xref: /sqlite-3.40.0/src/os_win.c (revision aeb4e6ee)
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 #ifndef SQLITE_OMIT_AUTOINIT
1922   int rc = sqlite3_initialize();
1923   if( rc ) return rc;
1924 #endif
1925   if( type==SQLITE_WIN32_DATA_DIRECTORY_TYPE ){
1926     ppDirectory = &sqlite3_data_directory;
1927   }else if( type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE ){
1928     ppDirectory = &sqlite3_temp_directory;
1929   }
1930   assert( !ppDirectory || type==SQLITE_WIN32_DATA_DIRECTORY_TYPE
1931           || type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE
1932   );
1933   assert( !ppDirectory || sqlite3MemdebugHasType(*ppDirectory, MEMTYPE_HEAP) );
1934   if( ppDirectory ){
1935     char *zCopy = 0;
1936     if( zValue && zValue[0] ){
1937       zCopy = sqlite3_mprintf("%s", zValue);
1938       if ( zCopy==0 ){
1939         return SQLITE_NOMEM_BKPT;
1940       }
1941     }
1942     sqlite3_free(*ppDirectory);
1943     *ppDirectory = zCopy;
1944     return SQLITE_OK;
1945   }
1946   return SQLITE_ERROR;
1947 }
1948 
1949 /*
1950 ** This function is the same as sqlite3_win32_set_directory (below); however,
1951 ** it accepts a UTF-16 string.
1952 */
1953 int sqlite3_win32_set_directory16(
1954   unsigned long type, /* Identifier for directory being set or reset */
1955   const void *zValue  /* New value for directory being set or reset */
1956 ){
1957   int rc;
1958   char *zUtf8 = 0;
1959   if( zValue ){
1960     zUtf8 = sqlite3_win32_unicode_to_utf8(zValue);
1961     if( zUtf8==0 ) return SQLITE_NOMEM_BKPT;
1962   }
1963   rc = sqlite3_win32_set_directory8(type, zUtf8);
1964   if( zUtf8 ) sqlite3_free(zUtf8);
1965   return rc;
1966 }
1967 
1968 /*
1969 ** This function sets the data directory or the temporary directory based on
1970 ** the provided arguments.  The type argument must be 1 in order to set the
1971 ** data directory or 2 in order to set the temporary directory.  The zValue
1972 ** argument is the name of the directory to use.  The return value will be
1973 ** SQLITE_OK if successful.
1974 */
1975 int sqlite3_win32_set_directory(
1976   unsigned long type, /* Identifier for directory being set or reset */
1977   void *zValue        /* New value for directory being set or reset */
1978 ){
1979   return sqlite3_win32_set_directory16(type, zValue);
1980 }
1981 
1982 /*
1983 ** The return value of winGetLastErrorMsg
1984 ** is zero if the error message fits in the buffer, or non-zero
1985 ** otherwise (if the message was truncated).
1986 */
1987 static int winGetLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){
1988   /* FormatMessage returns 0 on failure.  Otherwise it
1989   ** returns the number of TCHARs written to the output
1990   ** buffer, excluding the terminating null char.
1991   */
1992   DWORD dwLen = 0;
1993   char *zOut = 0;
1994 
1995   if( osIsNT() ){
1996 #if SQLITE_OS_WINRT
1997     WCHAR zTempWide[SQLITE_WIN32_MAX_ERRMSG_CHARS+1];
1998     dwLen = osFormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
1999                              FORMAT_MESSAGE_IGNORE_INSERTS,
2000                              NULL,
2001                              lastErrno,
2002                              0,
2003                              zTempWide,
2004                              SQLITE_WIN32_MAX_ERRMSG_CHARS,
2005                              0);
2006 #else
2007     LPWSTR zTempWide = NULL;
2008     dwLen = osFormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
2009                              FORMAT_MESSAGE_FROM_SYSTEM |
2010                              FORMAT_MESSAGE_IGNORE_INSERTS,
2011                              NULL,
2012                              lastErrno,
2013                              0,
2014                              (LPWSTR) &zTempWide,
2015                              0,
2016                              0);
2017 #endif
2018     if( dwLen > 0 ){
2019       /* allocate a buffer and convert to UTF8 */
2020       sqlite3BeginBenignMalloc();
2021       zOut = winUnicodeToUtf8(zTempWide);
2022       sqlite3EndBenignMalloc();
2023 #if !SQLITE_OS_WINRT
2024       /* free the system buffer allocated by FormatMessage */
2025       osLocalFree(zTempWide);
2026 #endif
2027     }
2028   }
2029 #ifdef SQLITE_WIN32_HAS_ANSI
2030   else{
2031     char *zTemp = NULL;
2032     dwLen = osFormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
2033                              FORMAT_MESSAGE_FROM_SYSTEM |
2034                              FORMAT_MESSAGE_IGNORE_INSERTS,
2035                              NULL,
2036                              lastErrno,
2037                              0,
2038                              (LPSTR) &zTemp,
2039                              0,
2040                              0);
2041     if( dwLen > 0 ){
2042       /* allocate a buffer and convert to UTF8 */
2043       sqlite3BeginBenignMalloc();
2044       zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
2045       sqlite3EndBenignMalloc();
2046       /* free the system buffer allocated by FormatMessage */
2047       osLocalFree(zTemp);
2048     }
2049   }
2050 #endif
2051   if( 0 == dwLen ){
2052     sqlite3_snprintf(nBuf, zBuf, "OsError 0x%lx (%lu)", lastErrno, lastErrno);
2053   }else{
2054     /* copy a maximum of nBuf chars to output buffer */
2055     sqlite3_snprintf(nBuf, zBuf, "%s", zOut);
2056     /* free the UTF8 buffer */
2057     sqlite3_free(zOut);
2058   }
2059   return 0;
2060 }
2061 
2062 /*
2063 **
2064 ** This function - winLogErrorAtLine() - is only ever called via the macro
2065 ** winLogError().
2066 **
2067 ** This routine is invoked after an error occurs in an OS function.
2068 ** It logs a message using sqlite3_log() containing the current value of
2069 ** error code and, if possible, the human-readable equivalent from
2070 ** FormatMessage.
2071 **
2072 ** The first argument passed to the macro should be the error code that
2073 ** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN).
2074 ** The two subsequent arguments should be the name of the OS function that
2075 ** failed and the associated file-system path, if any.
2076 */
2077 #define winLogError(a,b,c,d)   winLogErrorAtLine(a,b,c,d,__LINE__)
2078 static int winLogErrorAtLine(
2079   int errcode,                    /* SQLite error code */
2080   DWORD lastErrno,                /* Win32 last error */
2081   const char *zFunc,              /* Name of OS function that failed */
2082   const char *zPath,              /* File path associated with error */
2083   int iLine                       /* Source line number where error occurred */
2084 ){
2085   char zMsg[500];                 /* Human readable error text */
2086   int i;                          /* Loop counter */
2087 
2088   zMsg[0] = 0;
2089   winGetLastErrorMsg(lastErrno, sizeof(zMsg), zMsg);
2090   assert( errcode!=SQLITE_OK );
2091   if( zPath==0 ) zPath = "";
2092   for(i=0; zMsg[i] && zMsg[i]!='\r' && zMsg[i]!='\n'; i++){}
2093   zMsg[i] = 0;
2094   sqlite3_log(errcode,
2095       "os_win.c:%d: (%lu) %s(%s) - %s",
2096       iLine, lastErrno, zFunc, zPath, zMsg
2097   );
2098 
2099   return errcode;
2100 }
2101 
2102 /*
2103 ** The number of times that a ReadFile(), WriteFile(), and DeleteFile()
2104 ** will be retried following a locking error - probably caused by
2105 ** antivirus software.  Also the initial delay before the first retry.
2106 ** The delay increases linearly with each retry.
2107 */
2108 #ifndef SQLITE_WIN32_IOERR_RETRY
2109 # define SQLITE_WIN32_IOERR_RETRY 10
2110 #endif
2111 #ifndef SQLITE_WIN32_IOERR_RETRY_DELAY
2112 # define SQLITE_WIN32_IOERR_RETRY_DELAY 25
2113 #endif
2114 static int winIoerrRetry = SQLITE_WIN32_IOERR_RETRY;
2115 static int winIoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;
2116 
2117 /*
2118 ** The "winIoerrCanRetry1" macro is used to determine if a particular I/O
2119 ** error code obtained via GetLastError() is eligible to be retried.  It
2120 ** must accept the error code DWORD as its only argument and should return
2121 ** non-zero if the error code is transient in nature and the operation
2122 ** responsible for generating the original error might succeed upon being
2123 ** retried.  The argument to this macro should be a variable.
2124 **
2125 ** Additionally, a macro named "winIoerrCanRetry2" may be defined.  If it
2126 ** is defined, it will be consulted only when the macro "winIoerrCanRetry1"
2127 ** returns zero.  The "winIoerrCanRetry2" macro is completely optional and
2128 ** may be used to include additional error codes in the set that should
2129 ** result in the failing I/O operation being retried by the caller.  If
2130 ** defined, the "winIoerrCanRetry2" macro must exhibit external semantics
2131 ** identical to those of the "winIoerrCanRetry1" macro.
2132 */
2133 #if !defined(winIoerrCanRetry1)
2134 #define winIoerrCanRetry1(a) (((a)==ERROR_ACCESS_DENIED)        || \
2135                               ((a)==ERROR_SHARING_VIOLATION)    || \
2136                               ((a)==ERROR_LOCK_VIOLATION)       || \
2137                               ((a)==ERROR_DEV_NOT_EXIST)        || \
2138                               ((a)==ERROR_NETNAME_DELETED)      || \
2139                               ((a)==ERROR_SEM_TIMEOUT)          || \
2140                               ((a)==ERROR_NETWORK_UNREACHABLE))
2141 #endif
2142 
2143 /*
2144 ** If a ReadFile() or WriteFile() error occurs, invoke this routine
2145 ** to see if it should be retried.  Return TRUE to retry.  Return FALSE
2146 ** to give up with an error.
2147 */
2148 static int winRetryIoerr(int *pnRetry, DWORD *pError){
2149   DWORD e = osGetLastError();
2150   if( *pnRetry>=winIoerrRetry ){
2151     if( pError ){
2152       *pError = e;
2153     }
2154     return 0;
2155   }
2156   if( winIoerrCanRetry1(e) ){
2157     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
2158     ++*pnRetry;
2159     return 1;
2160   }
2161 #if defined(winIoerrCanRetry2)
2162   else if( winIoerrCanRetry2(e) ){
2163     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
2164     ++*pnRetry;
2165     return 1;
2166   }
2167 #endif
2168   if( pError ){
2169     *pError = e;
2170   }
2171   return 0;
2172 }
2173 
2174 /*
2175 ** Log a I/O error retry episode.
2176 */
2177 static void winLogIoerr(int nRetry, int lineno){
2178   if( nRetry ){
2179     sqlite3_log(SQLITE_NOTICE,
2180       "delayed %dms for lock/sharing conflict at line %d",
2181       winIoerrRetryDelay*nRetry*(nRetry+1)/2, lineno
2182     );
2183   }
2184 }
2185 
2186 /*
2187 ** This #if does not rely on the SQLITE_OS_WINCE define because the
2188 ** corresponding section in "date.c" cannot use it.
2189 */
2190 #if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \
2191     (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)
2192 /*
2193 ** The MSVC CRT on Windows CE may not have a localtime() function.
2194 ** So define a substitute.
2195 */
2196 #  include <time.h>
2197 struct tm *__cdecl localtime(const time_t *t)
2198 {
2199   static struct tm y;
2200   FILETIME uTm, lTm;
2201   SYSTEMTIME pTm;
2202   sqlite3_int64 t64;
2203   t64 = *t;
2204   t64 = (t64 + 11644473600)*10000000;
2205   uTm.dwLowDateTime = (DWORD)(t64 & 0xFFFFFFFF);
2206   uTm.dwHighDateTime= (DWORD)(t64 >> 32);
2207   osFileTimeToLocalFileTime(&uTm,&lTm);
2208   osFileTimeToSystemTime(&lTm,&pTm);
2209   y.tm_year = pTm.wYear - 1900;
2210   y.tm_mon = pTm.wMonth - 1;
2211   y.tm_wday = pTm.wDayOfWeek;
2212   y.tm_mday = pTm.wDay;
2213   y.tm_hour = pTm.wHour;
2214   y.tm_min = pTm.wMinute;
2215   y.tm_sec = pTm.wSecond;
2216   return &y;
2217 }
2218 #endif
2219 
2220 #if SQLITE_OS_WINCE
2221 /*************************************************************************
2222 ** This section contains code for WinCE only.
2223 */
2224 #define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]
2225 
2226 /*
2227 ** Acquire a lock on the handle h
2228 */
2229 static void winceMutexAcquire(HANDLE h){
2230    DWORD dwErr;
2231    do {
2232      dwErr = osWaitForSingleObject(h, INFINITE);
2233    } while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);
2234 }
2235 /*
2236 ** Release a lock acquired by winceMutexAcquire()
2237 */
2238 #define winceMutexRelease(h) ReleaseMutex(h)
2239 
2240 /*
2241 ** Create the mutex and shared memory used for locking in the file
2242 ** descriptor pFile
2243 */
2244 static int winceCreateLock(const char *zFilename, winFile *pFile){
2245   LPWSTR zTok;
2246   LPWSTR zName;
2247   DWORD lastErrno;
2248   BOOL bLogged = FALSE;
2249   BOOL bInit = TRUE;
2250 
2251   zName = winUtf8ToUnicode(zFilename);
2252   if( zName==0 ){
2253     /* out of memory */
2254     return SQLITE_IOERR_NOMEM_BKPT;
2255   }
2256 
2257   /* Initialize the local lockdata */
2258   memset(&pFile->local, 0, sizeof(pFile->local));
2259 
2260   /* Replace the backslashes from the filename and lowercase it
2261   ** to derive a mutex name. */
2262   zTok = osCharLowerW(zName);
2263   for (;*zTok;zTok++){
2264     if (*zTok == '\\') *zTok = '_';
2265   }
2266 
2267   /* Create/open the named mutex */
2268   pFile->hMutex = osCreateMutexW(NULL, FALSE, zName);
2269   if (!pFile->hMutex){
2270     pFile->lastErrno = osGetLastError();
2271     sqlite3_free(zName);
2272     return winLogError(SQLITE_IOERR, pFile->lastErrno,
2273                        "winceCreateLock1", zFilename);
2274   }
2275 
2276   /* Acquire the mutex before continuing */
2277   winceMutexAcquire(pFile->hMutex);
2278 
2279   /* Since the names of named mutexes, semaphores, file mappings etc are
2280   ** case-sensitive, take advantage of that by uppercasing the mutex name
2281   ** and using that as the shared filemapping name.
2282   */
2283   osCharUpperW(zName);
2284   pFile->hShared = osCreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
2285                                         PAGE_READWRITE, 0, sizeof(winceLock),
2286                                         zName);
2287 
2288   /* Set a flag that indicates we're the first to create the memory so it
2289   ** must be zero-initialized */
2290   lastErrno = osGetLastError();
2291   if (lastErrno == ERROR_ALREADY_EXISTS){
2292     bInit = FALSE;
2293   }
2294 
2295   sqlite3_free(zName);
2296 
2297   /* If we succeeded in making the shared memory handle, map it. */
2298   if( pFile->hShared ){
2299     pFile->shared = (winceLock*)osMapViewOfFile(pFile->hShared,
2300              FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
2301     /* If mapping failed, close the shared memory handle and erase it */
2302     if( !pFile->shared ){
2303       pFile->lastErrno = osGetLastError();
2304       winLogError(SQLITE_IOERR, pFile->lastErrno,
2305                   "winceCreateLock2", zFilename);
2306       bLogged = TRUE;
2307       osCloseHandle(pFile->hShared);
2308       pFile->hShared = NULL;
2309     }
2310   }
2311 
2312   /* If shared memory could not be created, then close the mutex and fail */
2313   if( pFile->hShared==NULL ){
2314     if( !bLogged ){
2315       pFile->lastErrno = lastErrno;
2316       winLogError(SQLITE_IOERR, pFile->lastErrno,
2317                   "winceCreateLock3", zFilename);
2318       bLogged = TRUE;
2319     }
2320     winceMutexRelease(pFile->hMutex);
2321     osCloseHandle(pFile->hMutex);
2322     pFile->hMutex = NULL;
2323     return SQLITE_IOERR;
2324   }
2325 
2326   /* Initialize the shared memory if we're supposed to */
2327   if( bInit ){
2328     memset(pFile->shared, 0, sizeof(winceLock));
2329   }
2330 
2331   winceMutexRelease(pFile->hMutex);
2332   return SQLITE_OK;
2333 }
2334 
2335 /*
2336 ** Destroy the part of winFile that deals with wince locks
2337 */
2338 static void winceDestroyLock(winFile *pFile){
2339   if (pFile->hMutex){
2340     /* Acquire the mutex */
2341     winceMutexAcquire(pFile->hMutex);
2342 
2343     /* The following blocks should probably assert in debug mode, but they
2344        are to cleanup in case any locks remained open */
2345     if (pFile->local.nReaders){
2346       pFile->shared->nReaders --;
2347     }
2348     if (pFile->local.bReserved){
2349       pFile->shared->bReserved = FALSE;
2350     }
2351     if (pFile->local.bPending){
2352       pFile->shared->bPending = FALSE;
2353     }
2354     if (pFile->local.bExclusive){
2355       pFile->shared->bExclusive = FALSE;
2356     }
2357 
2358     /* De-reference and close our copy of the shared memory handle */
2359     osUnmapViewOfFile(pFile->shared);
2360     osCloseHandle(pFile->hShared);
2361 
2362     /* Done with the mutex */
2363     winceMutexRelease(pFile->hMutex);
2364     osCloseHandle(pFile->hMutex);
2365     pFile->hMutex = NULL;
2366   }
2367 }
2368 
2369 /*
2370 ** An implementation of the LockFile() API of Windows for CE
2371 */
2372 static BOOL winceLockFile(
2373   LPHANDLE phFile,
2374   DWORD dwFileOffsetLow,
2375   DWORD dwFileOffsetHigh,
2376   DWORD nNumberOfBytesToLockLow,
2377   DWORD nNumberOfBytesToLockHigh
2378 ){
2379   winFile *pFile = HANDLE_TO_WINFILE(phFile);
2380   BOOL bReturn = FALSE;
2381 
2382   UNUSED_PARAMETER(dwFileOffsetHigh);
2383   UNUSED_PARAMETER(nNumberOfBytesToLockHigh);
2384 
2385   if (!pFile->hMutex) return TRUE;
2386   winceMutexAcquire(pFile->hMutex);
2387 
2388   /* Wanting an exclusive lock? */
2389   if (dwFileOffsetLow == (DWORD)SHARED_FIRST
2390        && nNumberOfBytesToLockLow == (DWORD)SHARED_SIZE){
2391     if (pFile->shared->nReaders == 0 && pFile->shared->bExclusive == 0){
2392        pFile->shared->bExclusive = TRUE;
2393        pFile->local.bExclusive = TRUE;
2394        bReturn = TRUE;
2395     }
2396   }
2397 
2398   /* Want a read-only lock? */
2399   else if (dwFileOffsetLow == (DWORD)SHARED_FIRST &&
2400            nNumberOfBytesToLockLow == 1){
2401     if (pFile->shared->bExclusive == 0){
2402       pFile->local.nReaders ++;
2403       if (pFile->local.nReaders == 1){
2404         pFile->shared->nReaders ++;
2405       }
2406       bReturn = TRUE;
2407     }
2408   }
2409 
2410   /* Want a pending lock? */
2411   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
2412            && nNumberOfBytesToLockLow == 1){
2413     /* If no pending lock has been acquired, then acquire it */
2414     if (pFile->shared->bPending == 0) {
2415       pFile->shared->bPending = TRUE;
2416       pFile->local.bPending = TRUE;
2417       bReturn = TRUE;
2418     }
2419   }
2420 
2421   /* Want a reserved lock? */
2422   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
2423            && nNumberOfBytesToLockLow == 1){
2424     if (pFile->shared->bReserved == 0) {
2425       pFile->shared->bReserved = TRUE;
2426       pFile->local.bReserved = TRUE;
2427       bReturn = TRUE;
2428     }
2429   }
2430 
2431   winceMutexRelease(pFile->hMutex);
2432   return bReturn;
2433 }
2434 
2435 /*
2436 ** An implementation of the UnlockFile API of Windows for CE
2437 */
2438 static BOOL winceUnlockFile(
2439   LPHANDLE phFile,
2440   DWORD dwFileOffsetLow,
2441   DWORD dwFileOffsetHigh,
2442   DWORD nNumberOfBytesToUnlockLow,
2443   DWORD nNumberOfBytesToUnlockHigh
2444 ){
2445   winFile *pFile = HANDLE_TO_WINFILE(phFile);
2446   BOOL bReturn = FALSE;
2447 
2448   UNUSED_PARAMETER(dwFileOffsetHigh);
2449   UNUSED_PARAMETER(nNumberOfBytesToUnlockHigh);
2450 
2451   if (!pFile->hMutex) return TRUE;
2452   winceMutexAcquire(pFile->hMutex);
2453 
2454   /* Releasing a reader lock or an exclusive lock */
2455   if (dwFileOffsetLow == (DWORD)SHARED_FIRST){
2456     /* Did we have an exclusive lock? */
2457     if (pFile->local.bExclusive){
2458       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE);
2459       pFile->local.bExclusive = FALSE;
2460       pFile->shared->bExclusive = FALSE;
2461       bReturn = TRUE;
2462     }
2463 
2464     /* Did we just have a reader lock? */
2465     else if (pFile->local.nReaders){
2466       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE
2467              || nNumberOfBytesToUnlockLow == 1);
2468       pFile->local.nReaders --;
2469       if (pFile->local.nReaders == 0)
2470       {
2471         pFile->shared->nReaders --;
2472       }
2473       bReturn = TRUE;
2474     }
2475   }
2476 
2477   /* Releasing a pending lock */
2478   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
2479            && nNumberOfBytesToUnlockLow == 1){
2480     if (pFile->local.bPending){
2481       pFile->local.bPending = FALSE;
2482       pFile->shared->bPending = FALSE;
2483       bReturn = TRUE;
2484     }
2485   }
2486   /* Releasing a reserved lock */
2487   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
2488            && nNumberOfBytesToUnlockLow == 1){
2489     if (pFile->local.bReserved) {
2490       pFile->local.bReserved = FALSE;
2491       pFile->shared->bReserved = FALSE;
2492       bReturn = TRUE;
2493     }
2494   }
2495 
2496   winceMutexRelease(pFile->hMutex);
2497   return bReturn;
2498 }
2499 /*
2500 ** End of the special code for wince
2501 *****************************************************************************/
2502 #endif /* SQLITE_OS_WINCE */
2503 
2504 /*
2505 ** Lock a file region.
