL)ReadFile,                0 },
930 
931 #define osReadFile ((BOOL(WINAPI*)(HANDLE,LPVOID,DWORD,LPDWORD, \
932         LPOVERLAPPED))aSyscall[52].pCurrent)
933 
934   { "SetEndOfFile",            (SYSCALL)SetEndOfFile,            0 },
935 
936 #define osSetEndOfFile ((BOOL(WINAPI*)(HANDLE))aSyscall[53].pCurrent)
937 
938 #if !SQLITE_OS_WINRT
939   { "SetFilePointer",          (SYSCALL)SetFilePointer,          0 },
940 #else
941   { "SetFilePointer",          (SYSCALL)0,                       0 },
942 #endif
943 
944 #define osSetFilePointer ((DWORD(WINAPI*)(HANDLE,LONG,PLONG, \
945         DWORD))aSyscall[54].pCurrent)
946 
947 #if !SQLITE_OS_WINRT
948   { "Sleep",                   (SYSCALL)Sleep,                   0 },
949 #else
950   { "Sleep",                   (SYSCALL)0,                       0 },
951 #endif
952 
953 #define osSleep ((VOID(WINAPI*)(DWORD))aSyscall[55].pCurrent)
954 
955   { "SystemTimeToFileTime",    (SYSCALL)SystemTimeToFileTime,    0 },
956 
957 #define osSystemTimeToFileTime ((BOOL(WINAPI*)(CONST SYSTEMTIME*, \
958         LPFILETIME))aSyscall[56].pCurrent)
959 
960 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
961   { "UnlockFile",              (SYSCALL)UnlockFile,              0 },
962 #else
963   { "UnlockFile",              (SYSCALL)0,                       0 },
964 #endif
965 
966 #ifndef osUnlockFile
967 #define osUnlockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
968         DWORD))aSyscall[57].pCurrent)
969 #endif
970 
971 #if !SQLITE_OS_WINCE
972   { "UnlockFileEx",            (SYSCALL)UnlockFileEx,            0 },
973 #else
974   { "UnlockFileEx",            (SYSCALL)0,                       0 },
975 #endif
976 
977 #define osUnlockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
978         LPOVERLAPPED))aSyscall[58].pCurrent)
979 
980 #if SQLITE_OS_WINCE || !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
981   { "UnmapViewOfFile",         (SYSCALL)UnmapViewOfFile,         0 },
982 #else
983   { "UnmapViewOfFile",         (SYSCALL)0,                       0 },
984 #endif
985 
986 #define osUnmapViewOfFile ((BOOL(WINAPI*)(LPCVOID))aSyscall[59].pCurrent)
987 
988   { "WideCharToMultiByte",     (SYSCALL)WideCharToMultiByte,     0 },
989 
990 #define osWideCharToMultiByte ((int(WINAPI*)(UINT,DWORD,LPCWSTR,int,LPSTR,int, \
991         LPCSTR,LPBOOL))aSyscall[60].pCurrent)
992 
993   { "WriteFile",               (SYSCALL)WriteFile,               0 },
994 
995 #define osWriteFile ((BOOL(WINAPI*)(HANDLE,LPCVOID,DWORD,LPDWORD, \
996         LPOVERLAPPED))aSyscall[61].pCurrent)
997 
998 #if SQLITE_OS_WINRT
999   { "CreateEventExW",          (SYSCALL)CreateEventExW,          0 },
1000 #else
1001   { "CreateEventExW",          (SYSCALL)0,                       0 },
1002 #endif
1003 
1004 #define osCreateEventExW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,LPCWSTR, \
1005         DWORD,DWORD))aSyscall[62].pCurrent)
1006 
1007 #if !SQLITE_OS_WINRT
1008   { "WaitForSingleObject",     (SYSCALL)WaitForSingleObject,     0 },
1009 #else
1010   { "WaitForSingleObject",     (SYSCALL)0,                       0 },
1011 #endif
1012 
1013 #define osWaitForSingleObject ((DWORD(WINAPI*)(HANDLE, \
1014         DWORD))aSyscall[63].pCurrent)
1015 
1016 #if !SQLITE_OS_WINCE
1017   { "WaitForSingleObjectEx",   (SYSCALL)WaitForSingleObjectEx,   0 },
1018 #else
1019   { "WaitForSingleObjectEx",   (SYSCALL)0,                       0 },
1020 #endif
1021 
1022 #define osWaitForSingleObjectEx ((DWORD(WINAPI*)(HANDLE,DWORD, \
1023         BOOL))aSyscall[64].pCurrent)
1024 
1025 #if SQLITE_OS_WINRT
1026   { "SetFilePointerEx",        (SYSCALL)SetFilePointerEx,        0 },
1027 #else
1028   { "SetFilePointerEx",        (SYSCALL)0,                       0 },
1029 #endif
1030 
1031 #define osSetFilePointerEx ((BOOL(WINAPI*)(HANDLE,LARGE_INTEGER, \
1032         PLARGE_INTEGER,DWORD))aSyscall[65].pCurrent)
1033 
1034 #if SQLITE_OS_WINRT
1035   { "GetFileInformationByHandleEx", (SYSCALL)GetFileInformationByHandleEx, 0 },
1036 #else
1037   { "GetFileInformationByHandleEx", (SYSCALL)0,                  0 },
1038 #endif
1039 
1040 #define osGetFileInformationByHandleEx ((BOOL(WINAPI*)(HANDLE, \
1041         FILE_INFO_BY_HANDLE_CLASS,LPVOID,DWORD))aSyscall[66].pCurrent)
1042 
1043 #if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
1044   { "MapViewOfFileFromApp",    (SYSCALL)MapViewOfFileFromApp,    0 },
1045 #else
1046   { "MapViewOfFileFromApp",    (SYSCALL)0,                       0 },
1047 #endif
1048 
1049 #define osMapViewOfFileFromApp ((LPVOID(WINAPI*)(HANDLE,ULONG,ULONG64, \
1050         SIZE_T))aSyscall[67].pCurrent)
1051 
1052 #if SQLITE_OS_WINRT
1053   { "CreateFile2",             (SYSCALL)CreateFile2,             0 },
1054 #else
1055   { "CreateFile2",             (SYSCALL)0,                       0 },
1056 #endif
1057 
1058 #define osCreateFile2 ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD,DWORD, \
1059         LPCREATEFILE2_EXTENDED_PARAMETERS))aSyscall[68].pCurrent)
1060 
1061 #if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_LOAD_EXTENSION)
1062   { "LoadPackagedLibrary",     (SYSCALL)LoadPackagedLibrary,     0 },
1063 #else
1064   { "LoadPackagedLibrary",     (SYSCALL)0,                       0 },
1065 #endif
1066 
1067 #define osLoadPackagedLibrary ((HMODULE(WINAPI*)(LPCWSTR, \
1068         DWORD))aSyscall[69].pCurrent)
1069 
1070 #if SQLITE_OS_WINRT
1071   { "GetTickCount64",          (SYSCALL)GetTickCount64,          0 },
1072 #else
1073   { "GetTickCount64",          (SYSCALL)0,                       0 },
1074 #endif
1075 
1076 #define osGetTickCount64 ((ULONGLONG(WINAPI*)(VOID))aSyscall[70].pCurrent)
1077 
1078 #if SQLITE_OS_WINRT
1079   { "GetNativeSystemInfo",     (SYSCALL)GetNativeSystemInfo,     0 },
1080 #else
1081   { "GetNativeSystemInfo",     (SYSCALL)0,                       0 },
1082 #endif
1083 
1084 #define osGetNativeSystemInfo ((VOID(WINAPI*)( \
1085         LPSYSTEM_INFO))aSyscall[71].pCurrent)
1086 
1087 #if defined(SQLITE_WIN32_HAS_ANSI)
1088   { "OutputDebugStringA",      (SYSCALL)OutputDebugStringA,      0 },
1089 #else
1090   { "OutputDebugStringA",      (SYSCALL)0,                       0 },
1091 #endif
1092 
1093 #define osOutputDebugStringA ((VOID(WINAPI*)(LPCSTR))aSyscall[72].pCurrent)
1094 
1095 #if defined(SQLITE_WIN32_HAS_WIDE)
1096   { "OutputDebugStringW",      (SYSCALL)OutputDebugStringW,      0 },
1097 #else
1098   { "OutputDebugStringW",      (SYSCALL)0,                       0 },
1099 #endif
1100 
1101 #define osOutputDebugStringW ((VOID(WINAPI*)(LPCWSTR))aSyscall[73].pCurrent)
1102 
1103   { "GetProcessHeap",          (SYSCALL)GetProcessHeap,          0 },
1104 
1105 #define osGetProcessHeap ((HANDLE(WINAPI*)(VOID))aSyscall[74].pCurrent)
1106 
1107 #if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
1108   { "CreateFileMappingFromApp", (SYSCALL)CreateFileMappingFromApp, 0 },
1109 #else
1110   { "CreateFileMappingFromApp", (SYSCALL)0,                      0 },
1111 #endif
1112 
1113 #define osCreateFileMappingFromApp ((HANDLE(WINAPI*)(HANDLE, \
1114         LPSECURITY_ATTRIBUTES,ULONG,ULONG64,LPCWSTR))aSyscall[75].pCurrent)
1115 
1116 /*
1117 ** NOTE: On some sub-platforms, the InterlockedCompareExchange "function"
1118 **       is really just a macro that uses a compiler intrinsic (e.g. x64).
1119 **       So do not try to make this is into a redefinable interface.
1120 */
1121 #if defined(InterlockedCompareExchange)
1122   { "InterlockedCompareExchange", (SYSCALL)0,                    0 },
1123 
1124 #define osInterlockedCompareExchange InterlockedCompareExchange
1125 #else
1126   { "InterlockedCompareExchange", (SYSCALL)InterlockedCompareExchange, 0 },
1127 
1128 #define osInterlockedCompareExchange ((LONG(WINAPI*)(LONG \
1129         SQLITE_WIN32_VOLATILE*, LONG,LONG))aSyscall[76].pCurrent)
1130 #endif /* defined(InterlockedCompareExchange) */
1131 
1132 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
1133   { "UuidCreate",               (SYSCALL)UuidCreate,             0 },
1134 #else
1135   { "UuidCreate",               (SYSCALL)0,                      0 },
1136 #endif
1137 
1138 #define osUuidCreate ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[77].pCurrent)
1139 
1140 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
1141   { "UuidCreateSequential",     (SYSCALL)UuidCreateSequential,   0 },
1142 #else
1143   { "UuidCreateSequential",     (SYSCALL)0,                      0 },
1144 #endif
1145 
1146 #define osUuidCreateSequential \
1147         ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[78].pCurrent)
1148 
1149 #if !defined(SQLITE_NO_SYNC) && SQLITE_MAX_MMAP_SIZE>0
1150   { "FlushViewOfFile",          (SYSCALL)FlushViewOfFile,        0 },
1151 #else
1152   { "FlushViewOfFile",          (SYSCALL)0,                      0 },
1153 #endif
1154 
1155 #define osFlushViewOfFile \
1156         ((BOOL(WINAPI*)(LPCVOID,SIZE_T))aSyscall[79].pCurrent)
1157 
1158 }; /* End of the overrideable system calls */
1159 
1160 /*
1161 ** This is the xSetSystemCall() method of sqlite3_vfs for all of the
1162 ** "win32" VFSes.  Return SQLITE_OK opon successfully updating the
1163 ** system call pointer, or SQLITE_NOTFOUND if there is no configurable
1164 ** system call named zName.
1165 */
1166 static int winSetSystemCall(
1167   sqlite3_vfs *pNotUsed,        /* The VFS pointer.  Not used */
1168   const char *zName,            /* Name of system call to override */
1169   sqlite3_syscall_ptr pNewFunc  /* Pointer to new system call value */
1170 ){
1171   unsigned int i;
1172   int rc = SQLITE_NOTFOUND;
1173 
1174   UNUSED_PARAMETER(pNotUsed);
1175   if( zName==0 ){
1176     /* If no zName is given, restore all system calls to their default
1177     ** settings and return NULL
1178     */
1179     rc = SQLITE_OK;
1180     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1181       if( aSyscall[i].pDefault ){
1182         aSyscall[i].pCurrent = aSyscall[i].pDefault;
1183       }
1184     }
1185   }else{
1186     /* If zName is specified, operate on only the one system call
1187     ** specified.
1188     */
1189     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1190       if( strcmp(zName, aSyscall[i].zName)==0 ){
1191         if( aSyscall[i].pDefault==0 ){
1192           aSyscall[i].pDefault = aSyscall[i].pCurrent;
1193         }
1194         rc = SQLITE_OK;
1195         if( pNewFunc==0 ) pNewFunc = aSyscall[i].pDefault;
1196         aSyscall[i].pCurrent = pNewFunc;
1197         break;
1198       }
1199     }
1200   }
1201   return rc;
1202 }
1203 
1204 /*
1205 ** Return the value of a system call.  Return NULL if zName is not a
1206 ** recognized system call name.  NULL is also returned if the system call
1207 ** is currently undefined.
1208 */
1209 static sqlite3_syscall_ptr winGetSystemCall(
1210   sqlite3_vfs *pNotUsed,
1211   const char *zName
1212 ){
1213   unsigned int i;
1214 
1215   UNUSED_PARAMETER(pNotUsed);
1216   for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1217     if( strcmp(zName, aSyscall[i].zName)==0 ) return aSyscall[i].pCurrent;
1218   }
1219   return 0;
1220 }
1221 
1222 /*
1223 ** Return the name of the first system call after zName.  If zName==NULL
1224 ** then return the name of the first system call.  Return NULL if zName
1225 ** is the last system call or if zName is not the name of a valid
1226 ** system call.
1227 */
1228 static const char *winNextSystemCall(sqlite3_vfs *p, const char *zName){
1229   int i = -1;
1230 
1231   UNUSED_PARAMETER(p);
1232   if( zName ){
1233     for(i=0; i<ArraySize(aSyscall)-1; i++){
1234       if( strcmp(zName, aSyscall[i].zName)==0 ) break;
1235     }
1236   }
1237   for(i++; i<ArraySize(aSyscall); i++){
1238     if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;
1239   }
1240   return 0;
1241 }
1242 
1243 #ifdef SQLITE_WIN32_MALLOC
1244 /*
1245 ** If a Win32 native heap has been configured, this function will attempt to
1246 ** compact it.  Upon success, SQLITE_OK will be returned.  Upon failure, one
1247 ** of SQLITE_NOMEM, SQLITE_ERROR, or SQLITE_NOTFOUND will be returned.  The
1248 ** "pnLargest" argument, if non-zero, will be used to return the size of the
1249 ** largest committed free block in the heap, in bytes.
1250 */
1251 int sqlite3_win32_compact_heap(LPUINT pnLargest){
1252   int rc = SQLITE_OK;
1253   UINT nLargest = 0;
1254   HANDLE hHeap;
1255 
1256   winMemAssertMagic();
1257   hHeap = winMemGetHeap();
1258   assert( hHeap!=0 );
1259   assert( hHeap!=INVALID_HANDLE_VALUE );
1260 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1261   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1262 #endif
1263 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
1264   if( (nLargest=osHeapCompact(hHeap, SQLITE_WIN32_HEAP_FLAGS))==0 ){
1265     DWORD lastErrno = osGetLastError();
1266     if( lastErrno==NO_ERROR ){
1267       sqlite3_log(SQLITE_NOMEM, "failed to HeapCompact (no space), heap=%p",
1268                   (void*)hHeap);
1269       rc = SQLITE_NOMEM_BKPT;
1270     }else{
1271       sqlite3_log(SQLITE_ERROR, "failed to HeapCompact (%lu), heap=%p",
1272                   osGetLastError(), (void*)hHeap);
1273       rc = SQLITE_ERROR;
1274     }
1275   }
1276 #else
1277   sqlite3_log(SQLITE_NOTFOUND, "failed to HeapCompact, heap=%p",
1278               (void*)hHeap);
1279   rc = SQLITE_NOTFOUND;
1280 #endif
1281   if( pnLargest ) *pnLargest = nLargest;
1282   return rc;
1283 }
1284 
1285 /*
1286 ** If a Win32 native heap has been configured, this function will attempt to
1287 ** destroy and recreate it.  If the Win32 native heap is not isolated and/or
1288 ** the sqlite3_memory_used() function does not return zero, SQLITE_BUSY will
1289 ** be returned and no changes will be made to the Win32 native heap.
1290 */
1291 int sqlite3_win32_reset_heap(){
1292   int rc;
1293   MUTEX_LOGIC( sqlite3_mutex *pMainMtx; ) /* The main static mutex */
1294   MUTEX_LOGIC( sqlite3_mutex *pMem; )    /* The memsys static mutex */
1295   MUTEX_LOGIC( pMainMtx = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
1296   MUTEX_LOGIC( pMem = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); )
1297   sqlite3_mutex_enter(pMainMtx);
1298   sqlite3_mutex_enter(pMem);
1299   winMemAssertMagic();
1300   if( winMemGetHeap()!=NULL && winMemGetOwned() && sqlite3_memory_used()==0 ){
1301     /*
1302     ** At this point, there should be no outstanding memory allocations on
1303     ** the heap.  Also, since both the main and memsys locks are currently
1304     ** being held by us, no other function (i.e. from another thread) should
1305     ** be able to even access the heap.  Attempt to destroy and recreate our
1306     ** isolated Win32 native heap now.
1307     */
1308     assert( winMemGetHeap()!=NULL );
1309     assert( winMemGetOwned() );
1310     assert( sqlite3_memory_used()==0 );
1311     winMemShutdown(winMemGetDataPtr());
1312     assert( winMemGetHeap()==NULL );
1313     assert( !winMemGetOwned() );
1314     assert( sqlite3_memory_used()==0 );
1315     rc = winMemInit(winMemGetDataPtr());
1316     assert( rc!=SQLITE_OK || winMemGetHeap()!=NULL );
1317     assert( rc!=SQLITE_OK || winMemGetOwned() );
1318     assert( rc!=SQLITE_OK || sqlite3_memory_used()==0 );
1319   }else{
1320     /*
1321     ** The Win32 native heap cannot be modified because it may be in use.
1322     */
1323     rc = SQLITE_BUSY;
1324   }
1325   sqlite3_mutex_leave(pMem);
1326   sqlite3_mutex_leave(pMainMtx);
1327   return rc;
1328 }
1329 #endif /* SQLITE_WIN32_MALLOC */
1330 
1331 /*
1332 ** This function outputs the specified (ANSI) string to the Win32 debugger
1333 ** (if available).
1334 */
1335 
1336 void sqlite3_win32_write_debug(const char *zBuf, int nBuf){
1337   char zDbgBuf[SQLITE_WIN32_DBG_BUF_SIZE];
1338   int nMin = MIN(nBuf, (SQLITE_WIN32_DBG_BUF_SIZE - 1)); /* may be negative. */
1339   if( nMin<-1 ) nMin = -1; /* all negative values become -1. */
1340   assert( nMin==-1 || nMin==0 || nMin<SQLITE_WIN32_DBG_BUF_SIZE );
1341 #ifdef SQLITE_ENABLE_API_ARMOR
1342   if( !zBuf ){
1343     (void)SQLITE_MISUSE_BKPT;
1344     return;
1345   }
1346 #endif
1347 #if defined(SQLITE_WIN32_HAS_ANSI)
1348   if( nMin>0 ){
1349     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1350     memcpy(zDbgBuf, zBuf, nMin);
1351     osOutputDebugStringA(zDbgBuf);
1352   }else{
1353     osOutputDebugStringA(zBuf);
1354   }
1355 #elif defined(SQLITE_WIN32_HAS_WIDE)
1356   memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1357   if ( osMultiByteToWideChar(
1358           osAreFileApisANSI() ? CP_ACP : CP_OEMCP, 0, zBuf,
1359           nMin, (LPWSTR)zDbgBuf, SQLITE_WIN32_DBG_BUF_SIZE/sizeof(WCHAR))<=0 ){
1360     return;
1361   }
1362   osOutputDebugStringW((LPCWSTR)zDbgBuf);
1363 #else
1364   if( nMin>0 ){
1365     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1366     memcpy(zDbgBuf, zBuf, nMin);
1367     fprintf(stderr, "%s", zDbgBuf);
1368   }else{
1369     fprintf(stderr, "%s", zBuf);
1370   }
1371 #endif
1372 }
1373 
1374 /*
1375 ** The following routine suspends the current thread for at least ms
1376 ** milliseconds.  This is equivalent to the Win32 Sleep() interface.
1377 */
1378 #if SQLITE_OS_WINRT
1379 static HANDLE sleepObj = NULL;
1380 #endif
1381 
1382 void sqlite3_win32_sleep(DWORD milliseconds){
1383 #if SQLITE_OS_WINRT
1384   if ( sleepObj==NULL ){
1385     sleepObj = osCreateEventExW(NULL, NULL, CREATE_EVENT_MANUAL_RESET,
1386                                 SYNCHRONIZE);
1387   }
1388   assert( sleepObj!=NULL );
1389   osWaitForSingleObjectEx(sleepObj, milliseconds, FALSE);
1390 #else
1391   osSleep(milliseconds);
1392 #endif
1393 }
1394 
1395 #if SQLITE_MAX_WORKER_THREADS>0 && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \
1396         SQLITE_THREADSAFE>0
1397 DWORD sqlite3Win32Wait(HANDLE hObject){
1398   DWORD rc;
1399   while( (rc = osWaitForSingleObjectEx(hObject, INFINITE,
1400                                        TRUE))==WAIT_IO_COMPLETION ){}
1401   return rc;
1402 }
1403 #endif
1404 
1405 /*
1406 ** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
1407 ** or WinCE.  Return false (zero) for Win95, Win98, or WinME.
1408 **
1409 ** Here is an interesting observation:  Win95, Win98, and WinME lack
1410 ** the LockFileEx() API.  But we can still statically link against that
1411 ** API as long as we don't call it when running Win95/98/ME.  A call to
1412 ** this routine is used to determine if the host is Win95/98/ME or
1413 ** WinNT/2K/XP so that we will know whether or not we can safely call
1414 ** the LockFileEx() API.
1415 */
1416 
1417 #if !SQLITE_WIN32_GETVERSIONEX
1418 # define osIsNT()  (1)
1419 #elif SQLITE_OS_WINCE || SQLITE_OS_WINRT || !defined(SQLITE_WIN32_HAS_ANSI)
1420 # define osIsNT()  (1)
1421 #elif !defined(SQLITE_WIN32_HAS_WIDE)
1422 # define osIsNT()  (0)
1423 #else
1424 # define osIsNT()  ((sqlite3_os_type==2) || sqlite3_win32_is_nt())
1425 #endif
1426 
1427 /*
1428 ** This function determines if the machine is running a version of Windows
1429 ** based on the NT kernel.
1430 */
1431 int sqlite3_win32_is_nt(void){
1432 #if SQLITE_OS_WINRT
1433   /*
1434   ** NOTE: The WinRT sub-platform is always assumed to be based on the NT
1435   **       kernel.
1436   */
1437   return 1;
1438 #elif SQLITE_WIN32_GETVERSIONEX
1439   if( osInterlockedCompareExchange(&sqlite3_os_type, 0, 0)==0 ){
1440 #if defined(SQLITE_WIN32_HAS_ANSI)
1441     OSVERSIONINFOA sInfo;
1442     sInfo.dwOSVersionInfoSize = sizeof(sInfo);
1443     osGetVersionExA(&sInfo);
1444     osInterlockedCompareExchange(&sqlite3_os_type,
1445         (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
1446 #elif defined(SQLITE_WIN32_HAS_WIDE)
1447     OSVERSIONINFOW sInfo;
1448     sInfo.dwOSVersionInfoSize = sizeof(sInfo);
1449     osGetVersionExW(&sInfo);
1450     osInterlockedCompareExchange(&sqlite3_os_type,
1451         (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
1452 #endif
1453   }
1454   return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;
1455 #elif SQLITE_TEST
1456   return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;
1457 #else
1458   /*
1459   ** NOTE: All sub-platforms where the GetVersionEx[AW] functions are
1460   **       deprecated are always assumed to be based on the NT kernel.
1461   */
1462   return 1;
1463 #endif
1464 }
1465 
1466 #ifdef SQLITE_WIN32_MALLOC
1467 /*
1468 ** Allocate nBytes of memory.
1469 */
1470 static void *winMemMalloc(int nBytes){
1471   HANDLE hHeap;
1472   void *p;
1473 
1474   winMemAssertMagic();
1475   hHeap = winMemGetHeap();
1476   assert( hHeap!=0 );
1477   assert( hHeap!=INVALID_HANDLE_VALUE );
1478 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1479   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1480 #endif
1481   assert( nBytes>=0 );
1482   p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
1483   if( !p ){
1484     sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%lu), heap=%p",
1485                 nBytes, osGetLastError(), (void*)hHeap);
1486   }
1487   return p;
1488 }
1489 
1490 /*
1491 ** Free memory.
1492 */
1493 static void winMemFree(void *pPrior){
1494   HANDLE hHeap;
1495 
1496   winMemAssertMagic();
1497   hHeap = winMemGetHeap();
1498   assert( hHeap!=0 );
1499   assert( hHeap!=INVALID_HANDLE_VALUE );
1500 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1501   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
1502 #endif
1503   if( !pPrior ) return; /* Passing NULL to HeapFree is undefined. */
1504   if( !osHeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){
1505     sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%lu), heap=%p",
1506                 pPrior, osGetLastError(), (void*)hHeap);
1507   }
1508 }
1509 
1510 /*
1511 ** Change the size of an existing memory allocation
1512 */
1513 static void *winMemRealloc(void *pPrior, int nBytes){
1514   HANDLE hHeap;
1515   void *p;
1516 
1517   winMemAssertMagic();
1518   hHeap = winMemGetHeap();
1519   assert( hHeap!=0 );
1520   assert( hHeap!=INVALID_HANDLE_VALUE );
1521 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1522   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
1523 #endif
1524   assert( nBytes>=0 );
1525   if( !pPrior ){
1526     p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
1527   }else{
1528     p = osHeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);
1529   }
1530   if( !p ){
1531     sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%lu), heap=%p",
1532                 pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, osGetLastError(),
1533                 (void*)hHeap);
1534   }
1535   return p;
1536 }
1537 
1538 /*
1539 ** Return the size of an outstanding allocation, in bytes.
