xref: /sqlite-3.40.0/src/os_win.c (revision b80bb6ce)
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;       /* Usable size of mapped region */
288   sqlite3_int64 mmapSizeActual; /* Actual size of mapped region */
289   sqlite3_int64 mmapSizeMax;    /* Configured FCNTL_MMAP_SIZE value */
290 #endif
291 };
292 
293 /*
294 ** The winVfsAppData structure is used for the pAppData member for all of the
295 ** Win32 VFS variants.
296 */
297 typedef struct winVfsAppData winVfsAppData;
298 struct winVfsAppData {
299   const sqlite3_io_methods *pMethod; /* The file I/O methods to use. */
300   void *pAppData;                    /* The extra pAppData, if any. */
301   BOOL bNoLock;                      /* Non-zero if locking is disabled. */
302 };
303 
304 /*
305 ** Allowed values for winFile.ctrlFlags
306 */
307 #define WINFILE_RDONLY          0x02   /* Connection is read only */
308 #define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */
309 #define WINFILE_PSOW            0x10   /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
310 
311 /*
312  * The size of the buffer used by sqlite3_win32_write_debug().
313  */
314 #ifndef SQLITE_WIN32_DBG_BUF_SIZE
315 #  define SQLITE_WIN32_DBG_BUF_SIZE   ((int)(4096-sizeof(DWORD)))
316 #endif
317 
318 /*
319  * If compiled with SQLITE_WIN32_MALLOC on Windows, we will use the
320  * various Win32 API heap functions instead of our own.
321  */
322 #ifdef SQLITE_WIN32_MALLOC
323 
324 /*
325  * If this is non-zero, an isolated heap will be created by the native Win32
326  * allocator subsystem; otherwise, the default process heap will be used.  This
327  * setting has no effect when compiling for WinRT.  By default, this is enabled
328  * and an isolated heap will be created to store all allocated data.
329  *
330  ******************************************************************************
331  * WARNING: It is important to note that when this setting is non-zero and the
332  *          winMemShutdown function is called (e.g. by the sqlite3_shutdown
333  *          function), all data that was allocated using the isolated heap will
334  *          be freed immediately and any attempt to access any of that freed
335  *          data will almost certainly result in an immediate access violation.
336  ******************************************************************************
337  */
338 #ifndef SQLITE_WIN32_HEAP_CREATE
339 #  define SQLITE_WIN32_HEAP_CREATE        (TRUE)
340 #endif
341 
342 /*
343  * This is the maximum possible initial size of the Win32-specific heap, in
344  * bytes.
345  */
346 #ifndef SQLITE_WIN32_HEAP_MAX_INIT_SIZE
347 #  define SQLITE_WIN32_HEAP_MAX_INIT_SIZE (4294967295U)
348 #endif
349 
350 /*
351  * This is the extra space for the initial size of the Win32-specific heap,
352  * in bytes.  This value may be zero.
353  */
354 #ifndef SQLITE_WIN32_HEAP_INIT_EXTRA
355 #  define SQLITE_WIN32_HEAP_INIT_EXTRA  (4194304)
356 #endif
357 
358 /*
359  * Calculate the maximum legal cache size, in pages, based on the maximum
360  * possible initial heap size and the default page size, setting aside the
361  * needed extra space.
362  */
363 #ifndef SQLITE_WIN32_MAX_CACHE_SIZE
364 #  define SQLITE_WIN32_MAX_CACHE_SIZE   (((SQLITE_WIN32_HEAP_MAX_INIT_SIZE) - \
365                                           (SQLITE_WIN32_HEAP_INIT_EXTRA)) / \
366                                          (SQLITE_DEFAULT_PAGE_SIZE))
367 #endif
368 
369 /*
370  * This is cache size used in the calculation of the initial size of the
371  * Win32-specific heap.  It cannot be negative.
372  */
373 #ifndef SQLITE_WIN32_CACHE_SIZE
374 #  if SQLITE_DEFAULT_CACHE_SIZE>=0
375 #    define SQLITE_WIN32_CACHE_SIZE     (SQLITE_DEFAULT_CACHE_SIZE)
376 #  else
377 #    define SQLITE_WIN32_CACHE_SIZE     (-(SQLITE_DEFAULT_CACHE_SIZE))
378 #  endif
379 #endif
380 
381 /*
382  * Make sure that the calculated cache size, in pages, cannot cause the
383  * initial size of the Win32-specific heap to exceed the maximum amount
384  * of memory that can be specified in the call to HeapCreate.
385  */
386 #if SQLITE_WIN32_CACHE_SIZE>SQLITE_WIN32_MAX_CACHE_SIZE
387 #  undef SQLITE_WIN32_CACHE_SIZE
388 #  define SQLITE_WIN32_CACHE_SIZE       (2000)
389 #endif
390 
391 /*
392  * The initial size of the Win32-specific heap.  This value may be zero.
393  */
394 #ifndef SQLITE_WIN32_HEAP_INIT_SIZE
395 #  define SQLITE_WIN32_HEAP_INIT_SIZE   ((SQLITE_WIN32_CACHE_SIZE) * \
396                                          (SQLITE_DEFAULT_PAGE_SIZE) + \
397                                          (SQLITE_WIN32_HEAP_INIT_EXTRA))
398 #endif
399 
400 /*
401  * The maximum size of the Win32-specific heap.  This value may be zero.