2506 */
2507 static BOOL winLockFile(
2508   LPHANDLE phFile,
2509   DWORD flags,
2510   DWORD offsetLow,
2511   DWORD offsetHigh,
2512   DWORD numBytesLow,
2513   DWORD numBytesHigh
2514 ){
2515 #if SQLITE_OS_WINCE
2516   /*
2517   ** NOTE: Windows CE is handled differently here due its lack of the Win32
2518   **       API LockFile.
2519   */
2520   return winceLockFile(phFile, offsetLow, offsetHigh,
2521                        numBytesLow, numBytesHigh);
2522 #else
2523   if( osIsNT() ){
2524     OVERLAPPED ovlp;
2525     memset(&ovlp, 0, sizeof(OVERLAPPED));
2526     ovlp.Offset = offsetLow;
2527     ovlp.OffsetHigh = offsetHigh;
2528     return osLockFileEx(*phFile, flags, 0, numBytesLow, numBytesHigh, &ovlp);
2529   }else{
2530     return osLockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
2531                       numBytesHigh);
2532   }
2533 #endif
2534 }
2535 
2536 /*
2537 ** Unlock a file region.
2538  */
2539 static BOOL winUnlockFile(
2540   LPHANDLE phFile,
2541   DWORD offsetLow,
2542   DWORD offsetHigh,
2543   DWORD numBytesLow,
2544   DWORD numBytesHigh
2545 ){
2546 #if SQLITE_OS_WINCE
2547   /*
2548   ** NOTE: Windows CE is handled differently here due its lack of the Win32
2549   **       API UnlockFile.
2550   */
2551   return winceUnlockFile(phFile, offsetLow, offsetHigh,
2552                          numBytesLow, numBytesHigh);
2553 #else
2554   if( osIsNT() ){
2555     OVERLAPPED ovlp;
2556     memset(&ovlp, 0, sizeof(OVERLAPPED));
2557     ovlp.Offset = offsetLow;
2558     ovlp.OffsetHigh = offsetHigh;
2559     return osUnlockFileEx(*phFile, 0, numBytesLow, numBytesHigh, &ovlp);
2560   }else{
2561     return osUnlockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
2562                         numBytesHigh);
2563   }
2564 #endif
2565 }
2566 
2567 /*****************************************************************************
2568 ** The next group of routines implement the I/O methods specified
2569 ** by the sqlite3_io_methods object.
2570 ******************************************************************************/
2571 
2572 /*
2573 ** Some Microsoft compilers lack this definition.
2574 */
2575 #ifndef INVALID_SET_FILE_POINTER
2576 # define INVALID_SET_FILE_POINTER ((DWORD)-1)
2577 #endif
2578 
2579 /*
2580 ** Move the current position of the file handle passed as the first
2581 ** argument to offset iOffset within the file. If successful, return 0.
2582 ** Otherwise, set pFile->lastErrno and return non-zero.
2583 */
2584 static int winSeekFile(winFile *pFile, sqlite3_int64 iOffset){
2585 #if !SQLITE_OS_WINRT
2586   LONG upperBits;                 /* Most sig. 32 bits of new offset */
2587   LONG lowerBits;                 /* Least sig. 32 bits of new offset */
2588   DWORD dwRet;                    /* Value returned by SetFilePointer() */
2589   DWORD lastErrno;                /* Value returned by GetLastError() */
2590 
2591   OSTRACE(("SEEK file=%p, offset=%lld\n", pFile->h, iOffset));
2592 
2593   upperBits = (LONG)((iOffset>>32) & 0x7fffffff);
2594   lowerBits = (LONG)(iOffset & 0xffffffff);
2595 
2596   /* API oddity: If successful, SetFilePointer() returns a dword
2597   ** containing the lower 32-bits of the new file-offset. Or, if it fails,
2598   ** it returns INVALID_SET_FILE_POINTER. However according to MSDN,
2599   ** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine
2600   ** whether an error has actually occurred, it is also necessary to call
2601   ** GetLastError().
2602   */
2603   dwRet = osSetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
2604 
2605   if( (dwRet==INVALID_SET_FILE_POINTER
2606       && ((lastErrno = osGetLastError())!=NO_ERROR)) ){
2607     pFile->lastErrno = lastErrno;
2608     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
2609                 "winSeekFile", pFile->zPath);
2610     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
2611     return 1;
2612   }
2613 
2614   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
2615   return 0;
2616 #else
2617   /*
2618   ** Same as above, except that this implementation works for WinRT.
2619   */
2620 
2621   LARGE_INTEGER x;                /* The new offset */
2622   BOOL bRet;                      /* Value returned by SetFilePointerEx() */
2623 
2624   x.QuadPart = iOffset;
2625   bRet = osSetFilePointerEx(pFile->h, x, 0, FILE_BEGIN);
2626 
2627   if(!bRet){
2628     pFile->lastErrno = osGetLastError();
2629     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
2630                 "winSeekFile", pFile->zPath);
2631     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
2632     return 1;
2633   }
2634 
2635   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
2636   return 0;
2637 #endif
2638 }
2639 
2640 #if SQLITE_MAX_MMAP_SIZE>0
2641 /* Forward references to VFS helper methods used for memory mapped files */
2642 static int winMapfile(winFile*, sqlite3_int64);
2643 static int winUnmapfile(winFile*);
2644 #endif
2645 
2646 /*
2647 ** Close a file.
2648 **
2649 ** It is reported that an attempt to close a handle might sometimes
2650 ** fail.  This is a very unreasonable result, but Windows is notorious
2651 ** for being unreasonable so I do not doubt that it might happen.  If
2652 ** the close fails, we pause for 100 milliseconds and try again.  As
2653 ** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before
2654 ** giving up and returning an error.
2655 */
2656 #define MX_CLOSE_ATTEMPT 3
2657 static int winClose(sqlite3_file *id){
2658   int rc, cnt = 0;
2659   winFile *pFile = (winFile*)id;
2660 
2661   assert( id!=0 );
2662 #ifndef SQLITE_OMIT_WAL
2663   assert( pFile->pShm==0 );
2664 #endif
2665   assert( pFile->h!=NULL && pFile->h!=INVALID_HANDLE_VALUE );
2666   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p\n",
2667            osGetCurrentProcessId(), pFile, pFile->h));
2668 
2669 #if SQLITE_MAX_MMAP_SIZE>0
2670   winUnmapfile(pFile);
2671 #endif
2672 
2673   do{
2674     rc = osCloseHandle(pFile->h);
2675     /* SimulateIOError( rc=0; cnt=MX_CLOSE_ATTEMPT; ); */
2676   }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (sqlite3_win32_sleep(100), 1) );
2677 #if SQLITE_OS_WINCE
2678 #define WINCE_DELETION_ATTEMPTS 3
2679   {
2680     winVfsAppData *pAppData = (winVfsAppData*)pFile->pVfs->pAppData;
2681     if( pAppData==NULL || !pAppData->bNoLock ){
2682       winceDestroyLock(pFile);
2683     }
2684   }
2685   if( pFile->zDeleteOnClose ){
2686     int cnt = 0;
2687     while(
2688            osDeleteFileW(pFile->zDeleteOnClose)==0
2689         && osGetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff
2690         && cnt++ < WINCE_DELETION_ATTEMPTS
2691     ){
2692        sqlite3_win32_sleep(100);  /* Wait a little before trying again */
2693     }
2694     sqlite3_free(pFile->zDeleteOnClose);
2695   }
2696 #endif
2697   if( rc ){
2698     pFile->h = NULL;
2699   }
2700   OpenCounter(-1);
2701   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p, rc=%s\n",
2702            osGetCurrentProcessId(), pFile, pFile->h, rc ? "ok" : "failed"));
2703   return rc ? SQLITE_OK
2704             : winLogError(SQLITE_IOERR_CLOSE, osGetLastError(),
2705                           "winClose", pFile->zPath);
2706 }
2707 
2708 /*
2709 ** Read data from a file into a buffer.  Return SQLITE_OK if all
2710 ** bytes were read successfully and SQLITE_IOERR if anything goes
2711 ** wrong.
2712 */
2713 static int winRead(
2714   sqlite3_file *id,          /* File to read from */
2715   void *pBuf,                /* Write content into this buffer */
2716   int amt,                   /* Number of bytes to read */
2717   sqlite3_int64 offset       /* Begin reading at this offset */
2718 ){
2719 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2720   OVERLAPPED overlapped;          /* The offset for ReadFile. */
2721 #endif
2722   winFile *pFile = (winFile*)id;  /* file handle */
2723   DWORD nRead;                    /* Number of bytes actually read from file */
2724   int nRetry = 0;                 /* Number of retrys */
2725 
2726   assert( id!=0 );
2727   assert( amt>0 );
2728   assert( offset>=0 );
2729   SimulateIOError(return SQLITE_IOERR_READ);
2730   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
2731            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
2732            pFile->h, pBuf, amt, offset, pFile->locktype));
2733 
2734 #if SQLITE_MAX_MMAP_SIZE>0
2735   /* Deal with as much of this read request as possible by transfering
2736   ** data from the memory mapping using memcpy().  */
2737   if( offset<pFile->mmapSize ){
2738     if( offset+amt <= pFile->mmapSize ){
2739       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
2740       OSTRACE(("READ-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2741                osGetCurrentProcessId(), pFile, pFile->h));
2742       return SQLITE_OK;
2743     }else{
2744       int nCopy = (int)(pFile->mmapSize - offset);
2745       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);
2746       pBuf = &((u8 *)pBuf)[nCopy];
2747       amt -= nCopy;
2748       offset += nCopy;
2749     }
2750   }
2751 #endif
2752 
2753 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2754   if( winSeekFile(pFile, offset) ){
2755     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
2756              osGetCurrentProcessId(), pFile, pFile->h));
2757     return SQLITE_FULL;
2758   }
2759   while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
2760 #else
2761   memset(&overlapped, 0, sizeof(OVERLAPPED));
2762   overlapped.Offset = (LONG)(offset & 0xffffffff);
2763   overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2764   while( !osReadFile(pFile->h, pBuf, amt, &nRead, &overlapped) &&
2765          osGetLastError()!=ERROR_HANDLE_EOF ){
2766 #endif
2767     DWORD lastErrno;
2768     if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
2769     pFile->lastErrno = lastErrno;
2770     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_READ\n",
2771              osGetCurrentProcessId(), pFile, pFile->h));
2772     return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,
2773                        "winRead", pFile->zPath);
2774   }
2775   winLogIoerr(nRetry, __LINE__);
2776   if( nRead<(DWORD)amt ){
2777     /* Unread parts of the buffer must be zero-filled */
2778     memset(&((char*)pBuf)[nRead], 0, amt-nRead);
2779     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_SHORT_READ\n",
2780              osGetCurrentProcessId(), pFile, pFile->h));
2781     return SQLITE_IOERR_SHORT_READ;
2782   }
2783 
2784   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2785            osGetCurrentProcessId(), pFile, pFile->h));
2786   return SQLITE_OK;
2787 }
2788 
2789 /*
2790 ** Write data from a buffer into a file.  Return SQLITE_OK on success
2791 ** or some other error code on failure.
2792 */
2793 static int winWrite(
2794   sqlite3_file *id,               /* File to write into */
2795   const void *pBuf,               /* The bytes to be written */
2796   int amt,                        /* Number of bytes to write */
2797   sqlite3_int64 offset            /* Offset into the file to begin writing at */
2798 ){
2799   int rc = 0;                     /* True if error has occurred, else false */
2800   winFile *pFile = (winFile*)id;  /* File handle */
2801   int nRetry = 0;                 /* Number of retries */
2802 
2803   assert( amt>0 );
2804   assert( pFile );
2805   SimulateIOError(return SQLITE_IOERR_WRITE);
2806   SimulateDiskfullError(return SQLITE_FULL);
2807 
2808   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
2809            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
2810            pFile->h, pBuf, amt, offset, pFile->locktype));
2811 
2812 #if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0
2813   /* Deal with as much of this write request as possible by transfering
2814   ** data from the memory mapping using memcpy().  */
2815   if( offset<pFile->mmapSize ){
2816     if( offset+amt <= pFile->mmapSize ){
2817       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
2818       OSTRACE(("WRITE-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2819                osGetCurrentProcessId(), pFile, pFile->h));
2820       return SQLITE_OK;
2821     }else{
2822       int nCopy = (int)(pFile->mmapSize - offset);
2823       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);
2824       pBuf = &((u8 *)pBuf)[nCopy];
2825       amt -= nCopy;
2826       offset += nCopy;
2827     }
2828   }
2829 #endif
2830 
2831 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2832   rc = winSeekFile(pFile, offset);
2833   if( rc==0 ){
2834 #else
2835   {
2836 #endif
2837 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2838     OVERLAPPED overlapped;        /* The offset for WriteFile. */
2839 #endif
2840     u8 *aRem = (u8 *)pBuf;        /* Data yet to be written */
2841     int nRem = amt;               /* Number of bytes yet to be written */
2842     DWORD nWrite;                 /* Bytes written by each WriteFile() call */
2843     DWORD lastErrno = NO_ERROR;   /* Value returned by GetLastError() */
2844 
2845 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2846     memset(&overlapped, 0, sizeof(OVERLAPPED));
2847     overlapped.Offset = (LONG)(offset & 0xffffffff);
2848     overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2849 #endif
2850 
2851     while( nRem>0 ){
2852 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2853       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, 0) ){
2854 #else
2855       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, &overlapped) ){
2856 #endif
2857         if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
2858         break;
2859       }
2860       assert( nWrite==0 || nWrite<=(DWORD)nRem );
2861       if( nWrite==0 || nWrite>(DWORD)nRem ){
2862         lastErrno = osGetLastError();
2863         break;
2864       }
2865 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2866       offset += nWrite;
2867       overlapped.Offset = (LONG)(offset & 0xffffffff);
2868       overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2869 #endif
2870       aRem += nWrite;
2871       nRem -= nWrite;
2872     }
2873     if( nRem>0 ){
2874       pFile->lastErrno = lastErrno;
2875       rc = 1;
2876     }
2877   }
2878 
2879   if( rc ){
2880     if(   ( pFile->lastErrno==ERROR_HANDLE_DISK_FULL )
2881        || ( pFile->lastErrno==ERROR_DISK_FULL )){
2882       OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
2883                osGetCurrentProcessId(), pFile, pFile->h));
2884       return winLogError(SQLITE_FULL, pFile->lastErrno,
2885                          "winWrite1", pFile->zPath);
2886     }
2887     OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_WRITE\n",
2888              osGetCurrentProcessId(), pFile, pFile->h));
2889     return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,
2890                        "winWrite2", pFile->zPath);
2891   }else{
2892     winLogIoerr(nRetry, __LINE__);
2893   }
2894   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2895            osGetCurrentProcessId(), pFile, pFile->h));
2896   return SQLITE_OK;
2897 }
2898 
2899 /*
2900 ** Truncate an open file to a specified size
2901 */
2902 static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
2903   winFile *pFile = (winFile*)id;  /* File handle object */
2904   int rc = SQLITE_OK;             /* Return code for this function */
2905   DWORD lastErrno;
2906 #if SQLITE_MAX_MMAP_SIZE>0
2907   sqlite3_int64 oldMmapSize;
2908   if( pFile->nFetchOut>0 ){
2909     /* File truncation is a no-op if there are outstanding memory mapped
2910     ** pages.  This is because truncating the file means temporarily unmapping
2911     ** the file, and that might delete memory out from under existing cursors.
2912     **
2913     ** This can result in incremental vacuum not truncating the file,
2914     ** if there is an active read cursor when the incremental vacuum occurs.
2915     ** No real harm comes of this - the database file is not corrupted,
2916     ** though some folks might complain that the file is bigger than it
2917     ** needs to be.
2918     **
2919     ** The only feasible work-around is to defer the truncation until after
2920     ** all references to memory-mapped content are closed.  That is doable,
2921     ** but involves adding a few branches in the common write code path which
2922     ** could slow down normal operations slightly.  Hence, we have decided for
2923     ** now to simply make trancations a no-op if there are pending reads.  We
2924     ** can maybe revisit this decision in the future.
2925     */
2926     return SQLITE_OK;
2927   }
2928 #endif
2929 
2930   assert( pFile );
2931   SimulateIOError(return SQLITE_IOERR_TRUNCATE);
2932   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, size=%lld, lock=%d\n",
2933            osGetCurrentProcessId(), pFile, pFile->h, nByte, pFile->locktype));
2934 
2935   /* If the user has configured a chunk-size for this file, truncate the
2936   ** file so that it consists of an integer number of chunks (i.e. the
2937   ** actual file size after the operation may be larger than the requested
2938   ** size).
2939   */
2940   if( pFile->szChunk>0 ){
2941     nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
2942   }
2943 
2944 #if SQLITE_MAX_MMAP_SIZE>0
2945   if( pFile->pMapRegion ){
2946     oldMmapSize = pFile->mmapSize;
2947   }else{
2948     oldMmapSize = 0;
2949   }
2950   winUnmapfile(pFile);
2951 #endif
2952 
2953   /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
2954   if( winSeekFile(pFile, nByte) ){
2955     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
2956                      "winTruncate1", pFile->zPath);
2957   }else if( 0==osSetEndOfFile(pFile->h) &&
2958             ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){
2959     pFile->lastErrno = lastErrno;
2960     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
2961                      "winTruncate2", pFile->zPath);
2962   }
2963 
2964 #if SQLITE_MAX_MMAP_SIZE>0
2965   if( rc==SQLITE_OK && oldMmapSize>0 ){
2966     if( oldMmapSize>nByte ){
2967       winMapfile(pFile, -1);
2968     }else{
2969       winMapfile(pFile, oldMmapSize);
2970     }
2971   }
2972 #endif
2973 
2974   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, rc=%s\n",
2975            osGetCurrentProcessId(), pFile, pFile->h, sqlite3ErrName(rc)));
2976   return rc;
2977 }
2978 
2979 #ifdef SQLITE_TEST
2980 /*
2981 ** Count the number of fullsyncs and normal syncs.  This is used to test
2982 ** that syncs and fullsyncs are occuring at the right times.
2983 */
2984 int sqlite3_sync_count = 0;
2985 int sqlite3_fullsync_count = 0;
2986 #endif
2987 
2988 /*
2989 ** Make sure all writes to a particular file are committed to disk.