1540 */
1541 static int winMemSize(void *p){
1542   HANDLE hHeap;
1543   SIZE_T n;
1544 
1545   winMemAssertMagic();
1546   hHeap = winMemGetHeap();
1547   assert( hHeap!=0 );
1548   assert( hHeap!=INVALID_HANDLE_VALUE );
1549 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1550   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, p) );
1551 #endif
1552   if( !p ) return 0;
1553   n = osHeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);
1554   if( n==(SIZE_T)-1 ){
1555     sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%lu), heap=%p",
1556                 p, osGetLastError(), (void*)hHeap);
1557     return 0;
1558   }
1559   return (int)n;
1560 }
1561 
1562 /*
1563 ** Round up a request size to the next valid allocation size.
1564 */
1565 static int winMemRoundup(int n){
1566   return n;
1567 }
1568 
1569 /*
1570 ** Initialize this module.
1571 */
1572 static int winMemInit(void *pAppData){
1573   winMemData *pWinMemData = (winMemData *)pAppData;
1574 
1575   if( !pWinMemData ) return SQLITE_ERROR;
1576   assert( pWinMemData->magic1==WINMEM_MAGIC1 );
1577   assert( pWinMemData->magic2==WINMEM_MAGIC2 );
1578 
1579 #if !SQLITE_OS_WINRT && SQLITE_WIN32_HEAP_CREATE
1580   if( !pWinMemData->hHeap ){
1581     DWORD dwInitialSize = SQLITE_WIN32_HEAP_INIT_SIZE;
1582     DWORD dwMaximumSize = (DWORD)sqlite3GlobalConfig.nHeap;
1583     if( dwMaximumSize==0 ){
1584       dwMaximumSize = SQLITE_WIN32_HEAP_MAX_SIZE;
1585     }else if( dwInitialSize>dwMaximumSize ){
1586       dwInitialSize = dwMaximumSize;
1587     }
1588     pWinMemData->hHeap = osHeapCreate(SQLITE_WIN32_HEAP_FLAGS,
1589                                       dwInitialSize, dwMaximumSize);
1590     if( !pWinMemData->hHeap ){
1591       sqlite3_log(SQLITE_NOMEM,
1592           "failed to HeapCreate (%lu), flags=%u, initSize=%lu, maxSize=%lu",
1593           osGetLastError(), SQLITE_WIN32_HEAP_FLAGS, dwInitialSize,
1594           dwMaximumSize);
1595       return SQLITE_NOMEM_BKPT;
1596     }
1597     pWinMemData->bOwned = TRUE;
1598     assert( pWinMemData->bOwned );
1599   }
1600 #else
1601   pWinMemData->hHeap = osGetProcessHeap();
1602   if( !pWinMemData->hHeap ){
1603     sqlite3_log(SQLITE_NOMEM,
1604         "failed to GetProcessHeap (%lu)", osGetLastError());
1605     return SQLITE_NOMEM_BKPT;
1606   }
1607   pWinMemData->bOwned = FALSE;
1608   assert( !pWinMemData->bOwned );
1609 #endif
1610   assert( pWinMemData->hHeap!=0 );
1611   assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
1612 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1613   assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1614 #endif
1615   return SQLITE_OK;
1616 }
1617 
1618 /*
1619 ** Deinitialize this module.
1620 */
1621 static void winMemShutdown(void *pAppData){
1622   winMemData *pWinMemData = (winMemData *)pAppData;
1623 
1624   if( !pWinMemData ) return;
1625   assert( pWinMemData->magic1==WINMEM_MAGIC1 );
1626   assert( pWinMemData->magic2==WINMEM_MAGIC2 );
1627 
1628   if( pWinMemData->hHeap ){
1629     assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
1630 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1631     assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1632 #endif
1633     if( pWinMemData->bOwned ){
1634       if( !osHeapDestroy(pWinMemData->hHeap) ){
1635         sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%lu), heap=%p",
1636                     osGetLastError(), (void*)pWinMemData->hHeap);
1637       }
1638       pWinMemData->bOwned = FALSE;
1639     }
1640     pWinMemData->hHeap = NULL;
1641   }
1642 }
1643 
1644 /*
1645 ** Populate the low-level memory allocation function pointers in
1646 ** sqlite3GlobalConfig.m with pointers to the routines in this file. The
1647 ** arguments specify the block of memory to manage.
1648 **
1649 ** This routine is only called by sqlite3_config(), and therefore
1650 ** is not required to be threadsafe (it is not).
1651 */
1652 const sqlite3_mem_methods *sqlite3MemGetWin32(void){
1653   static const sqlite3_mem_methods winMemMethods = {
1654     winMemMalloc,
1655     winMemFree,
1656     winMemRealloc,
1657     winMemSize,
1658     winMemRoundup,
1659     winMemInit,
1660     winMemShutdown,
1661     &win_mem_data
1662   };
1663   return &winMemMethods;
1664 }
1665 
1666 void sqlite3MemSetDefault(void){
1667   sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetWin32());
1668 }
1669 #endif /* SQLITE_WIN32_MALLOC */
1670 
1671 /*
1672 ** Convert a UTF-8 string to Microsoft Unicode.
1673 **
1674 ** Space to hold the returned string is obtained from sqlite3_malloc().
1675 */
1676 static LPWSTR winUtf8ToUnicode(const char *zText){
1677   int nChar;
1678   LPWSTR zWideText;
1679 
1680   nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, NULL, 0);
1681   if( nChar==0 ){
1682     return 0;
1683   }
1684   zWideText = sqlite3MallocZero( nChar*sizeof(WCHAR) );
1685   if( zWideText==0 ){
1686     return 0;
1687   }
1688   nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, zWideText,
1689                                 nChar);
1690   if( nChar==0 ){
1691     sqlite3_free(zWideText);
1692     zWideText = 0;
1693   }
1694   return zWideText;
1695 }
1696 
1697 /*
1698 ** Convert a Microsoft Unicode string to UTF-8.
1699 **
1700 ** Space to hold the returned string is obtained from sqlite3_malloc().
1701 */
1702 static char *winUnicodeToUtf8(LPCWSTR zWideText){
1703   int nByte;
1704   char *zText;
1705 
1706   nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, 0, 0, 0, 0);
1707   if( nByte == 0 ){
1708     return 0;
1709   }
1710   zText = sqlite3MallocZero( nByte );
1711   if( zText==0 ){
1712     return 0;
1713   }
1714   nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, zText, nByte,
1715                                 0, 0);
1716   if( nByte == 0 ){
1717     sqlite3_free(zText);
1718     zText = 0;
1719   }
1720   return zText;
1721 }
1722 
1723 /*
1724 ** Convert an ANSI string to Microsoft Unicode, using the ANSI or OEM
1725 ** code page.
1726 **
1727 ** Space to hold the returned string is obtained from sqlite3_malloc().
1728 */
1729 static LPWSTR winMbcsToUnicode(const char *zText, int useAnsi){
1730   int nByte;
1731   LPWSTR zMbcsText;
1732   int codepage = useAnsi ? CP_ACP : CP_OEMCP;
1733 
1734   nByte = osMultiByteToWideChar(codepage, 0, zText, -1, NULL,
1735                                 0)*sizeof(WCHAR);
1736   if( nByte==0 ){
1737     return 0;
1738   }
1739   zMbcsText = sqlite3MallocZero( nByte*sizeof(WCHAR) );
1740   if( zMbcsText==0 ){
1741     return 0;
1742   }
1743   nByte = osMultiByteToWideChar(codepage, 0, zText, -1, zMbcsText,
1744                                 nByte);
1745   if( nByte==0 ){
1746     sqlite3_free(zMbcsText);
1747     zMbcsText = 0;
1748   }
1749   return zMbcsText;
1750 }
1751 
1752 /*
1753 ** Convert a Microsoft Unicode string to a multi-byte character string,
1754 ** using the ANSI or OEM code page.
1755 **
1756 ** Space to hold the returned string is obtained from sqlite3_malloc().
1757 */
1758 static char *winUnicodeToMbcs(LPCWSTR zWideText, int useAnsi){
1759   int nByte;
1760   char *zText;
1761   int codepage = useAnsi ? CP_ACP : CP_OEMCP;
1762 
1763   nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, 0, 0, 0, 0);
1764   if( nByte == 0 ){
1765     return 0;
1766   }
1767   zText = sqlite3MallocZero( nByte );
1768   if( zText==0 ){
1769     return 0;
1770   }
1771   nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, zText,
1772                                 nByte, 0, 0);
1773   if( nByte == 0 ){
1774     sqlite3_free(zText);
1775     zText = 0;
1776   }
1777   return zText;
1778 }
1779 
1780 /*
1781 ** Convert a multi-byte character string to UTF-8.
1782 **
1783 ** Space to hold the returned string is obtained from sqlite3_malloc().
1784 */
1785 static char *winMbcsToUtf8(const char *zText, int useAnsi){
1786   char *zTextUtf8;
1787   LPWSTR zTmpWide;
1788 
1789   zTmpWide = winMbcsToUnicode(zText, useAnsi);
1790   if( zTmpWide==0 ){
1791     return 0;
1792   }
1793   zTextUtf8 = winUnicodeToUtf8(zTmpWide);
1794   sqlite3_free(zTmpWide);
1795   return zTextUtf8;
1796 }
1797 
1798 /*
1799 ** Convert a UTF-8 string to a multi-byte character string.
1800 **
1801 ** Space to hold the returned string is obtained from sqlite3_malloc().
1802 */
1803 static char *winUtf8ToMbcs(const char *zText, int useAnsi){
1804   char *zTextMbcs;
1805   LPWSTR zTmpWide;
1806 
1807   zTmpWide = winUtf8ToUnicode(zText);
1808   if( zTmpWide==0 ){
1809     return 0;
1810   }
1811   zTextMbcs = winUnicodeToMbcs(zTmpWide, useAnsi);
1812   sqlite3_free(zTmpWide);
1813   return zTextMbcs;
1814 }
1815 
1816 /*
1817 ** This is a public wrapper for the winUtf8ToUnicode() function.
1818 */
1819 LPWSTR sqlite3_win32_utf8_to_unicode(const char *zText){
1820 #ifdef SQLITE_ENABLE_API_ARMOR
1821   if( !zText ){
1822     (void)SQLITE_MISUSE_BKPT;
1823     return 0;
1824   }
1825 #endif
1826 #ifndef SQLITE_OMIT_AUTOINIT
1827   if( sqlite3_initialize() ) return 0;
1828 #endif
1829   return winUtf8ToUnicode(zText);
1830 }
1831 
1832 /*
1833 ** This is a public wrapper for the winUnicodeToUtf8() function.
1834 */
1835 char *sqlite3_win32_unicode_to_utf8(LPCWSTR zWideText){
1836 #ifdef SQLITE_ENABLE_API_ARMOR
1837   if( !zWideText ){
1838     (void)SQLITE_MISUSE_BKPT;
1839     return 0;
1840   }
1841 #endif
1842 #ifndef SQLITE_OMIT_AUTOINIT
1843   if( sqlite3_initialize() ) return 0;
1844 #endif
1845   return winUnicodeToUtf8(zWideText);
1846 }
1847 
1848 /*
1849 ** This is a public wrapper for the winMbcsToUtf8() function.
1850 */
1851 char *sqlite3_win32_mbcs_to_utf8(const char *zText){
1852 #ifdef SQLITE_ENABLE_API_ARMOR
1853   if( !zText ){
1854     (void)SQLITE_MISUSE_BKPT;
1855     return 0;
1856   }
1857 #endif
1858 #ifndef SQLITE_OMIT_AUTOINIT
1859   if( sqlite3_initialize() ) return 0;
1860 #endif
1861   return winMbcsToUtf8(zText, osAreFileApisANSI());
1862 }
1863 
1864 /*
1865 ** This is a public wrapper for the winMbcsToUtf8() function.
1866 */
1867 char *sqlite3_win32_mbcs_to_utf8_v2(const char *zText, int useAnsi){
1868 #ifdef SQLITE_ENABLE_API_ARMOR
1869   if( !zText ){
1870     (void)SQLITE_MISUSE_BKPT;
1871     return 0;
1872   }
1873 #endif
1874 #ifndef SQLITE_OMIT_AUTOINIT
1875   if( sqlite3_initialize() ) return 0;
1876 #endif
1877   return winMbcsToUtf8(zText, useAnsi);
1878 }
1879 
1880 /*
1881 ** This is a public wrapper for the winUtf8ToMbcs() function.
1882 */
1883 char *sqlite3_win32_utf8_to_mbcs(const char *zText){
1884 #ifdef SQLITE_ENABLE_API_ARMOR
1885   if( !zText ){
1886     (void)SQLITE_MISUSE_BKPT;
1887     return 0;
1888   }
1889 #endif
1890 #ifndef SQLITE_OMIT_AUTOINIT
1891   if( sqlite3_initialize() ) return 0;
1892 #endif
1893   return winUtf8ToMbcs(zText, osAreFileApisANSI());
1894 }
1895 
1896 /*
1897 ** This is a public wrapper for the winUtf8ToMbcs() function.
1898 */
1899 char *sqlite3_win32_utf8_to_mbcs_v2(const char *zText, int useAnsi){
1900 #ifdef SQLITE_ENABLE_API_ARMOR
1901   if( !zText ){
1902     (void)SQLITE_MISUSE_BKPT;
1903     return 0;
1904   }
1905 #endif
1906 #ifndef SQLITE_OMIT_AUTOINIT
1907   if( sqlite3_initialize() ) return 0;
1908 #endif
1909   return winUtf8ToMbcs(zText, useAnsi);
1910 }
1911 
1912 /*
1913 ** This function is the same as sqlite3_win32_set_directory (below); however,
1914 ** it accepts a UTF-8 string.
1915 */
1916 int sqlite3_win32_set_directory8(
1917   unsigned long type, /* Identifier for directory being set or reset */
1918   const char *zValue  /* New value for directory being set or reset */
1919 ){
1920   char **ppDirectory = 0;
1921   int rc;
1922 #ifndef SQLITE_OMIT_AUTOINIT
1923   rc = sqlite3_initialize();
1924   if( rc ) return rc;
1925 #endif
1926   sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
1927   if( type==SQLITE_WIN32_DATA_DIRECTORY_TYPE ){
1928     ppDirectory = &sqlite3_data_directory;
1929   }else if( type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE ){
1930     ppDirectory = &sqlite3_temp_directory;
1931   }
1932   assert( !ppDirectory || type==SQLITE_WIN32_DATA_DIRECTORY_TYPE
1933           || type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE
1934   );
1935   assert( !ppDirectory || sqlite3MemdebugHasType(*ppDirectory, MEMTYPE_HEAP) );
1936   if( ppDirectory ){
1937     char *zCopy = 0;
1938     if( zValue && zValue[0] ){
1939       zCopy = sqlite3_mprintf("%s", zValue);
1940       if ( zCopy==0 ){
1941         rc = SQLITE_NOMEM_BKPT;
1942         goto set_directory8_done;
1943       }
1944     }
1945     sqlite3_free(*ppDirectory);
1946     *ppDirectory = zCopy;
1947     rc = SQLITE_OK;
1948   }else{
1949     rc = SQLITE_ERROR;
1950   }
1951 set_directory8_done:
1952   sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
1953   return rc;
1954 }
1955 
1956 /*
1957 ** This function is the same as sqlite3_win32_set_directory (below); however,
1958 ** it accepts a UTF-16 string.
1959 */
1960 int sqlite3_win32_set_directory16(
1961   unsigned long type, /* Identifier for directory being set or reset */
1962   const void *zValue  /* New value for directory being set or reset */
1963 ){
1964   int rc;
1965   char *zUtf8 = 0;
1966   if( zValue ){
1967     zUtf8 = sqlite3_win32_unicode_to_utf8(zValue);
1968     if( zUtf8==0 ) return SQLITE_NOMEM_BKPT;
1969   }
1970   rc = sqlite3_win32_set_directory8(type, zUtf8);
1971   if( zUtf8 ) sqlite3_free(zUtf8);
1972   return rc;
1973 }
1974 
1975 /*
1976 ** This function sets the data directory or the temporary directory based on
1977 ** the provided arguments.  The type argument must be 1 in order to set the
1978 ** data directory or 2 in order to set the temporary directory.  The zValue
1979 ** argument is the name of the directory to use.  The return value will be
1980 ** SQLITE_OK if successful.
1981 */
1982 int sqlite3_win32_set_directory(
1983   unsigned long type, /* Identifier for directory being set or reset */
1984   void *zValue        /* New value for directory being set or reset */
1985 ){
1986   return sqlite3_win32_set_directory16(type, zValue);
1987 }
1988 
1989 /*
1990 ** The return value of winGetLastErrorMsg
1991 ** is zero if the error message fits in the buffer, or non-zero
1992 ** otherwise (if the message was truncated).
1993 */
1994 static int winGetLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){
1995   /* FormatMessage returns 0 on failure.  Otherwise it
1996   ** returns the number of TCHARs written to the output
1997   ** buffer, excluding the terminating null char.
1998   */
1999   DWORD dwLen = 0;
2000   char *zOut = 0;
2001 
2002   if( osIsNT() ){
2003 #if SQLITE_OS_WINRT
2004     WCHAR zTempWide[SQLITE_WIN32_MAX_ERRMSG_CHARS+1];
2005     dwLen = osFormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
2006                              FORMAT_MESSAGE_IGNORE_INSERTS,
2007                              NULL,
2008                              lastErrno,
2009                              0,
2010                              zTempWide,
2011                              SQLITE_WIN32_MAX_ERRMSG_CHARS,
2012                              0);
2013 #else
2014     LPWSTR zTempWide = NULL;
2015     dwLen = osFormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
2016                              FORMAT_MESSAGE_FROM_SYSTEM |
2017                              FORMAT_MESSAGE_IGNORE_INSERTS,
2018                              NULL,
2019                              lastErrno,
2020                              0,
2021                              (LPWSTR) &zTempWide,
2022                              0,
2023                              0);
2024 #endif
2025     if( dwLen > 0 ){
2026       /* allocate a buffer and convert to UTF8 */
2027       sqlite3BeginBenignMalloc();
2028       zOut = winUnicodeToUtf8(zTempWide);
2029       sqlite3EndBenignMalloc();
2030 #if !SQLITE_OS_WINRT
2031       /* free the system buffer allocated by FormatMessage */
2032       osLocalFree(zTempWide);
2033 #endif
2034     }
2035   }
2036 #ifdef SQLITE_WIN32_HAS_ANSI
2037   else{
2038     char *zTemp = NULL;
2039     dwLen = osFormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
2040                              FORMAT_MESSAGE_FROM_SYSTEM |
2041                              FORMAT_MESSAGE_IGNORE_INSERTS,
2042                              NULL,
2043                              lastErrno,
2044                              0,
2045                              (LPSTR) &zTemp,
2046                              0,
2047                              0);
2048     if( dwLen > 0 ){
2049       /* allocate a buffer and convert to UTF8 */
2050       sqlite3BeginBenignMalloc();
2051       zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
2052       sqlite3EndBenignMalloc();
2053       /* free the system buffer allocated by FormatMessage */
2054       osLocalFree(zTemp);
2055     }
2056   }
2057 #endif
2058   if( 0 == dwLen ){
2059     sqlite3_snprintf(nBuf, zBuf, "OsError 0x%lx (%lu)", lastErrno, lastErrno);
2060   }else{
2061     /* copy a maximum of nBuf chars to output buffer */
2062     sqlite3_snprintf(nBuf, zBuf, "%s", zOut);
2063     /* free the UTF8 buffer */
2064     sqlite3_free(zOut);
2065   }
2066   return 0;
2067 }
2068 
2069 /*
2070 **
2071 ** This function - winLogErrorAtLine() - is only ever called via the macro
2072 ** winLogError().
2073 **
2074 ** This routine is invoked after an error occurs in an OS function.
2075 ** It logs a message using sqlite3_log() containing the current value of
2076 ** error code and, if possible, the human-readable equivalent from
2077 ** FormatMessage.
2078 **
2079 ** The first argument passed to the macro should be the error code that
2080 ** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN).
2081 ** The two subsequent arguments should be the name of the OS function that
2082 ** failed and the associated file-system path, if any.
2083 */
2084 #define winLogError(a,b,c,d)   winLogErrorAtLine(a,b,c,d,__LINE__)
2085 static int winLogErrorAtLine(
2086   int errcode,                    /* SQLite error code */
2087   DWORD lastErrno,                /* Win32 last error */
2088   const char *zFunc,              /* Name of OS function that failed */
2089   const char *zPath,              /* File path associated with error */
2090   int iLine                       /* Source line number where error occurred */
2091 ){
2092   char zMsg[500];                 /* Human readable error text */
2093   int i;                          /* Loop counter */
2094 
2095   zMsg[0] = 0;
2096   winGetLastErrorMsg(lastErrno, sizeof(zMsg), zMsg);
2097   assert( errcode!=SQLITE_OK );
2098   if( zPath==0 ) zPath = "";
2099   for(i=0; zMsg[i] && zMsg[i]!='\r' && zMsg[i]!='\n'; i++){}
2100   zMsg[i] = 0;
2101   sqlite3_log(errcode,
2102       "os_win.c:%d: (%lu) %s(%s) - %s",
2103       iLine, lastErrno, zFunc, zPath, zMsg
2104   );
2105 
2106   return errcode;
2107 }
2108 
2109 /*
2110 ** The number of times that a ReadFile(), WriteFile(), and DeleteFile()
2111 ** will be retried following a locking error - probably caused by
2112 ** antivirus software.  Also the initial delay before the first retry.
2113 ** The delay increases linearly with each retry.
2114 */
2115 #ifndef SQLITE_WIN32_IOERR_RETRY
2116 # define SQLITE_WIN32_IOERR_RETRY 10
2117 #endif
2118 #ifndef SQLITE_WIN32_IOERR_RETRY_DELAY
2119 # define SQLITE_WIN32_IOERR_RETRY_DELAY 25
2120 #endif
2121 static int winIoerrRetry = SQLITE_WIN32_IOERR_RETRY;
2122 static int winIoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;
2123 
2124 /*
2125 ** The "winIoerrCanRetry1" macro is used to determine if a particular I/O
2126 ** error code obtained via GetLastError() is eligible to be retried.  It
2127 ** must accept the error code DWORD as its only argument and should return
2128 ** non-zero if the error code is transient in nature and the operation
2129 ** responsible for generating the original error might succeed upon being
2130 ** retried.  The argument to this macro should be a variable.
2131 **
2132 ** Additionally, a macro named "winIoerrCanRetry2" may be defined.  If it
2133 ** is defined, it will be consulted only when the macro "winIoerrCanRetry1"
2134 ** returns zero.  The "winIoerrCanRetry2" macro is completely optional and
2135 ** may be used to include additional error codes in the set that should
2136 ** result in the failing I/O operation being retried by the caller.  If
2137 ** defined, the "winIoerrCanRetry2" macro must exhibit external semantics
2138 ** identical to those of the "winIoerrCanRetry1" macro.
2139 */
2140 #if !defined(winIoerrCanRetry1)
2141 #define winIoerrCanRetry1(a) (((a)==ERROR_ACCESS_DENIED)        || \
2142                               ((a)==ERROR_SHARING_VIOLATION)    || \
2143                               ((a)==ERROR_LOCK_VIOLATION)       || \
2144                               ((a)==ERROR_DEV_NOT_EXIST)        || \
2145                               ((a)==ERROR_NETNAME_DELETED)      || \
2146                               ((a)==ERROR_SEM_TIMEOUT)          || \
2147                               ((a)==ERROR_NETWORK_UNREACHABLE))
2148 #endif
2149 
2150 /*
2151 ** If a ReadFile() or WriteFile() error occurs, invoke this routine
2152 ** to see if it should be retried.  Return TRUE to retry.  Return FALSE
2153 ** to give up with an error.
2154 */
2155 static int winRetryIoerr(int *pnRetry, DWORD *pError){
2156   DWORD e = osGetLastError();
2157   if( *pnRetry>=winIoerrRetry ){
2158     if( pError ){
2159       *pError = e;
2160     }
2161     return 0;
2162   }
2163   if( winIoerrCanRetry1(e) ){
2164     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
2165     ++*pnRetry;
2166     return 1;
2167   }
2168 #if defined(winIoerrCanRetry2)
2169   else if( winIoerrCanRetry2(e) ){
2170     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
2171     ++*pnRetry;
2172     return 1;
2173   }
2174 #endif
2175   if( pError ){
2176     *pError = e;
2177   }
2178   return 0;
2179 }
2180 
2181 /*
2182 ** Log a I/O error retry episode.
2183 */
2184 static void winLogIoerr(int nRetry, int lineno){
2185   if( nRetry ){
2186     sqlite3_log(SQLITE_NOTICE,
2187       "delayed %dms for lock/sharing conflict at line %d",
2188       winIoerrRetryDelay*nRetry*(nRetry+1)/2, lineno
2189     );
2190   }
2191 }
2192 
2193 /*
2194 ** This #if does not rely on the SQLITE_OS_WINCE define because the
2195 ** corresponding section in "date.c" cannot use it.
2196 */
2197 #if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \
2198     (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)
2199 /*
2200 ** The MSVC CRT on Windows CE may not have a localtime() function.