2990 */
2991 static int winSync(sqlite3_file *id, int flags){
2992 #ifndef SQLITE_NO_SYNC
2993   /*
2994   ** Used only when SQLITE_NO_SYNC is not defined.
2995    */
2996   BOOL rc;
2997 #endif
2998 #if !defined(NDEBUG) || !defined(SQLITE_NO_SYNC) || \
2999     defined(SQLITE_HAVE_OS_TRACE)
3000   /*
3001   ** Used when SQLITE_NO_SYNC is not defined and by the assert() and/or
3002   ** OSTRACE() macros.
3003    */
3004   winFile *pFile = (winFile*)id;
3005 #else
3006   UNUSED_PARAMETER(id);
3007 #endif
3008 
3009   assert( pFile );
3010   /* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */
3011   assert((flags&0x0F)==SQLITE_SYNC_NORMAL
3012       || (flags&0x0F)==SQLITE_SYNC_FULL
3013   );
3014 
3015   /* Unix cannot, but some systems may return SQLITE_FULL from here. This
3016   ** line is to test that doing so does not cause any problems.
3017   */
3018   SimulateDiskfullError( return SQLITE_FULL );
3019 
3020   OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, flags=%x, lock=%d\n",
3021            osGetCurrentProcessId(), pFile, pFile->h, flags,
3022            pFile->locktype));
3023 
3024 #ifndef SQLITE_TEST
3025   UNUSED_PARAMETER(flags);
3026 #else
3027   if( (flags&0x0F)==SQLITE_SYNC_FULL ){
3028     sqlite3_fullsync_count++;
3029   }
3030   sqlite3_sync_count++;
3031 #endif
3032 
3033   /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
3034   ** no-op
3035   */
3036 #ifdef SQLITE_NO_SYNC
3037   OSTRACE(("SYNC-NOP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
3038            osGetCurrentProcessId(), pFile, pFile->h));
3039   return SQLITE_OK;
3040 #else
3041 #if SQLITE_MAX_MMAP_SIZE>0
3042   if( pFile->pMapRegion ){
3043     if( osFlushViewOfFile(pFile->pMapRegion, 0) ){
3044       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
3045                "rc=SQLITE_OK\n", osGetCurrentProcessId(),
3046                pFile, pFile->pMapRegion));
3047     }else{
3048       pFile->lastErrno = osGetLastError();
3049       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
3050                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(),
3051                pFile, pFile->pMapRegion));
3052       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
3053                          "winSync1", pFile->zPath);
3054     }
3055   }
3056 #endif
3057   rc = osFlushFileBuffers(pFile->h);
3058   SimulateIOError( rc=FALSE );
3059   if( rc ){
3060     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
3061              osGetCurrentProcessId(), pFile, pFile->h));
3062     return SQLITE_OK;
3063   }else{
3064     pFile->lastErrno = osGetLastError();
3065     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_FSYNC\n",
3066              osGetCurrentProcessId(), pFile, pFile->h));
3067     return winLogError(SQLITE_IOERR_FSYNC, pFile->lastErrno,
3068                        "winSync2", pFile->zPath);
3069   }
3070 #endif
3071 }
3072 
3073 /*
3074 ** Determine the current size of a file in bytes
3075 */
3076 static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
3077   winFile *pFile = (winFile*)id;
3078   int rc = SQLITE_OK;
3079 
3080   assert( id!=0 );
3081   assert( pSize!=0 );
3082   SimulateIOError(return SQLITE_IOERR_FSTAT);
3083   OSTRACE(("SIZE file=%p, pSize=%p\n", pFile->h, pSize));
3084 
3085 #if SQLITE_OS_WINRT
3086   {
3087     FILE_STANDARD_INFO info;
3088     if( osGetFileInformationByHandleEx(pFile->h, FileStandardInfo,
3089                                      &info, sizeof(info)) ){
3090       *pSize = info.EndOfFile.QuadPart;
3091     }else{
3092       pFile->lastErrno = osGetLastError();
3093       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
3094                        "winFileSize", pFile->zPath);
3095     }
3096   }
3097 #else
3098   {
3099     DWORD upperBits;
3100     DWORD lowerBits;
3101     DWORD lastErrno;
3102 
3103     lowerBits = osGetFileSize(pFile->h, &upperBits);
3104     *pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;
3105     if(   (lowerBits == INVALID_FILE_SIZE)
3106        && ((lastErrno = osGetLastError())!=NO_ERROR) ){
3107       pFile->lastErrno = lastErrno;
3108       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
3109                        "winFileSize", pFile->zPath);
3110     }
3111   }
3112 #endif
3113   OSTRACE(("SIZE file=%p, pSize=%p, *pSize=%lld, rc=%s\n",
3114            pFile->h, pSize, *pSize, sqlite3ErrName(rc)));
3115   return rc;
3116 }
3117 
3118 /*
3119 ** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.
3120 */
3121 #ifndef LOCKFILE_FAIL_IMMEDIATELY
3122 # define LOCKFILE_FAIL_IMMEDIATELY 1
3123 #endif
3124 
3125 #ifndef LOCKFILE_EXCLUSIVE_LOCK
3126 # define LOCKFILE_EXCLUSIVE_LOCK 2
3127 #endif
3128 
3129 /*
3130 ** Historically, SQLite has used both the LockFile and LockFileEx functions.
3131 ** When the LockFile function was used, it was always expected to fail
3132 ** immediately if the lock could not be obtained.  Also, it always expected to
3133 ** obtain an exclusive lock.  These flags are used with the LockFileEx function
3134 ** and reflect those expectations; therefore, they should not be changed.
3135 */
3136 #ifndef SQLITE_LOCKFILE_FLAGS
3137 # define SQLITE_LOCKFILE_FLAGS   (LOCKFILE_FAIL_IMMEDIATELY | \
3138                                   LOCKFILE_EXCLUSIVE_LOCK)
3139 #endif
3140 
3141 /*
3142 ** Currently, SQLite never calls the LockFileEx function without wanting the
3143 ** call to fail immediately if the lock cannot be obtained.
3144 */
3145 #ifndef SQLITE_LOCKFILEEX_FLAGS
3146 # define SQLITE_LOCKFILEEX_FLAGS (LOCKFILE_FAIL_IMMEDIATELY)
3147 #endif
3148 
3149 /*
3150 ** Acquire a reader lock.
3151 ** Different API routines are called depending on whether or not this
3152 ** is Win9x or WinNT.
3153 */
3154 static int winGetReadLock(winFile *pFile){
3155   int res;
3156   OSTRACE(("READ-LOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
3157   if( osIsNT() ){
3158 #if SQLITE_OS_WINCE
3159     /*
3160     ** NOTE: Windows CE is handled differently here due its lack of the Win32
3161     **       API LockFileEx.
3162     */
3163     res = winceLockFile(&pFile->h, SHARED_FIRST, 0, 1, 0);
3164 #else
3165     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS, SHARED_FIRST, 0,
3166                       SHARED_SIZE, 0);
3167 #endif
3168   }
3169 #ifdef SQLITE_WIN32_HAS_ANSI
3170   else{
3171     int lk;
3172     sqlite3_randomness(sizeof(lk), &lk);
3173     pFile->sharedLockByte = (short)((lk & 0x7fffffff)%(SHARED_SIZE - 1));
3174     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
3175                       SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
3176   }
3177 #endif
3178   if( res == 0 ){
3179     pFile->lastErrno = osGetLastError();
3180     /* No need to log a failure to lock */
3181   }
3182   OSTRACE(("READ-LOCK file=%p, result=%d\n", pFile->h, res));
3183   return res;
3184 }
3185 
3186 /*
3187 ** Undo a readlock
3188 */
3189 static int winUnlockReadLock(winFile *pFile){
3190   int res;
3191   DWORD lastErrno;
3192   OSTRACE(("READ-UNLOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
3193   if( osIsNT() ){
3194     res = winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
3195   }
3196 #ifdef SQLITE_WIN32_HAS_ANSI
3197   else{
3198     res = winUnlockFile(&pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
3199   }
3200 #endif
3201   if( res==0 && ((lastErrno = osGetLastError())!=ERROR_NOT_LOCKED) ){
3202     pFile->lastErrno = lastErrno;
3203     winLogError(SQLITE_IOERR_UNLOCK, pFile->lastErrno,
3204                 "winUnlockReadLock", pFile->zPath);
3205   }
3206   OSTRACE(("READ-UNLOCK file=%p, result=%d\n", pFile->h, res));
3207   return res;
3208 }
3209 
3210 /*
3211 ** Lock the file with the lock specified by parameter locktype - one
3212 ** of the following:
3213 **
3214 **     (1) SHARED_LOCK
3215 **     (2) RESERVED_LOCK
3216 **     (3) PENDING_LOCK
3217 **     (4) EXCLUSIVE_LOCK
3218 **
3219 ** Sometimes when requesting one lock state, additional lock states
3220 ** are inserted in between.  The locking might fail on one of the later
3221 ** transitions leaving the lock state different from what it started but
3222 ** still short of its goal.  The following chart shows the allowed
3223 ** transitions and the inserted intermediate states:
3224 **
3225 **    UNLOCKED -> SHARED
3226 **    SHARED -> RESERVED
3227 **    SHARED -> (PENDING) -> EXCLUSIVE
3228 **    RESERVED -> (PENDING) -> EXCLUSIVE
3229 **    PENDING -> EXCLUSIVE
3230 **
3231 ** This routine will only increase a lock.  The winUnlock() routine
3232 ** erases all locks at once and returns us immediately to locking level 0.
3233 ** It is not possible to lower the locking level one step at a time.  You
3234 ** must go straight to locking level 0.
3235 */
3236 static int winLock(sqlite3_file *id, int locktype){
3237   int rc = SQLITE_OK;    /* Return code from subroutines */
3238   int res = 1;           /* Result of a Windows lock call */
3239   int newLocktype;       /* Set pFile->locktype to this value before exiting */
3240   int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
3241   winFile *pFile = (winFile*)id;
3242   DWORD lastErrno = NO_ERROR;
3243 
3244   assert( id!=0 );
3245   OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",
3246            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
3247 
3248   /* If there is already a lock of this type or more restrictive on the
3249   ** OsFile, do nothing. Don't use the end_lock: exit path, as
3250   ** sqlite3OsEnterMutex() hasn't been called yet.
3251   */
3252   if( pFile->locktype>=locktype ){
3253     OSTRACE(("LOCK-HELD file=%p, rc=SQLITE_OK\n", pFile->h));
3254     return SQLITE_OK;
3255   }
3256 
3257   /* Do not allow any kind of write-lock on a read-only database
3258   */
3259   if( (pFile->ctrlFlags & WINFILE_RDONLY)!=0 && locktype>=RESERVED_LOCK ){
3260     return SQLITE_IOERR_LOCK;
3261   }
3262 
3263   /* Make sure the locking sequence is correct
3264   */
3265   assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
3266   assert( locktype!=PENDING_LOCK );
3267   assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
3268 
3269   /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
3270   ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
3271   ** the PENDING_LOCK byte is temporary.
3272   */
3273   newLocktype = pFile->locktype;
3274   if( pFile->locktype==NO_LOCK
3275    || (locktype==EXCLUSIVE_LOCK && pFile->locktype<=RESERVED_LOCK)
3276   ){
3277     int cnt = 3;
3278     while( cnt-->0 && (res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
3279                                          PENDING_BYTE, 0, 1, 0))==0 ){
3280       /* Try 3 times to get the pending lock.  This is needed to work
3281       ** around problems caused by indexing and/or anti-virus software on
3282       ** Windows systems.
3283       ** If you are using this code as a model for alternative VFSes, do not
3284       ** copy this retry logic.  It is a hack intended for Windows only.
3285       */
3286       lastErrno = osGetLastError();
3287       OSTRACE(("LOCK-PENDING-FAIL file=%p, count=%d, result=%d\n",
3288                pFile->h, cnt, res));
3289       if( lastErrno==ERROR_INVALID_HANDLE ){
3290         pFile->lastErrno = lastErrno;
3291         rc = SQLITE_IOERR_LOCK;
3292         OSTRACE(("LOCK-FAIL file=%p, count=%d, rc=%s\n",
3293                  pFile->h, cnt, sqlite3ErrName(rc)));
3294         return rc;
3295       }
3296       if( cnt ) sqlite3_win32_sleep(1);
3297     }
3298     gotPendingLock = res;
3299     if( !res ){
3300       lastErrno = osGetLastError();
3301     }
3302   }
3303 
3304   /* Acquire a shared lock
3305   */
3306   if( locktype==SHARED_LOCK && res ){
3307     assert( pFile->locktype==NO_LOCK );
3308     res = winGetReadLock(pFile);
3309     if( res ){
3310       newLocktype = SHARED_LOCK;
3311     }else{
3312       lastErrno = osGetLastError();
3313     }
3314   }
3315 
3316   /* Acquire a RESERVED lock
3317   */
3318   if( locktype==RESERVED_LOCK && res ){
3319     assert( pFile->locktype==SHARED_LOCK );
3320     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, RESERVED_BYTE, 0, 1, 0);
3321     if( res ){
3322       newLocktype = RESERVED_LOCK;
3323     }else{
3324       lastErrno = osGetLastError();
3325     }
3326   }
3327 
3328   /* Acquire a PENDING lock
3329   */
3330   if( locktype==EXCLUSIVE_LOCK && res ){
3331     newLocktype = PENDING_LOCK;
3332     gotPendingLock = 0;
3333   }
3334 
3335   /* Acquire an EXCLUSIVE lock
3336   */
3337   if( locktype==EXCLUSIVE_LOCK && res ){
3338     assert( pFile->locktype>=SHARED_LOCK );
3339     res = winUnlockReadLock(pFile);
3340     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, SHARED_FIRST, 0,
3341                       SHARED_SIZE, 0);
3342     if( res ){
3343       newLocktype = EXCLUSIVE_LOCK;
3344     }else{
3345       lastErrno = osGetLastError();
3346       winGetReadLock(pFile);
3347     }
3348   }
3349 
3350   /* If we are holding a PENDING lock that ought to be released, then
3351   ** release it now.
3352   */
3353   if( gotPendingLock && locktype==SHARED_LOCK ){
3354     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
3355   }
3356 
3357   /* Update the state of the lock has held in the file descriptor then
3358   ** return the appropriate result code.
3359   */
3360   if( res ){
3361     rc = SQLITE_OK;
3362   }else{
3363     pFile->lastErrno = lastErrno;
3364     rc = SQLITE_BUSY;
3365     OSTRACE(("LOCK-FAIL file=%p, wanted=%d, got=%d\n",
3366              pFile->h, locktype, newLocktype));
3367   }
3368   pFile->locktype = (u8)newLocktype;
3369   OSTRACE(("LOCK file=%p, lock=%d, rc=%s\n",
3370            pFile->h, pFile->locktype, sqlite3ErrName(rc)));
3371   return rc;
3372 }
3373 
3374 /*
3375 ** This routine checks if there is a RESERVED lock held on the specified
3376 ** file by this or any other process. If such a lock is held, return
3377 ** non-zero, otherwise zero.
3378 */
3379 static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
3380   int res;
3381   winFile *pFile = (winFile*)id;
3382 
3383   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
3384   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));
3385 
3386   assert( id!=0 );
3387   if( pFile->locktype>=RESERVED_LOCK ){
3388     res = 1;
3389     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (local)\n", pFile->h, res));
3390   }else{
3391     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE,0,1,0);
3392     if( res ){
3393       winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
3394     }
3395     res = !res;
3396     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (remote)\n", pFile->h, res));
3397   }
3398   *pResOut = res;
3399   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
3400            pFile->h, pResOut, *pResOut));
3401   return SQLITE_OK;
3402 }
3403 
3404 /*
3405 ** Lower the locking level on file descriptor id to locktype.  locktype
3406 ** must be either NO_LOCK or SHARED_LOCK.
3407 **
3408 ** If the locking level of the file descriptor is already at or below
3409 ** the requested locking level, this routine is a no-op.
3410 **
3411 ** It is not possible for this routine to fail if the second argument
3412 ** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
3413 ** might return SQLITE_IOERR;
3414 */
3415 static int winUnlock(sqlite3_file *id, int locktype){
3416   int type;
3417   winFile *pFile = (winFile*)id;
3418   int rc = SQLITE_OK;
3419   assert( pFile!=0 );
3420   assert( locktype<=SHARED_LOCK );
3421   OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
3422            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
3423   type = pFile->locktype;
3424   if( type>=EXCLUSIVE_LOCK ){
3425     winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
3426     if( locktype==SHARED_LOCK && !winGetReadLock(pFile) ){
3427       /* This should never happen.  We should always be able to
3428       ** reacquire the read lock */
3429       rc = winLogError(SQLITE_IOERR_UNLOCK, osGetLastError(),
3430                        "winUnlock", pFile->zPath);
3431     }
3432   }
3433   if( type>=RESERVED_LOCK ){
3434     winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
3435   }
3436   if( locktype==NO_LOCK && type>=SHARED_LOCK ){
3437     winUnlockReadLock(pFile);
3438   }
3439   if( type>=PENDING_LOCK ){
3440     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
3441   }
3442   pFile->locktype = (u8)locktype;
3443   OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",
3444            pFile->h, pFile->locktype, sqlite3ErrName(rc)));
3445   return rc;
3446 }
3447 
3448 /******************************************************************************
3449 ****************************** No-op Locking **********************************
3450 **
3451 ** Of the various locking implementations available, this is by far the
3452 ** simplest:  locking is ignored.  No attempt is made to lock the database
3453 ** file for reading or writing.
3454 **
3455 ** This locking mode is appropriate for use on read-only databases
3456 ** (ex: databases that are burned into CD-ROM, for example.)  It can
3457 ** also be used if the application employs some external mechanism to
3458 ** prevent simultaneous access of the same database by two or more
3459 ** database connections.  But there is a serious risk of database
3460 ** corruption if this locking mode is used in situations where multiple
3461 ** database connections are accessing the same database file at the same
3462 ** time and one or more of those connections are writing.
3463 */
3464 
3465 static int winNolockLock(sqlite3_file *id, int locktype){
3466   UNUSED_PARAMETER(id);
3467   UNUSED_PARAMETER(locktype);
3468   return SQLITE_OK;
3469 }
3470 
3471 static int winNolockCheckReservedLock(sqlite3_file *id, int *pResOut){
3472   UNUSED_PARAMETER(id);
3473   UNUSED_PARAMETER(pResOut);
3474   return SQLITE_OK;
3475 }
3476 
3477 static int winNolockUnlock(sqlite3_file *id, int locktype){
3478   UNUSED_PARAMETER(id);
3479   UNUSED_PARAMETER(locktype);
3480   return SQLITE_OK;
3481 }
3482 
3483 /******************* End of the no-op lock implementation *********************
3484 ******************************************************************************/
3485 
3486 /*
3487 ** If *pArg is initially negative then this is a query.  Set *pArg to
3488 ** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
3489 **
3490 ** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.
3491 */
3492 static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){
3493   if( *pArg<0 ){
3494     *pArg = (pFile->ctrlFlags & mask)!=0;
3495   }else if( (*pArg)==0 ){
3496     pFile->ctrlFlags &= ~mask;
3497   }else{
3498     pFile->ctrlFlags |= mask;
3499   }
3500 }
3501 
3502 /* Forward references to VFS helper methods used for temporary files */
3503 static int winGetTempname(sqlite3_vfs *, char **);
3504 static int winIsDir(const void *);
3505 static BOOL winIsLongPathPrefix(const char *);
3506 static BOOL winIsDriveLetterAndColon(const char *);
3507 
3508 /*
3509 ** Control and query of the open file handle.
3510 */
3511 static int winFileControl(sqlite3_file *id, int op, void *pArg){
3512   winFile *pFile = (winFile*)id;
3513   OSTRACE(("FCNTL file=%p, op=%d, pArg=%p\n", pFile->h, op, pArg));
3514   switch( op ){
3515     case SQLITE_FCNTL_LOCKSTATE: {
3516       *(int*)pArg = pFile->locktype;
3517       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3518       return SQLITE_OK;
3519     }
3520     case SQLITE_FCNTL_LAST_ERRNO: {
3521       *(int*)pArg = (int)pFile->lastErrno;
3522       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3523       return SQLITE_OK;
3524     }
3525     case SQLITE_FCNTL_CHUNK_SIZE: {
3526       pFile->szChunk = *(int *)pArg;
3527       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3528       return SQLITE_OK;
3529     }
3530     case SQLITE_FCNTL_SIZE_HINT: {
3531       if( pFile->szChunk>0 ){
3532         sqlite3_int64 oldSz;
3533         int rc = winFileSize(id, &oldSz);
3534         if( rc==SQLITE_OK ){
3535           sqlite3_int64 newSz = *(sqlite3_int64*)pArg;
3536           if( newSz>oldSz ){
3537             SimulateIOErrorBenign(1);
3538             rc = winTruncate(id, newSz);
3539             SimulateIOErrorBenign(0);
3540           }
3541         }
3542         OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3543         return rc;
3544       }
3545       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3546       return SQLITE_OK;
3547     }
3548     case SQLITE_FCNTL_PERSIST_WAL: {
3549       winModeBit(pFile, WINFILE_PERSIST_WAL, (int*)pArg);
3550       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3551       return SQLITE_OK;
3552     }
3553     case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
3554       winModeBit(pFile, WINFILE_PSOW, (int*)pArg);
3555       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3556       return SQLITE_OK;
3557     }
3558     case SQLITE_FCNTL_VFSNAME: {
3559       *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
3560       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3561       return SQLITE_OK;
3562     }
3563     case SQLITE_FCNTL_WIN32_AV_RETRY: {
3564       int *a = (int*)pArg;
3565       if( a[0]>0 ){
3566         winIoerrRetry = a[0];
3567       }else{
3568         a[0] = winIoerrRetry;
3569       }
3570       if( a[1]>0 ){
3571         winIoerrRetryDelay = a[1];
3572       }else{
3573         a[1] = winIoerrRetryDelay;
3574       }
3575       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3576       return SQLITE_OK;
3577     }
3578     case SQLITE_FCNTL_WIN32_GET_HANDLE: {
3579       LPHANDLE phFile = (LPHANDLE)pArg;
3580       *phFile = pFile->h;
3581       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3582       return SQLITE_OK;
3583     }
3584 #ifdef SQLITE_TEST
3585     case SQLITE_FCNTL_WIN32_SET_HANDLE: {
3586       LPHANDLE phFile = (LPHANDLE)pArg;
3587       HANDLE hOldFile = pFile->h;
3588       pFile->h = *phFile;
3589       *phFile = hOldFile;
3590       OSTRACE(("FCNTL oldFile=%p, newFile=%p, rc=SQLITE_OK\n",
3591                hOldFile, pFile->h));
3592       return SQLITE_OK;
3593     }
3594 #endif
3595     case SQLITE_FCNTL_TEMPFILENAME: {
3596       char *zTFile = 0;
3597       int rc = winGetTempname(pFile->pVfs, &zTFile);
3598       if( rc==SQLITE_OK ){
3599         *(char**)pArg = zTFile;
3600       }
3601       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3602       return rc;
3603     }
3604 #if SQLITE_MAX_MMAP_SIZE>0
3605     case SQLITE_FCNTL_MMAP_SIZE: {
3606       i64 newLimit = *(i64*)pArg;
3607       int rc = SQLITE_OK;
3608       if( newLimit>sqlite3GlobalConfig.mxMmap ){
3609         newLimit = sqlite3GlobalConfig.mxMmap;
3610       }
3611 
3612       /* The value of newLimit may be eventually cast to (SIZE_T) and passed
3613       ** to MapViewOfFile(). Restrict its value to 2GB if (SIZE_T) is not at
3614       ** least a 64-bit type. */
3615       if( newLimit>0 && sizeof(SIZE_T)<8 ){
3616         newLimit = (newLimit & 0x7FFFFFFF);
3617       }
3618 
3619       *(i64*)pArg = pFile->mmapSizeMax;
3620       if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
3621         pFile->mmapSizeMax = newLimit;
3622         if( pFile->mmapSize>0 ){
3623           winUnmapfile(pFile);
3624           rc = winMapfile(pFile, -1);
3625         }
3626       }
3627       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3628       return rc;
3629     }
3630 #endif
3631   }
3632   OSTRACE(("FCNTL file=%p, rc=SQLITE_NOTFOUND\n", pFile->h));
3633   return SQLITE_NOTFOUND;
3634 }
3635 
3636 /*
3637 ** Return the sector size in bytes of the underlying block device for
3638 ** the specified file. This is almost always 512 bytes, but may be
3639 ** larger for some devices.
3640 **
3641 ** SQLite code assumes this function cannot fail. It also assumes that
3642 ** if two files are created in the same file-system directory (i.e.
3643 ** a database and its journal file) that the sector size will be the
3644 ** same for both.
3645 */
3646 static int winSectorSize(sqlite3_file *id){
3647   (void)id;
3648   return SQLITE_DEFAULT_SECTOR_SIZE;
3649 }
3650 
3651 /*
3652 ** Return a vector of device characteristics.
3653 */
3654 static int winDeviceCharacteristics(sqlite3_file *id){
3655   winFile *p = (winFile*)id;
3656   return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |
3657          ((p->ctrlFlags & WINFILE_PSOW)?SQLITE_IOCAP_POWERSAFE_OVERWRITE:0);
3658 }
3659 
3660 /*
3661 ** Windows will only let you create file view mappings
3662 ** on allocation size granularity boundaries.
3663 ** During sqlite3_os_init() we do a GetSystemInfo()
3664 ** to get the granularity size.
3665 */
3666 static SYSTEM_INFO winSysInfo;
3667 
3668 #ifndef SQLITE_OMIT_WAL
3669 
3670 /*
3671 ** Helper functions to obtain and relinquish the global mutex. The
3672 ** global mutex is used to protect the winLockInfo objects used by
3673 ** this file, all of which may be shared by multiple threads.
3674 **
3675 ** Function winShmMutexHeld() is used to assert() that the global mutex
3676 ** is held when required. This function is only used as part of assert()
3677 ** statements. e.g.
3678 **
3679 **   winShmEnterMutex()
3680 **     assert( winShmMutexHeld() );
3681 **   winShmLeaveMutex()
3682 */
3683 static sqlite3_mutex *winBigLock = 0;
3684 static void winShmEnterMutex(void){
3685   sqlite3_mutex_enter(winBigLock);
3686 }
3687 static void winShmLeaveMutex(void){
3688   sqlite3_mutex_leave(winBigLock);
3689 }
3690 #ifndef NDEBUG
3691 static int winShmMutexHeld(void) {
3692   return sqlite3_mutex_held(winBigLock);
3693 }
3694 #endif
3695 
3696 /*
3697 ** Object used to represent a single file opened and mmapped to provide
3698 ** shared memory.  When multiple threads all reference the same
3699 ** log-summary, each thread has its own winFile object, but they all
3700 ** point to a single instance of this object.  In other words, each
3701 ** log-summary is opened only once per process.
3702 **
3703 ** winShmMutexHeld() must be true when creating or destroying
3704 ** this object or while reading or writing the following fields:
3705 **
3706 **      nRef
3707 **      pNext
3708 **
3709 ** The following fields are read-only after the object is created:
3710 **
3711 **      fid
3712 **      zFilename
3713 **
3714 ** Either winShmNode.mutex must be held or winShmNode.nRef==0 and
3715 ** winShmMutexHeld() is true when reading or writing any other field
3716 ** in this structure.
3717 **
3718 */
3719 struct winShmNode {
3720   sqlite3_mutex *mutex;      /* Mutex to access this object */
3721   char *zFilename;           /* Name of the file */
3722   winFile hFile;             /* File handle from winOpen */
3723 
3724   int szRegion;              /* Size of shared-memory regions */
3725   int nRegion;               /* Size of array apRegion */
3726   u8 isReadonly;             /* True if read-only */
3727   u8 isUnlocked;             /* True if no DMS lock held */
3728 
3729   struct ShmRegion {
3730     HANDLE hMap;             /* File handle from CreateFileMapping */
3731     void *pMap;
3732   } *aRegion;
3733   DWORD lastErrno;           /* The Windows errno from the last I/O error */
3734 
3735   int nRef;                  /* Number of winShm objects pointing to this */
3736   winShm *pFirst;            /* All winShm objects pointing to this */
3737   winShmNode *pNext;         /* Next in list of all winShmNode objects */
3738 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3739   u8 nextShmId;              /* Next available winShm.id value */
3740 #endif
3741 };
3742 
3743 /*
3744 ** A global array of all winShmNode objects.
3745 **
3746 ** The winShmMutexHeld() must be true while reading or writing this list.
3747 */
3748 static winShmNode *winShmNodeList = 0;
3749 
3750 /*
3751 ** Structure used internally by this VFS to record the state of an
3752 ** open shared memory connection.
3753 **
3754 ** The following fields are initialized when this object is created and
3755 ** are read-only thereafter:
3756 **
3757 **    winShm.pShmNode
3758 **    winShm.id
3759 **
3760 ** All other fields are read/write.  The winShm.pShmNode->mutex must be held
3761 ** while accessing any read/write fields.
3762 */
3763 struct winShm {
3764   winShmNode *pShmNode;      /* The underlying winShmNode object */
3765   winShm *pNext;             /* Next winShm with the same winShmNode */
3766   u8 hasMutex;               /* True if holding the winShmNode mutex */
3767   u16 sharedMask;            /* Mask of shared locks held */
3768   u16 exclMask;              /* Mask of exclusive locks held */
3769 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3770   u8 id;                     /* Id of this connection with its winShmNode */
3771 #endif
3772 };
3773 
3774 /*
3775 ** Constants used for locking
3776 */
3777 #define WIN_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)        /* first lock byte */
3778 #define WIN_SHM_DMS    (WIN_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */
3779 
3780 /*
3781 ** Apply advisory locks for all n bytes beginning at ofst.
3782 */
3783 #define WINSHM_UNLCK  1
3784 #define WINSHM_RDLCK  2
3785 #define WINSHM_WRLCK  3
3786 static int winShmSystemLock(
3787   winShmNode *pFile,    /* Apply locks to this open shared-memory segment */
3788   int lockType,         /* WINSHM_UNLCK, WINSHM_RDLCK, or WINSHM_WRLCK */
3789   int ofst,             /* Offset to first byte to be locked/unlocked */
3790   int nByte             /* Number of bytes to lock or unlock */
3791 ){
3792   int rc = 0;           /* Result code form Lock/UnlockFileEx() */
3793 
3794   /* Access to the winShmNode object is serialized by the caller */
3795   assert( pFile->nRef==0 || sqlite3_mutex_held(pFile->mutex) );
3796 
3797   OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",
3798            pFile->hFile.h, lockType, ofst, nByte));
3799 
3800   /* Release/Acquire the system-level lock */
3801   if( lockType==WINSHM_UNLCK ){
3802     rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);
3803   }else{
3804     /* Initialize the locking parameters */
3805     DWORD dwFlags = LOCKFILE_FAIL_IMMEDIATELY;
3806     if( lockType == WINSHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
3807     rc = winLockFile(&pFile->hFile.h, dwFlags, ofst, 0, nByte, 0);
3808   }
3809 
3810   if( rc!= 0 ){
3811     rc = SQLITE_OK;
3812   }else{
3813     pFile->lastErrno =  osGetLastError();
3814     rc = SQLITE_BUSY;
3815   }
3816 
3817   OSTRACE(("SHM-LOCK file=%p, func=%s, errno=%lu, rc=%s\n",
3818            pFile->hFile.h, (lockType == WINSHM_UNLCK) ? "winUnlockFile" :
3819            "winLockFile", pFile->lastErrno, sqlite3ErrName(rc)));
3820 
3821   return rc;
3822 }
3823 
3824 /* Forward references to VFS methods */
3825 static int winOpen(sqlite3_vfs*,const char*,sqlite3_file*,int,int*);
3826 static int winDelete(sqlite3_vfs *,const char*,int);
3827 
3828 /*
3829 ** Purge the winShmNodeList list of all entries with winShmNode.nRef==0.
3830 **
3831 ** This is not a VFS shared-memory method; it is a utility function called
3832 ** by VFS shared-memory methods.
3833 */
3834 static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){
3835   winShmNode **pp;
3836   winShmNode *p;
3837   assert( winShmMutexHeld() );
3838   OSTRACE(("SHM-PURGE pid=%lu, deleteFlag=%d\n",
3839            osGetCurrentProcessId(), deleteFlag));
3840   pp = &winShmNodeList;
3841   while( (p = *pp)!=0 ){
3842     if( p->nRef==0 ){
3843       int i;
3844       if( p->mutex ){ sqlite3_mutex_free(p->mutex); }
3845       for(i=0; i<p->nRegion; i++){
3846         BOOL bRc = osUnmapViewOfFile(p->aRegion[i].pMap);
3847         OSTRACE(("SHM-PURGE-UNMAP pid=%lu, region=%d, rc=%s\n",
3848                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
3849         UNUSED_VARIABLE_VALUE(bRc);
3850         bRc = osCloseHandle(p->aRegion[i].hMap);
3851         OSTRACE(("SHM-PURGE-CLOSE pid=%lu, region=%d, rc=%s\n",
3852                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
3853         UNUSED_VARIABLE_VALUE(bRc);
3854       }
3855       if( p->hFile.h!=NULL && p->hFile.h!=INVALID_HANDLE_VALUE ){
3856         SimulateIOErrorBenign(1);
3857         winClose((sqlite3_file *)&p->hFile);
3858         SimulateIOErrorBenign(0);
3859       }
3860       if( deleteFlag ){
3861         SimulateIOErrorBenign(1);
3862         sqlite3BeginBenignMalloc();
3863         winDelete(pVfs, p->zFilename, 0);
3864         sqlite3EndBenignMalloc();
3865         SimulateIOErrorBenign(0);
3866       }
3867       *pp = p->pNext;
3868       sqlite3_free(p->aRegion);
3869       sqlite3_free(p);
3870     }else{
3871       pp = &p->pNext;
3872     }
3873   }
3874 }
3875 
3876 /*
3877 ** The DMS lock has not yet been taken on shm file pShmNode. Attempt to
3878 ** take it now. Return SQLITE_OK if successful, or an SQLite error
3879 ** code otherwise.
3880 **
3881 ** If the DMS cannot be locked because this is a readonly_shm=1
3882 ** connection and no other process already holds a lock, return
3883 ** SQLITE_READONLY_CANTINIT and set pShmNode->isUnlocked=1.
3884 */
3885 static int winLockSharedMemory(winShmNode *pShmNode){
3886   int rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, WIN_SHM_DMS, 1);
3887 
3888   if( rc==SQLITE_OK ){
3889     if( pShmNode->isReadonly ){
3890       pShmNode->isUnlocked = 1;
3891       winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3892       return SQLITE_READONLY_CANTINIT;
3893     }else if( winTruncate((sqlite3_file*)&pShmNode->hFile, 0) ){
3894       winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3895       return winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),
3896                          "winLockSharedMemory", pShmNode->zFilename);
3897     }
3898   }
3899 
3900   if( rc==SQLITE_OK ){
3901     winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3902   }
3903 
3904   return winShmSystemLock(pShmNode, WINSHM_RDLCK, WIN_SHM_DMS, 1);
3905 }
3906 
3907 /*
3908 ** Open the shared-memory area associated with database file pDbFd.
3909 **
3910 ** When opening a new shared-memory file, if no other instances of that
3911 ** file are currently open, in this process or in other processes, then
3912 ** the file must be truncated to zero length or have its header cleared.
3913 */
3914 static int winOpenSharedMemory(winFile *pDbFd){
3915   struct winShm *p;                  /* The connection to be opened */
3916   winShmNode *pShmNode = 0;          /* The underlying mmapped file */
3917   int rc = SQLITE_OK;                /* Result code */
3918   winShmNode *pNew;                  /* Newly allocated winShmNode */
3919   int nName;                         /* Size of zName in bytes */
3920 
3921   assert( pDbFd->pShm==0 );    /* Not previously opened */
3922 
3923   /* Allocate space for the new sqlite3_shm object.  Also speculatively
3924   ** allocate space for a new winShmNode and filename.
3925   */
3926   p = sqlite3MallocZero( sizeof(*p) );
3927   if( p==0 ) return SQLITE_IOERR_NOMEM_BKPT;
3928   nName = sqlite3Strlen30(pDbFd->zPath);
3929   pNew = sqlite3MallocZero( sizeof(*pShmNode) + nName + 17 );
3930   if( pNew==0 ){
3931     sqlite3_free(p);
3932     return SQLITE_IOERR_NOMEM_BKPT;
3933   }
3934   pNew->zFilename = (char*)&pNew[1];
3935   sqlite3_snprintf(nName+15, pNew->zFilename, "%s-shm", pDbFd->zPath);
3936   sqlite3FileSuffix3(pDbFd->zPath, pNew->zFilename);
3937 
3938   /* Look to see if there is an existing winShmNode that can be used.
3939   ** If no matching winShmNode currently exists, create a new one.
3940   */
3941   winShmEnterMutex();
3942   for(pShmNode = winShmNodeList; pShmNode; pShmNode=pShmNode->pNext){
3943     /* TBD need to come up with better match here.  Perhaps
3944     ** use FILE_ID_BOTH_DIR_INFO Structure.
3945     */
3946     if( sqlite3StrICmp(pShmNode->zFilename, pNew->zFilename)==0 ) break;
3947   }
3948   if( pShmNode ){
3949     sqlite3_free(pNew);
3950   }else{
3951     int inFlags = SQLITE_OPEN_WAL;
3952     int outFlags = 0;
3953 
3954     pShmNode = pNew;
3955     pNew = 0;
3956     ((winFile*)(&pShmNode->hFile))->h = INVALID_HANDLE_VALUE;
3957     pShmNode->pNext = winShmNodeList;
3958     winShmNodeList = pShmNode;
3959 
3960     if( sqlite3GlobalConfig.bCoreMutex ){
3961       pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
3962       if( pShmNode->mutex==0 ){
3963         rc = SQLITE_IOERR_NOMEM_BKPT;
3964         goto shm_open_err;
3965       }
3966     }
3967 
3968     if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
3969       inFlags |= SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
3970     }else{
3971       inFlags |= SQLITE_OPEN_READONLY;
3972     }
3973     rc = winOpen(pDbFd->pVfs, pShmNode->zFilename,
3974                  (sqlite3_file*)&pShmNode->hFile,
3975                  inFlags, &outFlags);
3976     if( rc!=SQLITE_OK ){
3977       rc = winLogError(rc, osGetLastError(), "winOpenShm",
3978                        pShmNode->zFilename);
3979       goto shm_open_err;
3980     }
3981     if( outFlags==SQLITE_OPEN_READONLY ) pShmNode->isReadonly = 1;
3982 
3983     rc = winLockSharedMemory(pShmNode);
3984     if( rc!=SQLITE_OK && rc!=SQLITE_READONLY_CANTINIT ) goto shm_open_err;
3985   }
3986 
3987   /* Make the new connection a child of the winShmNode */
3988   p->pShmNode = pShmNode;
3989 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3990   p->id = pShmNode->nextShmId++;
3991 #endif
3992   pShmNode->nRef++;
3993   pDbFd->pShm = p;
3994   winShmLeaveMutex();
3995 
3996   /* The reference count on pShmNode has already been incremented under
3997   ** the cover of the winShmEnterMutex() mutex and the pointer from the
3998   ** new (struct winShm) object to the pShmNode has been set. All that is
3999   ** left to do is to link the new object into the linked list starting
4000   ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex
4001   ** mutex.
4002   */
4003   sqlite3_mutex_enter(pShmNode->mutex);
4004   p->pNext = pShmNode->pFirst;
4005   pShmNode->pFirst = p;
4006   sqlite3_mutex_leave(pShmNode->mutex);
4007   return rc;
4008 
4009   /* Jump here on any error */
4010 shm_open_err:
4011   winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
4012   winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */
4013   sqlite3_free(p);
4014   sqlite3_free(pNew);
4015   winShmLeaveMutex();
4016   return rc;
4017 }
4018 
4019 /*
4020 ** Close a connection to shared-memory.  Delete the underlying
4021 ** storage if deleteFlag is true.