2201 ** So define a substitute.
2202 */
2203 #  include <time.h>
2204 struct tm *__cdecl localtime(const time_t *t)
2205 {
2206   static struct tm y;
2207   FILETIME uTm, lTm;
2208   SYSTEMTIME pTm;
2209   sqlite3_int64 t64;
2210   t64 = *t;
2211   t64 = (t64 + 11644473600)*10000000;
2212   uTm.dwLowDateTime = (DWORD)(t64 & 0xFFFFFFFF);
2213   uTm.dwHighDateTime= (DWORD)(t64 >> 32);
2214   osFileTimeToLocalFileTime(&uTm,&lTm);
2215   osFileTimeToSystemTime(&lTm,&pTm);
2216   y.tm_year = pTm.wYear - 1900;
2217   y.tm_mon = pTm.wMonth - 1;
2218   y.tm_wday = pTm.wDayOfWeek;
2219   y.tm_mday = pTm.wDay;
2220   y.tm_hour = pTm.wHour;
2221   y.tm_min = pTm.wMinute;
2222   y.tm_sec = pTm.wSecond;
2223   return &y;
2224 }
2225 #endif
2226 
2227 #if SQLITE_OS_WINCE
2228 /*************************************************************************
2229 ** This section contains code for WinCE only.
2230 */
2231 #define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]
2232 
2233 /*
2234 ** Acquire a lock on the handle h
2235 */
2236 static void winceMutexAcquire(HANDLE h){
2237    DWORD dwErr;
2238    do {
2239      dwErr = osWaitForSingleObject(h, INFINITE);
2240    } while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);
2241 }
2242 /*
2243 ** Release a lock acquired by winceMutexAcquire()
2244 */
2245 #define winceMutexRelease(h) ReleaseMutex(h)
2246 
2247 /*
2248 ** Create the mutex and shared memory used for locking in the file
2249 ** descriptor pFile
2250 */
2251 static int winceCreateLock(const char *zFilename, winFile *pFile){
2252   LPWSTR zTok;
2253   LPWSTR zName;
2254   DWORD lastErrno;
2255   BOOL bLogged = FALSE;
2256   BOOL bInit = TRUE;
2257 
2258   zName = winUtf8ToUnicode(zFilename);
2259   if( zName==0 ){
2260     /* out of memory */
2261     return SQLITE_IOERR_NOMEM_BKPT;
2262   }
2263 
2264   /* Initialize the local lockdata */
2265   memset(&pFile->local, 0, sizeof(pFile->local));
2266 
2267   /* Replace the backslashes from the filename and lowercase it
2268   ** to derive a mutex name. */
2269   zTok = osCharLowerW(zName);
2270   for (;*zTok;zTok++){
2271     if (*zTok == '\\') *zTok = '_';
2272   }
2273 
2274   /* Create/open the named mutex */
2275   pFile->hMutex = osCreateMutexW(NULL, FALSE, zName);
2276   if (!pFile->hMutex){
2277     pFile->lastErrno = osGetLastError();
2278     sqlite3_free(zName);
2279     return winLogError(SQLITE_IOERR, pFile->lastErrno,
2280                        "winceCreateLock1", zFilename);
2281   }
2282 
2283   /* Acquire the mutex before continuing */
2284   winceMutexAcquire(pFile->hMutex);
2285 
2286   /* Since the names of named mutexes, semaphores, file mappings etc are
2287   ** case-sensitive, take advantage of that by uppercasing the mutex name
2288   ** and using that as the shared filemapping name.
2289   */
2290   osCharUpperW(zName);
2291   pFile->hShared = osCreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
2292                                         PAGE_READWRITE, 0, sizeof(winceLock),
2293                                         zName);
2294 
2295   /* Set a flag that indicates we're the first to create the memory so it
2296   ** must be zero-initialized */
2297   lastErrno = osGetLastError();
2298   if (lastErrno == ERROR_ALREADY_EXISTS){
2299     bInit = FALSE;
2300   }
2301 
2302   sqlite3_free(zName);
2303 
2304   /* If we succeeded in making the shared memory handle, map it. */
2305   if( pFile->hShared ){
2306     pFile->shared = (winceLock*)osMapViewOfFile(pFile->hShared,
2307              FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
2308     /* If mapping failed, close the shared memory handle and erase it */
2309     if( !pFile->shared ){
2310       pFile->lastErrno = osGetLastError();
2311       winLogError(SQLITE_IOERR, pFile->lastErrno,
2312                   "winceCreateLock2", zFilename);
2313       bLogged = TRUE;
2314       osCloseHandle(pFile->hShared);
2315       pFile->hShared = NULL;
2316     }
2317   }
2318 
2319   /* If shared memory could not be created, then close the mutex and fail */
2320   if( pFile->hShared==NULL ){
2321     if( !bLogged ){
2322       pFile->lastErrno = lastErrno;
2323       winLogError(SQLITE_IOERR, pFile->lastErrno,
2324                   "winceCreateLock3", zFilename);
2325       bLogged = TRUE;
2326     }
2327     winceMutexRelease(pFile->hMutex);
2328     osCloseHandle(pFile->hMutex);
2329     pFile->hMutex = NULL;
2330     return SQLITE_IOERR;
2331   }
2332 
2333   /* Initialize the shared memory if we're supposed to */
2334   if( bInit ){
2335     memset(pFile->shared, 0, sizeof(winceLock));
2336   }
2337 
2338   winceMutexRelease(pFile->hMutex);
2339   return SQLITE_OK;
2340 }
2341 
2342 /*
2343 ** Destroy the part of winFile that deals with wince locks
2344 */
2345 static void winceDestroyLock(winFile *pFile){
2346   if (pFile->hMutex){
2347     /* Acquire the mutex */
2348     winceMutexAcquire(pFile->hMutex);
2349 
2350     /* The following blocks should probably assert in debug mode, but they
2351        are to cleanup in case any locks remained open */
2352     if (pFile->local.nReaders){
2353       pFile->shared->nReaders --;
2354     }
2355     if (pFile->local.bReserved){
2356       pFile->shared->bReserved = FALSE;
2357     }
2358     if (pFile->local.bPending){
2359       pFile->shared->bPending = FALSE;
2360     }
2361     if (pFile->local.bExclusive){
2362       pFile->shared->bExclusive = FALSE;
2363     }
2364 
2365     /* De-reference and close our copy of the shared memory handle */
2366     osUnmapViewOfFile(pFile->shared);
2367     osCloseHandle(pFile->hShared);
2368 
2369     /* Done with the mutex */
2370     winceMutexRelease(pFile->hMutex);
2371     osCloseHandle(pFile->hMutex);
2372     pFile->hMutex = NULL;
2373   }
2374 }
2375 
2376 /*
2377 ** An implementation of the LockFile() API of Windows for CE
2378 */
2379 static BOOL winceLockFile(
2380   LPHANDLE phFile,
2381   DWORD dwFileOffsetLow,
2382   DWORD dwFileOffsetHigh,
2383   DWORD nNumberOfBytesToLockLow,
2384   DWORD nNumberOfBytesToLockHigh
2385 ){
2386   winFile *pFile = HANDLE_TO_WINFILE(phFile);
2387   BOOL bReturn = FALSE;
2388 
2389   UNUSED_PARAMETER(dwFileOffsetHigh);
2390   UNUSED_PARAMETER(nNumberOfBytesToLockHigh);
2391 
2392   if (!pFile->hMutex) return TRUE;
2393   winceMutexAcquire(pFile->hMutex);
2394 
2395   /* Wanting an exclusive lock? */
2396   if (dwFileOffsetLow == (DWORD)SHARED_FIRST
2397        && nNumberOfBytesToLockLow == (DWORD)SHARED_SIZE){
2398     if (pFile->shared->nReaders == 0 && pFile->shared->bExclusive == 0){
2399        pFile->shared->bExclusive = TRUE;
2400        pFile->local.bExclusive = TRUE;
2401        bReturn = TRUE;
2402     }
2403   }
2404 
2405   /* Want a read-only lock? */
2406   else if (dwFileOffsetLow == (DWORD)SHARED_FIRST &&
2407            nNumberOfBytesToLockLow == 1){
2408     if (pFile->shared->bExclusive == 0){
2409       pFile->local.nReaders ++;
2410       if (pFile->local.nReaders == 1){
2411         pFile->shared->nReaders ++;
2412       }
2413       bReturn = TRUE;
2414     }
2415   }
2416 
2417   /* Want a pending lock? */
2418   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
2419            && nNumberOfBytesToLockLow == 1){
2420     /* If no pending lock has been acquired, then acquire it */
2421     if (pFile->shared->bPending == 0) {
2422       pFile->shared->bPending = TRUE;
2423       pFile->local.bPending = TRUE;
2424       bReturn = TRUE;
2425     }
2426   }
2427 
2428   /* Want a reserved lock? */
2429   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
2430            && nNumberOfBytesToLockLow == 1){
2431     if (pFile->shared->bReserved == 0) {
2432       pFile->shared->bReserved = TRUE;
2433       pFile->local.bReserved = TRUE;
2434       bReturn = TRUE;
2435     }
2436   }
2437 
2438   winceMutexRelease(pFile->hMutex);
2439   return bReturn;
2440 }
2441 
2442 /*
2443 ** An implementation of the UnlockFile API of Windows for CE
2444 */
2445 static BOOL winceUnlockFile(
2446   LPHANDLE phFile,
2447   DWORD dwFileOffsetLow,
2448   DWORD dwFileOffsetHigh,
2449   DWORD nNumberOfBytesToUnlockLow,
2450   DWORD nNumberOfBytesToUnlockHigh
2451 ){
2452   winFile *pFile = HANDLE_TO_WINFILE(phFile);
2453   BOOL bReturn = FALSE;
2454 
2455   UNUSED_PARAMETER(dwFileOffsetHigh);
2456   UNUSED_PARAMETER(nNumberOfBytesToUnlockHigh);
2457 
2458   if (!pFile->hMutex) return TRUE;
2459   winceMutexAcquire(pFile->hMutex);
2460 
2461   /* Releasing a reader lock or an exclusive lock */
2462   if (dwFileOffsetLow == (DWORD)SHARED_FIRST){
2463     /* Did we have an exclusive lock? */
2464     if (pFile->local.bExclusive){
2465       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE);
2466       pFile->local.bExclusive = FALSE;
2467       pFile->shared->bExclusive = FALSE;
2468       bReturn = TRUE;
2469     }
2470 
2471     /* Did we just have a reader lock? */
2472     else if (pFile->local.nReaders){
2473       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE
2474              || nNumberOfBytesToUnlockLow == 1);
2475       pFile->local.nReaders --;
2476       if (pFile->local.nReaders == 0)
2477       {
2478         pFile->shared->nReaders --;
2479       }
2480       bReturn = TRUE;
2481     }
2482   }
2483 
2484   /* Releasing a pending lock */
2485   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
2486            && nNumberOfBytesToUnlockLow == 1){
2487     if (pFile->local.bPending){
2488       pFile->local.bPending = FALSE;
2489       pFile->shared->bPending = FALSE;
2490       bReturn = TRUE;
2491     }
2492   }
2493   /* Releasing a reserved lock */
2494   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
2495            && nNumberOfBytesToUnlockLow == 1){
2496     if (pFile->local.bReserved) {
2497       pFile->local.bReserved = FALSE;
2498       pFile->shared->bReserved = FALSE;
2499       bReturn = TRUE;
2500     }
2501   }
2502 
2503   winceMutexRelease(pFile->hMutex);
2504   return bReturn;
2505 }
2506 /*
2507 ** End of the special code for wince
2508 *****************************************************************************/
2509 #endif /* SQLITE_OS_WINCE */
2510 
2511 /*
2512 ** Lock a file region.
2513 */
2514 static BOOL winLockFile(
2515   LPHANDLE phFile,
2516   DWORD flags,
2517   DWORD offsetLow,
2518   DWORD offsetHigh,
2519   DWORD numBytesLow,
2520   DWORD numBytesHigh
2521 ){
2522 #if SQLITE_OS_WINCE
2523   /*
2524   ** NOTE: Windows CE is handled differently here due its lack of the Win32
2525   **       API LockFile.
2526   */
2527   return winceLockFile(phFile, offsetLow, offsetHigh,
2528                        numBytesLow, numBytesHigh);
2529 #else
2530   if( osIsNT() ){
2531     OVERLAPPED ovlp;
2532     memset(&ovlp, 0, sizeof(OVERLAPPED));
2533     ovlp.Offset = offsetLow;
2534     ovlp.OffsetHigh = offsetHigh;
2535     return osLockFileEx(*phFile, flags, 0, numBytesLow, numBytesHigh, &ovlp);
2536   }else{
2537     return osLockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
2538                       numBytesHigh);
2539   }
2540 #endif
2541 }
2542 
2543 /*
2544 ** Unlock a file region.
2545  */
2546 static BOOL winUnlockFile(
2547   LPHANDLE phFile,
2548   DWORD offsetLow,
2549   DWORD offsetHigh,
2550   DWORD numBytesLow,
2551   DWORD numBytesHigh
2552 ){
2553 #if SQLITE_OS_WINCE
2554   /*
2555   ** NOTE: Windows CE is handled differently here due its lack of the Win32
2556   **       API UnlockFile.
2557   */
2558   return winceUnlockFile(phFile, offsetLow, offsetHigh,
2559                          numBytesLow, numBytesHigh);
2560 #else
2561   if( osIsNT() ){
2562     OVERLAPPED ovlp;
2563     memset(&ovlp, 0, sizeof(OVERLAPPED));
2564     ovlp.Offset = offsetLow;
2565     ovlp.OffsetHigh = offsetHigh;
2566     return osUnlockFileEx(*phFile, 0, numBytesLow, numBytesHigh, &ovlp);
2567   }else{
2568     return osUnlockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
2569                         numBytesHigh);
2570   }
2571 #endif
2572 }
2573 
2574 /*****************************************************************************
2575 ** The next group of routines implement the I/O methods specified
2576 ** by the sqlite3_io_methods object.
2577 ******************************************************************************/
2578 
2579 /*
2580 ** Some Microsoft compilers lack this definition.
2581 */
2582 #ifndef INVALID_SET_FILE_POINTER
2583 # define INVALID_SET_FILE_POINTER ((DWORD)-1)
2584 #endif
2585 
2586 /*
2587 ** Move the current position of the file handle passed as the first
2588 ** argument to offset iOffset within the file. If successful, return 0.
2589 ** Otherwise, set pFile->lastErrno and return non-zero.
2590 */
2591 static int winSeekFile(winFile *pFile, sqlite3_int64 iOffset){
2592 #if !SQLITE_OS_WINRT
2593   LONG upperBits;                 /* Most sig. 32 bits of new offset */
2594   LONG lowerBits;                 /* Least sig. 32 bits of new offset */
2595   DWORD dwRet;                    /* Value returned by SetFilePointer() */
2596   DWORD lastErrno;                /* Value returned by GetLastError() */
2597 
2598   OSTRACE(("SEEK file=%p, offset=%lld\n", pFile->h, iOffset));
2599 
2600   upperBits = (LONG)((iOffset>>32) & 0x7fffffff);
2601   lowerBits = (LONG)(iOffset & 0xffffffff);
2602 
2603   /* API oddity: If successful, SetFilePointer() returns a dword
2604   ** containing the lower 32-bits of the new file-offset. Or, if it fails,
2605   ** it returns INVALID_SET_FILE_POINTER. However according to MSDN,
2606   ** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine
2607   ** whether an error has actually occurred, it is also necessary to call
2608   ** GetLastError().
2609   */
2610   dwRet = osSetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
2611 
2612   if( (dwRet==INVALID_SET_FILE_POINTER
2613       && ((lastErrno = osGetLastError())!=NO_ERROR)) ){
2614     pFile->lastErrno = lastErrno;
2615     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
2616                 "winSeekFile", pFile->zPath);
2617     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
2618     return 1;
2619   }
2620 
2621   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
2622   return 0;
2623 #else
2624   /*
2625   ** Same as above, except that this implementation works for WinRT.
2626   */
2627 
2628   LARGE_INTEGER x;                /* The new offset */
2629   BOOL bRet;                      /* Value returned by SetFilePointerEx() */
2630 
2631   x.QuadPart = iOffset;
2632   bRet = osSetFilePointerEx(pFile->h, x, 0, FILE_BEGIN);
2633 
2634   if(!bRet){
2635     pFile->lastErrno = osGetLastError();
2636     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
2637                 "winSeekFile", pFile->zPath);
2638     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
2639     return 1;
2640   }
2641 
2642   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
2643   return 0;
2644 #endif
2645 }
2646 
2647 #if SQLITE_MAX_MMAP_SIZE>0
2648 /* Forward references to VFS helper methods used for memory mapped files */
2649 static int winMapfile(winFile*, sqlite3_int64);
2650 static int winUnmapfile(winFile*);
2651 #endif
2652 
2653 /*
2654 ** Close a file.
2655 **
2656 ** It is reported that an attempt to close a handle might sometimes
2657 ** fail.  This is a very unreasonable result, but Windows is notorious
2658 ** for being unreasonable so I do not doubt that it might happen.  If
2659 ** the close fails, we pause for 100 milliseconds and try again.  As
2660 ** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before
2661 ** giving up and returning an error.
2662 */
2663 #define MX_CLOSE_ATTEMPT 3
2664 static int winClose(sqlite3_file *id){
2665   int rc, cnt = 0;
2666   winFile *pFile = (winFile*)id;
2667 
2668   assert( id!=0 );
2669 #ifndef SQLITE_OMIT_WAL
2670   assert( pFile->pShm==0 );
2671 #endif
2672   assert( pFile->h!=NULL && pFile->h!=INVALID_HANDLE_VALUE );
2673   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p\n",
2674            osGetCurrentProcessId(), pFile, pFile->h));
2675 
2676 #if SQLITE_MAX_MMAP_SIZE>0
2677   winUnmapfile(pFile);
2678 #endif
2679 
2680   do{
2681     rc = osCloseHandle(pFile->h);
2682     /* SimulateIOError( rc=0; cnt=MX_CLOSE_ATTEMPT; ); */
2683   }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (sqlite3_win32_sleep(100), 1) );
2684 #if SQLITE_OS_WINCE
2685 #define WINCE_DELETION_ATTEMPTS 3
2686   {
2687     winVfsAppData *pAppData = (winVfsAppData*)pFile->pVfs->pAppData;
2688     if( pAppData==NULL || !pAppData->bNoLock ){
2689       winceDestroyLock(pFile);
2690     }
2691   }
2692   if( pFile->zDeleteOnClose ){
2693     int cnt = 0;
2694     while(
2695            osDeleteFileW(pFile->zDeleteOnClose)==0
2696         && osGetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff
2697         && cnt++ < WINCE_DELETION_ATTEMPTS
2698     ){
2699        sqlite3_win32_sleep(100);  /* Wait a little before trying again */
2700     }
2701     sqlite3_free(pFile->zDeleteOnClose);
2702   }
2703 #endif
2704   if( rc ){
2705     pFile->h = NULL;
2706   }
2707   OpenCounter(-1);
2708   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p, rc=%s\n",
2709            osGetCurrentProcessId(), pFile, pFile->h, rc ? "ok" : "failed"));
2710   return rc ? SQLITE_OK
2711             : winLogError(SQLITE_IOERR_CLOSE, osGetLastError(),
2712                           "winClose", pFile->zPath);
2713 }
2714 
2715 /*
2716 ** Read data from a file into a buffer.  Return SQLITE_OK if all
2717 ** bytes were read successfully and SQLITE_IOERR if anything goes
2718 ** wrong.
2719 */
2720 static int winRead(
2721   sqlite3_file *id,          /* File to read from */
2722   void *pBuf,                /* Write content into this buffer */
2723   int amt,                   /* Number of bytes to read */
2724   sqlite3_int64 offset       /* Begin reading at this offset */
2725 ){
2726 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2727   OVERLAPPED overlapped;          /* The offset for ReadFile. */
2728 #endif
2729   winFile *pFile = (winFile*)id;  /* file handle */
2730   DWORD nRead;                    /* Number of bytes actually read from file */
2731   int nRetry = 0;                 /* Number of retrys */
2732 
2733   assert( id!=0 );
2734   assert( amt>0 );
2735   assert( offset>=0 );
2736   SimulateIOError(return SQLITE_IOERR_READ);
2737   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
2738            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
2739            pFile->h, pBuf, amt, offset, pFile->locktype));
2740 
2741 #if SQLITE_MAX_MMAP_SIZE>0
2742   /* Deal with as much of this read request as possible by transfering
2743   ** data from the memory mapping using memcpy().  */
2744   if( offset<pFile->mmapSize ){
2745     if( offset+amt <= pFile->mmapSize ){
2746       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
2747       OSTRACE(("READ-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2748                osGetCurrentProcessId(), pFile, pFile->h));
2749       return SQLITE_OK;
2750     }else{
2751       int nCopy = (int)(pFile->mmapSize - offset);
2752       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);
2753       pBuf = &((u8 *)pBuf)[nCopy];
2754       amt -= nCopy;
2755       offset += nCopy;
2756     }
2757   }
2758 #endif
2759 
2760 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2761   if( winSeekFile(pFile, offset) ){
2762     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
2763              osGetCurrentProcessId(), pFile, pFile->h));
2764     return SQLITE_FULL;
2765   }
2766   while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
2767 #else
2768   memset(&overlapped, 0, sizeof(OVERLAPPED));
2769   overlapped.Offset = (LONG)(offset & 0xffffffff);
2770   overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2771   while( !osReadFile(pFile->h, pBuf, amt, &nRead, &overlapped) &&
2772          osGetLastError()!=ERROR_HANDLE_EOF ){
2773 #endif
2774     DWORD lastErrno;
2775     if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
2776     pFile->lastErrno = lastErrno;
2777     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_READ\n",
2778              osGetCurrentProcessId(), pFile, pFile->h));
2779     return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,
2780                        "winRead", pFile->zPath);
2781   }
2782   winLogIoerr(nRetry, __LINE__);
2783   if( nRead<(DWORD)amt ){
2784     /* Unread parts of the buffer must be zero-filled */
2785     memset(&((char*)pBuf)[nRead], 0, amt-nRead);
2786     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_SHORT_READ\n",
2787              osGetCurrentProcessId(), pFile, pFile->h));
2788     return SQLITE_IOERR_SHORT_READ;
2789   }
2790 
2791   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2792            osGetCurrentProcessId(), pFile, pFile->h));
2793   return SQLITE_OK;
2794 }
2795 
2796 /*
2797 ** Write data from a buffer into a file.  Return SQLITE_OK on success
2798 ** or some other error code on failure.
2799 */
2800 static int winWrite(
2801   sqlite3_file *id,               /* File to write into */
2802   const void *pBuf,               /* The bytes to be written */
2803   int amt,                        /* Number of bytes to write */
2804   sqlite3_int64 offset            /* Offset into the file to begin writing at */
2805 ){
2806   int rc = 0;                     /* True if error has occurred, else false */
2807   winFile *pFile = (winFile*)id;  /* File handle */
2808   int nRetry = 0;                 /* Number of retries */
2809 
2810   assert( amt>0 );
2811   assert( pFile );
2812   SimulateIOError(return SQLITE_IOERR_WRITE);
2813   SimulateDiskfullError(return SQLITE_FULL);
2814 
2815   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
2816            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
2817            pFile->h, pBuf, amt, offset, pFile->locktype));
2818 
2819 #if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0
2820   /* Deal with as much of this write request as possible by transfering
2821   ** data from the memory mapping using memcpy().  */
2822   if( offset<pFile->mmapSize ){
2823     if( offset+amt <= pFile->mmapSize ){
2824       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
2825       OSTRACE(("WRITE-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2826                osGetCurrentProcessId(), pFile, pFile->h));
2827       return SQLITE_OK;
2828     }else{
2829       int nCopy = (int)(pFile->mmapSize - offset);
2830       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);
2831       pBuf = &((u8 *)pBuf)[nCopy];
2832       amt -= nCopy;
2833       offset += nCopy;
2834     }
2835   }
2836 #endif
2837 
2838 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2839   rc = winSeekFile(pFile, offset);
2840   if( rc==0 ){
2841 #else
2842   {
2843 #endif
2844 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2845     OVERLAPPED overlapped;        /* The offset for WriteFile. */
2846 #endif
2847     u8 *aRem = (u8 *)pBuf;        /* Data yet to be written */
2848     int nRem = amt;               /* Number of bytes yet to be written */
2849     DWORD nWrite;                 /* Bytes written by each WriteFile() call */
2850     DWORD lastErrno = NO_ERROR;   /* Value returned by GetLastError() */
2851 
2852 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2853     memset(&overlapped, 0, sizeof(OVERLAPPED));
2854     overlapped.Offset = (LONG)(offset & 0xffffffff);
2855     overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2856 #endif
2857 
2858     while( nRem>0 ){
2859 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2860       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, 0) ){
2861 #else
2862       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, &overlapped) ){
2863 #endif
2864         if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
2865         break;
2866       }
2867       assert( nWrite==0 || nWrite<=(DWORD)nRem );
2868       if( nWrite==0 || nWrite>(DWORD)nRem ){
2869         lastErrno = osGetLastError();
2870         break;
2871       }
2872 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2873       offset += nWrite;
2874       overlapped.Offset = (LONG)(offset & 0xffffffff);
2875       overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2876 #endif
2877       aRem += nWrite;
2878       nRem -= nWrite;
2879     }
2880     if( nRem>0 ){
2881       pFile->lastErrno = lastErrno;
2882       rc = 1;
2883     }
2884   }
2885 
2886   if( rc ){
2887     if(   ( pFile->lastErrno==ERROR_HANDLE_DISK_FULL )
2888        || ( pFile->lastErrno==ERROR_DISK_FULL )){
2889       OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
2890                osGetCurrentProcessId(), pFile, pFile->h));
2891       return winLogError(SQLITE_FULL, pFile->lastErrno,
2892                          "winWrite1", pFile->zPath);
2893     }
2894     OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_WRITE\n",
2895              osGetCurrentProcessId(), pFile, pFile->h));
2896     return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,
2897                        "winWrite2", pFile->zPath);
2898   }else{
2899     winLogIoerr(nRetry, __LINE__);
2900   }
2901   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2902            osGetCurrentProcessId(), pFile, pFile->h));
2903   return SQLITE_OK;
2904 }
2905 
2906 /*
2907 ** Truncate an open file to a specified size
2908 */
2909 static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
2910   winFile *pFile = (winFile*)id;  /* File handle object */
2911   int rc = SQLITE_OK;             /* Return code for this function */
2912   DWORD lastErrno;
2913 #if SQLITE_MAX_MMAP_SIZE>0
2914   sqlite3_int64 oldMmapSize;
2915   if( pFile->nFetchOut>0 ){
2916     /* File truncation is a no-op if there are outstanding memory mapped
2917     ** pages.  This is because truncating the file means temporarily unmapping
2918     ** the file, and that might delete memory out from under existing cursors.