4022 */
4023 static int winShmUnmap(
4024   sqlite3_file *fd,          /* Database holding shared memory */
4025   int deleteFlag             /* Delete after closing if true */
4026 ){
4027   winFile *pDbFd;       /* Database holding shared-memory */
4028   winShm *p;            /* The connection to be closed */
4029   winShmNode *pShmNode; /* The underlying shared-memory file */
4030   winShm **pp;          /* For looping over sibling connections */
4031 
4032   pDbFd = (winFile*)fd;
4033   p = pDbFd->pShm;
4034   if( p==0 ) return SQLITE_OK;
4035   pShmNode = p->pShmNode;
4036 
4037   /* Remove connection p from the set of connections associated
4038   ** with pShmNode */
4039   sqlite3_mutex_enter(pShmNode->mutex);
4040   for(pp=&pShmNode->pFirst; (*pp)!=p; pp = &(*pp)->pNext){}
4041   *pp = p->pNext;
4042 
4043   /* Free the connection p */
4044   sqlite3_free(p);
4045   pDbFd->pShm = 0;
4046   sqlite3_mutex_leave(pShmNode->mutex);
4047 
4048   /* If pShmNode->nRef has reached 0, then close the underlying
4049   ** shared-memory file, too */
4050   winShmEnterMutex();
4051   assert( pShmNode->nRef>0 );
4052   pShmNode->nRef--;
4053   if( pShmNode->nRef==0 ){
4054     winShmPurge(pDbFd->pVfs, deleteFlag);
4055   }
4056   winShmLeaveMutex();
4057 
4058   return SQLITE_OK;
4059 }
4060 
4061 /*
4062 ** Change the lock state for a shared-memory segment.
4063 */
4064 static int winShmLock(
4065   sqlite3_file *fd,          /* Database file holding the shared memory */
4066   int ofst,                  /* First lock to acquire or release */
4067   int n,                     /* Number of locks to acquire or release */
4068   int flags                  /* What to do with the lock */
4069 ){
4070   winFile *pDbFd = (winFile*)fd;        /* Connection holding shared memory */
4071   winShm *p = pDbFd->pShm;              /* The shared memory being locked */
4072   winShm *pX;                           /* For looping over all siblings */
4073   winShmNode *pShmNode = p->pShmNode;
4074   int rc = SQLITE_OK;                   /* Result code */
4075   u16 mask;                             /* Mask of locks to take or release */
4076 
4077   assert( ofst>=0 && ofst+n<=SQLITE_SHM_NLOCK );
4078   assert( n>=1 );
4079   assert( flags==(SQLITE_SHM_LOCK | SQLITE_SHM_SHARED)
4080        || flags==(SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE)
4081        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED)
4082        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE) );
4083   assert( n==1 || (flags & SQLITE_SHM_EXCLUSIVE)!=0 );
4084 
4085   mask = (u16)((1U<<(ofst+n)) - (1U<<ofst));
4086   assert( n>1 || mask==(1<<ofst) );
4087   sqlite3_mutex_enter(pShmNode->mutex);
4088   if( flags & SQLITE_SHM_UNLOCK ){
4089     u16 allMask = 0; /* Mask of locks held by siblings */
4090 
4091     /* See if any siblings hold this same lock */
4092     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4093       if( pX==p ) continue;
4094       assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );
4095       allMask |= pX->sharedMask;
4096     }
4097 
4098     /* Unlock the system-level locks */
4099     if( (mask & allMask)==0 ){
4100       rc = winShmSystemLock(pShmNode, WINSHM_UNLCK, ofst+WIN_SHM_BASE, n);
4101     }else{
4102       rc = SQLITE_OK;
4103     }
4104 
4105     /* Undo the local locks */
4106     if( rc==SQLITE_OK ){
4107       p->exclMask &= ~mask;
4108       p->sharedMask &= ~mask;
4109     }
4110   }else if( flags & SQLITE_SHM_SHARED ){
4111     u16 allShared = 0;  /* Union of locks held by connections other than "p" */
4112 
4113     /* Find out which shared locks are already held by sibling connections.
4114     ** If any sibling already holds an exclusive lock, go ahead and return
4115     ** SQLITE_BUSY.
4116     */
4117     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4118       if( (pX->exclMask & mask)!=0 ){
4119         rc = SQLITE_BUSY;
4120         break;
4121       }
4122       allShared |= pX->sharedMask;
4123     }
4124 
4125     /* Get shared locks at the system level, if necessary */
4126     if( rc==SQLITE_OK ){
4127       if( (allShared & mask)==0 ){
4128         rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, ofst+WIN_SHM_BASE, n);
4129       }else{
4130         rc = SQLITE_OK;
4131       }
4132     }
4133 
4134     /* Get the local shared locks */
4135     if( rc==SQLITE_OK ){
4136       p->sharedMask |= mask;
4137     }
4138   }else{
4139     /* Make sure no sibling connections hold locks that will block this
4140     ** lock.  If any do, return SQLITE_BUSY right away.
4141     */
4142     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4143       if( (pX->exclMask & mask)!=0 || (pX->sharedMask & mask)!=0 ){
4144         rc = SQLITE_BUSY;
4145         break;
4146       }
4147     }
4148 
4149     /* Get the exclusive locks at the system level.  Then if successful
4150     ** also mark the local connection as being locked.
4151     */
4152     if( rc==SQLITE_OK ){
4153       rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, ofst+WIN_SHM_BASE, n);
4154       if( rc==SQLITE_OK ){
4155         assert( (p->sharedMask & mask)==0 );
4156         p->exclMask |= mask;
4157       }
4158     }
4159   }
4160   sqlite3_mutex_leave(pShmNode->mutex);
4161   OSTRACE(("SHM-LOCK pid=%lu, id=%d, sharedMask=%03x, exclMask=%03x, rc=%s\n",
4162            osGetCurrentProcessId(), p->id, p->sharedMask, p->exclMask,
4163            sqlite3ErrName(rc)));
4164   return rc;
4165 }
4166 
4167 /*
4168 ** Implement a memory barrier or memory fence on shared memory.
4169 **
4170 ** All loads and stores begun before the barrier must complete before
4171 ** any load or store begun after the barrier.
4172 */
4173 static void winShmBarrier(
4174   sqlite3_file *fd          /* Database holding the shared memory */
4175 ){
4176   UNUSED_PARAMETER(fd);
4177   sqlite3MemoryBarrier();   /* compiler-defined memory barrier */
4178   winShmEnterMutex();       /* Also mutex, for redundancy */
4179   winShmLeaveMutex();
4180 }
4181 
4182 /*
4183 ** This function is called to obtain a pointer to region iRegion of the
4184 ** shared-memory associated with the database file fd. Shared-memory regions
4185 ** are numbered starting from zero. Each shared-memory region is szRegion
4186 ** bytes in size.
4187 **
4188 ** If an error occurs, an error code is returned and *pp is set to NULL.
4189 **
4190 ** Otherwise, if the isWrite parameter is 0 and the requested shared-memory
4191 ** region has not been allocated (by any client, including one running in a
4192 ** separate process), then *pp is set to NULL and SQLITE_OK returned. If
4193 ** isWrite is non-zero and the requested shared-memory region has not yet
4194 ** been allocated, it is allocated by this function.
4195 **
4196 ** If the shared-memory region has already been allocated or is allocated by
4197 ** this call as described above, then it is mapped into this processes
4198 ** address space (if it is not already), *pp is set to point to the mapped
4199 ** memory and SQLITE_OK returned.
4200 */
4201 static int winShmMap(
4202   sqlite3_file *fd,               /* Handle open on database file */
4203   int iRegion,                    /* Region to retrieve */
4204   int szRegion,                   /* Size of regions */
4205   int isWrite,                    /* True to extend file if necessary */
4206   void volatile **pp              /* OUT: Mapped memory */
4207 ){
4208   winFile *pDbFd = (winFile*)fd;
4209   winShm *pShm = pDbFd->pShm;
4210   winShmNode *pShmNode;
4211   DWORD protect = PAGE_READWRITE;
4212   DWORD flags = FILE_MAP_WRITE | FILE_MAP_READ;
4213   int rc = SQLITE_OK;
4214 
4215   if( !pShm ){
4216     rc = winOpenSharedMemory(pDbFd);
4217     if( rc!=SQLITE_OK ) return rc;
4218     pShm = pDbFd->pShm;
4219     assert( pShm!=0 );
4220   }
4221   pShmNode = pShm->pShmNode;
4222 
4223   sqlite3_mutex_enter(pShmNode->mutex);
4224   if( pShmNode->isUnlocked ){
4225     rc = winLockSharedMemory(pShmNode);
4226     if( rc!=SQLITE_OK ) goto shmpage_out;
4227     pShmNode->isUnlocked = 0;
4228   }
4229   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
4230 
4231   if( pShmNode->nRegion<=iRegion ){
4232     struct ShmRegion *apNew;           /* New aRegion[] array */
4233     int nByte = (iRegion+1)*szRegion;  /* Minimum required file size */
4234     sqlite3_int64 sz;                  /* Current size of wal-index file */
4235 
4236     pShmNode->szRegion = szRegion;
4237 
4238     /* The requested region is not mapped into this processes address space.
4239     ** Check to see if it has been allocated (i.e. if the wal-index file is
4240     ** large enough to contain the requested region).
4241     */
4242     rc = winFileSize((sqlite3_file *)&pShmNode->hFile, &sz);
4243     if( rc!=SQLITE_OK ){
4244       rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
4245                        "winShmMap1", pDbFd->zPath);
4246       goto shmpage_out;
4247     }
4248 
4249     if( sz<nByte ){
4250       /* The requested memory region does not exist. If isWrite is set to
4251       ** zero, exit early. *pp will be set to NULL and SQLITE_OK returned.
4252       **
4253       ** Alternatively, if isWrite is non-zero, use ftruncate() to allocate
4254       ** the requested memory region.
4255       */
4256       if( !isWrite ) goto shmpage_out;
4257       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, nByte);
4258       if( rc!=SQLITE_OK ){
4259         rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
4260                          "winShmMap2", pDbFd->zPath);
4261         goto shmpage_out;
4262       }
4263     }
4264 
4265     /* Map the requested memory region into this processes address space. */
4266     apNew = (struct ShmRegion *)sqlite3_realloc64(
4267         pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])
4268     );
4269     if( !apNew ){
4270       rc = SQLITE_IOERR_NOMEM_BKPT;
4271       goto shmpage_out;
4272     }
4273     pShmNode->aRegion = apNew;
4274 
4275     if( pShmNode->isReadonly ){
4276       protect = PAGE_READONLY;
4277       flags = FILE_MAP_READ;
4278     }
4279 
4280     while( pShmNode->nRegion<=iRegion ){
4281       HANDLE hMap = NULL;         /* file-mapping handle */
4282       void *pMap = 0;             /* Mapped memory region */
4283 
4284 #if SQLITE_OS_WINRT
4285       hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,
4286           NULL, protect, nByte, NULL
4287       );
4288 #elif defined(SQLITE_WIN32_HAS_WIDE)
4289       hMap = osCreateFileMappingW(pShmNode->hFile.h,
4290           NULL, protect, 0, nByte, NULL
4291       );
4292 #elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
4293       hMap = osCreateFileMappingA(pShmNode->hFile.h,
4294           NULL, protect, 0, nByte, NULL
4295       );
4296 #endif
4297       OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
4298                osGetCurrentProcessId(), pShmNode->nRegion, nByte,
4299                hMap ? "ok" : "failed"));
4300       if( hMap ){
4301         int iOffset = pShmNode->nRegion*szRegion;
4302         int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
4303 #if SQLITE_OS_WINRT
4304         pMap = osMapViewOfFileFromApp(hMap, flags,
4305             iOffset - iOffsetShift, szRegion + iOffsetShift
4306         );
4307 #else
4308         pMap = osMapViewOfFile(hMap, flags,
4309             0, iOffset - iOffsetShift, szRegion + iOffsetShift
4310         );
4311 #endif
4312         OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",
4313                  osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
4314                  szRegion, pMap ? "ok" : "failed"));
4315       }
4316       if( !pMap ){
4317         pShmNode->lastErrno = osGetLastError();
4318         rc = winLogError(SQLITE_IOERR_SHMMAP, pShmNode->lastErrno,
4319                          "winShmMap3", pDbFd->zPath);
4320         if( hMap ) osCloseHandle(hMap);
4321         goto shmpage_out;
4322       }
4323 
4324       pShmNode->aRegion[pShmNode->nRegion].pMap = pMap;
4325       pShmNode->aRegion[pShmNode->nRegion].hMap = hMap;
4326       pShmNode->nRegion++;
4327     }
4328   }
4329 
4330 shmpage_out:
4331   if( pShmNode->nRegion>iRegion ){
4332     int iOffset = iRegion*szRegion;
4333     int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
4334     char *p = (char *)pShmNode->aRegion[iRegion].pMap;
4335     *pp = (void *)&p[iOffsetShift];
4336   }else{
4337     *pp = 0;
4338   }
4339   if( pShmNode->isReadonly && rc==SQLITE_OK ) rc = SQLITE_READONLY;
4340   sqlite3_mutex_leave(pShmNode->mutex);
4341   return rc;
4342 }
4343 
4344 #else
4345 # define winShmMap     0
4346 # define winShmLock    0
4347 # define winShmBarrier 0
4348 # define winShmUnmap   0
4349 #endif /* #ifndef SQLITE_OMIT_WAL */
4350 
4351 /*
4352 ** Cleans up the mapped region of the specified file, if any.
4353 */
4354 #if SQLITE_MAX_MMAP_SIZE>0
4355 static int winUnmapfile(winFile *pFile){
4356   assert( pFile!=0 );
4357   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, pMapRegion=%p, "
4358            "mmapSize=%lld, mmapSizeMax=%lld\n",
4359            osGetCurrentProcessId(), pFile, pFile->hMap, pFile->pMapRegion,
4360            pFile->mmapSize, pFile->mmapSizeMax));
4361   if( pFile->pMapRegion ){
4362     if( !osUnmapViewOfFile(pFile->pMapRegion) ){
4363       pFile->lastErrno = osGetLastError();
4364       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, pMapRegion=%p, "
4365                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(), pFile,
4366                pFile->pMapRegion));
4367       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
4368                          "winUnmapfile1", pFile->zPath);
4369     }
4370     pFile->pMapRegion = 0;
4371     pFile->mmapSize = 0;
4372   }
4373   if( pFile->hMap!=NULL ){
4374     if( !osCloseHandle(pFile->hMap) ){
4375       pFile->lastErrno = osGetLastError();
4376       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, rc=SQLITE_IOERR_MMAP\n",
4377                osGetCurrentProcessId(), pFile, pFile->hMap));
4378       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
4379                          "winUnmapfile2", pFile->zPath);
4380     }
4381     pFile->hMap = NULL;
4382   }
4383   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4384            osGetCurrentProcessId(), pFile));
4385   return SQLITE_OK;
4386 }
4387 
4388 /*
4389 ** Memory map or remap the file opened by file-descriptor pFd (if the file
4390 ** is already mapped, the existing mapping is replaced by the new). Or, if
4391 ** there already exists a mapping for this file, and there are still
4392 ** outstanding xFetch() references to it, this function is a no-op.
4393 **
4394 ** If parameter nByte is non-negative, then it is the requested size of
4395 ** the mapping to create. Otherwise, if nByte is less than zero, then the
4396 ** requested size is the size of the file on disk. The actual size of the
4397 ** created mapping is either the requested size or the value configured
4398 ** using SQLITE_FCNTL_MMAP_SIZE, whichever is smaller.
4399 **
4400 ** SQLITE_OK is returned if no error occurs (even if the mapping is not
4401 ** recreated as a result of outstanding references) or an SQLite error
4402 ** code otherwise.
4403 */
4404 static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
4405   sqlite3_int64 nMap = nByte;
4406   int rc;
4407 
4408   assert( nMap>=0 || pFd->nFetchOut==0 );
4409   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, size=%lld\n",
4410            osGetCurrentProcessId(), pFd, nByte));
4411 
4412   if( pFd->nFetchOut>0 ) return SQLITE_OK;
4413 
4414   if( nMap<0 ){
4415     rc = winFileSize((sqlite3_file*)pFd, &nMap);
4416     if( rc ){
4417       OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_IOERR_FSTAT\n",
4418                osGetCurrentProcessId(), pFd));
4419       return SQLITE_IOERR_FSTAT;
4420     }
4421   }
4422   if( nMap>pFd->mmapSizeMax ){
4423     nMap = pFd->mmapSizeMax;
4424   }
4425   nMap &= ~(sqlite3_int64)(winSysInfo.dwPageSize - 1);
4426 
4427   if( nMap==0 && pFd->mmapSize>0 ){
4428     winUnmapfile(pFd);
4429   }
4430   if( nMap!=pFd->mmapSize ){
4431     void *pNew = 0;
4432     DWORD protect = PAGE_READONLY;
4433     DWORD flags = FILE_MAP_READ;
4434 
4435     winUnmapfile(pFd);
4436 #ifdef SQLITE_MMAP_READWRITE
4437     if( (pFd->ctrlFlags & WINFILE_RDONLY)==0 ){
4438       protect = PAGE_READWRITE;
4439       flags |= FILE_MAP_WRITE;
4440     }
4441 #endif
4442 #if SQLITE_OS_WINRT
4443     pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);
4444 #elif defined(SQLITE_WIN32_HAS_WIDE)
4445     pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,
4446                                 (DWORD)((nMap>>32) & 0xffffffff),
4447                                 (DWORD)(nMap & 0xffffffff), NULL);
4448 #elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
4449     pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,
4450                                 (DWORD)((nMap>>32) & 0xffffffff),
4451                                 (DWORD)(nMap & 0xffffffff), NULL);
4452 #endif
4453     if( pFd->hMap==NULL ){
4454       pFd->lastErrno = osGetLastError();
4455       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
4456                        "winMapfile1", pFd->zPath);
4457       /* Log the error, but continue normal operation using xRead/xWrite */
4458       OSTRACE(("MAP-FILE-CREATE pid=%lu, pFile=%p, rc=%s\n",
4459                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4460       return SQLITE_OK;
4461     }
4462     assert( (nMap % winSysInfo.dwPageSize)==0 );
4463     assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );
4464 #if SQLITE_OS_WINRT
4465     pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, (SIZE_T)nMap);
4466 #else
4467     pNew = osMapViewOfFile(pFd->hMap, flags, 0, 0, (SIZE_T)nMap);
4468 #endif
4469     if( pNew==NULL ){
4470       osCloseHandle(pFd->hMap);
4471       pFd->hMap = NULL;
4472       pFd->lastErrno = osGetLastError();
4473       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
4474                        "winMapfile2", pFd->zPath);
4475       /* Log the error, but continue normal operation using xRead/xWrite */
4476       OSTRACE(("MAP-FILE-MAP pid=%lu, pFile=%p, rc=%s\n",
4477                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4478       return SQLITE_OK;
4479     }
4480     pFd->pMapRegion = pNew;
4481     pFd->mmapSize = nMap;
4482   }
4483 
4484   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4485            osGetCurrentProcessId(), pFd));
4486   return SQLITE_OK;
4487 }
4488 #endif /* SQLITE_MAX_MMAP_SIZE>0 */
4489 
4490 /*
4491 ** If possible, return a pointer to a mapping of file fd starting at offset
4492 ** iOff. The mapping must be valid for at least nAmt bytes.
4493 **
4494 ** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
4495 ** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
4496 ** Finally, if an error does occur, return an SQLite error code. The final
4497 ** value of *pp is undefined in this case.
4498 **
4499 ** If this function does return a pointer, the caller must eventually
4500 ** release the reference by calling winUnfetch().
4501 */
4502 static int winFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
4503 #if SQLITE_MAX_MMAP_SIZE>0
4504   winFile *pFd = (winFile*)fd;   /* The underlying database file */
4505 #endif
4506   *pp = 0;
4507 
4508   OSTRACE(("FETCH pid=%lu, pFile=%p, offset=%lld, amount=%d, pp=%p\n",
4509            osGetCurrentProcessId(), fd, iOff, nAmt, pp));
4510 
4511 #if SQLITE_MAX_MMAP_SIZE>0
4512   if( pFd->mmapSizeMax>0 ){
4513     if( pFd->pMapRegion==0 ){
4514       int rc = winMapfile(pFd, -1);
4515       if( rc!=SQLITE_OK ){
4516         OSTRACE(("FETCH pid=%lu, pFile=%p, rc=%s\n",
4517                  osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4518         return rc;
4519       }
4520     }
4521     if( pFd->mmapSize >= iOff+nAmt ){
4522       assert( pFd->pMapRegion!=0 );
4523       *pp = &((u8 *)pFd->pMapRegion)[iOff];
4524       pFd->nFetchOut++;
4525     }
4526   }
4527 #endif
4528 
4529   OSTRACE(("FETCH pid=%lu, pFile=%p, pp=%p, *pp=%p, rc=SQLITE_OK\n",
4530            osGetCurrentProcessId(), fd, pp, *pp));
4531   return SQLITE_OK;
4532 }
4533 
4534 /*
4535 ** If the third argument is non-NULL, then this function releases a
4536 ** reference obtained by an earlier call to winFetch(). The second
4537 ** argument passed to this function must be the same as the corresponding
4538 ** argument that was passed to the winFetch() invocation.
4539 **
4540 ** Or, if the third argument is NULL, then this function is being called
4541 ** to inform the VFS layer that, according to POSIX, any existing mapping
4542 ** may now be invalid and should be unmapped.
4543 */
4544 static int winUnfetch(sqlite3_file *fd, i64 iOff, void *p){
4545 #if SQLITE_MAX_MMAP_SIZE>0
4546   winFile *pFd = (winFile*)fd;   /* The underlying database file */
4547 
4548   /* If p==0 (unmap the entire file) then there must be no outstanding
4549   ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
4550   ** then there must be at least one outstanding.  */
4551   assert( (p==0)==(pFd->nFetchOut==0) );
4552 
4553   /* If p!=0, it must match the iOff value. */
4554   assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );
4555 
4556   OSTRACE(("UNFETCH pid=%lu, pFile=%p, offset=%lld, p=%p\n",
4557            osGetCurrentProcessId(), pFd, iOff, p));
4558 
4559   if( p ){
4560     pFd->nFetchOut--;
4561   }else{
4562     /* FIXME:  If Windows truly always prevents truncating or deleting a
4563     ** file while a mapping is held, then the following winUnmapfile() call
4564     ** is unnecessary can be omitted - potentially improving
4565     ** performance.  */
4566     winUnmapfile(pFd);
4567   }
4568 
4569   assert( pFd->nFetchOut>=0 );
4570 #endif
4571 
4572   OSTRACE(("UNFETCH pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4573            osGetCurrentProcessId(), fd));
4574   return SQLITE_OK;
4575 }
4576 
4577 /*
4578 ** Here ends the implementation of all sqlite3_file methods.
4579 **
4580 ********************** End sqlite3_file Methods *******************************
4581 ******************************************************************************/
4582 
4583 /*
4584 ** This vector defines all the methods that can operate on an
4585 ** sqlite3_file for win32.
4586 */
4587 static const sqlite3_io_methods winIoMethod = {
4588   3,                              /* iVersion */
4589   winClose,                       /* xClose */
4590   winRead,                        /* xRead */
4591   winWrite,                       /* xWrite */
4592   winTruncate,                    /* xTruncate */
4593   winSync,                        /* xSync */
4594   winFileSize,                    /* xFileSize */
4595   winLock,                        /* xLock */
4596   winUnlock,                      /* xUnlock */
4597   winCheckReservedLock,           /* xCheckReservedLock */
4598   winFileControl,                 /* xFileControl */
4599   winSectorSize,                  /* xSectorSize */
4600   winDeviceCharacteristics,       /* xDeviceCharacteristics */
4601   winShmMap,                      /* xShmMap */
4602   winShmLock,                     /* xShmLock */
4603   winShmBarrier,                  /* xShmBarrier */
4604   winShmUnmap,                    /* xShmUnmap */
4605   winFetch,                       /* xFetch */
4606   winUnfetch                      /* xUnfetch */
4607 };
4608 
4609 /*
4610 ** This vector defines all the methods that can operate on an
4611 ** sqlite3_file for win32 without performing any locking.
4612 */
4613 static const sqlite3_io_methods winIoNolockMethod = {
4614   3,                              /* iVersion */
4615   winClose,                       /* xClose */
4616   winRead,                        /* xRead */
4617   winWrite,                       /* xWrite */
4618   winTruncate,                    /* xTruncate */
4619   winSync,                        /* xSync */
4620   winFileSize,                    /* xFileSize */
4621   winNolockLock,                  /* xLock */
4622   winNolockUnlock,                /* xUnlock */
4623   winNolockCheckReservedLock,     /* xCheckReservedLock */
4624   winFileControl,                 /* xFileControl */
4625   winSectorSize,                  /* xSectorSize */
4626   winDeviceCharacteristics,       /* xDeviceCharacteristics */
4627   winShmMap,                      /* xShmMap */
4628   winShmLock,                     /* xShmLock */
4629   winShmBarrier,                  /* xShmBarrier */
4630   winShmUnmap,                    /* xShmUnmap */
4631   winFetch,                       /* xFetch */
4632   winUnfetch                      /* xUnfetch */
4633 };
4634 
4635 static winVfsAppData winAppData = {
4636   &winIoMethod,       /* pMethod */
4637   0,                  /* pAppData */
4638   0                   /* bNoLock */
4639 };
4640 
4641 static winVfsAppData winNolockAppData = {
4642   &winIoNolockMethod, /* pMethod */
4643   0,                  /* pAppData */
4644   1                   /* bNoLock */
4645 };
4646 
4647 /****************************************************************************
4648 **************************** sqlite3_vfs methods ****************************
4649 **
4650 ** This division contains the implementation of methods on the
4651 ** sqlite3_vfs object.
4652 */
4653 
4654 #if defined(__CYGWIN__)
4655 /*
4656 ** Convert a filename from whatever the underlying operating system
4657 ** supports for filenames into UTF-8.  Space to hold the result is
4658 ** obtained from malloc and must be freed by the calling function.
4659 */
4660 static char *winConvertToUtf8Filename(const void *zFilename){
4661   char *zConverted = 0;
4662   if( osIsNT() ){
4663     zConverted = winUnicodeToUtf8(zFilename);
4664   }
4665 #ifdef SQLITE_WIN32_HAS_ANSI
4666   else{
4667     zConverted = winMbcsToUtf8(zFilename, osAreFileApisANSI());
4668   }
4669 #endif
4670   /* caller will handle out of memory */
4671   return zConverted;
4672 }
4673 #endif
4674 
4675 /*
4676 ** Convert a UTF-8 filename into whatever form the underlying
4677 ** operating system wants filenames in.  Space to hold the result
4678 ** is obtained from malloc and must be freed by the calling
4679 ** function.
4680 */
4681 static void *winConvertFromUtf8Filename(const char *zFilename){
4682   void *zConverted = 0;
4683   if( osIsNT() ){
4684     zConverted = winUtf8ToUnicode(zFilename);
4685   }
4686 #ifdef SQLITE_WIN32_HAS_ANSI
4687   else{
4688     zConverted = winUtf8ToMbcs(zFilename, osAreFileApisANSI());
4689   }
4690 #endif
4691   /* caller will handle out of memory */
4692   return zConverted;
4693 }
4694 
4695 /*
4696 ** This function returns non-zero if the specified UTF-8 string buffer
4697 ** ends with a directory separator character or one was successfully
4698 ** added to it.
4699 */
4700 static int winMakeEndInDirSep(int nBuf, char *zBuf){
4701   if( zBuf ){
4702     int nLen = sqlite3Strlen30(zBuf);
4703     if( nLen>0 ){
4704       if( winIsDirSep(zBuf[nLen-1]) ){
4705         return 1;
4706       }else if( nLen+1<nBuf ){
4707         zBuf[nLen] = winGetDirSep();
4708         zBuf[nLen+1] = '\0';
4709         return 1;
4710       }
4711     }
4712   }
4713   return 0;
4714 }
4715 
4716 /*
4717 ** Create a temporary file name and store the resulting pointer into pzBuf.
4718 ** The pointer returned in pzBuf must be freed via sqlite3_free().
4719 */
4720 static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
4721   static char zChars[] =
4722     "abcdefghijklmnopqrstuvwxyz"
4723     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
4724     "0123456789";
4725   size_t i, j;
4726   int nPre = sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX);
4727   int nMax, nBuf, nDir, nLen;
4728   char *zBuf;
4729 
4730   /* It's odd to simulate an io-error here, but really this is just
4731   ** using the io-error infrastructure to test that SQLite handles this
4732   ** function failing.
4733   */
4734   SimulateIOError( return SQLITE_IOERR );
4735 
4736   /* Allocate a temporary buffer to store the fully qualified file
4737   ** name for the temporary file.  If this fails, we cannot continue.
4738   */
4739   nMax = pVfs->mxPathname; nBuf = nMax + 2;
4740   zBuf = sqlite3MallocZero( nBuf );
4741   if( !zBuf ){
4742     OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4743     return SQLITE_IOERR_NOMEM_BKPT;
4744   }
4745 
4746   /* Figure out the effective temporary directory.  First, check if one
4747   ** has been explicitly set by the application; otherwise, use the one
4748   ** configured by the operating system.
4749   */
4750   nDir = nMax - (nPre + 15);
4751   assert( nDir>0 );
4752   if( sqlite3_temp_directory ){
4753     int nDirLen = sqlite3Strlen30(sqlite3_temp_directory);
4754     if( nDirLen>0 ){
4755       if( !winIsDirSep(sqlite3_temp_directory[nDirLen-1]) ){
4756         nDirLen++;
4757       }
4758       if( nDirLen>nDir ){
4759         sqlite3_free(zBuf);
4760         OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4761         return winLogError(SQLITE_ERROR, 0, "winGetTempname1", 0);
4762       }
4763       sqlite3_snprintf(nMax, zBuf, "%s", sqlite3_temp_directory);
4764     }
4765   }
4766 #if defined(__CYGWIN__)
4767   else{
4768     static const char *azDirs[] = {
4769        0, /* getenv("SQLITE_TMPDIR") */
4770        0, /* getenv("TMPDIR") */
4771        0, /* getenv("TMP") */
4772        0, /* getenv("TEMP") */
4773        0, /* getenv("USERPROFILE") */
4774        "/var/tmp",
4775        "/usr/tmp",
4776        "/tmp",
4777        ".",
4778        0        /* List terminator */
4779     };
4780     unsigned int i;
4781     const char *zDir = 0;
4782 
4783     if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");
4784     if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");
4785     if( !azDirs[2] ) azDirs[2] = getenv("TMP");
4786     if( !azDirs[3] ) azDirs[3] = getenv("TEMP");
4787     if( !azDirs[4] ) azDirs[4] = getenv("USERPROFILE");
4788     for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); zDir=azDirs[i++]){
4789       void *zConverted;
4790       if( zDir==0 ) continue;
4791       /* If the path starts with a drive letter followed by the colon
4792       ** character, assume it is already a native Win32 path; otherwise,
4793       ** it must be converted to a native Win32 path via the Cygwin API
4794       ** prior to using it.
4795       */
4796       if( winIsDriveLetterAndColon(zDir) ){
4797         zConverted = winConvertFromUtf8Filename(zDir);
4798         if( !zConverted ){
4799           sqlite3_free(zBuf);
4800           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4801           return SQLITE_IOERR_NOMEM_BKPT;
4802         }
4803         if( winIsDir(zConverted) ){
4804           sqlite3_snprintf(nMax, zBuf, "%s", zDir);
4805           sqlite3_free(zConverted);
4806           break;
4807         }
4808         sqlite3_free(zConverted);
4809       }else{
4810         zConverted = sqlite3MallocZero( nMax+1 );
4811         if( !zConverted ){
4812           sqlite3_free(zBuf);
4813           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4814           return SQLITE_IOERR_NOMEM_BKPT;
4815         }
4816         if( cygwin_conv_path(
4817                 osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A, zDir,
4818                 zConverted, nMax+1)<0 ){
4819           sqlite3_free(zConverted);
4820           sqlite3_free(zBuf);
4821           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_CONVPATH\n"));
4822           return winLogError(SQLITE_IOERR_CONVPATH, (DWORD)errno,
4823                              "winGetTempname2", zDir);
4824         }
4825         if( winIsDir(zConverted) ){
4826           /* At this point, we know the candidate directory exists and should
4827           ** be used.  However, we may need to convert the string containing
4828           ** its name into UTF-8 (i.e. if it is UTF-16 right now).
4829           */
4830           char *zUtf8 = winConvertToUtf8Filename(zConverted);
4831           if( !zUtf8 ){
4832             sqlite3_free(zConverted);
4833             sqlite3_free(zBuf);
4834             OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4835             return SQLITE_IOERR_NOMEM_BKPT;
4836           }
4837           sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
4838           sqlite3_free(zUtf8);
4839           sqlite3_free(zConverted);
4840           break;
4841         }
4842         sqlite3_free(zConverted);
4843       }
4844     }
4845   }
4846 #elif !SQLITE_OS_WINRT && !defined(__CYGWIN__)
4847   else if( osIsNT() ){
4848     char *zMulti;
4849     LPWSTR zWidePath = sqlite3MallocZero( nMax*sizeof(WCHAR) );
4850     if( !zWidePath ){
4851       sqlite3_free(zBuf);
4852       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4853       return SQLITE_IOERR_NOMEM_BKPT;
4854     }
4855     if( osGetTempPathW(nMax, zWidePath)==0 ){
4856       sqlite3_free(zWidePath);
4857       sqlite3_free(zBuf);
4858       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
4859       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
4860                          "winGetTempname2", 0);
4861     }
4862     zMulti = winUnicodeToUtf8(zWidePath);
4863     if( zMulti ){
4864       sqlite3_snprintf(nMax, zBuf, "%s", zMulti);
4865       sqlite3_free(zMulti);
4866       sqlite3_free(zWidePath);
4867     }else{
4868       sqlite3_free(zWidePath);
4869       sqlite3_free(zBuf);
4870       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4871       return SQLITE_IOERR_NOMEM_BKPT;
4872     }
4873   }
4874 #ifdef SQLITE_WIN32_HAS_ANSI
4875   else{
4876     char *zUtf8;
4877     char *zMbcsPath = sqlite3MallocZero( nMax );
4878     if( !zMbcsPath ){
4879       sqlite3_free(zBuf);
4880       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4881       return SQLITE_IOERR_NOMEM_BKPT;
4882     }
4883     if( osGetTempPathA(nMax, zMbcsPath)==0 ){
4884       sqlite3_free(zBuf);
4885       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
4886       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
4887                          "winGetTempname3", 0);
4888     }
4889     zUtf8 = winMbcsToUtf8(zMbcsPath, osAreFileApisANSI());
4890     if( zUtf8 ){
4891       sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
4892       sqlite3_free(zUtf8);
4893     }else{
4894       sqlite3_free(zBuf);
4895       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4896       return SQLITE_IOERR_NOMEM_BKPT;
4897     }
4898   }
4899 #endif /* SQLITE_WIN32_HAS_ANSI */
4900 #endif /* !SQLITE_OS_WINRT */
4901 
4902   /*
4903   ** Check to make sure the temporary directory ends with an appropriate
4904   ** separator.  If it does not and there is not enough space left to add
4905   ** one, fail.
4906   */
4907   if( !winMakeEndInDirSep(nDir+1, zBuf) ){
4908     sqlite3_free(zBuf);
4909     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4910     return winLogError(SQLITE_ERROR, 0, "winGetTempname4", 0);
4911   }
4912 
4913   /*
4914   ** Check that the output buffer is large enough for the temporary file
4915   ** name in the following format:
4916   **
4917   **   "<temporary_directory>/etilqs_XXXXXXXXXXXXXXX\0\0"
4918   **
4919   ** If not, return SQLITE_ERROR.  The number 17 is used here in order to
4920   ** account for the space used by the 15 character random suffix and the
4921   ** two trailing NUL characters.  The final directory separator character
4922   ** has already added if it was not already present.
4923   */
4924   nLen = sqlite3Strlen30(zBuf);
4925   if( (nLen + nPre + 17) > nBuf ){
4926     sqlite3_free(zBuf);
4927     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4928     return winLogError(SQLITE_ERROR, 0, "winGetTempname5", 0);
4929   }
4930 
4931   sqlite3_snprintf(nBuf-16-nLen, zBuf+nLen, SQLITE_TEMP_FILE_PREFIX);
4932 
4933   j = sqlite3Strlen30(zBuf);
4934   sqlite3_randomness(15, &zBuf[j]);
4935   for(i=0; i<15; i++, j++){
4936     zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
4937   }
4938   zBuf[j] = 0;
4939   zBuf[j+1] = 0;
4940   *pzBuf = zBuf;
4941 
4942   OSTRACE(("TEMP-FILENAME name=%s, rc=SQLITE_OK\n", zBuf));
4943   return SQLITE_OK;
4944 }
4945 
4946 /*
4947 ** Return TRUE if the named file is really a directory.  Return false if
4948 ** it is something other than a directory, or if there is any kind of memory
4949 ** allocation failure.
4950 */
4951 static int winIsDir(const void *zConverted){
4952   DWORD attr;
4953   int rc = 0;
4954   DWORD lastErrno;
4955 
4956   if( osIsNT() ){
4957     int cnt = 0;
4958     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
4959     memset(&sAttrData, 0, sizeof(sAttrData));
4960     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
4961                              GetFileExInfoStandard,
4962                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
4963     if( !rc ){
4964       return 0; /* Invalid name? */
4965     }
4966     attr = sAttrData.dwFileAttributes;
4967 #if SQLITE_OS_WINCE==0
4968   }else{
4969     attr = osGetFileAttributesA((char*)zConverted);
4970 #endif
4971   }
4972   return (attr!=INVALID_FILE_ATTRIBUTES) && (attr&FILE_ATTRIBUTE_DIRECTORY);
4973 }
4974 
4975 /* forward reference */
4976 static int winAccess(
4977   sqlite3_vfs *pVfs,         /* Not used on win32 */
4978   const char *zFilename,     /* Name of file to check */
4979   int flags,                 /* Type of test to make on this file */
4980   int *pResOut               /* OUT: Result */
4981 );
4982 
4983 /*
4984 ** Open a file.
4985 */
4986 static int winOpen(
4987   sqlite3_vfs *pVfs,        /* Used to get maximum path length and AppData */
4988   const char *zName,        /* Name of the file (UTF-8) */
4989   sqlite3_file *id,         /* Write the SQLite file handle here */
4990   int flags,                /* Open mode flags */
4991   int *pOutFlags            /* Status return flags */
4992 ){
4993   HANDLE h;
4994   DWORD lastErrno = 0;
4995   DWORD dwDesiredAccess;
4996   DWORD dwShareMode;
4997   DWORD dwCreationDisposition;
4998   DWORD dwFlagsAndAttributes = 0;
4999 #if SQLITE_OS_WINCE
5000   int isTemp = 0;
5001 #endif
5002   winVfsAppData *pAppData;
5003   winFile *pFile = (winFile*)id;
5004   void *zConverted;              /* Filename in OS encoding */
5005   const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */
5006   int cnt = 0;
5007 
5008   /* If argument zPath is a NULL pointer, this function is required to open
5009   ** a temporary file. Use this buffer to store the file name in.
5010   */
5011   char *zTmpname = 0; /* For temporary filename, if necessary. */
5012 
5013   int rc = SQLITE_OK;            /* Function Return Code */
5014 #if !defined(NDEBUG) || SQLITE_OS_WINCE
5015   int eType = flags&0xFFFFFF00;  /* Type of file to open */
5016 #endif
5017 
5018   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
5019   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
5020   int isCreate     = (flags & SQLITE_OPEN_CREATE);
5021   int isReadonly   = (flags & SQLITE_OPEN_READONLY);
5022   int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
5023 
5024 #ifndef NDEBUG
5025   int isOpenJournal = (isCreate && (
5026         eType==SQLITE_OPEN_SUPER_JOURNAL
5027      || eType==SQLITE_OPEN_MAIN_JOURNAL
5028      || eType==SQLITE_OPEN_WAL
5029   ));
5030 #endif
5031 
5032   OSTRACE(("OPEN name=%s, pFile=%p, flags=%x, pOutFlags=%p\n",
5033            zUtf8Name, id, flags, pOutFlags));
5034 
5035   /* Check the following statements are true:
5036   **
5037   **   (a) Exactly one of the READWRITE and READONLY flags must be set, and
5038   **   (b) if CREATE is set, then READWRITE must also be set, and
5039   **   (c) if EXCLUSIVE is set, then CREATE must also be set.
5040   **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
5041   */
5042   assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
5043   assert(isCreate==0 || isReadWrite);
5044   assert(isExclusive==0 || isCreate);
5045   assert(isDelete==0 || isCreate);
5046 
5047   /* The main DB, main journal, WAL file and super-journal are never
5048   ** automatically deleted. Nor are they ever temporary files.  */
5049   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
5050   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
5051   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_SUPER_JOURNAL );
5052   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );
5053 
5054   /* Assert that the upper layer has set one of the "file-type" flags. */
5055   assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB
5056        || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL
5057        || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_SUPER_JOURNAL
5058        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
5059   );
5060 
5061   assert( pFile!=0 );
5062   memset(pFile, 0, sizeof(winFile));
5063   pFile->h = INVALID_HANDLE_VALUE;
5064 
5065 #if SQLITE_OS_WINRT
5066   if( !zUtf8Name && !sqlite3_temp_directory ){
5067     sqlite3_log(SQLITE_ERROR,
5068         "sqlite3_temp_directory variable should be set for WinRT");
5069   }
5070 #endif
5071 
5072   /* If the second argument to this function is NULL, generate a
5073   ** temporary file name to use
5074   */
5075   if( !zUtf8Name ){
5076     assert( isDelete && !isOpenJournal );
5077     rc = winGetTempname(pVfs, &zTmpname);
5078     if( rc!=SQLITE_OK ){
5079       OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));
5080       return rc;
5081     }
5082     zUtf8Name = zTmpname;
5083   }
5084 
5085   /* Database filenames are double-zero terminated if they are not
5086   ** URIs with parameters.  Hence, they can always be passed into
5087   ** sqlite3_uri_parameter().