2919     **
2920     ** This can result in incremental vacuum not truncating the file,
2921     ** if there is an active read cursor when the incremental vacuum occurs.
2922     ** No real harm comes of this - the database file is not corrupted,
2923     ** though some folks might complain that the file is bigger than it
2924     ** needs to be.
2925     **
2926     ** The only feasible work-around is to defer the truncation until after
2927     ** all references to memory-mapped content are closed.  That is doable,
2928     ** but involves adding a few branches in the common write code path which
2929     ** could slow down normal operations slightly.  Hence, we have decided for
2930     ** now to simply make trancations a no-op if there are pending reads.  We
2931     ** can maybe revisit this decision in the future.
2932     */
2933     return SQLITE_OK;
2934   }
2935 #endif
2936 
2937   assert( pFile );
2938   SimulateIOError(return SQLITE_IOERR_TRUNCATE);
2939   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, size=%lld, lock=%d\n",
2940            osGetCurrentProcessId(), pFile, pFile->h, nByte, pFile->locktype));
2941 
2942   /* If the user has configured a chunk-size for this file, truncate the
2943   ** file so that it consists of an integer number of chunks (i.e. the
2944   ** actual file size after the operation may be larger than the requested
2945   ** size).
2946   */
2947   if( pFile->szChunk>0 ){
2948     nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
2949   }
2950 
2951 #if SQLITE_MAX_MMAP_SIZE>0
2952   if( pFile->pMapRegion ){
2953     oldMmapSize = pFile->mmapSize;
2954   }else{
2955     oldMmapSize = 0;
2956   }
2957   winUnmapfile(pFile);
2958 #endif
2959 
2960   /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
2961   if( winSeekFile(pFile, nByte) ){
2962     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
2963                      "winTruncate1", pFile->zPath);
2964   }else if( 0==osSetEndOfFile(pFile->h) &&
2965             ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){
2966     pFile->lastErrno = lastErrno;
2967     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
2968                      "winTruncate2", pFile->zPath);
2969   }
2970 
2971 #if SQLITE_MAX_MMAP_SIZE>0
2972   if( rc==SQLITE_OK && oldMmapSize>0 ){
2973     if( oldMmapSize>nByte ){
2974       winMapfile(pFile, -1);
2975     }else{
2976       winMapfile(pFile, oldMmapSize);
2977     }
2978   }
2979 #endif
2980 
2981   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, rc=%s\n",
2982            osGetCurrentProcessId(), pFile, pFile->h, sqlite3ErrName(rc)));
2983   return rc;
2984 }
2985 
2986 #ifdef SQLITE_TEST
2987 /*
2988 ** Count the number of fullsyncs and normal syncs.  This is used to test
2989 ** that syncs and fullsyncs are occuring at the right times.
2990 */
2991 int sqlite3_sync_count = 0;
2992 int sqlite3_fullsync_count = 0;
2993 #endif
2994 
2995 /*
2996 ** Make sure all writes to a particular file are committed to disk.
2997 */
2998 static int winSync(sqlite3_file *id, int flags){
2999 #ifndef SQLITE_NO_SYNC
3000   /*
3001   ** Used only when SQLITE_NO_SYNC is not defined.
3002    */
3003   BOOL rc;
3004 #endif
3005 #if !defined(NDEBUG) || !defined(SQLITE_NO_SYNC) || \
3006     defined(SQLITE_HAVE_OS_TRACE)
3007   /*
3008   ** Used when SQLITE_NO_SYNC is not defined and by the assert() and/or
3009   ** OSTRACE() macros.
3010    */
3011   winFile *pFile = (winFile*)id;
3012 #else
3013   UNUSED_PARAMETER(id);
3014 #endif
3015 
3016   assert( pFile );
3017   /* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */
3018   assert((flags&0x0F)==SQLITE_SYNC_NORMAL
3019       || (flags&0x0F)==SQLITE_SYNC_FULL
3020   );
3021 
3022   /* Unix cannot, but some systems may return SQLITE_FULL from here. This
3023   ** line is to test that doing so does not cause any problems.
3024   */
3025   SimulateDiskfullError( return SQLITE_FULL );
3026 
3027   OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, flags=%x, lock=%d\n",
3028            osGetCurrentProcessId(), pFile, pFile->h, flags,
3029            pFile->locktype));
3030 
3031 #ifndef SQLITE_TEST
3032   UNUSED_PARAMETER(flags);
3033 #else
3034   if( (flags&0x0F)==SQLITE_SYNC_FULL ){
3035     sqlite3_fullsync_count++;
3036   }
3037   sqlite3_sync_count++;
3038 #endif
3039 
3040   /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
3041   ** no-op
3042   */
3043 #ifdef SQLITE_NO_SYNC
3044   OSTRACE(("SYNC-NOP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
3045            osGetCurrentProcessId(), pFile, pFile->h));
3046   return SQLITE_OK;
3047 #else
3048 #if SQLITE_MAX_MMAP_SIZE>0
3049   if( pFile->pMapRegion ){
3050     if( osFlushViewOfFile(pFile->pMapRegion, 0) ){
3051       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
3052                "rc=SQLITE_OK\n", osGetCurrentProcessId(),
3053                pFile, pFile->pMapRegion));
3054     }else{
3055       pFile->lastErrno = osGetLastError();
3056       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
3057                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(),
3058                pFile, pFile->pMapRegion));
3059       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
3060                          "winSync1", pFile->zPath);
3061     }
3062   }
3063 #endif
3064   rc = osFlushFileBuffers(pFile->h);
3065   SimulateIOError( rc=FALSE );
3066   if( rc ){
3067     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
3068              osGetCurrentProcessId(), pFile, pFile->h));
3069     return SQLITE_OK;
3070   }else{
3071     pFile->lastErrno = osGetLastError();
3072     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_FSYNC\n",
3073              osGetCurrentProcessId(), pFile, pFile->h));
3074     return winLogError(SQLITE_IOERR_FSYNC, pFile->lastErrno,
3075                        "winSync2", pFile->zPath);
3076   }
3077 #endif
3078 }
3079 
3080 /*
3081 ** Determine the current size of a file in bytes
3082 */
3083 static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
3084   winFile *pFile = (winFile*)id;
3085   int rc = SQLITE_OK;
3086 
3087   assert( id!=0 );
3088   assert( pSize!=0 );
3089   SimulateIOError(return SQLITE_IOERR_FSTAT);
3090   OSTRACE(("SIZE file=%p, pSize=%p\n", pFile->h, pSize));
3091 
3092 #if SQLITE_OS_WINRT
3093   {
3094     FILE_STANDARD_INFO info;
3095     if( osGetFileInformationByHandleEx(pFile->h, FileStandardInfo,
3096                                      &info, sizeof(info)) ){
3097       *pSize = info.EndOfFile.QuadPart;
3098     }else{
3099       pFile->lastErrno = osGetLastError();
3100       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
3101                        "winFileSize", pFile->zPath);
3102     }
3103   }
3104 #else
3105   {
3106     DWORD upperBits;
3107     DWORD lowerBits;
3108     DWORD lastErrno;
3109 
3110     lowerBits = osGetFileSize(pFile->h, &upperBits);
3111     *pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;
3112     if(   (lowerBits == INVALID_FILE_SIZE)
3113        && ((lastErrno = osGetLastError())!=NO_ERROR) ){
3114       pFile->lastErrno = lastErrno;
3115       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
3116                        "winFileSize", pFile->zPath);
3117     }
3118   }
3119 #endif
3120   OSTRACE(("SIZE file=%p, pSize=%p, *pSize=%lld, rc=%s\n",
3121            pFile->h, pSize, *pSize, sqlite3ErrName(rc)));
3122   return rc;
3123 }
3124 
3125 /*
3126 ** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.
3127 */
3128 #ifndef LOCKFILE_FAIL_IMMEDIATELY
3129 # define LOCKFILE_FAIL_IMMEDIATELY 1
3130 #endif
3131 
3132 #ifndef LOCKFILE_EXCLUSIVE_LOCK
3133 # define LOCKFILE_EXCLUSIVE_LOCK 2
3134 #endif
3135 
3136 /*
3137 ** Historically, SQLite has used both the LockFile and LockFileEx functions.
3138 ** When the LockFile function was used, it was always expected to fail
3139 ** immediately if the lock could not be obtained.  Also, it always expected to
3140 ** obtain an exclusive lock.  These flags are used with the LockFileEx function
3141 ** and reflect those expectations; therefore, they should not be changed.
3142 */
3143 #ifndef SQLITE_LOCKFILE_FLAGS
3144 # define SQLITE_LOCKFILE_FLAGS   (LOCKFILE_FAIL_IMMEDIATELY | \
3145                                   LOCKFILE_EXCLUSIVE_LOCK)
3146 #endif
3147 
3148 /*
3149 ** Currently, SQLite never calls the LockFileEx function without wanting the
3150 ** call to fail immediately if the lock cannot be obtained.
3151 */
3152 #ifndef SQLITE_LOCKFILEEX_FLAGS
3153 # define SQLITE_LOCKFILEEX_FLAGS (LOCKFILE_FAIL_IMMEDIATELY)
3154 #endif
3155 
3156 /*
3157 ** Acquire a reader lock.
3158 ** Different API routines are called depending on whether or not this
3159 ** is Win9x or WinNT.
3160 */
3161 static int winGetReadLock(winFile *pFile){
3162   int res;
3163   OSTRACE(("READ-LOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
3164   if( osIsNT() ){
3165 #if SQLITE_OS_WINCE
3166     /*
3167     ** NOTE: Windows CE is handled differently here due its lack of the Win32
3168     **       API LockFileEx.
3169     */
3170     res = winceLockFile(&pFile->h, SHARED_FIRST, 0, 1, 0);
3171 #else
3172     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS, SHARED_FIRST, 0,
3173                       SHARED_SIZE, 0);
3174 #endif
3175   }
3176 #ifdef SQLITE_WIN32_HAS_ANSI
3177   else{
3178     int lk;
3179     sqlite3_randomness(sizeof(lk), &lk);
3180     pFile->sharedLockByte = (short)((lk & 0x7fffffff)%(SHARED_SIZE - 1));
3181     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
3182                       SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
3183   }
3184 #endif
3185   if( res == 0 ){
3186     pFile->lastErrno = osGetLastError();
3187     /* No need to log a failure to lock */
3188   }
3189   OSTRACE(("READ-LOCK file=%p, result=%d\n", pFile->h, res));
3190   return res;
3191 }
3192 
3193 /*
3194 ** Undo a readlock
3195 */
3196 static int winUnlockReadLock(winFile *pFile){
3197   int res;
3198   DWORD lastErrno;
3199   OSTRACE(("READ-UNLOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
3200   if( osIsNT() ){
3201     res = winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
3202   }
3203 #ifdef SQLITE_WIN32_HAS_ANSI
3204   else{
3205     res = winUnlockFile(&pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
3206   }
3207 #endif
3208   if( res==0 && ((lastErrno = osGetLastError())!=ERROR_NOT_LOCKED) ){
3209     pFile->lastErrno = lastErrno;
3210     winLogError(SQLITE_IOERR_UNLOCK, pFile->lastErrno,
3211                 "winUnlockReadLock", pFile->zPath);
3212   }
3213   OSTRACE(("READ-UNLOCK file=%p, result=%d\n", pFile->h, res));
3214   return res;
3215 }
3216 
3217 /*
3218 ** Lock the file with the lock specified by parameter locktype - one
3219 ** of the following:
3220 **
3221 **     (1) SHARED_LOCK
3222 **     (2) RESERVED_LOCK
3223 **     (3) PENDING_LOCK
3224 **     (4) EXCLUSIVE_LOCK
3225 **
3226 ** Sometimes when requesting one lock state, additional lock states
3227 ** are inserted in between.  The locking might fail on one of the later
3228 ** transitions leaving the lock state different from what it started but
3229 ** still short of its goal.  The following chart shows the allowed
3230 ** transitions and the inserted intermediate states:
3231 **
3232 **    UNLOCKED -> SHARED
3233 **    SHARED -> RESERVED
3234 **    SHARED -> (PENDING) -> EXCLUSIVE
3235 **    RESERVED -> (PENDING) -> EXCLUSIVE
3236 **    PENDING -> EXCLUSIVE
3237 **
3238 ** This routine will only increase a lock.  The winUnlock() routine
3239 ** erases all locks at once and returns us immediately to locking level 0.
3240 ** It is not possible to lower the locking level one step at a time.  You
3241 ** must go straight to locking level 0.
3242 */
3243 static int winLock(sqlite3_file *id, int locktype){
3244   int rc = SQLITE_OK;    /* Return code from subroutines */
3245   int res = 1;           /* Result of a Windows lock call */
3246   int newLocktype;       /* Set pFile->locktype to this value before exiting */
3247   int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
3248   winFile *pFile = (winFile*)id;
3249   DWORD lastErrno = NO_ERROR;
3250 
3251   assert( id!=0 );
3252   OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",
3253            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
3254 
3255   /* If there is already a lock of this type or more restrictive on the
3256   ** OsFile, do nothing. Don't use the end_lock: exit path, as
3257   ** sqlite3OsEnterMutex() hasn't been called yet.
3258   */
3259   if( pFile->locktype>=locktype ){
3260     OSTRACE(("LOCK-HELD file=%p, rc=SQLITE_OK\n", pFile->h));
3261     return SQLITE_OK;
3262   }
3263 
3264   /* Do not allow any kind of write-lock on a read-only database
3265   */
3266   if( (pFile->ctrlFlags & WINFILE_RDONLY)!=0 && locktype>=RESERVED_LOCK ){
3267     return SQLITE_IOERR_LOCK;
3268   }
3269 
3270   /* Make sure the locking sequence is correct
3271   */
3272   assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
3273   assert( locktype!=PENDING_LOCK );
3274   assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
3275 
3276   /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
3277   ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
3278   ** the PENDING_LOCK byte is temporary.
3279   */
3280   newLocktype = pFile->locktype;
3281   if( pFile->locktype==NO_LOCK
3282    || (locktype==EXCLUSIVE_LOCK && pFile->locktype<=RESERVED_LOCK)
3283   ){
3284     int cnt = 3;
3285     while( cnt-->0 && (res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
3286                                          PENDING_BYTE, 0, 1, 0))==0 ){
3287       /* Try 3 times to get the pending lock.  This is needed to work
3288       ** around problems caused by indexing and/or anti-virus software on
3289       ** Windows systems.
3290       ** If you are using this code as a model for alternative VFSes, do not
3291       ** copy this retry logic.  It is a hack intended for Windows only.
3292       */
3293       lastErrno = osGetLastError();
3294       OSTRACE(("LOCK-PENDING-FAIL file=%p, count=%d, result=%d\n",
3295                pFile->h, cnt, res));
3296       if( lastErrno==ERROR_INVALID_HANDLE ){
3297         pFile->lastErrno = lastErrno;
3298         rc = SQLITE_IOERR_LOCK;
3299         OSTRACE(("LOCK-FAIL file=%p, count=%d, rc=%s\n",
3300                  pFile->h, cnt, sqlite3ErrName(rc)));
3301         return rc;
3302       }
3303       if( cnt ) sqlite3_win32_sleep(1);
3304     }
3305     gotPendingLock = res;
3306     if( !res ){
3307       lastErrno = osGetLastError();
3308     }
3309   }
3310 
3311   /* Acquire a shared lock
3312   */
3313   if( locktype==SHARED_LOCK && res ){
3314     assert( pFile->locktype==NO_LOCK );
3315     res = winGetReadLock(pFile);
3316     if( res ){
3317       newLocktype = SHARED_LOCK;
3318     }else{
3319       lastErrno = osGetLastError();
3320     }
3321   }
3322 
3323   /* Acquire a RESERVED lock
3324   */
3325   if( locktype==RESERVED_LOCK && res ){
3326     assert( pFile->locktype==SHARED_LOCK );
3327     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, RESERVED_BYTE, 0, 1, 0);
3328     if( res ){
3329       newLocktype = RESERVED_LOCK;
3330     }else{
3331       lastErrno = osGetLastError();
3332     }
3333   }
3334 
3335   /* Acquire a PENDING lock
3336   */
3337   if( locktype==EXCLUSIVE_LOCK && res ){
3338     newLocktype = PENDING_LOCK;
3339     gotPendingLock = 0;
3340   }
3341 
3342   /* Acquire an EXCLUSIVE lock
3343   */
3344   if( locktype==EXCLUSIVE_LOCK && res ){
3345     assert( pFile->locktype>=SHARED_LOCK );
3346     res = winUnlockReadLock(pFile);
3347     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, SHARED_FIRST, 0,
3348                       SHARED_SIZE, 0);
3349     if( res ){
3350       newLocktype = EXCLUSIVE_LOCK;
3351     }else{
3352       lastErrno = osGetLastError();
3353       winGetReadLock(pFile);
3354     }
3355   }
3356 
3357   /* If we are holding a PENDING lock that ought to be released, then
3358   ** release it now.
3359   */
3360   if( gotPendingLock && locktype==SHARED_LOCK ){
3361     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
3362   }
3363 
3364   /* Update the state of the lock has held in the file descriptor then
3365   ** return the appropriate result code.
3366   */
3367   if( res ){
3368     rc = SQLITE_OK;
3369   }else{
3370     pFile->lastErrno = lastErrno;
3371     rc = SQLITE_BUSY;
3372     OSTRACE(("LOCK-FAIL file=%p, wanted=%d, got=%d\n",
3373              pFile->h, locktype, newLocktype));
3374   }
3375   pFile->locktype = (u8)newLocktype;
3376   OSTRACE(("LOCK file=%p, lock=%d, rc=%s\n",
3377            pFile->h, pFile->locktype, sqlite3ErrName(rc)));
3378   return rc;
3379 }
3380 
3381 /*
3382 ** This routine checks if there is a RESERVED lock held on the specified
3383 ** file by this or any other process. If such a lock is held, return
3384 ** non-zero, otherwise zero.
3385 */
3386 static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
3387   int res;
3388   winFile *pFile = (winFile*)id;
3389 
3390   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
3391   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));
3392 
3393   assert( id!=0 );
3394   if( pFile->locktype>=RESERVED_LOCK ){
3395     res = 1;
3396     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (local)\n", pFile->h, res));
3397   }else{
3398     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE,0,1,0);
3399     if( res ){
3400       winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
3401     }
3402     res = !res;
3403     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (remote)\n", pFile->h, res));
3404   }
3405   *pResOut = res;
3406   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
3407            pFile->h, pResOut, *pResOut));
3408   return SQLITE_OK;
3409 }
3410 
3411 /*
3412 ** Lower the locking level on file descriptor id to locktype.  locktype
3413 ** must be either NO_LOCK or SHARED_LOCK.
3414 **
3415 ** If the locking level of the file descriptor is already at or below
3416 ** the requested locking level, this routine is a no-op.
3417 **
3418 ** It is not possible for this routine to fail if the second argument
3419 ** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
3420 ** might return SQLITE_IOERR;
3421 */
3422 static int winUnlock(sqlite3_file *id, int locktype){
3423   int type;
3424   winFile *pFile = (winFile*)id;
3425   int rc = SQLITE_OK;
3426   assert( pFile!=0 );
3427   assert( locktype<=SHARED_LOCK );
3428   OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
3429            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
3430   type = pFile->locktype;
3431   if( type>=EXCLUSIVE_LOCK ){
3432     winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
3433     if( locktype==SHARED_LOCK && !winGetReadLock(pFile) ){
3434       /* This should never happen.  We should always be able to
3435       ** reacquire the read lock */
3436       rc = winLogError(SQLITE_IOERR_UNLOCK, osGetLastError(),
3437                        "winUnlock", pFile->zPath);
3438     }
3439   }
3440   if( type>=RESERVED_LOCK ){
3441     winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
3442   }
3443   if( locktype==NO_LOCK && type>=SHARED_LOCK ){
3444     winUnlockReadLock(pFile);
3445   }
3446   if( type>=PENDING_LOCK ){
3447     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
3448   }
3449   pFile->locktype = (u8)locktype;
3450   OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",
3451            pFile->h, pFile->locktype, sqlite3ErrName(rc)));
3452   return rc;
3453 }
3454 
3455 /******************************************************************************
3456 ****************************** No-op Locking **********************************
3457 **
3458 ** Of the various locking implementations available, this is by far the
3459 ** simplest:  locking is ignored.  No attempt is made to lock the database
3460 ** file for reading or writing.
3461 **
3462 ** This locking mode is appropriate for use on read-only databases
3463 ** (ex: databases that are burned into CD-ROM, for example.)  It can
3464 ** also be used if the application employs some external mechanism to
3465 ** prevent simultaneous access of the same database by two or more
3466 ** database connections.  But there is a serious risk of database
3467 ** corruption if this locking mode is used in situations where multiple
3468 ** database connections are accessing the same database file at the same
3469 ** time and one or more of those connections are writing.
3470 */
3471 
3472 static int winNolockLock(sqlite3_file *id, int locktype){
3473   UNUSED_PARAMETER(id);
3474   UNUSED_PARAMETER(locktype);
3475   return SQLITE_OK;
3476 }
3477 
3478 static int winNolockCheckReservedLock(sqlite3_file *id, int *pResOut){
3479   UNUSED_PARAMETER(id);
3480   UNUSED_PARAMETER(pResOut);
3481   return SQLITE_OK;
3482 }
3483 
3484 static int winNolockUnlock(sqlite3_file *id, int locktype){
3485   UNUSED_PARAMETER(id);
3486   UNUSED_PARAMETER(locktype);
3487   return SQLITE_OK;
3488 }
3489 
3490 /******************* End of the no-op lock implementation *********************
3491 ******************************************************************************/
3492 
3493 /*
3494 ** If *pArg is initially negative then this is a query.  Set *pArg to
3495 ** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
3496 **
3497 ** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.
3498 */
3499 static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){
3500   if( *pArg<0 ){
3501     *pArg = (pFile->ctrlFlags & mask)!=0;
3502   }else if( (*pArg)==0 ){
3503     pFile->ctrlFlags &= ~mask;
3504   }else{
3505     pFile->ctrlFlags |= mask;
3506   }
3507 }
3508 
3509 /* Forward references to VFS helper methods used for temporary files */
3510 static int winGetTempname(sqlite3_vfs *, char **);
3511 static int winIsDir(const void *);
3512 static BOOL winIsLongPathPrefix(const char *);
3513 static BOOL winIsDriveLetterAndColon(const char *);
3514 
3515 /*
3516 ** Control and query of the open file handle.