5088   */
5089   assert( (eType!=SQLITE_OPEN_MAIN_DB) || (flags & SQLITE_OPEN_URI) ||
5090        zUtf8Name[sqlite3Strlen30(zUtf8Name)+1]==0 );
5091 
5092   /* Convert the filename to the system encoding. */
5093   zConverted = winConvertFromUtf8Filename(zUtf8Name);
5094   if( zConverted==0 ){
5095     sqlite3_free(zTmpname);
5096     OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));
5097     return SQLITE_IOERR_NOMEM_BKPT;
5098   }
5099 
5100   if( winIsDir(zConverted) ){
5101     sqlite3_free(zConverted);
5102     sqlite3_free(zTmpname);
5103     OSTRACE(("OPEN name=%s, rc=SQLITE_CANTOPEN_ISDIR", zUtf8Name));
5104     return SQLITE_CANTOPEN_ISDIR;
5105   }
5106 
5107   if( isReadWrite ){
5108     dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
5109   }else{
5110     dwDesiredAccess = GENERIC_READ;
5111   }
5112 
5113   /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is
5114   ** created. SQLite doesn't use it to indicate "exclusive access"
5115   ** as it is usually understood.
5116   */
5117   if( isExclusive ){
5118     /* Creates a new file, only if it does not already exist. */
5119     /* If the file exists, it fails. */
5120     dwCreationDisposition = CREATE_NEW;
5121   }else if( isCreate ){
5122     /* Open existing file, or create if it doesn't exist */
5123     dwCreationDisposition = OPEN_ALWAYS;
5124   }else{
5125     /* Opens a file, only if it exists. */
5126     dwCreationDisposition = OPEN_EXISTING;
5127   }
5128 
5129   if( 0==sqlite3_uri_boolean(zName, "exclusive", 0) ){
5130     dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
5131   }else{
5132     dwShareMode = 0;
5133   }
5134 
5135   if( isDelete ){
5136 #if SQLITE_OS_WINCE
5137     dwFlagsAndAttributes = FILE_ATTRIBUTE_HIDDEN;
5138     isTemp = 1;
5139 #else
5140     dwFlagsAndAttributes = FILE_ATTRIBUTE_TEMPORARY
5141                                | FILE_ATTRIBUTE_HIDDEN
5142                                | FILE_FLAG_DELETE_ON_CLOSE;
5143 #endif
5144   }else{
5145     dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
5146   }
5147   /* Reports from the internet are that performance is always
5148   ** better if FILE_FLAG_RANDOM_ACCESS is used.  Ticket #2699. */
5149 #if SQLITE_OS_WINCE
5150   dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
5151 #endif
5152 
5153   if( osIsNT() ){
5154 #if SQLITE_OS_WINRT
5155     CREATEFILE2_EXTENDED_PARAMETERS extendedParameters;
5156     extendedParameters.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
5157     extendedParameters.dwFileAttributes =
5158             dwFlagsAndAttributes & FILE_ATTRIBUTE_MASK;
5159     extendedParameters.dwFileFlags = dwFlagsAndAttributes & FILE_FLAG_MASK;
5160     extendedParameters.dwSecurityQosFlags = SECURITY_ANONYMOUS;
5161     extendedParameters.lpSecurityAttributes = NULL;
5162     extendedParameters.hTemplateFile = NULL;
5163     do{
5164       h = osCreateFile2((LPCWSTR)zConverted,
5165                         dwDesiredAccess,
5166                         dwShareMode,
5167                         dwCreationDisposition,
5168                         &extendedParameters);
5169       if( h!=INVALID_HANDLE_VALUE ) break;
5170       if( isReadWrite ){
5171         int rc2, isRO = 0;
5172         sqlite3BeginBenignMalloc();
5173         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5174         sqlite3EndBenignMalloc();
5175         if( rc2==SQLITE_OK && isRO ) break;
5176       }
5177     }while( winRetryIoerr(&cnt, &lastErrno) );
5178 #else
5179     do{
5180       h = osCreateFileW((LPCWSTR)zConverted,
5181                         dwDesiredAccess,
5182                         dwShareMode, NULL,
5183                         dwCreationDisposition,
5184                         dwFlagsAndAttributes,
5185                         NULL);
5186       if( h!=INVALID_HANDLE_VALUE ) break;
5187       if( isReadWrite ){
5188         int rc2, isRO = 0;
5189         sqlite3BeginBenignMalloc();
5190         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5191         sqlite3EndBenignMalloc();
5192         if( rc2==SQLITE_OK && isRO ) break;
5193       }
5194     }while( winRetryIoerr(&cnt, &lastErrno) );
5195 #endif
5196   }
5197 #ifdef SQLITE_WIN32_HAS_ANSI
5198   else{
5199     do{
5200       h = osCreateFileA((LPCSTR)zConverted,
5201                         dwDesiredAccess,
5202                         dwShareMode, NULL,
5203                         dwCreationDisposition,
5204                         dwFlagsAndAttributes,
5205                         NULL);
5206       if( h!=INVALID_HANDLE_VALUE ) break;
5207       if( isReadWrite ){
5208         int rc2, isRO = 0;
5209         sqlite3BeginBenignMalloc();
5210         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5211         sqlite3EndBenignMalloc();
5212         if( rc2==SQLITE_OK && isRO ) break;
5213       }
5214     }while( winRetryIoerr(&cnt, &lastErrno) );
5215   }
5216 #endif
5217   winLogIoerr(cnt, __LINE__);
5218 
5219   OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
5220            dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
5221 
5222   if( h==INVALID_HANDLE_VALUE ){
5223     sqlite3_free(zConverted);
5224     sqlite3_free(zTmpname);
5225     if( isReadWrite && !isExclusive ){
5226       return winOpen(pVfs, zName, id,
5227          ((flags|SQLITE_OPEN_READONLY) &
5228                      ~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
5229          pOutFlags);
5230     }else{
5231       pFile->lastErrno = lastErrno;
5232       winLogError(SQLITE_CANTOPEN, pFile->lastErrno, "winOpen", zUtf8Name);
5233       return SQLITE_CANTOPEN_BKPT;
5234     }
5235   }
5236 
5237   if( pOutFlags ){
5238     if( isReadWrite ){
5239       *pOutFlags = SQLITE_OPEN_READWRITE;
5240     }else{
5241       *pOutFlags = SQLITE_OPEN_READONLY;
5242     }
5243   }
5244 
5245   OSTRACE(("OPEN file=%p, name=%s, access=%lx, pOutFlags=%p, *pOutFlags=%d, "
5246            "rc=%s\n", h, zUtf8Name, dwDesiredAccess, pOutFlags, pOutFlags ?
5247            *pOutFlags : 0, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
5248 
5249   pAppData = (winVfsAppData*)pVfs->pAppData;
5250 
5251 #if SQLITE_OS_WINCE
5252   {
5253     if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
5254          && ((pAppData==NULL) || !pAppData->bNoLock)
5255          && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
5256     ){
5257       osCloseHandle(h);
5258       sqlite3_free(zConverted);
5259       sqlite3_free(zTmpname);
5260       OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
5261       return rc;
5262     }
5263   }
5264   if( isTemp ){
5265     pFile->zDeleteOnClose = zConverted;
5266   }else
5267 #endif
5268   {
5269     sqlite3_free(zConverted);
5270   }
5271 
5272   sqlite3_free(zTmpname);
5273   id->pMethods = pAppData ? pAppData->pMethod : &winIoMethod;
5274   pFile->pVfs = pVfs;
5275   pFile->h = h;
5276   if( isReadonly ){
5277     pFile->ctrlFlags |= WINFILE_RDONLY;
5278   }
5279   if( (flags & SQLITE_OPEN_MAIN_DB)
5280    && sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE)
5281   ){
5282     pFile->ctrlFlags |= WINFILE_PSOW;
5283   }
5284   pFile->lastErrno = NO_ERROR;
5285   pFile->zPath = zName;
5286 #if SQLITE_MAX_MMAP_SIZE>0
5287   pFile->hMap = NULL;
5288   pFile->pMapRegion = 0;
5289   pFile->mmapSize = 0;
5290   pFile->mmapSizeMax = sqlite3GlobalConfig.szMmap;
5291 #endif
5292 
5293   OpenCounter(+1);
5294   return rc;
5295 }
5296 
5297 /*
5298 ** Delete the named file.
5299 **
5300 ** Note that Windows does not allow a file to be deleted if some other
5301 ** process has it open.  Sometimes a virus scanner or indexing program
5302 ** will open a journal file shortly after it is created in order to do
5303 ** whatever it does.  While this other process is holding the
5304 ** file open, we will be unable to delete it.  To work around this
5305 ** problem, we delay 100 milliseconds and try to delete again.  Up
5306 ** to MX_DELETION_ATTEMPTs deletion attempts are run before giving
5307 ** up and returning an error.
5308 */
5309 static int winDelete(
5310   sqlite3_vfs *pVfs,          /* Not used on win32 */
5311   const char *zFilename,      /* Name of file to delete */
5312   int syncDir                 /* Not used on win32 */
5313 ){
5314   int cnt = 0;
5315   int rc;
5316   DWORD attr;
5317   DWORD lastErrno = 0;
5318   void *zConverted;
5319   UNUSED_PARAMETER(pVfs);
5320   UNUSED_PARAMETER(syncDir);
5321 
5322   SimulateIOError(return SQLITE_IOERR_DELETE);
5323   OSTRACE(("DELETE name=%s, syncDir=%d\n", zFilename, syncDir));
5324 
5325   zConverted = winConvertFromUtf8Filename(zFilename);
5326   if( zConverted==0 ){
5327     OSTRACE(("DELETE name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
5328     return SQLITE_IOERR_NOMEM_BKPT;
5329   }
5330   if( osIsNT() ){
5331     do {
5332 #if SQLITE_OS_WINRT
5333       WIN32_FILE_ATTRIBUTE_DATA sAttrData;
5334       memset(&sAttrData, 0, sizeof(sAttrData));
5335       if ( osGetFileAttributesExW(zConverted, GetFileExInfoStandard,
5336                                   &sAttrData) ){
5337         attr = sAttrData.dwFileAttributes;
5338       }else{
5339         lastErrno = osGetLastError();
5340         if( lastErrno==ERROR_FILE_NOT_FOUND
5341          || lastErrno==ERROR_PATH_NOT_FOUND ){
5342           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5343         }else{
5344           rc = SQLITE_ERROR;
5345         }
5346         break;
5347       }
5348 #else
5349       attr = osGetFileAttributesW(zConverted);
5350 #endif
5351       if ( attr==INVALID_FILE_ATTRIBUTES ){
5352         lastErrno = osGetLastError();
5353         if( lastErrno==ERROR_FILE_NOT_FOUND
5354          || lastErrno==ERROR_PATH_NOT_FOUND ){
5355           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5356         }else{
5357           rc = SQLITE_ERROR;
5358         }
5359         break;
5360       }
5361       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
5362         rc = SQLITE_ERROR; /* Files only. */
5363         break;
5364       }
5365       if ( osDeleteFileW(zConverted) ){
5366         rc = SQLITE_OK; /* Deleted OK. */
5367         break;
5368       }
5369       if ( !winRetryIoerr(&cnt, &lastErrno) ){
5370         rc = SQLITE_ERROR; /* No more retries. */
5371         break;
5372       }
5373     } while(1);
5374   }
5375 #ifdef SQLITE_WIN32_HAS_ANSI
5376   else{
5377     do {
5378       attr = osGetFileAttributesA(zConverted);
5379       if ( attr==INVALID_FILE_ATTRIBUTES ){
5380         lastErrno = osGetLastError();
5381         if( lastErrno==ERROR_FILE_NOT_FOUND
5382          || lastErrno==ERROR_PATH_NOT_FOUND ){
5383           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5384         }else{
5385           rc = SQLITE_ERROR;
5386         }
5387         break;
5388       }
5389       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
5390         rc = SQLITE_ERROR; /* Files only. */
5391         break;
5392       }
5393       if ( osDeleteFileA(zConverted) ){
5394         rc = SQLITE_OK; /* Deleted OK. */
5395         break;
5396       }
5397       if ( !winRetryIoerr(&cnt, &lastErrno) ){
5398         rc = SQLITE_ERROR; /* No more retries. */
5399         break;
5400       }
5401     } while(1);
5402   }
5403 #endif
5404   if( rc && rc!=SQLITE_IOERR_DELETE_NOENT ){
5405     rc = winLogError(SQLITE_IOERR_DELETE, lastErrno, "winDelete", zFilename);
5406   }else{
5407     winLogIoerr(cnt, __LINE__);
5408   }
5409   sqlite3_free(zConverted);
5410   OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));
5411   return rc;
5412 }
5413 
5414 /*
5415 ** Check the existence and status of a file.
5416 */
5417 static int winAccess(
5418   sqlite3_vfs *pVfs,         /* Not used on win32 */
5419   const char *zFilename,     /* Name of file to check */
5420   int flags,                 /* Type of test to make on this file */
5421   int *pResOut               /* OUT: Result */
5422 ){
5423   DWORD attr;
5424   int rc = 0;
5425   DWORD lastErrno = 0;
5426   void *zConverted;
5427   UNUSED_PARAMETER(pVfs);
5428 
5429   SimulateIOError( return SQLITE_IOERR_ACCESS; );
5430   OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",
5431            zFilename, flags, pResOut));
5432 
5433   zConverted = winConvertFromUtf8Filename(zFilename);
5434   if( zConverted==0 ){
5435     OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
5436     return SQLITE_IOERR_NOMEM_BKPT;
5437   }
5438   if( osIsNT() ){
5439     int cnt = 0;
5440     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
5441     memset(&sAttrData, 0, sizeof(sAttrData));
5442     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
5443                              GetFileExInfoStandard,
5444                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
5445     if( rc ){
5446       /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
5447       ** as if it does not exist.
5448       */
5449       if(    flags==SQLITE_ACCESS_EXISTS
5450           && sAttrData.nFileSizeHigh==0
5451           && sAttrData.nFileSizeLow==0 ){
5452         attr = INVALID_FILE_ATTRIBUTES;
5453       }else{
5454         attr = sAttrData.dwFileAttributes;
5455       }
5456     }else{
5457       winLogIoerr(cnt, __LINE__);
5458       if( lastErrno!=ERROR_FILE_NOT_FOUND && lastErrno!=ERROR_PATH_NOT_FOUND ){
5459         sqlite3_free(zConverted);
5460         return winLogError(SQLITE_IOERR_ACCESS, lastErrno, "winAccess",
5461                            zFilename);
5462       }else{
5463         attr = INVALID_FILE_ATTRIBUTES;
5464       }
5465     }
5466   }
5467 #ifdef SQLITE_WIN32_HAS_ANSI
5468   else{
5469     attr = osGetFileAttributesA((char*)zConverted);
5470   }
5471 #endif
5472   sqlite3_free(zConverted);
5473   switch( flags ){
5474     case SQLITE_ACCESS_READ:
5475     case SQLITE_ACCESS_EXISTS:
5476       rc = attr!=INVALID_FILE_ATTRIBUTES;
5477       break;
5478     case SQLITE_ACCESS_READWRITE:
5479       rc = attr!=INVALID_FILE_ATTRIBUTES &&
5480              (attr & FILE_ATTRIBUTE_READONLY)==0;
5481       break;
5482     default:
5483       assert(!"Invalid flags argument");
5484   }
5485   *pResOut = rc;
5486   OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
5487            zFilename, pResOut, *pResOut));
5488   return SQLITE_OK;
5489 }
5490 
5491 /*
5492 ** Returns non-zero if the specified path name starts with the "long path"
5493 ** prefix.
5494 */
5495 static BOOL winIsLongPathPrefix(
5496   const char *zPathname
5497 ){
5498   return ( zPathname[0]=='\\' && zPathname[1]=='\\'
5499         && zPathname[2]=='?'  && zPathname[3]=='\\' );
5500 }
5501 
5502 /*
5503 ** Returns non-zero if the specified path name starts with a drive letter
5504 ** followed by a colon character.
5505 */
5506 static BOOL winIsDriveLetterAndColon(
5507   const char *zPathname
5508 ){
5509   return ( sqlite3Isalpha(zPathname[0]) && zPathname[1]==':' );
5510 }
5511 
5512 /*
5513 ** Returns non-zero if the specified path name should be used verbatim.  If
5514 ** non-zero is returned from this function, the calling function must simply
5515 ** use the provided path name verbatim -OR- resolve it into a full path name
5516 ** using the GetFullPathName Win32 API function (if available).
5517 */
5518 static BOOL winIsVerbatimPathname(
5519   const char *zPathname
5520 ){
5521   /*
5522   ** If the path name starts with a forward slash or a backslash, it is either
5523   ** a legal UNC name, a volume relative path, or an absolute path name in the
5524   ** "Unix" format on Windows.  There is no easy way to differentiate between
5525   ** the final two cases; therefore, we return the safer return value of TRUE
5526   ** so that callers of this function will simply use it verbatim.
5527   */
5528   if ( winIsDirSep(zPathname[0]) ){
5529     return TRUE;
5530   }
5531 
5532   /*
5533   ** If the path name starts with a letter and a colon it is either a volume
5534   ** relative path or an absolute path.  Callers of this function must not
5535   ** attempt to treat it as a relative path name (i.e. they should simply use
5536   ** it verbatim).
5537   */
5538   if ( winIsDriveLetterAndColon(zPathname) ){
5539     return TRUE;
5540   }
5541 
5542   /*
5543   ** If we get to this point, the path name should almost certainly be a purely
5544   ** relative one (i.e. not a UNC name, not absolute, and not volume relative).
5545   */
5546   return FALSE;
5547 }
5548 
5549 /*
5550 ** Turn a relative pathname into a full pathname.  Write the full
5551 ** pathname into zOut[].  zOut[] will be at least pVfs->mxPathname
5552 ** bytes in size.
5553 */
5554 static int winFullPathname(
5555   sqlite3_vfs *pVfs,            /* Pointer to vfs object */
5556   const char *zRelative,        /* Possibly relative input path */
5557   int nFull,                    /* Size of output buffer in bytes */
5558   char *zFull                   /* Output buffer */
5559 ){
5560 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
5561   DWORD nByte;
5562   void *zConverted;
5563   char *zOut;
5564 #endif
5565 
5566   /* If this path name begins with "/X:" or "\\?\", where "X" is any
5567   ** alphabetic character, discard the initial "/" from the pathname.
5568   */
5569   if( zRelative[0]=='/' && (winIsDriveLetterAndColon(zRelative+1)
5570        || winIsLongPathPrefix(zRelative+1)) ){
5571     zRelative++;
5572   }
5573 
5574 #if defined(__CYGWIN__)
5575   SimulateIOError( return SQLITE_ERROR );
5576   UNUSED_PARAMETER(nFull);
5577   assert( nFull>=pVfs->mxPathname );
5578   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5579     /*
5580     ** NOTE: We are dealing with a relative path name and the data
5581     **       directory has been set.  Therefore, use it as the basis
5582     **       for converting the relative path name to an absolute
5583     **       one by prepending the data directory and a slash.
5584     */
5585     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
5586     if( !zOut ){
5587       return SQLITE_IOERR_NOMEM_BKPT;
5588     }
5589     if( cygwin_conv_path(
5590             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A) |
5591             CCP_RELATIVE, zRelative, zOut, pVfs->mxPathname+1)<0 ){
5592       sqlite3_free(zOut);
5593       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
5594                          "winFullPathname1", zRelative);
5595     }else{
5596       char *zUtf8 = winConvertToUtf8Filename(zOut);
5597       if( !zUtf8 ){
5598         sqlite3_free(zOut);
5599         return SQLITE_IOERR_NOMEM_BKPT;
5600       }
5601       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5602                        sqlite3_data_directory, winGetDirSep(), zUtf8);
5603       sqlite3_free(zUtf8);
5604       sqlite3_free(zOut);
5605     }
5606   }else{
5607     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
5608     if( !zOut ){
5609       return SQLITE_IOERR_NOMEM_BKPT;
5610     }
5611     if( cygwin_conv_path(
5612             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A),
5613             zRelative, zOut, pVfs->mxPathname+1)<0 ){
5614       sqlite3_free(zOut);
5615       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
5616                          "winFullPathname2", zRelative);
5617     }else{
5618       char *zUtf8 = winConvertToUtf8Filename(zOut);
5619       if( !zUtf8 ){
5620         sqlite3_free(zOut);
5621         return SQLITE_IOERR_NOMEM_BKPT;
5622       }
5623       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zUtf8);
5624       sqlite3_free(zUtf8);
5625       sqlite3_free(zOut);
5626     }
5627   }
5628   return SQLITE_OK;
5629 #endif
5630 
5631 #if (SQLITE_OS_WINCE || SQLITE_OS_WINRT) && !defined(__CYGWIN__)
5632   SimulateIOError( return SQLITE_ERROR );
5633   /* WinCE has no concept of a relative pathname, or so I am told. */
5634   /* WinRT has no way to convert a relative path to an absolute one. */
5635   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5636     /*
5637     ** NOTE: We are dealing with a relative path name and the data
5638     **       directory has been set.  Therefore, use it as the basis
5639     **       for converting the relative path name to an absolute
5640     **       one by prepending the data directory and a backslash.
5641     */
5642     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5643                      sqlite3_data_directory, winGetDirSep(), zRelative);
5644   }else{
5645     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zRelative);
5646   }
5647   return SQLITE_OK;
5648 #endif
5649 
5650 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
5651   /* It's odd to simulate an io-error here, but really this is just
5652   ** using the io-error infrastructure to test that SQLite handles this
5653   ** function failing. This function could fail if, for example, the
5654   ** current working directory has been unlinked.
5655   */
5656   SimulateIOError( return SQLITE_ERROR );
5657   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5658     /*
5659     ** NOTE: We are dealing with a relative path name and the data
5660     **       directory has been set.  Therefore, use it as the basis
5661     **       for converting the relative path name to an absolute
5662     **       one by prepending the data directory and a backslash.
5663     */
5664     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5665                      sqlite3_data_directory, winGetDirSep(), zRelative);
5666     return SQLITE_OK;
5667   }
5668   zConverted = winConvertFromUtf8Filename(zRelative);
5669   if( zConverted==0 ){
5670     return SQLITE_IOERR_NOMEM_BKPT;
5671   }
5672   if( osIsNT() ){
5673     LPWSTR zTemp;
5674     nByte = osGetFullPathNameW((LPCWSTR)zConverted, 0, 0, 0);
5675     if( nByte==0 ){
5676       sqlite3_free(zConverted);
5677       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5678                          "winFullPathname1", zRelative);
5679     }
5680     nByte += 3;
5681     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
5682     if( zTemp==0 ){
5683       sqlite3_free(zConverted);
5684       return SQLITE_IOERR_NOMEM_BKPT;
5685     }
5686     nByte = osGetFullPathNameW((LPCWSTR)zConverted, nByte, zTemp, 0);
5687     if( nByte==0 ){
5688       sqlite3_free(zConverted);
5689       sqlite3_free(zTemp);
5690       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5691                          "winFullPathname2", zRelative);
5692     }
5693     sqlite3_free(zConverted);
5694     zOut = winUnicodeToUtf8(zTemp);
5695     sqlite3_free(zTemp);
5696   }
5697 #ifdef SQLITE_WIN32_HAS_ANSI
5698   else{
5699     char *zTemp;
5700     nByte = osGetFullPathNameA((char*)zConverted, 0, 0, 0);
5701     if( nByte==0 ){
5702       sqlite3_free(zConverted);
5703       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5704                          "winFullPathname3", 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 = osGetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
5713     if( nByte==0 ){
5714       sqlite3_free(zConverted);
5715       sqlite3_free(zTemp);
5716       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5717                          "winFullPathname4", zRelative);
5718     }
5719     sqlite3_free(zConverted);
5720     zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
5721     sqlite3_free(zTemp);
5722   }
5723 #endif
5724   if( zOut ){
5725     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zOut);
5726     sqlite3_free(zOut);
5727     return SQLITE_OK;
5728   }else{
5729     return SQLITE_IOERR_NOMEM_BKPT;
5730   }
5731 #endif
5732 }
5733 
5734 #ifndef SQLITE_OMIT_LOAD_EXTENSION
5735 /*
5736 ** Interfaces for opening a shared library, finding entry points
5737 ** within the shared library, and closing the shared library.
5738 */
5739 static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
5740   HANDLE h;
5741 #if defined(__CYGWIN__)
5742   int nFull = pVfs->mxPathname+1;
5743   char *zFull = sqlite3MallocZero( nFull );
5744   void *zConverted = 0;
5745   if( zFull==0 ){
5746     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5747     return 0;
5748   }
5749   if( winFullPathname(pVfs, zFilename, nFull, zFull)!=SQLITE_OK ){
5750     sqlite3_free(zFull);
5751     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5752     return 0;
5753   }
5754   zConverted = winConvertFromUtf8Filename(zFull);
5755   sqlite3_free(zFull);
5756 #else
5757   void *zConverted = winConvertFromUtf8Filename(zFilename);
5758   UNUSED_PARAMETER(pVfs);
5759 #endif
5760   if( zConverted==0 ){
5761     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5762     return 0;
5763   }
5764   if( osIsNT() ){
5765 #if SQLITE_OS_WINRT
5766     h = osLoadPackagedLibrary((LPCWSTR)zConverted, 0);
5767 #else
5768     h = osLoadLibraryW((LPCWSTR)zConverted);
5769 #endif
5770   }
5771 #ifdef SQLITE_WIN32_HAS_ANSI
5772   else{
5773     h = osLoadLibraryA((char*)zConverted);
5774   }
5775 #endif
5776   OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)h));
5777   sqlite3_free(zConverted);
5778   return (void*)h;
5779 }
5780 static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
5781   UNUSED_PARAMETER(pVfs);
5782   winGetLastErrorMsg(osGetLastError(), nBuf, zBufOut);
5783 }
5784 static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){
5785   FARPROC proc;
5786   UNUSED_PARAMETER(pVfs);
5787   proc = osGetProcAddressA((HANDLE)pH, zSym);
5788   OSTRACE(("DLSYM handle=%p, symbol=%s, address=%p\n",
5789            (void*)pH, zSym, (void*)proc));
5790   return (void(*)(void))proc;
5791 }
5792 static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
5793   UNUSED_PARAMETER(pVfs);
5794   osFreeLibrary((HANDLE)pHandle);
5795   OSTRACE(("DLCLOSE handle=%p\n", (void*)pHandle));
5796 }
5797 #else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
5798   #define winDlOpen  0
5799   #define winDlError 0
5800   #define winDlSym   0
5801   #define winDlClose 0
5802 #endif
5803 
5804 /* State information for the randomness gatherer. */
5805 typedef struct EntropyGatherer EntropyGatherer;
5806 struct EntropyGatherer {
5807   unsigned char *a;   /* Gather entropy into this buffer */
5808   int na;             /* Size of a[] in bytes */
5809   int i;              /* XOR next input into a[i] */
5810   int nXor;           /* Number of XOR operations done */
5811 };
5812 
5813 #if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)
5814 /* Mix sz bytes of entropy into p. */
5815 static void xorMemory(EntropyGatherer *p, unsigned char *x, int sz){
5816   int j, k;
5817   for(j=0, k=p->i; j<sz; j++){
5818     p->a[k++] ^= x[j];
5819     if( k>=p->na ) k = 0;
5820   }
5821   p->i = k;
5822   p->nXor += sz;
5823 }
5824 #endif /* !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS) */
5825 
5826 /*
5827 ** Write up to nBuf bytes of randomness into zBuf.
5828 */
5829 static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5830 #if defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS)
5831   UNUSED_PARAMETER(pVfs);
5832   memset(zBuf, 0, nBuf);
5833   return nBuf;
5834 #else
5835   EntropyGatherer e;
5836   UNUSED_PARAMETER(pVfs);
5837   memset(zBuf, 0, nBuf);
5838   e.a = (unsigned char*)zBuf;
5839   e.na = nBuf;
5840   e.nXor = 0;
5841   e.i = 0;
5842   {
5843     SYSTEMTIME x;
5844     osGetSystemTime(&x);
5845     xorMemory(&e, (unsigned char*)&x, sizeof(SYSTEMTIME));
5846   }
5847   {
5848     DWORD pid = osGetCurrentProcessId();
5849     xorMemory(&e, (unsigned char*)&pid, sizeof(DWORD));
5850   }
5851 #if SQLITE_OS_WINRT
5852   {
5853     ULONGLONG cnt = osGetTickCount64();
5854     xorMemory(&e, (unsigned char*)&cnt, sizeof(ULONGLONG));
5855   }
5856 #else
5857   {
5858     DWORD cnt = osGetTickCount();
5859     xorMemory(&e, (unsigned char*)&cnt, sizeof(DWORD));
5860   }
5861 #endif /* SQLITE_OS_WINRT */
5862   {
5863     LARGE_INTEGER i;
5864     osQueryPerformanceCounter(&i);
5865     xorMemory(&e, (unsigned char*)&i, sizeof(LARGE_INTEGER));
5866   }
5867 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
5868   {
5869     UUID id;
5870     memset(&id, 0, sizeof(UUID));
5871     osUuidCreate(&id);
5872     xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
5873     memset(&id, 0, sizeof(UUID));
5874     osUuidCreateSequential(&id);
5875     xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
5876   }
5877 #endif /* !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID */
5878   return e.nXor>nBuf ? nBuf : e.nXor;
5879 #endif /* defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS) */
5880 }
5881 
5882 
5883 /*
5884 ** Sleep for a little while.  Return the amount of time slept.
5885 */
5886 static int winSleep(sqlite3_vfs *pVfs, int microsec){
5887   sqlite3_win32_sleep((microsec+999)/1000);
5888   UNUSED_PARAMETER(pVfs);
5889   return ((microsec+999)/1000)*1000;
5890 }
5891 
5892 /*
5893 ** The following variable, if set to a non-zero value, is interpreted as
5894 ** the number of seconds since 1970 and is used to set the result of
5895 ** sqlite3OsCurrentTime() during testing.
5896 */
5897 #ifdef SQLITE_TEST
5898 int sqlite3_current_time = 0;  /* Fake system time in seconds since 1970. */
5899 #endif
5900 
5901 /*
5902 ** Find the current time (in Universal Coordinated Time).  Write into *piNow
5903 ** the current time and date as a Julian Day number times 86_400_000.  In
5904 ** other words, write into *piNow the number of milliseconds since the Julian
5905 ** epoch of noon in Greenwich on November 24, 4714 B.C according to the
5906 ** proleptic Gregorian calendar.
5907 **
5908 ** On success, return SQLITE_OK.  Return SQLITE_ERROR if the time and date
5909 ** cannot be found.
5910 */
5911 static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
5912   /* FILETIME structure is a 64-bit value representing the number of
5913      100-nanosecond intervals since January 1, 1601 (= JD 2305813.5).
5914   */
5915   FILETIME ft;
5916   static const sqlite3_int64 winFiletimeEpoch = 23058135*(sqlite3_int64)8640000;
5917 #ifdef SQLITE_TEST
5918   static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000;
5919 #endif
5920   /* 2^32 - to avoid use of LL and warnings in gcc */
5921   static const sqlite3_int64 max32BitValue =
5922       (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 +
5923       (sqlite3_int64)294967296;
5924 
5925 #if SQLITE_OS_WINCE
5926   SYSTEMTIME time;
5927   osGetSystemTime(&time);
5928   /* if SystemTimeToFileTime() fails, it returns zero. */
5929   if (!osSystemTimeToFileTime(&time,&ft)){
5930     return SQLITE_ERROR;
5931   }
5932 #else
5933   osGetSystemTimeAsFileTime( &ft );
5934 #endif
5935 
5936   *piNow = winFiletimeEpoch +
5937             ((((sqlite3_int64)ft.dwHighDateTime)*max32BitValue) +
5938                (sqlite3_int64)ft.dwLowDateTime)/(sqlite3_int64)10000;
5939 
5940 #ifdef SQLITE_TEST
5941   if( sqlite3_current_time ){
5942     *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;
5943   }
5944 #endif
5945   UNUSED_PARAMETER(pVfs);
5946   return SQLITE_OK;
5947 }
5948 
5949 /*
5950 ** Find the current time (in Universal Coordinated Time).  Write the
5951 ** current time and date as a Julian Day number into *prNow and
5952 ** return 0.  Return 1 if the time and date cannot be found.
5953 */
5954 static int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){
5955   int rc;
5956   sqlite3_int64 i;
5957   rc = winCurrentTimeInt64(pVfs, &i);
5958   if( !rc ){
5959     *prNow = i/86400000.0;
5960   }
5961   return rc;
5962 }
5963 
5964 /*
5965 ** The idea is that this function works like a combination of
5966 ** GetLastError() and FormatMessage() on Windows (or errno and
5967 ** strerror_r() on Unix). After an error is returned by an OS
5968 ** function, SQLite calls this function with zBuf pointing to
5969 ** a buffer of nBuf bytes. The OS layer should populate the
5970 ** buffer with a nul-terminated UTF-8 encoded error message
5971 ** describing the last IO error to have occurred within the calling
5972 ** thread.
5973 **
5974 ** If the error message is too large for the supplied buffer,
5975 ** it should be truncated. The return value of xGetLastError
5976 ** is zero if the error message fits in the buffer, or non-zero
5977 ** otherwise (if the message was truncated). If non-zero is returned,
5978 ** then it is not necessary to include the nul-terminator character
5979 ** in the output buffer.
5980 **
5981 ** Not supplying an error message will have no adverse effect
5982 ** on SQLite. It is fine to have an implementation that never
5983 ** returns an error message:
5984 **
5985 **   int xGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5986 **     assert(zBuf[0]=='\0');
5987 **     return 0;
5988 **   }
5989 **
5990 ** However if an error message is supplied, it will be incorporated
5991 ** by sqlite into the error message available to the user using
5992 ** sqlite3_errmsg(), possibly making IO errors easier to debug.
5993 */
5994 static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5995   DWORD e = osGetLastError();
5996   UNUSED_PARAMETER(pVfs);
5997   if( nBuf>0 ) winGetLastErrorMsg(e, nBuf, zBuf);
5998   return e;
5999 }
6000 
6001 /*
6002 ** Initialize and deinitialize the operating system interface.
6003 */
6004 int sqlite3_os_init(void){
6005   static sqlite3_vfs winVfs = {
6006     3,                     /* iVersion */
6007     sizeof(winFile),       /* szOsFile */
6008     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
6009     0,                     /* pNext */
6010     "win32",               /* zName */
6011     &winAppData,           /* pAppData */
6012     winOpen,               /* xOpen */
6013     winDelete,             /* xDelete */
6014     winAccess,             /* xAccess */
6015     winFullPathname,       /* xFullPathname */
6016     winDlOpen,             /* xDlOpen */
6017     winDlError,            /* xDlError */
6018     winDlSym,              /* xDlSym */
6019     winDlClose,            /* xDlClose */
6020     winRandomness,         /* xRandomness */
6021     winSleep,              /* xSleep */
6022     winCurrentTime,        /* xCurrentTime */
6023     winGetLastError,       /* xGetLastError */
6024     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6025     winSetSystemCall,      /* xSetSystemCall */
6026     winGetSystemCall,      /* xGetSystemCall */
6027     winNextSystemCall,     /* xNextSystemCall */
6028   };
6029 #if defined(SQLITE_WIN32_HAS_WIDE)
6030   static sqlite3_vfs winLongPathVfs = {
6031     3,                     /* iVersion */
6032     sizeof(winFile),       /* szOsFile */
6033     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
6034     0,                     /* pNext */
6035     "win32-longpath",      /* zName */
6036     &winAppData,           /* pAppData */
6037     winOpen,               /* xOpen */
6038     winDelete,             /* xDelete */
6039     winAccess,             /* xAccess */
6040     winFullPathname,       /* xFullPathname */
6041     winDlOpen,             /* xDlOpen */
6042     winDlError,            /* xDlError */
6043     winDlSym,              /* xDlSym */
6044     winDlClose,            /* xDlClose */
6045     winRandomness,         /* xRandomness */
6046     winSleep,              /* xSleep */
6047     winCurrentTime,        /* xCurrentTime */
6048     winGetLastError,       /* xGetLastError */
6049     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6050     winSetSystemCall,      /* xSetSystemCall */
6051     winGetSystemCall,      /* xGetSystemCall */
6052     winNextSystemCall,     /* xNextSystemCall */
6053   };
6054 #endif
6055   static sqlite3_vfs winNolockVfs = {
6056     3,                     /* iVersion */
6057     sizeof(winFile),       /* szOsFile */
6058     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
6059     0,                     /* pNext */
6060     "win32-none",          /* zName */
6061     &winNolockAppData,     /* pAppData */
6062     winOpen,               /* xOpen */
6063     winDelete,             /* xDelete */
6064     winAccess,             /* xAccess */
6065     winFullPathname,       /* xFullPathname */
6066     winDlOpen,             /* xDlOpen */
6067     winDlError,            /* xDlError */
6068     winDlSym,              /* xDlSym */
6069     winDlClose,            /* xDlClose */
6070     winRandomness,         /* xRandomness */
6071     winSleep,              /* xSleep */
6072     winCurrentTime,        /* xCurrentTime */
6073     winGetLastError,       /* xGetLastError */
6074     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6075     winSetSystemCall,      /* xSetSystemCall */
6076     winGetSystemCall,      /* xGetSystemCall */
6077     winNextSystemCall,     /* xNextSystemCall */
6078   };
6079 #if defined(SQLITE_WIN32_HAS_WIDE)
6080   static sqlite3_vfs winLongPathNolockVfs = {
6081     3,                     /* iVersion */
6082     sizeof(winFile),       /* szOsFile */
6083     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
6084     0,                     /* pNext */
6085     "win32-longpath-none", /* zName */
6086     &winNolockAppData,     /* pAppData */
6087     winOpen,               /* xOpen */
6088     winDelete,             /* xDelete */
6089     winAccess,             /* xAccess */
6090     winFullPathname,       /* xFullPathname */
6091     winDlOpen,             /* xDlOpen */
6092     winDlError,            /* xDlError */
6093     winDlSym,              /* xDlSym */
6094     winDlClose,            /* xDlClose */
6095     winRandomness,         /* xRandomness */
6096     winSleep,              /* xSleep */
6097     winCurrentTime,        /* xCurrentTime */
6098     winGetLastError,       /* xGetLastError */
6099     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6100     winSetSystemCall,      /* xSetSystemCall */
6101     winGetSystemCall,      /* xGetSystemCall */
6102     winNextSystemCall,     /* xNextSystemCall */
6103   };
6104 #endif
6105 
6106   /* Double-check that the aSyscall[] array has been constructed
6107   ** correctly.  See ticket [bb3a86e890c8e96ab] */
6108   assert( ArraySize(aSyscall)==80 );
6109 
6110   /* get memory map allocation granularity */
6111   memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
6112 #if SQLITE_OS_WINRT
6113   osGetNativeSystemInfo(&winSysInfo);
6114 #else
6115   osGetSystemInfo(&winSysInfo);
6116 #endif
6117   assert( winSysInfo.dwAllocationGranularity>0 );
6118   assert( winSysInfo.dwPageSize>0 );
6119 
6120   sqlite3_vfs_register(&winVfs, 1);
6121 
6122 #if defined(SQLITE_WIN32_HAS_WIDE)
6123   sqlite3_vfs_register(&winLongPathVfs, 0);
6124 #endif
6125 
6126   sqlite3_vfs_register(&winNolockVfs, 0);
6127 
6128 #if defined(SQLITE_WIN32_HAS_WIDE)
6129   sqlite3_vfs_register(&winLongPathNolockVfs, 0);
6130 #endif
6131 
6132 #ifndef SQLITE_OMIT_WAL
6133   winBigLock = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1);
6134 #endif
6135 
6136   return SQLITE_OK;
6137 }
6138 
6139 int sqlite3_os_end(void){
6140 #if SQLITE_OS_WINRT
6141   if( sleepObj!=NULL ){
6142     osCloseHandle(sleepObj);
6143     sleepObj = NULL;
6144   }
6145 #endif
6146 
6147 #ifndef SQLITE_OMIT_WAL
6148   winBigLock = 0;
6149 #endif
6150 
6151   return SQLITE_OK;
6152 }
6153 
6154 #endif /* SQLITE_OS_WIN */
6155