3517 */
3518 static int winFileControl(sqlite3_file *id, int op, void *pArg){
3519   winFile *pFile = (winFile*)id;
3520   OSTRACE(("FCNTL file=%p, op=%d, pArg=%p\n", pFile->h, op, pArg));
3521   switch( op ){
3522     case SQLITE_FCNTL_LOCKSTATE: {
3523       *(int*)pArg = pFile->locktype;
3524       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3525       return SQLITE_OK;
3526     }
3527     case SQLITE_FCNTL_LAST_ERRNO: {
3528       *(int*)pArg = (int)pFile->lastErrno;
3529       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3530       return SQLITE_OK;
3531     }
3532     case SQLITE_FCNTL_CHUNK_SIZE: {
3533       pFile->szChunk = *(int *)pArg;
3534       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3535       return SQLITE_OK;
3536     }
3537     case SQLITE_FCNTL_SIZE_HINT: {
3538       if( pFile->szChunk>0 ){
3539         sqlite3_int64 oldSz;
3540         int rc = winFileSize(id, &oldSz);
3541         if( rc==SQLITE_OK ){
3542           sqlite3_int64 newSz = *(sqlite3_int64*)pArg;
3543           if( newSz>oldSz ){
3544             SimulateIOErrorBenign(1);
3545             rc = winTruncate(id, newSz);
3546             SimulateIOErrorBenign(0);
3547           }
3548         }
3549         OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3550         return rc;
3551       }
3552       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3553       return SQLITE_OK;
3554     }
3555     case SQLITE_FCNTL_PERSIST_WAL: {
3556       winModeBit(pFile, WINFILE_PERSIST_WAL, (int*)pArg);
3557       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3558       return SQLITE_OK;
3559     }
3560     case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
3561       winModeBit(pFile, WINFILE_PSOW, (int*)pArg);
3562       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3563       return SQLITE_OK;
3564     }
3565     case SQLITE_FCNTL_VFSNAME: {
3566       *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
3567       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3568       return SQLITE_OK;
3569     }
3570     case SQLITE_FCNTL_WIN32_AV_RETRY: {
3571       int *a = (int*)pArg;
3572       if( a[0]>0 ){
3573         winIoerrRetry = a[0];
3574       }else{
3575         a[0] = winIoerrRetry;
3576       }
3577       if( a[1]>0 ){
3578         winIoerrRetryDelay = a[1];
3579       }else{
3580         a[1] = winIoerrRetryDelay;
3581       }
3582       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3583       return SQLITE_OK;
3584     }
3585     case SQLITE_FCNTL_WIN32_GET_HANDLE: {
3586       LPHANDLE phFile = (LPHANDLE)pArg;
3587       *phFile = pFile->h;
3588       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3589       return SQLITE_OK;
3590     }
3591 #ifdef SQLITE_TEST
3592     case SQLITE_FCNTL_WIN32_SET_HANDLE: {
3593       LPHANDLE phFile = (LPHANDLE)pArg;
3594       HANDLE hOldFile = pFile->h;
3595       pFile->h = *phFile;
3596       *phFile = hOldFile;
3597       OSTRACE(("FCNTL oldFile=%p, newFile=%p, rc=SQLITE_OK\n",
3598                hOldFile, pFile->h));
3599       return SQLITE_OK;
3600     }
3601 #endif
3602     case SQLITE_FCNTL_TEMPFILENAME: {
3603       char *zTFile = 0;
3604       int rc = winGetTempname(pFile->pVfs, &zTFile);
3605       if( rc==SQLITE_OK ){
3606         *(char**)pArg = zTFile;
3607       }
3608       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3609       return rc;
3610     }
3611 #if SQLITE_MAX_MMAP_SIZE>0
3612     case SQLITE_FCNTL_MMAP_SIZE: {
3613       i64 newLimit = *(i64*)pArg;
3614       int rc = SQLITE_OK;
3615       if( newLimit>sqlite3GlobalConfig.mxMmap ){
3616         newLimit = sqlite3GlobalConfig.mxMmap;
3617       }
3618 
3619       /* The value of newLimit may be eventually cast to (SIZE_T) and passed
3620       ** to MapViewOfFile(). Restrict its value to 2GB if (SIZE_T) is not at
3621       ** least a 64-bit type. */
3622       if( newLimit>0 && sizeof(SIZE_T)<8 ){
3623         newLimit = (newLimit & 0x7FFFFFFF);
3624       }
3625 
3626       *(i64*)pArg = pFile->mmapSizeMax;
3627       if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
3628         pFile->mmapSizeMax = newLimit;
3629         if( pFile->mmapSize>0 ){
3630           winUnmapfile(pFile);
3631           rc = winMapfile(pFile, -1);
3632         }
3633       }
3634       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3635       return rc;
3636     }
3637 #endif
3638   }
3639   OSTRACE(("FCNTL file=%p, rc=SQLITE_NOTFOUND\n", pFile->h));
3640   return SQLITE_NOTFOUND;
3641 }
3642 
3643 /*
3644 ** Return the sector size in bytes of the underlying block device for
3645 ** the specified file. This is almost always 512 bytes, but may be
3646 ** larger for some devices.
3647 **
3648 ** SQLite code assumes this function cannot fail. It also assumes that
3649 ** if two files are created in the same file-system directory (i.e.
3650 ** a database and its journal file) that the sector size will be the
3651 ** same for both.
3652 */
3653 static int winSectorSize(sqlite3_file *id){
3654   (void)id;
3655   return SQLITE_DEFAULT_SECTOR_SIZE;
3656 }
3657 
3658 /*
3659 ** Return a vector of device characteristics.
3660 */
3661 static int winDeviceCharacteristics(sqlite3_file *id){
3662   winFile *p = (winFile*)id;
3663   return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |
3664          ((p->ctrlFlags & WINFILE_PSOW)?SQLITE_IOCAP_POWERSAFE_OVERWRITE:0);
3665 }
3666 
3667 /*
3668 ** Windows will only let you create file view mappings
3669 ** on allocation size granularity boundaries.
3670 ** During sqlite3_os_init() we do a GetSystemInfo()
3671 ** to get the granularity size.
3672 */
3673 static SYSTEM_INFO winSysInfo;
3674 
3675 #ifndef SQLITE_OMIT_WAL
3676 
3677 /*
3678 ** Helper functions to obtain and relinquish the global mutex. The
3679 ** global mutex is used to protect the winLockInfo objects used by
3680 ** this file, all of which may be shared by multiple threads.
3681 **
3682 ** Function winShmMutexHeld() is used to assert() that the global mutex
3683 ** is held when required. This function is only used as part of assert()
3684 ** statements. e.g.
3685 **
3686 **   winShmEnterMutex()
3687 **     assert( winShmMutexHeld() );
3688 **   winShmLeaveMutex()
3689 */
3690 static sqlite3_mutex *winBigLock = 0;
3691 static void winShmEnterMutex(void){
3692   sqlite3_mutex_enter(winBigLock);
3693 }
3694 static void winShmLeaveMutex(void){
3695   sqlite3_mutex_leave(winBigLock);
3696 }
3697 #ifndef NDEBUG
3698 static int winShmMutexHeld(void) {
3699   return sqlite3_mutex_held(winBigLock);
3700 }
3701 #endif
3702 
3703 /*
3704 ** Object used to represent a single file opened and mmapped to provide
3705 ** shared memory.  When multiple threads all reference the same
3706 ** log-summary, each thread has its own winFile object, but they all
3707 ** point to a single instance of this object.  In other words, each
3708 ** log-summary is opened only once per process.
3709 **
3710 ** winShmMutexHeld() must be true when creating or destroying
3711 ** this object or while reading or writing the following fields:
3712 **
3713 **      nRef
3714 **      pNext
3715 **
3716 ** The following fields are read-only after the object is created:
3717 **
3718 **      fid
3719 **      zFilename
3720 **
3721 ** Either winShmNode.mutex must be held or winShmNode.nRef==0 and
3722 ** winShmMutexHeld() is true when reading or writing any other field
3723 ** in this structure.
3724 **
3725 */
3726 struct winShmNode {
3727   sqlite3_mutex *mutex;      /* Mutex to access this object */
3728   char *zFilename;           /* Name of the file */
3729   winFile hFile;             /* File handle from winOpen */
3730 
3731   int szRegion;              /* Size of shared-memory regions */
3732   int nRegion;               /* Size of array apRegion */
3733   u8 isReadonly;             /* True if read-only */
3734   u8 isUnlocked;             /* True if no DMS lock held */
3735 
3736   struct ShmRegion {
3737     HANDLE hMap;             /* File handle from CreateFileMapping */
3738     void *pMap;
3739   } *aRegion;
3740   DWORD lastErrno;           /* The Windows errno from the last I/O error */
3741 
3742   int nRef;                  /* Number of winShm objects pointing to this */
3743   winShm *pFirst;            /* All winShm objects pointing to this */
3744   winShmNode *pNext;         /* Next in list of all winShmNode objects */
3745 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3746   u8 nextShmId;              /* Next available winShm.id value */
3747 #endif
3748 };
3749 
3750 /*
3751 ** A global array of all winShmNode objects.
3752 **
3753 ** The winShmMutexHeld() must be true while reading or writing this list.
3754 */
3755 static winShmNode *winShmNodeList = 0;
3756 
3757 /*
3758 ** Structure used internally by this VFS to record the state of an
3759 ** open shared memory connection.
3760 **
3761 ** The following fields are initialized when this object is created and
3762 ** are read-only thereafter:
3763 **
3764 **    winShm.pShmNode
3765 **    winShm.id
3766 **
3767 ** All other fields are read/write.  The winShm.pShmNode->mutex must be held
3768 ** while accessing any read/write fields.
3769 */
3770 struct winShm {
3771   winShmNode *pShmNode;      /* The underlying winShmNode object */
3772   winShm *pNext;             /* Next winShm with the same winShmNode */
3773   u8 hasMutex;               /* True if holding the winShmNode mutex */
3774   u16 sharedMask;            /* Mask of shared locks held */
3775   u16 exclMask;              /* Mask of exclusive locks held */
3776 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3777   u8 id;                     /* Id of this connection with its winShmNode */
3778 #endif
3779 };
3780 
3781 /*
3782 ** Constants used for locking
3783 */
3784 #define WIN_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)        /* first lock byte */
3785 #define WIN_SHM_DMS    (WIN_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */
3786 
3787 /*
3788 ** Apply advisory locks for all n bytes beginning at ofst.
3789 */
3790 #define WINSHM_UNLCK  1
3791 #define WINSHM_RDLCK  2
3792 #define WINSHM_WRLCK  3
3793 static int winShmSystemLock(
3794   winShmNode *pFile,    /* Apply locks to this open shared-memory segment */
3795   int lockType,         /* WINSHM_UNLCK, WINSHM_RDLCK, or WINSHM_WRLCK */
3796   int ofst,             /* Offset to first byte to be locked/unlocked */
3797   int nByte             /* Number of bytes to lock or unlock */
3798 ){
3799   int rc = 0;           /* Result code form Lock/UnlockFileEx() */
3800 
3801   /* Access to the winShmNode object is serialized by the caller */
3802   assert( pFile->nRef==0 || sqlite3_mutex_held(pFile->mutex) );
3803 
3804   OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",
3805            pFile->hFile.h, lockType, ofst, nByte));
3806 
3807   /* Release/Acquire the system-level lock */
3808   if( lockType==WINSHM_UNLCK ){
3809     rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);
3810   }else{
3811     /* Initialize the locking parameters */
3812     DWORD dwFlags = LOCKFILE_FAIL_IMMEDIATELY;
3813     if( lockType == WINSHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
3814     rc = winLockFile(&pFile->hFile.h, dwFlags, ofst, 0, nByte, 0);
3815   }
3816 
3817   if( rc!= 0 ){
3818     rc = SQLITE_OK;
3819   }else{
3820     pFile->lastErrno =  osGetLastError();
3821     rc = SQLITE_BUSY;
3822   }
3823 
3824   OSTRACE(("SHM-LOCK file=%p, func=%s, errno=%lu, rc=%s\n",
3825            pFile->hFile.h, (lockType == WINSHM_UNLCK) ? "winUnlockFile" :
3826            "winLockFile", pFile->lastErrno, sqlite3ErrName(rc)));
3827 
3828   return rc;
3829 }
3830 
3831 /* Forward references to VFS methods */
3832 static int winOpen(sqlite3_vfs*,const char*,sqlite3_file*,int,int*);
3833 static int winDelete(sqlite3_vfs *,const char*,int);
3834 
3835 /*
3836 ** Purge the winShmNodeList list of all entries with winShmNode.nRef==0.
3837 **
3838 ** This is not a VFS shared-memory method; it is a utility function called
3839 ** by VFS shared-memory methods.
3840 */
3841 static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){
3842   winShmNode **pp;
3843   winShmNode *p;
3844   assert( winShmMutexHeld() );
3845   OSTRACE(("SHM-PURGE pid=%lu, deleteFlag=%d\n",
3846            osGetCurrentProcessId(), deleteFlag));
3847   pp = &winShmNodeList;
3848   while( (p = *pp)!=0 ){
3849     if( p->nRef==0 ){
3850       int i;
3851       if( p->mutex ){ sqlite3_mutex_free(p->mutex); }
3852       for(i=0; i<p->nRegion; i++){
3853         BOOL bRc = osUnmapViewOfFile(p->aRegion[i].pMap);
3854         OSTRACE(("SHM-PURGE-UNMAP pid=%lu, region=%d, rc=%s\n",
3855                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
3856         UNUSED_VARIABLE_VALUE(bRc);
3857         bRc = osCloseHandle(p->aRegion[i].hMap);
3858         OSTRACE(("SHM-PURGE-CLOSE pid=%lu, region=%d, rc=%s\n",
3859                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
3860         UNUSED_VARIABLE_VALUE(bRc);
3861       }
3862       if( p->hFile.h!=NULL && p->hFile.h!=INVALID_HANDLE_VALUE ){
3863         SimulateIOErrorBenign(1);
3864         winClose((sqlite3_file *)&p->hFile);
3865         SimulateIOErrorBenign(0);
3866       }
3867       if( deleteFlag ){
3868         SimulateIOErrorBenign(1);
3869         sqlite3BeginBenignMalloc();
3870         winDelete(pVfs, p->zFilename, 0);
3871         sqlite3EndBenignMalloc();
3872         SimulateIOErrorBenign(0);
3873       }
3874       *pp = p->pNext;
3875       sqlite3_free(p->aRegion);
3876       sqlite3_free(p);
3877     }else{
3878       pp = &p->pNext;
3879     }
3880   }
3881 }
3882 
3883 /*
3884 ** The DMS lock has not yet been taken on shm file pShmNode. Attempt to
3885 ** take it now. Return SQLITE_OK if successful, or an SQLite error
3886 ** code otherwise.
3887 **
3888 ** If the DMS cannot be locked because this is a readonly_shm=1
3889 ** connection and no other process already holds a lock, return
3890 ** SQLITE_READONLY_CANTINIT and set pShmNode->isUnlocked=1.
3891 */
3892 static int winLockSharedMemory(winShmNode *pShmNode){
3893   int rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, WIN_SHM_DMS, 1);
3894 
3895   if( rc==SQLITE_OK ){
3896     if( pShmNode->isReadonly ){
3897       pShmNode->isUnlocked = 1;
3898       winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3899       return SQLITE_READONLY_CANTINIT;
3900     }else if( winTruncate((sqlite3_file*)&pShmNode->hFile, 0) ){
3901       winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3902       return winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),
3903                          "winLockSharedMemory", pShmNode->zFilename);
3904     }
3905   }
3906 
3907   if( rc==SQLITE_OK ){
3908     winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3909   }
3910 
3911   return winShmSystemLock(pShmNode, WINSHM_RDLCK, WIN_SHM_DMS, 1);
3912 }
3913 
3914 /*
3915 ** Open the shared-memory area associated with database file pDbFd.
3916 **
3917 ** When opening a new shared-memory file, if no other instances of that
3918 ** file are currently open, in this process or in other processes, then
3919 ** the file must be truncated to zero length or have its header cleared.
3920 */
3921 static int winOpenSharedMemory(winFile *pDbFd){
3922   struct winShm *p;                  /* The connection to be opened */
3923   winShmNode *pShmNode = 0;          /* The underlying mmapped file */
3924   int rc = SQLITE_OK;                /* Result code */
3925   winShmNode *pNew;                  /* Newly allocated winShmNode */
3926   int nName;                         /* Size of zName in bytes */
3927 
3928   assert( pDbFd->pShm==0 );    /* Not previously opened */
3929 
3930   /* Allocate space for the new sqlite3_shm object.  Also speculatively
3931   ** allocate space for a new winShmNode and filename.
3932   */
3933   p = sqlite3MallocZero( sizeof(*p) );
3934   if( p==0 ) return SQLITE_IOERR_NOMEM_BKPT;
3935   nName = sqlite3Strlen30(pDbFd->zPath);
3936   pNew = sqlite3MallocZero( sizeof(*pShmNode) + nName + 17 );
3937   if( pNew==0 ){
3938     sqlite3_free(p);
3939     return SQLITE_IOERR_NOMEM_BKPT;
3940   }
3941   pNew->zFilename = (char*)&pNew[1];
3942   sqlite3_snprintf(nName+15, pNew->zFilename, "%s-shm", pDbFd->zPath);
3943   sqlite3FileSuffix3(pDbFd->zPath, pNew->zFilename);
3944 
3945   /* Look to see if there is an existing winShmNode that can be used.
3946   ** If no matching winShmNode currently exists, create a new one.
3947   */
3948   winShmEnterMutex();
3949   for(pShmNode = winShmNodeList; pShmNode; pShmNode=pShmNode->pNext){
3950     /* TBD need to come up with better match here.  Perhaps
3951     ** use FILE_ID_BOTH_DIR_INFO Structure.
3952     */
3953     if( sqlite3StrICmp(pShmNode->zFilename, pNew->zFilename)==0 ) break;
3954   }
3955   if( pShmNode ){
3956     sqlite3_free(pNew);
3957   }else{
3958     int inFlags = SQLITE_OPEN_WAL;
3959     int outFlags = 0;
3960 
3961     pShmNode = pNew;
3962     pNew = 0;
3963     ((winFile*)(&pShmNode->hFile))->h = INVALID_HANDLE_VALUE;
3964     pShmNode->pNext = winShmNodeList;
3965     winShmNodeList = pShmNode;
3966 
3967     if( sqlite3GlobalConfig.bCoreMutex ){
3968       pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
3969       if( pShmNode->mutex==0 ){
3970         rc = SQLITE_IOERR_NOMEM_BKPT;
3971         goto shm_open_err;
3972       }
3973     }
3974 
3975     if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
3976       inFlags |= SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
3977     }else{
3978       inFlags |= SQLITE_OPEN_READONLY;
3979     }
3980     rc = winOpen(pDbFd->pVfs, pShmNode->zFilename,
3981                  (sqlite3_file*)&pShmNode->hFile,
3982                  inFlags, &outFlags);
3983     if( rc!=SQLITE_OK ){
3984       rc = winLogError(rc, osGetLastError(), "winOpenShm",
3985                        pShmNode->zFilename);
3986       goto shm_open_err;
3987     }
3988     if( outFlags==SQLITE_OPEN_READONLY ) pShmNode->isReadonly = 1;
3989 
3990     rc = winLockSharedMemory(pShmNode);
3991     if( rc!=SQLITE_OK && rc!=SQLITE_READONLY_CANTINIT ) goto shm_open_err;
3992   }
3993 
3994   /* Make the new connection a child of the winShmNode */
3995   p->pShmNode = pShmNode;
3996 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3997   p->id = pShmNode->nextShmId++;
3998 #endif
3999   pShmNode->nRef++;
4000   pDbFd->pShm = p;
4001   winShmLeaveMutex();
4002 
4003   /* The reference count on pShmNode has already been incremented under
4004   ** the cover of the winShmEnterMutex() mutex and the pointer from the
4005   ** new (struct winShm) object to the pShmNode has been set. All that is
4006   ** left to do is to link the new object into the linked list starting
4007   ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex
4008   ** mutex.
4009   */
4010   sqlite3_mutex_enter(pShmNode->mutex);
4011   p->pNext = pShmNode->pFirst;
4012   pShmNode->pFirst = p;
4013   sqlite3_mutex_leave(pShmNode->mutex);
4014   return rc;
4015 
4016   /* Jump here on any error */
4017 shm_open_err:
4018   winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
4019   winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */
4020   sqlite3_free(p);
4021   sqlite3_free(pNew);
4022   winShmLeaveMutex();
4023   return rc;
4024 }
4025 
4026 /*
4027 ** Close a connection to shared-memory.  Delete the underlying
4028 ** storage if deleteFlag is true.
4029 */
4030 static int winShmUnmap(
4031   sqlite3_file *fd,          /* Database holding shared memory */
4032   int deleteFlag             /* Delete after closing if true */
4033 ){
4034   winFile *pDbFd;       /* Database holding shared-memory */
4035   winShm *p;            /* The connection to be closed */
4036   winShmNode *pShmNode; /* The underlying shared-memory file */
4037   winShm **pp;          /* For looping over sibling connections */
4038 
4039   pDbFd = (winFile*)fd;
4040   p = pDbFd->pShm;
4041   if( p==0 ) return SQLITE_OK;
4042   pShmNode = p->pShmNode;
4043 
4044   /* Remove connection p from the set of connections associated
4045   ** with pShmNode */
4046   sqlite3_mutex_enter(pShmNode->mutex);
4047   for(pp=&pShmNode->pFirst; (*pp)!=p; pp = &(*pp)->pNext){}
4048   *pp = p->pNext;
4049 
4050   /* Free the connection p */
4051   sqlite3_free(p);
4052   pDbFd->pShm = 0;
4053   sqlite3_mutex_leave(pShmNode->mutex);
4054 
4055   /* If pShmNode->nRef has reached 0, then close the underlying
4056   ** shared-memory file, too */
4057   winShmEnterMutex();
4058   assert( pShmNode->nRef>0 );
4059   pShmNode->nRef--;
4060   if( pShmNode->nRef==0 ){
4061     winShmPurge(pDbFd->pVfs, deleteFlag);
4062   }
4063   winShmLeaveMutex();
4064 
4065   return SQLITE_OK;
4066 }
4067 
4068 /*
4069 ** Change the lock state for a shared-memory segment.
4070 */
4071 static int winShmLock(
4072   sqlite3_file *fd,          /* Database file holding the shared memory */
4073   int ofst,                  /* First lock to acquire or release */
4074   int n,                     /* Number of locks to acquire or release */
4075   int flags                  /* What to do with the lock */
4076 ){
4077   winFile *pDbFd = (winFile*)fd;        /* Connection holding shared memory */
4078   winShm *p = pDbFd->pShm;              /* The shared memory being locked */
4079   winShm *pX;                           /* For looping over all siblings */
4080   winShmNode *pShmNode;
4081   int rc = SQLITE_OK;                   /* Result code */
4082   u16 mask;                             /* Mask of locks to take or release */
4083 
4084   if( p==0 ) return SQLITE_IOERR_SHMLOCK;
4085   pShmNode = p->pShmNode;
4086   if( NEVER(pShmNode==0) ) return SQLITE_IOERR_SHMLOCK;
4087 
4088   assert( ofst>=0 && ofst+n<=SQLITE_SHM_NLOCK );
4089   assert( n>=1 );
4090   assert( flags==(SQLITE_SHM_LOCK | SQLITE_SHM_SHARED)
4091        || flags==(SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE)
4092        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED)
4093        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE) );
4094   assert( n==1 || (flags & SQLITE_SHM_EXCLUSIVE)!=0 );
4095 
4096   mask = (u16)((1U<<(ofst+n)) - (1U<<ofst));
4097   assert( n>1 || mask==(1<<ofst) );
4098   sqlite3_mutex_enter(pShmNode->mutex);
4099   if( flags & SQLITE_SHM_UNLOCK ){
4100     u16 allMask = 0; /* Mask of locks held by siblings */
4101 
4102     /* See if any siblings hold this same lock */
4103     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4104       if( pX==p ) continue;
4105       assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );
4106       allMask |= pX->sharedMask;
4107     }
4108 
4109     /* Unlock the system-level locks */
4110     if( (mask & allMask)==0 ){
4111       rc = winShmSystemLock(pShmNode, WINSHM_UNLCK, ofst+WIN_SHM_BASE, n);
4112     }else{
4113       rc = SQLITE_OK;
4114     }
4115 
4116     /* Undo the local locks */
4117     if( rc==SQLITE_OK ){
4118       p->exclMask &= ~mask;
4119       p->sharedMask &= ~mask;
4120     }
4121   }else if( flags & SQLITE_SHM_SHARED ){
4122     u16 allShared = 0;  /* Union of locks held by connections other than "p" */
4123 
4124     /* Find out which shared locks are already held by sibling connections.
4125     ** If any sibling already holds an exclusive lock, go ahead and return
4126     ** SQLITE_BUSY.
4127     */
4128     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4129       if( (pX->exclMask & mask)!=0 ){
4130         rc = SQLITE_BUSY;
4131         break;
4132       }
4133       allShared |= pX->sharedMask;
4134     }
4135 
4136     /* Get shared locks at the system level, if necessary */
4137     if( rc==SQLITE_OK ){
4138       if( (allShared & mask)==0 ){
4139         rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, ofst+WIN_SHM_BASE, n);
4140       }else{
4141         rc = SQLITE_OK;
4142       }
4143     }
4144 
4145     /* Get the local shared locks */
4146     if( rc==SQLITE_OK ){
4147       p->sharedMask |= mask;
4148     }
4149   }else{
4150     /* Make sure no sibling connections hold locks that will block this
4151     ** lock.  If any do, return SQLITE_BUSY right away.
4152     */
4153     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4154       if( (pX->exclMask & mask)!=0 || (pX->sharedMask & mask)!=0 ){
4155         rc = SQLITE_BUSY;
4156         break;
4157       }
4158     }
4159 
4160     /* Get the exclusive locks at the system level.  Then if successful
4161     ** also mark the local connection as being locked.
4162     */
4163     if( rc==SQLITE_OK ){
4164       rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, ofst+WIN_SHM_BASE, n);
4165       if( rc==SQLITE_OK ){
4166         assert( (p->sharedMask & mask)==0 );
4167         p->exclMask |= mask;
4168       }
4169     }
4170   }
4171   sqlite3_mutex_leave(pShmNode->mutex);
4172   OSTRACE(("SHM-LOCK pid=%lu, id=%d, sharedMask=%03x, exclMask=%03x, rc=%s\n",
4173            osGetCurrentProcessId(), p->id, p->sharedMask, p->exclMask,
4174            sqlite3ErrName(rc)));
4175   return rc;
4176 }
4177 
4178 /*
4179 ** Implement a memory barrier or memory fence on shared memory.
4180 **
4181 ** All loads and stores begun before the barrier must complete before
4182 ** any load or store begun after the barrier.
4183 */
4184 static void winShmBarrier(
4185   sqlite3_file *fd          /* Database holding the shared memory */
4186 ){
4187   UNUSED_PARAMETER(fd);
4188   sqlite3MemoryBarrier();   /* compiler-defined memory barrier */
4189   winShmEnterMutex();       /* Also mutex, for redundancy */
4190   winShmLeaveMutex();
4191 }
4192 
4193 /*
4194 ** This function is called to obtain a pointer to region iRegion of the
4195 ** shared-memory associated with the database file fd. Shared-memory regions
4196 ** are numbered starting from zero. Each shared-memory region is szRegion
4197 ** bytes in size.
4198 **
4199 ** If an error occurs, an error code is returned and *pp is set to NULL.
4200 **
4201 ** Otherwise, if the isWrite parameter is 0 and the requested shared-memory
4202 ** region has not been allocated (by any client, including one running in a
4203 ** separate process), then *pp is set to NULL and SQLITE_OK returned. If
4204 ** isWrite is non-zero and the requested shared-memory region has not yet
4205 ** been allocated, it is allocated by this function.
4206 **
4207 ** If the shared-memory region has already been allocated or is allocated by
4208 ** this call as described above, then it is mapped into this processes
4209 ** address space (if it is not already), *pp is set to point to the mapped
4210 ** memory and SQLITE_OK returned.
4211 */
4212 static int winShmMap(
4213   sqlite3_file *fd,               /* Handle open on database file */
4214   int iRegion,                    /* Region to retrieve */
4215   int szRegion,                   /* Size of regions */
4216   int isWrite,                    /* True to extend file if necessary */
4217   void volatile **pp              /* OUT: Mapped memory */
4218 ){
4219   winFile *pDbFd = (winFile*)fd;
4220   winShm *pShm = pDbFd->pShm;
4221   winShmNode *pShmNode;
4222   DWORD protect = PAGE_READWRITE;
4223   DWORD flags = FILE_MAP_WRITE | FILE_MAP_READ;
4224   int rc = SQLITE_OK;
4225 
4226   if( !pShm ){
4227     rc = winOpenSharedMemory(pDbFd);
4228     if( rc!=SQLITE_OK ) return rc;
4229     pShm = pDbFd->pShm;
4230     assert( pShm!=0 );
4231   }
4232   pShmNode = pShm->pShmNode;
4233 
4234   sqlite3_mutex_enter(pShmNode->mutex);
4235   if( pShmNode->isUnlocked ){
4236     rc = winLockSharedMemory(pShmNode);
4237     if( rc!=SQLITE_OK ) goto shmpage_out;
4238     pShmNode->isUnlocked = 0;
4239   }
4240   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
4241 
4242   if( pShmNode->nRegion<=iRegion ){
4243     struct ShmRegion *apNew;           /* New aRegion[] array */
4244     int nByte = (iRegion+1)*szRegion;  /* Minimum required file size */
4245     sqlite3_int64 sz;                  /* Current size of wal-index file */
4246 
4247     pShmNode->szRegion = szRegion;
4248 
4249     /* The requested region is not mapped into this processes address space.
4250     ** Check to see if it has been allocated (i.e. if the wal-index file is
4251     ** large enough to contain the requested region).
4252     */
4253     rc = winFileSize((sqlite3_file *)&pShmNode->hFile, &sz);
4254     if( rc!=SQLITE_OK ){
4255       rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
4256                        "winShmMap1", pDbFd->zPath);
4257       goto shmpage_out;
4258     }
4259 
4260     if( sz<nByte ){
4261       /* The requested memory region does not exist. If isWrite is set to
4262       ** zero, exit early. *pp will be set to NULL and SQLITE_OK returned.
4263       **
4264       ** Alternatively, if isWrite is non-zero, use ftruncate() to allocate
4265       ** the requested memory region.
4266       */
4267       if( !isWrite ) goto shmpage_out;
4268       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, nByte);
4269       if( rc!=SQLITE_OK ){
4270         rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
4271                          "winShmMap2", pDbFd->zPath);
4272         goto shmpage_out;
4273       }
4274     }
4275 
4276     /* Map the requested memory region into this processes address space. */
4277     apNew = (struct ShmRegion *)sqlite3_realloc64(
4278         pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])
4279     );
4280     if( !apNew ){
4281       rc = SQLITE_IOERR_NOMEM_BKPT;
4282       goto shmpage_out;
4283     }
4284     pShmNode->aRegion = apNew;
4285 
4286     if( pShmNode->isReadonly ){
4287       protect = PAGE_READONLY;
4288       flags = FILE_MAP_READ;
4289     }
4290 
4291     while( pShmNode->nRegion<=iRegion ){
4292       HANDLE hMap = NULL;         /* file-mapping handle */
4293       void *pMap = 0;             /* Mapped memory region */
4294 
4295 #if SQLITE_OS_WINRT
4296       hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,
4297           NULL, protect, nByte, NULL
4298       );
4299 #elif defined(SQLITE_WIN32_HAS_WIDE)
4300       hMap = osCreateFileMappingW(pShmNode->hFile.h,
4301           NULL, protect, 0, nByte, NULL
4302       );
4303 #elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
4304       hMap = osCreateFileMappingA(pShmNode->hFile.h,
4305           NULL, protect, 0, nByte, NULL
4306       );
4307 #endif
4308       OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
4309                osGetCurrentProcessId(), pShmNode->nRegion, nByte,
4310                hMap ? "ok" : "failed"));
4311       if( hMap ){
4312         int iOffset = pShmNode->nRegion*szRegion;
4313         int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
4314 #if SQLITE_OS_WINRT
4315         pMap = osMapViewOfFileFromApp(hMap, flags,
4316             iOffset - iOffsetShift, szRegion + iOffsetShift
4317         );
4318 #else
4319         pMap = osMapViewOfFile(hMap, flags,
4320             0, iOffset - iOffsetShift, szRegion + iOffsetShift
4321         );
4322 #endif
4323         OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",
4324                  osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
4325                  szRegion, pMap ? "ok" : "failed"));
4326       }
4327       if( !pMap ){
4328         pShmNode->lastErrno = osGetLastError();
4329         rc = winLogError(SQLITE_IOERR_SHMMAP, pShmNode->lastErrno,
4330                          "winShmMap3", pDbFd->zPath);
4331         if( hMap ) osCloseHandle(hMap);
4332         goto shmpage_out;
4333       }
4334 
4335       pShmNode->aRegion[pShmNode->nRegion].pMap = pMap;
4336       pShmNode->aRegion[pShmNode->nRegion].hMap = hMap;
4337       pShmNode->nRegion++;
4338     }
4339   }
4340 
4341 shmpage_out:
4342   if( pShmNode->nRegion>iRegion ){
4343     int iOffset = iRegion*szRegion;
4344     int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
4345     char *p = (char *)pShmNode->aRegion[iRegion].pMap;
4346     *pp = (void *)&p[iOffsetShift];
4347   }else{
4348     *pp = 0;
4349   }
4350   if( pShmNode->isReadonly && rc==SQLITE_OK ) rc = SQLITE_READONLY;
4351   sqlite3_mutex_leave(pShmNode->mutex);
4352   return rc;
4353 }
4354 
4355 #else
4356 # define winShmMap     0
4357 # define winShmLock    0
4358 # define winShmBarrier 0
4359 # define winShmUnmap   0
4360 #endif /* #ifndef SQLITE_OMIT_WAL */
4361 
4362 /*
4363 ** Cleans up the mapped region of the specified file, if any.
4364 */
4365 #if SQLITE_MAX_MMAP_SIZE>0
4366 static int winUnmapfile(winFile *pFile){
4367   assert( pFile!=0 );
4368   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, pMapRegion=%p, "
4369            "mmapSize=%lld, mmapSizeMax=%lld\n",
4370            osGetCurrentProcessId(), pFile, pFile->hMap, pFile->pMapRegion,
4371            pFile->mmapSize, pFile->mmapSizeMax));
4372   if( pFile->pMapRegion ){
4373     if( !osUnmapViewOfFile(pFile->pMapRegion) ){
4374       pFile->lastErrno = osGetLastError();
4375       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, pMapRegion=%p, "
4376                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(), pFile,
4377                pFile->pMapRegion));
4378       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
4379                          "winUnmapfile1", pFile->zPath);
4380     }
4381     pFile->pMapRegion = 0;
4382     pFile->mmapSize = 0;
4383   }
4384   if( pFile->hMap!=NULL ){
4385     if( !osCloseHandle(pFile->hMap) ){
4386       pFile->lastErrno = osGetLastError();
4387       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, rc=SQLITE_IOERR_MMAP\n",
4388                osGetCurrentProcessId(), pFile, pFile->hMap));
4389       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
4390                          "winUnmapfile2", pFile->zPath);
4391     }
4392     pFile->hMap = NULL;
4393   }
4394   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4395            osGetCurrentProcessId(), pFile));
4396   return SQLITE_OK;
4397 }
4398 
4399 /*
4400 ** Memory map or remap the file opened by file-descriptor pFd (if the file
4401 ** is already mapped, the existing mapping is replaced by the new). Or, if
4402 ** there already exists a mapping for this file, and there are still
4403 ** outstanding xFetch() references to it, this function is a no-op.
4404 **
4405 ** If parameter nByte is non-negative, then it is the requested size of
4406 ** the mapping to create. Otherwise, if nByte is less than zero, then the
4407 ** requested size is the size of the file on disk. The actual size of the
4408 ** created mapping is either the requested size or the value configured
4409 ** using SQLITE_FCNTL_MMAP_SIZE, whichever is smaller.
4410 **
4411 ** SQLITE_OK is returned if no error occurs (even if the mapping is not
4412 ** recreated as a result of outstanding references) or an SQLite error
4413 ** code otherwise.
4414 */
4415 static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
4416   sqlite3_int64 nMap = nByte;
4417   int rc;
4418 
4419   assert( nMap>=0 || pFd->nFetchOut==0 );
4420   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, size=%lld\n",
4421            osGetCurrentProcessId(), pFd, nByte));
4422 
4423   if( pFd->nFetchOut>0 ) return SQLITE_OK;
4424 
4425   if( nMap<0 ){
4426     rc = winFileSize((sqlite3_file*)pFd, &nMap);
4427     if( rc ){
4428       OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_IOERR_FSTAT\n",
4429                osGetCurrentProcessId(), pFd));
4430       return SQLITE_IOERR_FSTAT;
4431     }
4432   }
4433   if( nMap>pFd->mmapSizeMax ){
4434     nMap = pFd->mmapSizeMax;
4435   }
4436   nMap &= ~(sqlite3_int64)(winSysInfo.dwPageSize - 1);
4437 
4438   if( nMap==0 && pFd->mmapSize>0 ){
4439     winUnmapfile(pFd);
4440   }
4441   if( nMap!=pFd->mmapSize ){
4442     void *pNew = 0;
4443     DWORD protect = PAGE_READONLY;
4444     DWORD flags = FILE_MAP_READ;
4445 
4446     winUnmapfile(pFd);
4447 #ifdef SQLITE_MMAP_READWRITE
4448     if( (pFd->ctrlFlags & WINFILE_RDONLY)==0 ){
4449       protect = PAGE_READWRITE;
4450       flags |= FILE_MAP_WRITE;
4451     }
4452 #endif
4453 #if SQLITE_OS_WINRT
4454     pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);
4455 #elif defined(SQLITE_WIN32_HAS_WIDE)
4456     pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,
4457                                 (DWORD)((nMap>>32) & 0xffffffff),
4458                                 (DWORD)(nMap & 0xffffffff), NULL);
4459 #elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
4460     pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,
4461                                 (DWORD)((nMap>>32) & 0xffffffff),
4462                                 (DWORD)(nMap & 0xffffffff), NULL);
4463 #endif
4464     if( pFd->hMap==NULL ){
4465       pFd->lastErrno = osGetLastError();
4466       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
4467                        "winMapfile1", pFd->zPath);
4468       /* Log the error, but continue normal operation using xRead/xWrite */
4469       OSTRACE(("MAP-FILE-CREATE pid=%lu, pFile=%p, rc=%s\n",
4470                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4471       return SQLITE_OK;
4472     }
4473     assert( (nMap % winSysInfo.dwPageSize)==0 );
4474     assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );
4475 #if SQLITE_OS_WINRT
4476     pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, (SIZE_T)nMap);
4477 #else
4478     pNew = osMapViewOfFile(pFd->hMap, flags, 0, 0, (SIZE_T)nMap);
4479 #endif
4480     if( pNew==NULL ){
4481       osCloseHandle(pFd->hMap);
4482       pFd->hMap = NULL;
4483       pFd->lastErrno = osGetLastError();
4484       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
4485                        "winMapfile2", pFd->zPath);
4486       /* Log the error, but continue normal operation using xRead/xWrite */
4487       OSTRACE(("MAP-FILE-MAP pid=%lu, pFile=%p, rc=%s\n",
4488                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4489       return SQLITE_OK;
4490     }
4491     pFd->pMapRegion = pNew;
4492     pFd->mmapSize = nMap;
4493   }
4494 
4495   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4496            osGetCurrentProcessId(), pFd));
4497   return SQLITE_OK;
4498 }
4499 #endif /* SQLITE_MAX_MMAP_SIZE>0 */
4500 
4501 /*
4502 ** If possible, return a pointer to a mapping of file fd starting at offset
4503 ** iOff. The mapping must be valid for at least nAmt bytes.
4504 **
4505 ** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
4506 ** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
4507 ** Finally, if an error does occur, return an SQLite error code. The final
4508 ** value of *pp is undefined in this case.
4509 **
4510 ** If this function does return a pointer, the caller must eventually
4511 ** release the reference by calling winUnfetch().
4512 */
4513 static int winFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
4514 #if SQLITE_MAX_MMAP_SIZE>0
4515   winFile *pFd = (winFile*)fd;   /* The underlying database file */
4516 #endif
4517   *pp = 0;
4518 
4519   OSTRACE(("FETCH pid=%lu, pFile=%p, offset=%lld, amount=%d, pp=%p\n",
4520            osGetCurrentProcessId(), fd, iOff, nAmt, pp));
4521 
4522 #if SQLITE_MAX_MMAP_SIZE>0
4523   if( pFd->mmapSizeMax>0 ){
4524     if( pFd->pMapRegion==0 ){
4525       int rc = winMapfile(pFd, -1);
4526       if( rc!=SQLITE_OK ){
4527         OSTRACE(("FETCH pid=%lu, pFile=%p, rc=%s\n",
4528                  osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4529         return rc;
4530       }
4531     }
4532     if( pFd->mmapSize >= iOff+nAmt ){
4533       assert( pFd->pMapRegion!=0 );
4534       *pp = &((u8 *)pFd->pMapRegion)[iOff];
4535       pFd->nFetchOut++;
4536     }
4537   }
4538 #endif
4539 
4540   OSTRACE(("FETCH pid=%lu, pFile=%p, pp=%p, *pp=%p, rc=SQLITE_OK\n",
4541            osGetCurrentProcessId(), fd, pp, *pp));
4542   return SQLITE_OK;
4543 }
4544 
4545 /*
4546 ** If the third argument is non-NULL, then this function releases a
4547 ** reference obtained by an earlier call to winFetch(). The second
4548 ** argument passed to this function must be the same as the corresponding
4549 ** argument that was passed to the winFetch() invocation.
4550 **
4551 ** Or, if the third argument is NULL, then this function is being called
4552 ** to inform the VFS layer that, according to POSIX, any existing mapping
4553 ** may now be invalid and should be unmapped.
4554 */
4555 static int winUnfetch(sqlite3_file *fd, i64 iOff, void *p){
4556 #if SQLITE_MAX_MMAP_SIZE>0
4557   winFile *pFd = (winFile*)fd;   /* The underlying database file */
4558 
4559   /* If p==0 (unmap the entire file) then there must be no outstanding
4560   ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
4561   ** then there must be at least one outstanding.  */
4562   assert( (p==0)==(pFd->nFetchOut==0) );
4563 
4564   /* If p!=0, it must match the iOff value. */
4565   assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );
4566 
4567   OSTRACE(("UNFETCH pid=%lu, pFile=%p, offset=%lld, p=%p\n",
4568            osGetCurrentProcessId(), pFd, iOff, p));
4569 
4570   if( p ){
4571     pFd->nFetchOut--;
4572   }else{
4573     /* FIXME:  If Windows truly always prevents truncating or deleting a
4574     ** file while a mapping is held, then the following winUnmapfile() call
4575     ** is unnecessary can be omitted - potentially improving
4576     ** performance.  */
4577     winUnmapfile(pFd);
4578   }
4579 
4580   assert( pFd->nFetchOut>=0 );
4581 #endif
4582 
4583   OSTRACE(("UNFETCH pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4584            osGetCurrentProcessId(), fd));
4585   return SQLITE_OK;
4586 }
4587 
4588 /*
4589 ** Here ends the implementation of all sqlite3_file methods.
4590 **
4591 ********************** End sqlite3_file Methods *******************************
4592 ******************************************************************************/
4593 
4594 /*
4595 ** This vector defines all the methods that can operate on an
4596 ** sqlite3_file for win32.
4597 */
4598 static const sqlite3_io_methods winIoMethod = {
4599   3,                              /* iVersion */
4600   winClose,                       /* xClose */
4601   winRead,                        /* xRead */
4602   winWrite,                       /* xWrite */
4603   winTruncate,                    /* xTruncate */
4604   winSync,                        /* xSync */
4605   winFileSize,                    /* xFileSize */
4606   winLock,                        /* xLock */
4607   winUnlock,                      /* xUnlock */
4608   winCheckReservedLock,           /* xCheckReservedLock */
4609   winFileControl,                 /* xFileControl */
4610   winSectorSize,                  /* xSectorSize */
4611   winDeviceCharacteristics,       /* xDeviceCharacteristics */
4612   winShmMap,                      /* xShmMap */
4613   winShmLock,                     /* xShmLock */
4614   winShmBarrier,                  /* xShmBarrier */
4615   winShmUnmap,                    /* xShmUnmap */
4616   winFetch,                       /* xFetch */
4617   winUnfetch                      /* xUnfetch */
4618 };
4619 
4620 /*
4621 ** This vector defines all the methods that can operate on an
4622 ** sqlite3_file for win32 without performing any locking.
4623 */
4624 static const sqlite3_io_methods winIoNolockMethod = {
4625   3,                              /* iVersion */
4626   winClose,                       /* xClose */
4627   winRead,                        /* xRead */
4628   winWrite,                       /* xWrite */
4629   winTruncate,                    /* xTruncate */
4630   winSync,                        /* xSync */
4631   winFileSize,                    /* xFileSize */
4632   winNolockLock,                  /* xLock */
4633   winNolockUnlock,                /* xUnlock */
4634   winNolockCheckReservedLock,     /* xCheckReservedLock */
4635   winFileControl,                 /* xFileControl */
4636   winSectorSize,                  /* xSectorSize */
4637   winDeviceCharacteristics,       /* xDeviceCharacteristics */
4638   winShmMap,                      /* xShmMap */
4639   winShmLock,                     /* xShmLock */
4640   winShmBarrier,                  /* xShmBarrier */
4641   winShmUnmap,                    /* xShmUnmap */
4642   winFetch,                       /* xFetch */
4643   winUnfetch                      /* xUnfetch */
4644 };
4645 
4646 static winVfsAppData winAppData = {
4647   &winIoMethod,       /* pMethod */
4648   0,                  /* pAppData */
4649   0                   /* bNoLock */
4650 };
4651 
4652 static winVfsAppData winNolockAppData = {
4653   &winIoNolockMethod, /* pMethod */
4654   0,                  /* pAppData */
4655   1                   /* bNoLock */
4656 };
4657 
4658 /****************************************************************************
4659 **************************** sqlite3_vfs methods ****************************
4660 **
4661 ** This division contains the implementation of methods on the
4662 ** sqlite3_vfs object.
4663 */
4664 
4665 #if defined(__CYGWIN__)
4666 /*
4667 ** Convert a filename from whatever the underlying operating system
4668 ** supports for filenames into UTF-8.  Space to hold the result is
4669 ** obtained from malloc and must be freed by the calling function.
4670 */
4671 static char *winConvertToUtf8Filename(const void *zFilename){
4672   char *zConverted = 0;
4673   if( osIsNT() ){
4674     zConverted = winUnicodeToUtf8(zFilename);
4675   }
4676 #ifdef SQLITE_WIN32_HAS_ANSI
4677   else{
4678     zConverted = winMbcsToUtf8(zFilename, osAreFileApisANSI());
4679   }
4680 #endif
4681   /* caller will handle out of memory */
4682   return zConverted;
4683 }
4684 #endif
4685 
4686 /*
4687 ** Convert a UTF-8 filename into whatever form the underlying
4688 ** operating system wants filenames in.  Space to hold the result
4689 ** is obtained from malloc and must be freed by the calling
4690 ** function.
4691 */
4692 static void *winConvertFromUtf8Filename(const char *zFilename){
4693   void *zConverted = 0;
4694   if( osIsNT() ){
4695     zConverted = winUtf8ToUnicode(zFilename);
4696   }
4697 #ifdef SQLITE_WIN32_HAS_ANSI
4698   else{
4699     zConverted = winUtf8ToMbcs(zFilename, osAreFileApisANSI());
4700   }
4701 #endif
4702   /* caller will handle out of memory */
4703   return zConverted;
4704 }
4705 
4706 /*
4707 ** This function returns non-zero if the specified UTF-8 string buffer
4708 ** ends with a directory separator character or one was successfully
4709 ** added to it.
4710 */
4711 static int winMakeEndInDirSep(int nBuf, char *zBuf){
4712   if( zBuf ){
4713     int nLen = sqlite3Strlen30(zBuf);
4714     if( nLen>0 ){
4715       if( winIsDirSep(zBuf[nLen-1]) ){
4716         return 1;
4717       }else if( nLen+1<nBuf ){
4718         zBuf[nLen] = winGetDirSep();
4719         zBuf[nLen+1] = '\0';
4720         return 1;
4721       }
4722     }
4723   }
4724   return 0;
4725 }
4726 
4727 /*
4728 ** If sqlite3_temp_directory is not, take the mutex and return true.
4729 **
4730 ** If sqlite3_temp_directory is NULL, omit the mutex and return false.
4731 */
4732 static int winTempDirDefined(void){
4733   sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
4734   if( sqlite3_temp_directory!=0 ) return 1;
4735   sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
4736   return 0;
4737 }
4738 
4739 /*
4740 ** Create a temporary file name and store the resulting pointer into pzBuf.
4741 ** The pointer returned in pzBuf must be freed via sqlite3_free().
4742 */
4743 static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
4744   static char zChars[] =
4745     "abcdefghijklmnopqrstuvwxyz"
4746     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
4747     "0123456789";
4748   size_t i, j;
4749   int nPre = sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX);
4750   int nMax, nBuf, nDir, nLen;
4751   char *zBuf;
4752 
4753   /* It's odd to simulate an io-error here, but really this is just
4754   ** using the io-error infrastructure to test that SQLite handles this
4755   ** function failing.
4756   */
4757   SimulateIOError( return SQLITE_IOERR );
4758 
4759   /* Allocate a temporary buffer to store the fully qualified file
4760   ** name for the temporary file.  If this fails, we cannot continue.
4761   */
4762   nMax = pVfs->mxPathname; nBuf = nMax + 2;
4763   zBuf = sqlite3MallocZero( nBuf );
4764   if( !zBuf ){
4765     OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4766     return SQLITE_IOERR_NOMEM_BKPT;
4767   }
4768 
4769   /* Figure out the effective temporary directory.  First, check if one
4770   ** has been explicitly set by the application; otherwise, use the one
4771   ** configured by the operating system.
4772   */
4773   nDir = nMax - (nPre + 15);
4774   assert( nDir>0 );
4775   if( winTempDirDefined() ){
4776     int nDirLen = sqlite3Strlen30(sqlite3_temp_directory);
4777     if( nDirLen>0 ){
4778       if( !winIsDirSep(sqlite3_temp_directory[nDirLen-1]) ){
4779         nDirLen++;
4780       }
4781       if( nDirLen>nDir ){
4782         sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
4783         sqlite3_free(zBuf);
4784         OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4785         return winLogError(SQLITE_ERROR, 0, "winGetTempname1", 0);
4786       }
4787       sqlite3_snprintf(nMax, zBuf, "%s", sqlite3_temp_directory);
4788     }
4789     sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR));
4790   }
4791 
4792 #if defined(__CYGWIN__)
4793   else{
4794     static const char *azDirs[] = {
4795        0, /* getenv("SQLITE_TMPDIR") */
4796        0, /* getenv("TMPDIR") */
4797        0, /* getenv("TMP") */
4798        0, /* getenv("TEMP") */
4799        0, /* getenv("USERPROFILE") */
4800        "/var/tmp",
4801        "/usr/tmp",
4802        "/tmp",
4803        ".",
4804        0        /* List terminator */
4805     };
4806     unsigned int i;
4807     const char *zDir = 0;
4808 
4809     if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");
4810     if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");
4811     if( !azDirs[2] ) azDirs[2] = getenv("TMP");
4812     if( !azDirs[3] ) azDirs[3] = getenv("TEMP");
4813     if( !azDirs[4] ) azDirs[4] = getenv("USERPROFILE");
4814     for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); zDir=azDirs[i++]){
4815       void *zConverted;
4816       if( zDir==0 ) continue;
4817       /* If the path starts with a drive letter followed by the colon
4818       ** character, assume it is already a native Win32 path; otherwise,
4819       ** it must be converted to a native Win32 path via the Cygwin API
4820       ** prior to using it.
4821       */
4822       if( winIsDriveLetterAndColon(zDir) ){
4823         zConverted = winConvertFromUtf8Filename(zDir);
4824         if( !zConverted ){
4825           sqlite3_free(zBuf);
4826           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4827           return SQLITE_IOERR_NOMEM_BKPT;
4828         }
4829         if( winIsDir(zConverted) ){
4830           sqlite3_snprintf(nMax, zBuf, "%s", zDir);
4831           sqlite3_free(zConverted);
4832           break;
4833         }
4834         sqlite3_free(zConverted);
4835       }else{
4836         zConverted = sqlite3MallocZero( nMax+1 );
4837         if( !zConverted ){
4838           sqlite3_free(zBuf);
4839           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4840           return SQLITE_IOERR_NOMEM_BKPT;
4841         }
4842         if( cygwin_conv_path(
4843                 osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A, zDir,
4844                 zConverted, nMax+1)<0 ){
4845           sqlite3_free(zConverted);
4846           sqlite3_free(zBuf);
4847           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_CONVPATH\n"));
4848           return winLogError(SQLITE_IOERR_CONVPATH, (DWORD)errno,
4849                              "winGetTempname2", zDir);
4850         }
4851         if( winIsDir(zConverted) ){
4852           /* At this point, we know the candidate directory exists and should
4853           ** be used.  However, we may need to convert the string containing
4854           ** its name into UTF-8 (i.e. if it is UTF-16 right now).
4855           */
4856           char *zUtf8 = winConvertToUtf8Filename(zConverted);
4857           if( !zUtf8 ){
4858             sqlite3_free(zConverted);
4859             sqlite3_free(zBuf);
4860             OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4861             return SQLITE_IOERR_NOMEM_BKPT;
4862           }
4863           sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
4864           sqlite3_free(zUtf8);
4865           sqlite3_free(zConverted);
4866           break;
4867         }
4868         sqlite3_free(zConverted);
4869       }
4870     }
4871   }
4872 #elif !SQLITE_OS_WINRT && !defined(__CYGWIN__)
4873   else if( osIsNT() ){
4874     char *zMulti;
4875     LPWSTR zWidePath = sqlite3MallocZero( nMax*sizeof(WCHAR) );
4876     if( !zWidePath ){
4877       sqlite3_free(zBuf);
4878       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4879       return SQLITE_IOERR_NOMEM_BKPT;
4880     }
4881     if( osGetTempPathW(nMax, zWidePath)==0 ){
4882       sqlite3_free(zWidePath);
4883       sqlite3_free(zBuf);
4884       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
4885       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
4886                          "winGetTempname2", 0);
4887     }
4888     zMulti = winUnicodeToUtf8(zWidePath);
4889     if( zMulti ){
4890       sqlite3_snprintf(nMax, zBuf, "%s", zMulti);
4891       sqlite3_free(zMulti);
4892       sqlite3_free(zWidePath);
4893     }else{
4894       sqlite3_free(zWidePath);
4895       sqlite3_free(zBuf);
4896       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4897       return SQLITE_IOERR_NOMEM_BKPT;
4898     }
4899   }
4900 #ifdef SQLITE_WIN32_HAS_ANSI
4901   else{
4902     char *zUtf8;
4903     char *zMbcsPath = sqlite3MallocZero( nMax );
4904     if( !zMbcsPath ){
4905       sqlite3_free(zBuf);
4906       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4907       return SQLITE_IOERR_NOMEM_BKPT;
4908     }
4909     if( osGetTempPathA(nMax, zMbcsPath)==0 ){
4910       sqlite3_free(zBuf);
4911       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
4912       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
4913                          "winGetTempname3", 0);
4914     }
4915     zUtf8 = winMbcsToUtf8(zMbcsPath, osAreFileApisANSI());
4916     if( zUtf8 ){
4917       sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
4918       sqlite3_free(zUtf8);
4919     }else{
4920       sqlite3_free(zBuf);
4921       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4922       return SQLITE_IOERR_NOMEM_BKPT;
4923     }
4924   }
4925 #endif /* SQLITE_WIN32_HAS_ANSI */
4926 #endif /* !SQLITE_OS_WINRT */
4927 
4928   /*
4929   ** Check to make sure the temporary directory ends with an appropriate
4930   ** separator.  If it does not and there is not enough space left to add
4931   ** one, fail.
4932   */
4933   if( !winMakeEndInDirSep(nDir+1, zBuf) ){
4934     sqlite3_free(zBuf);
4935     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4936     return winLogError(SQLITE_ERROR, 0, "winGetTempname4", 0);
4937   }
4938 
4939   /*
4940   ** Check that the output buffer is large enough for the temporary file
4941   ** name in the following format:
4942   **
4943   **   "<temporary_directory>/etilqs_XXXXXXXXXXXXXXX\0\0"
4944   **
4945   ** If not, return SQLITE_ERROR.  The number 17 is used here in order to
4946   ** account for the space used by the 15 character random suffix and the
4947   ** two trailing NUL characters.  The final directory separator character
4948   ** has already added if it was not already present.
4949   */
4950   nLen = sqlite3Strlen30(zBuf);
4951   if( (nLen + nPre + 17) > nBuf ){
4952     sqlite3_free(zBuf);
4953     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4954     return winLogError(SQLITE_ERROR, 0, "winGetTempname5", 0);
4955   }
4956 
4957   sqlite3_snprintf(nBuf-16-nLen, zBuf+nLen, SQLITE_TEMP_FILE_PREFIX);
4958 
4959   j = sqlite3Strlen30(zBuf);
4960   sqlite3_randomness(15, &zBuf[j]);
4961   for(i=0; i<15; i++, j++){
4962     zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
4963   }
4964   zBuf[j] = 0;
4965   zBuf[j+1] = 0;
4966   *pzBuf = zBuf;
4967 
4968   OSTRACE(("TEMP-FILENAME name=%s, rc=SQLITE_OK\n", zBuf));
4969   return SQLITE_OK;
4970 }
4971 
4972 /*
4973 ** Return TRUE if the named file is really a directory.  Return false if
4974 ** it is something other than a directory, or if there is any kind of memory
4975 ** allocation failure.
4976 */
4977 static int winIsDir(const void *zConverted){
4978   DWORD attr;
4979   int rc = 0;
4980   DWORD lastErrno;
4981 
4982   if( osIsNT() ){
4983     int cnt = 0;
4984     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
4985     memset(&sAttrData, 0, sizeof(sAttrData));
4986     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
4987                              GetFileExInfoStandard,
4988                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
4989     if( !rc ){
4990       return 0; /* Invalid name? */
4991     }
4992     attr = sAttrData.dwFileAttributes;
4993 #if SQLITE_OS_WINCE==0
4994   }else{
4995     attr = osGetFileAttributesA((char*)zConverted);
4996 #endif
4997   }
4998   return (attr!=INVALID_FILE_ATTRIBUTES) && (attr&FILE_ATTRIBUTE_DIRECTORY);
4999 }
5000 
5001 /* forward reference */
5002 static int winAccess(
5003   sqlite3_vfs *pVfs,         /* Not used on win32 */
5004   const char *zFilename,     /* Name of file to check */
5005   int flags,                 /* Type of test to make on this file */
5006   int *pResOut               /* OUT: Result */
5007 );
5008 
5009 /*
5010 ** Open a file.
5011 */
5012 static int winOpen(
5013   sqlite3_vfs *pVfs,        /* Used to get maximum path length and AppData */
5014   const char *zName,        /* Name of the file (UTF-8) */
5015   sqlite3_file *id,         /* Write the SQLite file handle here */
5016   int flags,                /* Open mode flags */
5017   int *pOutFlags            /* Status return flags */
5018 ){
5019   HANDLE h;
5020   DWORD lastErrno = 0;
5021   DWORD dwDesiredAccess;
5022   DWORD dwShareMode;
5023   DWORD dwCreationDisposition;
5024   DWORD dwFlagsAndAttributes = 0;
5025 #if SQLITE_OS_WINCE
5026   int isTemp = 0;
5027 #endif
5028   winVfsAppData *pAppData;
5029   winFile *pFile = (winFile*)id;
5030   void *zConverted;              /* Filename in OS encoding */
5031   const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */
5032   int cnt = 0;
5033 
5034   /* If argument zPath is a NULL pointer, this function is required to open
5035   ** a temporary file. Use this buffer to store the file name in.
5036   */
5037   char *zTmpname = 0; /* For temporary filename, if necessary. */
5038 
5039   int rc = SQLITE_OK;            /* Function Return Code */
5040 #if !defined(NDEBUG) || SQLITE_OS_WINCE
5041   int eType = flags&0xFFFFFF00;  /* Type of file to open */
5042 #endif
5043 
5044   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
5045   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
5046   int isCreate     = (flags & SQLITE_OPEN_CREATE);
5047   int isReadonly   = (flags & SQLITE_OPEN_READONLY);
5048   int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
5049 
5050 #ifndef NDEBUG
5051   int isOpenJournal = (isCreate && (
5052         eType==SQLITE_OPEN_SUPER_JOURNAL
5053      || eType==SQLITE_OPEN_MAIN_JOURNAL
5054      || eType==SQLITE_OPEN_WAL
5055   ));
5056 #endif
5057 
5058   OSTRACE(("OPEN name=%s, pFile=%p, flags=%x, pOutFlags=%p\n",
5059            zUtf8Name, id, flags, pOutFlags));
5060 
5061   /* Check the following statements are true:
5062   **
5063   **   (a) Exactly one of the READWRITE and READONLY flags must be set, and
5064   **   (b) if CREATE is set, then READWRITE must also be set, and
5065   **   (c) if EXCLUSIVE is set, then CREATE must also be set.
5066   **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
5067   */
5068   assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
5069   assert(isCreate==0 || isReadWrite);
5070   assert(isExclusive==0 || isCreate);
5071   assert(isDelete==0 || isCreate);
5072 
5073   /* The main DB, main journal, WAL file and super-journal are never
5074   ** automatically deleted. Nor are they ever temporary files.  */
5075   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
5076   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
5077   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_SUPER_JOURNAL );
5078   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );
5079 
5080   /* Assert that the upper layer has set one of the "file-type" flags. */
5081   assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB
5082        || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL
5083        || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_SUPER_JOURNAL
5084        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
5085   );
5086 
5087   assert( pFile!=0 );
5088   memset(pFile, 0, sizeof(winFile));
5089   pFile->h = INVALID_HANDLE_VALUE;
5090 
5091 #if SQLITE_OS_WINRT
5092   if( !zUtf8Name && !sqlite3_temp_directory ){
5093     sqlite3_log(SQLITE_ERROR,
5094         "sqlite3_temp_directory variable should be set for WinRT");
5095   }
5096 #endif
5097 
5098   /* If the second argument to this function is NULL, generate a
5099   ** temporary file name to use
5100   */
5101   if( !zUtf8Name ){
5102     assert( isDelete && !isOpenJournal );
5103     rc = winGetTempname(pVfs, &zTmpname);
5104     if( rc!=SQLITE_OK ){
5105       OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));
5106       return rc;
5107     }
5108     zUtf8Name = zTmpname;
5109   }
5110 
5111   /* Database filenames are double-zero terminated if they are not
5112   ** URIs with parameters.  Hence, they can always be passed into
5113   ** sqlite3_uri_parameter().
5114   */
5115   assert( (eType!=SQLITE_OPEN_MAIN_DB) || (flags & SQLITE_OPEN_URI) ||
5116        zUtf8Name[sqlite3Strlen30(zUtf8Name)+1]==0 );
5117 
5118   /* Convert the filename to the system encoding. */
5119   zConverted = winConvertFromUtf8Filename(zUtf8Name);
5120   if( zConverted==0 ){
5121     sqlite3_free(zTmpname);
5122     OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));
5123     return SQLITE_IOERR_NOMEM_BKPT;
5124   }
5125 
5126   if( winIsDir(zConverted) ){
5127     sqlite3_free(zConverted);
5128     sqlite3_free(zTmpname);
5129     OSTRACE(("OPEN name=%s, rc=SQLITE_CANTOPEN_ISDIR", zUtf8Name));
5130     return SQLITE_CANTOPEN_ISDIR;
5131   }
5132 
5133   if( isReadWrite ){
5134     dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
5135   }else{
5136     dwDesiredAccess = GENERIC_READ;
5137   }
5138 
5139   /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is
5140   ** created. SQLite doesn't use it to indicate "exclusive access"
5141   ** as it is usually understood.
5142   */
5143   if( isExclusive ){
5144     /* Creates a new file, only if it does not already exist. */
5145     /* If the file exists, it fails. */
5146     dwCreationDisposition = CREATE_NEW;
5147   }else if( isCreate ){
5148     /* Open existing file, or create if it doesn't exist */
5149     dwCreationDisposition = OPEN_ALWAYS;
5150   }else{
5151     /* Opens a file, only if it exists. */
5152     dwCreationDisposition = OPEN_EXISTING;
5153   }
5154 
5155   if( 0==sqlite3_uri_boolean(zName, "exclusive", 0) ){
5156     dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
5157   }else{
5158     dwShareMode = 0;
5159   }
5160 
5161   if( isDelete ){
5162 #if SQLITE_OS_WINCE
5163     dwFlagsAndAttributes = FILE_ATTRIBUTE_HIDDEN;
5164     isTemp = 1;
5165 #else
5166     dwFlagsAndAttributes = FILE_ATTRIBUTE_TEMPORARY
5167                                | FILE_ATTRIBUTE_HIDDEN
5168                                | FILE_FLAG_DELETE_ON_CLOSE;
5169 #endif
5170   }else{
5171     dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
5172   }
5173   /* Reports from the internet are that performance is always
5174   ** better if FILE_FLAG_RANDOM_ACCESS is used.  Ticket #2699. */
5175 #if SQLITE_OS_WINCE
5176   dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
5177 #endif
5178 
5179   if( osIsNT() ){
5180 #if SQLITE_OS_WINRT
5181     CREATEFILE2_EXTENDED_PARAMETERS extendedParameters;
5182     extendedParameters.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
5183     extendedParameters.dwFileAttributes =
5184             dwFlagsAndAttributes & FILE_ATTRIBUTE_MASK;
5185     extendedParameters.dwFileFlags = dwFlagsAndAttributes & FILE_FLAG_MASK;
5186     extendedParameters.dwSecurityQosFlags = SECURITY_ANONYMOUS;
5187     extendedParameters.lpSecurityAttributes = NULL;
5188     extendedParameters.hTemplateFile = NULL;
5189     do{
5190       h = osCreateFile2((LPCWSTR)zConverted,
5191                         dwDesiredAccess,
5192                         dwShareMode,
5193                         dwCreationDisposition,
5194                         &extendedParameters);
5195       if( h!=INVALID_HANDLE_VALUE ) break;
5196       if( isReadWrite ){
5197         int rc2, isRO = 0;
5198         sqlite3BeginBenignMalloc();
5199         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5200         sqlite3EndBenignMalloc();
5201         if( rc2==SQLITE_OK && isRO ) break;
5202       }
5203     }while( winRetryIoerr(&cnt, &lastErrno) );
5204 #else
5205     do{
5206       h = osCreateFileW((LPCWSTR)zConverted,
5207                         dwDesiredAccess,
5208                         dwShareMode, NULL,
5209                         dwCreationDisposition,
5210                         dwFlagsAndAttributes,
5211                         NULL);
5212       if( h!=INVALID_HANDLE_VALUE ) break;
5213       if( isReadWrite ){
5214         int rc2, isRO = 0;
5215         sqlite3BeginBenignMalloc();
5216         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5217         sqlite3EndBenignMalloc();
5218         if( rc2==SQLITE_OK && isRO ) break;
5219       }
5220     }while( winRetryIoerr(&cnt, &lastErrno) );
5221 #endif
5222   }
5223 #ifdef SQLITE_WIN32_HAS_ANSI
5224   else{
5225     do{
5226       h = osCreateFileA((LPCSTR)zConverted,
5227                         dwDesiredAccess,
5228                         dwShareMode, NULL,
5229                         dwCreationDisposition,
5230                         dwFlagsAndAttributes,
5231                         NULL);
5232       if( h!=INVALID_HANDLE_VALUE ) break;
5233       if( isReadWrite ){
5234         int rc2, isRO = 0;
5235         sqlite3BeginBenignMalloc();
5236         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5237         sqlite3EndBenignMalloc();
5238         if( rc2==SQLITE_OK && isRO ) break;
5239       }
5240     }while( winRetryIoerr(&cnt, &lastErrno) );
5241   }
5242 #endif
5243   winLogIoerr(cnt, __LINE__);
5244 
5245   OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
5246            dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
5247 
5248   if( h==INVALID_HANDLE_VALUE ){
5249     sqlite3_free(zConverted);
5250     sqlite3_free(zTmpname);
5251     if( isReadWrite && !isExclusive ){
5252       return winOpen(pVfs, zName, id,
5253          ((flags|SQLITE_OPEN_READONLY) &
5254                      ~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
5255          pOutFlags);
5256     }else{
5257       pFile->lastErrno = lastErrno;
5258       winLogError(SQLITE_CANTOPEN, pFile->lastErrno, "winOpen", zUtf8Name);
5259       return SQLITE_CANTOPEN_BKPT;
5260     }
5261   }
5262 
5263   if( pOutFlags ){
5264     if( isReadWrite ){
5265       *pOutFlags = SQLITE_OPEN_READWRITE;
5266     }else{
5267       *pOutFlags = SQLITE_OPEN_READONLY;
5268     }
5269   }
5270 
5271   OSTRACE(("OPEN file=%p, name=%s, access=%lx, pOutFlags=%p, *pOutFlags=%d, "
5272            "rc=%s\n", h, zUtf8Name, dwDesiredAccess, pOutFlags, pOutFlags ?
5273            *pOutFlags : 0, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
5274 
5275   pAppData = (winVfsAppData*)pVfs->pAppData;
5276 
5277 #if SQLITE_OS_WINCE
5278   {
5279     if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
5280          && ((pAppData==NULL) || !pAppData->bNoLock)
5281          && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
5282     ){
5283       osCloseHandle(h);
5284       sqlite3_free(zConverted);
5285       sqlite3_free(zTmpname);
5286       OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
5287       return rc;
5288     }
5289   }
5290   if( isTemp ){
5291     pFile->zDeleteOnClose = zConverted;
5292   }else
5293 #endif
5294   {
5295     sqlite3_free(zConverted);
5296   }
5297 
5298   sqlite3_free(zTmpname);
5299   id->pMethods = pAppData ? pAppData->pMethod : &winIoMethod;
5300   pFile->pVfs = pVfs;
5301   pFile->h = h;
5302   if( isReadonly ){
5303     pFile->ctrlFlags |= WINFILE_RDONLY;
5304   }
5305   if( (flags & SQLITE_OPEN_MAIN_DB)
5306    && sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE)
5307   ){
5308     pFile->ctrlFlags |= WINFILE_PSOW;
5309   }
5310   pFile->lastErrno = NO_ERROR;
5311   pFile->zPath = zName;
5312 #if SQLITE_MAX_MMAP_SIZE>0
5313   pFile->hMap = NULL;
5314   pFile->pMapRegion = 0;
5315   pFile->mmapSize = 0;
5316   pFile->mmapSizeMax = sqlite3GlobalConfig.szMmap;
5317 #endif
5318 
5319   OpenCounter(+1);
5320   return rc;
5321 }
5322 
5323 /*
5324 ** Delete the named file.
5325 **
5326 ** Note that Windows does not allow a file to be deleted if some other
5327 ** process has it open.  Sometimes a virus scanner or indexing program
5328 ** will open a journal file shortly after it is created in order to do
5329 ** whatever it does.  While this other process is holding the
5330 ** file open, we will be unable to delete it.  To work around this
5331 ** problem, we delay 100 milliseconds and try to delete again.  Up
5332 ** to MX_DELETION_ATTEMPTs deletion attempts are run before giving
5333 ** up and returning an error.
5334 */
5335 static int winDelete(
5336   sqlite3_vfs *pVfs,          /* Not used on win32 */
5337   const char *zFilename,      /* Name of file to delete */
5338   int syncDir                 /* Not used on win32 */
5339 ){
5340   int cnt = 0;
5341   int rc;
5342   DWORD attr;
5343   DWORD lastErrno = 0;
5344   void *zConverted;
5345   UNUSED_PARAMETER(pVfs);
5346   UNUSED_PARAMETER(syncDir);
5347 
5348   SimulateIOError(return SQLITE_IOERR_DELETE);
5349   OSTRACE(("DELETE name=%s, syncDir=%d\n", zFilename, syncDir));
5350 
5351   zConverted = winConvertFromUtf8Filename(zFilename);
5352   if( zConverted==0 ){
5353     OSTRACE(("DELETE name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
5354     return SQLITE_IOERR_NOMEM_BKPT;
5355   }
5356   if( osIsNT() ){
5357     do {
5358 #if SQLITE_OS_WINRT
5359       WIN32_FILE_ATTRIBUTE_DATA sAttrData;
5360       memset(&sAttrData, 0, sizeof(sAttrData));
5361       if ( osGetFileAttributesExW(zConverted, GetFileExInfoStandard,
5362                                   &sAttrData) ){
5363         attr = sAttrData.dwFileAttributes;
5364       }else{
5365         lastErrno = osGetLastError();
5366         if( lastErrno==ERROR_FILE_NOT_FOUND
5367          || lastErrno==ERROR_PATH_NOT_FOUND ){
5368           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5369         }else{
5370           rc = SQLITE_ERROR;
5371         }
5372         break;
5373       }
5374 #else
5375       attr = osGetFileAttributesW(zConverted);
5376 #endif
5377       if ( attr==INVALID_FILE_ATTRIBUTES ){
5378         lastErrno = osGetLastError();
5379         if( lastErrno==ERROR_FILE_NOT_FOUND
5380          || lastErrno==ERROR_PATH_NOT_FOUND ){
5381           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5382         }else{
5383           rc = SQLITE_ERROR;
5384         }
5385         break;
5386       }
5387       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
5388         rc = SQLITE_ERROR; /* Files only. */
5389         break;
5390       }
5391       if ( osDeleteFileW(zConverted) ){
5392         rc = SQLITE_OK; /* Deleted OK. */
5393         break;
5394       }
5395       if ( !winRetryIoerr(&cnt, &lastErrno) ){
5396         rc = SQLITE_ERROR; /* No more retries. */
5397         break;
5398       }
5399     } while(1);
5400   }
5401 #ifdef SQLITE_WIN32_HAS_ANSI
5402   else{
5403     do {
5404       attr = osGetFileAttributesA(zConverted);
5405       if ( attr==INVALID_FILE_ATTRIBUTES ){
5406         lastErrno = osGetLastError();
5407         if( lastErrno==ERROR_FILE_NOT_FOUND
5408          || lastErrno==ERROR_PATH_NOT_FOUND ){
5409           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5410         }else{
5411           rc = SQLITE_ERROR;
5412         }
5413         break;
5414       }
5415       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
5416         rc = SQLITE_ERROR; /* Files only. */
5417         break;
5418       }
5419       if ( osDeleteFileA(zConverted) ){
5420         rc = SQLITE_OK; /* Deleted OK. */
5421         break;
5422       }
5423       if ( !winRetryIoerr(&cnt, &lastErrno) ){
5424         rc = SQLITE_ERROR; /* No more retries. */
5425         break;
5426       }
5427     } while(1);
5428   }
5429 #endif
5430   if( rc && rc!=SQLITE_IOERR_DELETE_NOENT ){
5431     rc = winLogError(SQLITE_IOERR_DELETE, lastErrno, "winDelete", zFilename);
5432   }else{
5433     winLogIoerr(cnt, __LINE__);
5434   }
5435   sqlite3_free(zConverted);
5436   OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));
5437   return rc;
5438 }
5439 
5440 /*
5441 ** Check the existence and status of a file.
5442 */
5443 static int winAccess(
5444   sqlite3_vfs *pVfs,         /* Not used on win32 */
5445   const char *zFilename,     /* Name of file to check */
5446   int flags,                 /* Type of test to make on this file */
5447   int *pResOut               /* OUT: Result */
5448 ){
5449   DWORD attr;
5450   int rc = 0;
5451   DWORD lastErrno = 0;
5452   void *zConverted;
5453   UNUSED_PARAMETER(pVfs);
5454 
5455   SimulateIOError( return SQLITE_IOERR_ACCESS; );
5456   OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",
5457            zFilename, flags, pResOut));
5458 
5459   zConverted = winConvertFromUtf8Filename(zFilename);
5460   if( zConverted==0 ){
5461     OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
5462     return SQLITE_IOERR_NOMEM_BKPT;
5463   }
5464   if( osIsNT() ){
5465     int cnt = 0;
5466     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
5467     memset(&sAttrData, 0, sizeof(sAttrData));
5468     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
5469                              GetFileExInfoStandard,
5470                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
5471     if( rc ){
5472       /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
5473       ** as if it does not exist.
5474       */
5475       if(    flags==SQLITE_ACCESS_EXISTS
5476           && sAttrData.nFileSizeHigh==0
5477           && sAttrData.nFileSizeLow==0 ){
5478         attr = INVALID_FILE_ATTRIBUTES;
5479       }else{
5480         attr = sAttrData.dwFileAttributes;
5481       }
5482     }else{
5483       winLogIoerr(cnt, __LINE__);
5484       if( lastErrno!=ERROR_FILE_NOT_FOUND && lastErrno!=ERROR_PATH_NOT_FOUND ){
5485         sqlite3_free(zConverted);
5486         return winLogError(SQLITE_IOERR_ACCESS, lastErrno, "winAccess",
5487                            zFilename);
5488       }else{
5489         attr = INVALID_FILE_ATTRIBUTES;
5490       }
5491     }
5492   }
5493 #ifdef SQLITE_WIN32_HAS_ANSI
5494   else{
5495     attr = osGetFileAttributesA((char*)zConverted);
5496   }
5497 #endif
5498   sqlite3_free(zConverted);
5499   switch( flags ){
5500     case SQLITE_ACCESS_READ:
5501     case SQLITE_ACCESS_EXISTS:
5502       rc = attr!=INVALID_FILE_ATTRIBUTES;
5503       break;
5504     case SQLITE_ACCESS_READWRITE:
5505       rc = attr!=INVALID_FILE_ATTRIBUTES &&
5506              (attr & FILE_ATTRIBUTE_READONLY)==0;
5507       break;
5508     default:
5509       assert(!"Invalid flags argument");
5510   }
5511   *pResOut = rc;
5512   OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
5513            zFilename, pResOut, *pResOut));
5514   return SQLITE_OK;
5515 }
5516 
5517 /*
5518 ** Returns non-zero if the specified path name starts with the "long path"
5519 ** prefix.
5520 */
5521 static BOOL winIsLongPathPrefix(
5522   const char *zPathname
5523 ){
5524   return ( zPathname[0]=='\\' && zPathname[1]=='\\'
5525         && zPathname[2]=='?'  && zPathname[3]=='\\' );
5526 }
5527 
5528 /*
5529 ** Returns non-zero if the specified path name starts with a drive letter
5530 ** followed by a colon character.
5531 */
5532 static BOOL winIsDriveLetterAndColon(
5533   const char *zPathname
5534 ){
5535   return ( sqlite3Isalpha(zPathname[0]) && zPathname[1]==':' );
5536 }
5537 
5538 /*
5539 ** Returns non-zero if the specified path name should be used verbatim.  If
5540 ** non-zero is returned from this function, the calling function must simply
5541 ** use the provided path name verbatim -OR- resolve it into a full path name
5542 ** using the GetFullPathName Win32 API function (if available).
5543 */
5544 static BOOL winIsVerbatimPathname(
5545   const char *zPathname
5546 ){
5547   /*
5548   ** If the path name starts with a forward slash or a backslash, it is either
5549   ** a legal UNC name, a volume relative path, or an absolute path name in the
5550   ** "Unix" format on Windows.  There is no easy way to differentiate between
5551   ** the final two cases; therefore, we return the safer return value of TRUE
5552   ** so that callers of this function will simply use it verbatim.
5553   */
5554   if ( winIsDirSep(zPathname[0]) ){
5555     return TRUE;
5556   }
5557 
5558   /*
5559   ** If the path name starts with a letter and a colon it is either a volume
5560   ** relative path or an absolute path.  Callers of this function must not
5561   ** attempt to treat it as a relative path name (i.e. they should simply use
5562   ** it verbatim).
5563   */
5564   if ( winIsDriveLetterAndColon(zPathname) ){
5565     return TRUE;
5566   }
5567 
5568   /*
5569   ** If we get to this point, the path name should almost certainly be a purely
5570   ** relative one (i.e. not a UNC name, not absolute, and not volume relative).
5571   */
5572   return FALSE;
5573 }
5574 
5575 /*
5576 ** Turn a relative pathname into a full pathname.  Write the full
5577 ** pathname into zOut[].  zOut[] will be at least pVfs->mxPathname
5578 ** bytes in size.
5579 */
5580 static int winFullPathnameNoMutex(
5581   sqlite3_vfs *pVfs,            /* Pointer to vfs object */
5582   const char *zRelative,        /* Possibly relative input path */
5583   int nFull,                    /* Size of output buffer in bytes */
5584   char *zFull                   /* Output buffer */
5585 ){
5586 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
5587   DWORD nByte;
5588   void *zConverted;
5589   char *zOut;
5590 #endif
5591 
5592   /* If this path name begins with "/X:" or "\\?\", where "X" is any
5593   ** alphabetic character, discard the initial "/" from the pathname.
5594   */
5595   if( zRelative[0]=='/' && (winIsDriveLetterAndColon(zRelative+1)
5596        || winIsLongPathPrefix(zRelative+1)) ){
5597     zRelative++;
5598   }
5599 
5600 #if defined(__CYGWIN__)
5601   SimulateIOError( return SQLITE_ERROR );
5602   UNUSED_PARAMETER(nFull);
5603   assert( nFull>=pVfs->mxPathname );
5604   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5605     /*
5606     ** NOTE: We are dealing with a relative path name and the data
5607     **       directory has been set.  Therefore, use it as the basis
5608     **       for converting the relative path name to an absolute
5609     **       one by prepending the data directory and a slash.
5610     */
5611     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
5612     if( !zOut ){
5613       return SQLITE_IOERR_NOMEM_BKPT;
5614     }
5615     if( cygwin_conv_path(
5616             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A) |
5617             CCP_RELATIVE, zRelative, zOut, pVfs->mxPathname+1)<0 ){
5618       sqlite3_free(zOut);
5619       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
5620                          "winFullPathname1", zRelative);
5621     }else{
5622       char *zUtf8 = winConvertToUtf8Filename(zOut);
5623       if( !zUtf8 ){
5624         sqlite3_free(zOut);
5625         return SQLITE_IOERR_NOMEM_BKPT;
5626       }
5627       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5628                        sqlite3_data_directory, winGetDirSep(), zUtf8);
5629       sqlite3_free(zUtf8);
5630       sqlite3_free(zOut);
5631     }
5632   }else{
5633     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
5634     if( !zOut ){
5635       return SQLITE_IOERR_NOMEM_BKPT;
5636     }
5637     if( cygwin_conv_path(
5638             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A),
5639             zRelative, zOut, pVfs->mxPathname+1)<0 ){
5640       sqlite3_free(zOut);
5641       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
5642                          "winFullPathname2", zRelative);
5643     }else{
5644       char *zUtf8 = winConvertToUtf8Filename(zOut);
5645       if( !zUtf8 ){
5646         sqlite3_free(zOut);
5647         return SQLITE_IOERR_NOMEM_BKPT;
5648       }
5649       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zUtf8);
5650       sqlite3_free(zUtf8);
5651       sqlite3_free(zOut);
5652     }
5653   }
5654   return SQLITE_OK;
5655 #endif
5656 
5657 #if (SQLITE_OS_WINCE || SQLITE_OS_WINRT) && !defined(__CYGWIN__)
5658   SimulateIOError( return SQLITE_ERROR );
5659   /* WinCE has no concept of a relative pathname, or so I am told. */
5660   /* WinRT has no way to convert a relative path to an absolute one. */
5661   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5662     /*
5663     ** NOTE: We are dealing with a relative path name and the data
5664     **       directory has been set.  Therefore, use it as the basis
5665     **       for converting the relative path name to an absolute
5666     **       one by prepending the data directory and a backslash.
5667     */
5668     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5669                      sqlite3_data_directory, winGetDirSep(), zRelative);
5670   }else{
5671     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zRelative);
5672   }
5673   return SQLITE_OK;
5674 #endif
5675 
5676 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
5677   /* It's odd to simulate an io-error here, but really this is just
5678   ** using the io-error infrastructure to test that SQLite handles this
5679   ** function failing. This function could fail if, for example, the
5680   ** current working directory has been unlinked.
5681   */
5682   SimulateIOError( return SQLITE_ERROR );
5683   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5684     /*
5685     ** NOTE: We are dealing with a relative path name and the data
5686     **       directory has been set.  Therefore, use it as the basis
5687     **       for converting the relative path name to an absolute
5688     **       one by prepending the data directory and a backslash.
5689     */
5690     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5691                      sqlite3_data_directory, winGetDirSep(), zRelative);
5692     return SQLITE_OK;
5693   }
5694   zConverted = winConvertFromUtf8Filename(zRelative);
5695   if( zConverted==0 ){
5696     return SQLITE_IOERR_NOMEM_BKPT;
5697   }
5698   if( osIsNT() ){
5699     LPWSTR zTemp;
5700     nByte = osGetFullPathNameW((LPCWSTR)zConverted, 0, 0, 0);
5701     if( nByte==0 ){
5702       sqlite3_free(zConverted);
5703       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5704                          "winFullPathname1", zRelative);
5705     }
5706     nByte += 3;
5707     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
5708     if( zTemp==0 ){
5709       sqlite3_free(zConverted);
5710       return SQLITE_IOERR_NOMEM_BKPT;
5711     }
5712     nByte = osGetFullPathNameW((LPCWSTR)zConverted, nByte, zTemp, 0);
5713     if( nByte==0 ){
5714       sqlite3_free(zConverted);
5715       sqlite3_free(zTemp);
5716       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5717                          "winFullPathname2", zRelative);
5718     }
5719     sqlite3_free(zConverted);
5720     zOut = winUnicodeToUtf8(zTemp);
5721     sqlite3_free(zTemp);
5722   }
5723 #ifdef SQLITE_WIN32_HAS_ANSI
5724   else{
5725     char *zTemp;
5726     nByte = osGetFullPathNameA((char*)zConverted, 0, 0, 0);
5727     if( nByte==0 ){
5728       sqlite3_free(zConverted);
5729       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5730                          "winFullPathname3", zRelative);
5731     }
5732     nByte += 3;
5733     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
5734     if( zTemp==0 ){
5735       sqlite3_free(zConverted);
5736       return SQLITE_IOERR_NOMEM_BKPT;
5737     }
5738     nByte = osGetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
5739     if( nByte==0 ){
5740       sqlite3_free(zConverted);
5741       sqlite3_free(zTemp);
5742       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5743                          "winFullPathname4", zRelative);
5744     }
5745     sqlite3_free(zConverted);
5746     zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
5747     sqlite3_free(zTemp);
5748   }
5749 #endif
5750   if( zOut ){
5751     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zOut);
5752     sqlite3_free(zOut);
5753     return SQLITE_OK;
5754   }else{
5755     return SQLITE_IOERR_NOMEM_BKPT;
5756   }
5757 #endif
5758 }
5759 static int winFullPathname(
5760   sqlite3_vfs *pVfs,            /* Pointer to vfs object */
5761   const char *zRelative,        /* Possibly relative input path */
5762   int nFull,                    /* Size of output buffer in bytes */
5763   char *zFull                   /* Output buffer */
5764 ){
5765   int rc;
5766   MUTEX_LOGIC( sqlite3_mutex *pMutex; )
5767   MUTEX_LOGIC( pMutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_TEMPDIR); )
5768   sqlite3_mutex_enter(pMutex);
5769   rc = winFullPathnameNoMutex(pVfs, zRelative, nFull, zFull);
5770   sqlite3_mutex_leave(pMutex);
5771   return rc;
5772 }
5773 
5774 #ifndef SQLITE_OMIT_LOAD_EXTENSION
5775 /*
5776 ** Interfaces for opening a shared library, finding entry points
5777 ** within the shared library, and closing the shared library.
5778 */
5779 static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
5780   HANDLE h;
5781 #if defined(__CYGWIN__)
5782   int nFull = pVfs->mxPathname+1;
5783   char *zFull = sqlite3MallocZero( nFull );
5784   void *zConverted = 0;
5785   if( zFull==0 ){
5786     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5787     return 0;
5788   }
5789   if( winFullPathname(pVfs, zFilename, nFull, zFull)!=SQLITE_OK ){
5790     sqlite3_free(zFull);
5791     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5792     return 0;
5793   }
5794   zConverted = winConvertFromUtf8Filename(zFull);
5795   sqlite3_free(zFull);
5796 #else
5797   void *zConverted = winConvertFromUtf8Filename(zFilename);
5798   UNUSED_PARAMETER(pVfs);
5799 #endif
5800   if( zConverted==0 ){
5801     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5802     return 0;
5803   }
5804   if( osIsNT() ){
5805 #if SQLITE_OS_WINRT
5806     h = osLoadPackagedLibrary((LPCWSTR)zConverted, 0);
5807 #else
5808     h = osLoadLibraryW((LPCWSTR)zConverted);
5809 #endif
5810   }
5811 #ifdef SQLITE_WIN32_HAS_ANSI
5812   else{
5813     h = osLoadLibraryA((char*)zConverted);
5814   }
5815 #endif
5816   OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)h));
5817   sqlite3_free(zConverted);
5818   return (void*)h;
5819 }
5820 static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
5821   UNUSED_PARAMETER(pVfs);
5822   winGetLastErrorMsg(osGetLastError(), nBuf, zBufOut);
5823 }
5824 static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){
5825   FARPROC proc;
5826   UNUSED_PARAMETER(pVfs);
5827   proc = osGetProcAddressA((HANDLE)pH, zSym);
5828   OSTRACE(("DLSYM handle=%p, symbol=%s, address=%p\n",
5829            (void*)pH, zSym, (void*)proc));
5830   return (void(*)(void))proc;
5831 }
5832 static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
5833   UNUSED_PARAMETER(pVfs);
5834   osFreeLibrary((HANDLE)pHandle);
5835   OSTRACE(("DLCLOSE handle=%p\n", (void*)pHandle));
5836 }
5837 #else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
5838   #define winDlOpen  0
5839   #define winDlError 0
5840   #define winDlSym   0
5841   #define winDlClose 0
5842 #endif
5843 
5844 /* State information for the randomness gatherer. */
5845 typedef struct EntropyGatherer EntropyGatherer;
5846 struct EntropyGatherer {
5847   unsigned char *a;   /* Gather entropy into this buffer */
5848   int na;             /* Size of a[] in bytes */
5849   int i;              /* XOR next input into a[i] */
5850   int nXor;           /* Number of XOR operations done */
5851 };
5852 
5853 #if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)
5854 /* Mix sz bytes of entropy into p. */
5855 static void xorMemory(EntropyGatherer *p, unsigned char *x, int sz){
5856   int j, k;
5857   for(j=0, k=p->i; j<sz; j++){
5858     p->a[k++] ^= x[j];
5859     if( k>=p->na ) k = 0;
5860   }
5861   p->i = k;
5862   p->nXor += sz;
5863 }
5864 #endif /* !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS) */
5865 
5866 /*
5867 ** Write up to nBuf bytes of randomness into zBuf.
5868 */
5869 static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5870 #if defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS)
5871   UNUSED_PARAMETER(pVfs);
5872   memset(zBuf, 0, nBuf);
5873   return nBuf;
5874 #else
5875   EntropyGatherer e;
5876   UNUSED_PARAMETER(pVfs);
5877   memset(zBuf, 0, nBuf);
5878   e.a = (unsigned char*)zBuf;
5879   e.na = nBuf;
5880   e.nXor = 0;
5881   e.i = 0;
5882   {
5883     SYSTEMTIME x;
5884     osGetSystemTime(&x);
5885     xorMemory(&e, (unsigned char*)&x, sizeof(SYSTEMTIME));
5886   }
5887   {
5888     DWORD pid = osGetCurrentProcessId();
5889     xorMemory(&e, (unsigned char*)&pid, sizeof(DWORD));
5890   }
5891 #if SQLITE_OS_WINRT
5892   {
5893     ULONGLONG cnt = osGetTickCount64();
5894     xorMemory(&e, (unsigned char*)&cnt, sizeof(ULONGLONG));
5895   }
5896 #else
5897   {
5898     DWORD cnt = osGetTickCount();
5899     xorMemory(&e, (unsigned char*)&cnt, sizeof(DWORD));
5900   }
5901 #endif /* SQLITE_OS_WINRT */
5902   {
5903     LARGE_INTEGER i;
5904     osQueryPerformanceCounter(&i);
5905     xorMemory(&e, (unsigned char*)&i, sizeof(LARGE_INTEGER));
5906   }
5907 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
5908   {
5909     UUID id;
5910     memset(&id, 0, sizeof(UUID));
5911     osUuidCreate(&id);
5912     xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
5913     memset(&id, 0, sizeof(UUID));
5914     osUuidCreateSequential(&id);
5915     xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
5916   }
5917 #endif /* !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID */
5918   return e.nXor>nBuf ? nBuf : e.nXor;
5919 #endif /* defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS) */
5920 }
5921 
5922 
5923 /*
5924 ** Sleep for a little while.  Return the amount of time slept.
5925 */
5926 static int winSleep(sqlite3_vfs *pVfs, int microsec){
5927   sqlite3_win32_sleep((microsec+999)/1000);
5928   UNUSED_PARAMETER(pVfs);
5929   return ((microsec+999)/1000)*1000;
5930 }
5931 
5932 /*
5933 ** The following variable, if set to a non-zero value, is interpreted as
5934 ** the number of seconds since 1970 and is used to set the result of
5935 ** sqlite3OsCurrentTime() during testing.
5936 */
5937 #ifdef SQLITE_TEST
5938 int sqlite3_current_time = 0;  /* Fake system time in seconds since 1970. */
5939 #endif
5940 
5941 /*
5942 ** Find the current time (in Universal Coordinated Time).  Write into *piNow
5943 ** the current time and date as a Julian Day number times 86_400_000.  In
5944 ** other words, write into *piNow the number of milliseconds since the Julian
5945 ** epoch of noon in Greenwich on November 24, 4714 B.C according to the
5946 ** proleptic Gregorian calendar.
5947 **
5948 ** On success, return SQLITE_OK.  Return SQLITE_ERROR if the time and date
5949 ** cannot be found.
5950 */
5951 static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
5952   /* FILETIME structure is a 64-bit value representing the number of
5953      100-nanosecond intervals since January 1, 1601 (= JD 2305813.5).
5954   */
5955   FILETIME ft;
5956   static const sqlite3_int64 winFiletimeEpoch = 23058135*(sqlite3_int64)8640000;
5957 #ifdef SQLITE_TEST
5958   static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000;
5959 #endif
5960   /* 2^32 - to avoid use of LL and warnings in gcc */
5961   static const sqlite3_int64 max32BitValue =
5962       (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 +
5963       (sqlite3_int64)294967296;
5964 
5965 #if SQLITE_OS_WINCE
5966   SYSTEMTIME time;
5967   osGetSystemTime(&time);
5968   /* if SystemTimeToFileTime() fails, it returns zero. */
5969   if (!osSystemTimeToFileTime(&time,&ft)){
5970     return SQLITE_ERROR;
5971   }
5972 #else
5973   osGetSystemTimeAsFileTime( &ft );
5974 #endif
5975 
5976   *piNow = winFiletimeEpoch +
5977             ((((sqlite3_int64)ft.dwHighDateTime)*max32BitValue) +
5978                (sqlite3_int64)ft.dwLowDateTime)/(sqlite3_int64)10000;
5979 
5980 #ifdef SQLITE_TEST
5981   if( sqlite3_current_time ){
5982     *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;
5983   }
5984 #endif
5985   UNUSED_PARAMETER(pVfs);
5986   return SQLITE_OK;
5987 }
5988 
5989 /*
5990 ** Find the current time (in Universal Coordinated Time).  Write the
5991 ** current time and date as a Julian Day number into *prNow and
5992 ** return 0.  Return 1 if the time and date cannot be found.
5993 */
5994 static int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){
5995   int rc;
5996   sqlite3_int64 i;
5997   rc = winCurrentTimeInt64(pVfs, &i);
5998   if( !rc ){
5999     *prNow = i/86400000.0;
6000   }
6001   return rc;
6002 }
6003 
6004 /*
6005 ** The idea is that this function works like a combination of
6006 ** GetLastError() and FormatMessage() on Windows (or errno and
6007 ** strerror_r() on Unix). After an error is returned by an OS
6008 ** function, SQLite calls this function with zBuf pointing to
6009 ** a buffer of nBuf bytes. The OS layer should populate the
6010 ** buffer with a nul-terminated UTF-8 encoded error message
6011 ** describing the last IO error to have occurred within the calling
6012 ** thread.
6013 **
6014 ** If the error message is too large for the supplied buffer,
6015 ** it should be truncated. The return value of xGetLastError
6016 ** is zero if the error message fits in the buffer, or non-zero
6017 ** otherwise (if the message was truncated). If non-zero is returned,
6018 ** then it is not necessary to include the nul-terminator character
6019 ** in the output buffer.
6020 **
6021 ** Not supplying an error message will have no adverse effect
6022 ** on SQLite. It is fine to have an implementation that never
6023 ** returns an error message:
6024 **
6025 **   int xGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
6026 **     assert(zBuf[0]=='\0');
6027 **     return 0;
6028 **   }
6029 **
6030 ** However if an error message is supplied, it will be incorporated
6031 ** by sqlite into the error message available to the user using
6032 ** sqlite3_errmsg(), possibly making IO errors easier to debug.
6033 */
6034 static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
6035   DWORD e = osGetLastError();
6036   UNUSED_PARAMETER(pVfs);
6037   if( nBuf>0 ) winGetLastErrorMsg(e, nBuf, zBuf);
6038   return e;
6039 }
6040 
6041 /*
6042 ** Initialize and deinitialize the operating system interface.
6043 */
6044 int sqlite3_os_init(void){
6045   static sqlite3_vfs winVfs = {
6046     3,                     /* iVersion */
6047     sizeof(winFile),       /* szOsFile */
6048     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
6049     0,                     /* pNext */
6050     "win32",               /* zName */
6051     &winAppData,           /* pAppData */
6052     winOpen,               /* xOpen */
6053     winDelete,             /* xDelete */
6054     winAccess,             /* xAccess */
6055     winFullPathname,       /* xFullPathname */
6056     winDlOpen,             /* xDlOpen */
6057     winDlError,            /* xDlError */
6058     winDlSym,              /* xDlSym */
6059     winDlClose,            /* xDlClose */
6060     winRandomness,         /* xRandomness */
6061     winSleep,              /* xSleep */
6062     winCurrentTime,        /* xCurrentTime */
6063     winGetLastError,       /* xGetLastError */
6064     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6065     winSetSystemCall,      /* xSetSystemCall */
6066     winGetSystemCall,      /* xGetSystemCall */
6067     winNextSystemCall,     /* xNextSystemCall */
6068   };
6069 #if defined(SQLITE_WIN32_HAS_WIDE)
6070   static sqlite3_vfs winLongPathVfs = {
6071     3,                     /* iVersion */
6072     sizeof(winFile),       /* szOsFile */
6073     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
6074     0,                     /* pNext */
6075     "win32-longpath",      /* zName */
6076     &winAppData,           /* pAppData */
6077     winOpen,               /* xOpen */
6078     winDelete,             /* xDelete */
6079     winAccess,             /* xAccess */
6080     winFullPathname,       /* xFullPathname */
6081     winDlOpen,             /* xDlOpen */
6082     winDlError,            /* xDlError */
6083     winDlSym,              /* xDlSym */
6084     winDlClose,            /* xDlClose */
6085     winRandomness,         /* xRandomness */
6086     winSleep,              /* xSleep */
6087     winCurrentTime,        /* xCurrentTime */
6088     winGetLastError,       /* xGetLastError */
6089     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6090     winSetSystemCall,      /* xSetSystemCall */
6091     winGetSystemCall,      /* xGetSystemCall */
6092     winNextSystemCall,     /* xNextSystemCall */
6093   };
6094 #endif
6095   static sqlite3_vfs winNolockVfs = {
6096     3,                     /* iVersion */
6097     sizeof(winFile),       /* szOsFile */
6098     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
6099     0,                     /* pNext */
6100     "win32-none",          /* zName */
6101     &winNolockAppData,     /* pAppData */
6102     winOpen,               /* xOpen */
6103     winDelete,             /* xDelete */
6104     winAccess,             /* xAccess */
6105     winFullPathname,       /* xFullPathname */
6106     winDlOpen,             /* xDlOpen */
6107     winDlError,            /* xDlError */
6108     winDlSym,              /* xDlSym */
6109     winDlClose,            /* xDlClose */
6110     winRandomness,         /* xRandomness */
6111     winSleep,              /* xSleep */
6112     winCurrentTime,        /* xCurrentTime */
6113     winGetLastError,       /* xGetLastError */
6114     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6115     winSetSystemCall,      /* xSetSystemCall */
6116     winGetSystemCall,      /* xGetSystemCall */
6117     winNextSystemCall,     /* xNextSystemCall */
6118   };
6119 #if defined(SQLITE_WIN32_HAS_WIDE)
6120   static sqlite3_vfs winLongPathNolockVfs = {
6121     3,                     /* iVersion */
6122     sizeof(winFile),       /* szOsFile */
6123     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
6124     0,                     /* pNext */
6125     "win32-longpath-none", /* zName */
6126     &winNolockAppData,     /* pAppData */
6127     winOpen,               /* xOpen */
6128     winDelete,             /* xDelete */
6129     winAccess,             /* xAccess */
6130     winFullPathname,       /* xFullPathname */
6131     winDlOpen,             /* xDlOpen */
6132     winDlError,            /* xDlError */
6133     winDlSym,              /* xDlSym */
6134     winDlClose,            /* xDlClose */
6135     winRandomness,         /* xRandomness */
6136     winSleep,              /* xSleep */
6137     winCurrentTime,        /* xCurrentTime */
6138     winGetLastError,       /* xGetLastError */
6139     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6140     winSetSystemCall,      /* xSetSystemCall */
6141     winGetSystemCall,      /* xGetSystemCall */
6142     winNextSystemCall,     /* xNextSystemCall */
6143   };
6144 #endif
6145 
6146   /* Double-check that the aSyscall[] array has been constructed
6147   ** correctly.  See ticket [bb3a86e890c8e96ab] */
6148   assert( ArraySize(aSyscall)==80 );
6149 
6150   /* get memory map allocation granularity */
6151   memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
6152 #if SQLITE_OS_WINRT
6153   osGetNativeSystemInfo(&winSysInfo);
6154 #else
6155   osGetSystemInfo(&winSysInfo);
6156 #endif
6157   assert( winSysInfo.dwAllocationGranularity>0 );
6158   assert( winSysInfo.dwPageSize>0 );
6159 
6160   sqlite3_vfs_register(&winVfs, 1);
6161 
6162 #if defined(SQLITE_WIN32_HAS_WIDE)
6163   sqlite3_vfs_register(&winLongPathVfs, 0);
6164 #endif
6165 
6166   sqlite3_vfs_register(&winNolockVfs, 0);
6167 
6168 #if defined(SQLITE_WIN32_HAS_WIDE)
6169   sqlite3_vfs_register(&winLongPathNolockVfs, 0);
6170 #endif
6171 
6172 #ifndef SQLITE_OMIT_WAL
6173   winBigLock = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1);
6174 #endif
6175 
6176   return SQLITE_OK;
6177 }
6178 
6179 int sqlite3_os_end(void){
6180 #if SQLITE_OS_WINRT
6181   if( sleepObj!=NULL ){
6182     osCloseHandle(sleepObj);
6183     sleepObj = NULL;
6184   }
6185 #endif
6186 
6187 #ifndef SQLITE_OMIT_WAL
6188   winBigLock = 0;
6189 #endif
6190 
6191   return SQLITE_OK;
6192 }
6193 
6194 #endif /* SQLITE_OS_WIN */
6195