402  */
403 #ifndef SQLITE_WIN32_HEAP_MAX_SIZE
404 #  define SQLITE_WIN32_HEAP_MAX_SIZE    (0)
405 #endif
406 
407 /*
408  * The extra flags to use in calls to the Win32 heap APIs.  This value may be
409  * zero for the default behavior.
410  */
411 #ifndef SQLITE_WIN32_HEAP_FLAGS
412 #  define SQLITE_WIN32_HEAP_FLAGS       (0)
413 #endif
414 
415 
416 /*
417 ** The winMemData structure stores information required by the Win32-specific
418 ** sqlite3_mem_methods implementation.
419 */
420 typedef struct winMemData winMemData;
421 struct winMemData {
422 #ifndef NDEBUG
423   u32 magic1;   /* Magic number to detect structure corruption. */
424 #endif
425   HANDLE hHeap; /* The handle to our heap. */
426   BOOL bOwned;  /* Do we own the heap (i.e. destroy it on shutdown)? */
427 #ifndef NDEBUG
428   u32 magic2;   /* Magic number to detect structure corruption. */
429 #endif
430 };
431 
432 #ifndef NDEBUG
433 #define WINMEM_MAGIC1     0x42b2830b
434 #define WINMEM_MAGIC2     0xbd4d7cf4
435 #endif
436 
437 static struct winMemData win_mem_data = {
438 #ifndef NDEBUG
439   WINMEM_MAGIC1,
440 #endif
441   NULL, FALSE
442 #ifndef NDEBUG
443   ,WINMEM_MAGIC2
444 #endif
445 };
446 
447 #ifndef NDEBUG
448 #define winMemAssertMagic1() assert( win_mem_data.magic1==WINMEM_MAGIC1 )
449 #define winMemAssertMagic2() assert( win_mem_data.magic2==WINMEM_MAGIC2 )
450 #define winMemAssertMagic()  winMemAssertMagic1(); winMemAssertMagic2();
451 #else
452 #define winMemAssertMagic()
453 #endif
454 
455 #define winMemGetDataPtr()  &win_mem_data
456 #define winMemGetHeap()     win_mem_data.hHeap
457 #define winMemGetOwned()    win_mem_data.bOwned
458 
459 static void *winMemMalloc(int nBytes);
460 static void winMemFree(void *pPrior);
461 static void *winMemRealloc(void *pPrior, int nBytes);
462 static int winMemSize(void *p);
463 static int winMemRoundup(int n);
464 static int winMemInit(void *pAppData);
465 static void winMemShutdown(void *pAppData);
466 
467 const sqlite3_mem_methods *sqlite3MemGetWin32(void);
468 #endif /* SQLITE_WIN32_MALLOC */
469 
470 /*
471 ** The following variable is (normally) set once and never changes
472 ** thereafter.  It records whether the operating system is Win9x
473 ** or WinNT.
474 **
475 ** 0:   Operating system unknown.
476 ** 1:   Operating system is Win9x.
477 ** 2:   Operating system is WinNT.
478 **
479 ** In order to facilitate testing on a WinNT system, the test fixture
480 ** can manually set this value to 1 to emulate Win98 behavior.
481 */
482 #ifdef SQLITE_TEST
483 LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;
484 #else
485 static LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;
486 #endif
487 
488 #ifndef SYSCALL
489 #  define SYSCALL sqlite3_syscall_ptr
490 #endif
491 
492 /*
493 ** This function is not available on Windows CE or WinRT.
494  */
495 
496 #if SQLITE_OS_WINCE || SQLITE_OS_WINRT
497 #  define osAreFileApisANSI()       1
498 #endif
499 
500 /*
501 ** Many system calls are accessed through pointer-to-functions so that
502 ** they may be overridden at runtime to facilitate fault injection during
503 ** testing and sandboxing.  The following array holds the names and pointers
504 ** to all overrideable system calls.
505 */
506 static struct win_syscall {
507   const char *zName;            /* Name of the system call */
508   sqlite3_syscall_ptr pCurrent; /* Current value of the system call */
509   sqlite3_syscall_ptr pDefault; /* Default value */
510 } aSyscall[] = {
511 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
512   { "AreFileApisANSI",         (SYSCALL)AreFileApisANSI,         0 },
513 #else
514   { "AreFileApisANSI",         (SYSCALL)0,                       0 },
515 #endif
516 
517 #ifndef osAreFileApisANSI
518 #define osAreFileApisANSI ((BOOL(WINAPI*)(VOID))aSyscall[0].pCurrent)
519 #endif
520 
521 #if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)
522   { "CharLowerW",              (SYSCALL)CharLowerW,              0 },
523 #else
524   { "CharLowerW",              (SYSCALL)0,                       0 },
525 #endif
526 
527 #define osCharLowerW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[1].pCurrent)
528 
529 #if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)
530   { "CharUpperW",              (SYSCALL)CharUpperW,              0 },
531 #else
532   { "CharUpperW",              (SYSCALL)0,                       0 },
533 #endif
534 
535 #define osCharUpperW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[2].pCurrent)
536 
537   { "CloseHandle",             (SYSCALL)CloseHandle,             0 },
538 
539 #define osCloseHandle ((BOOL(WINAPI*)(HANDLE))aSyscall[3].pCurrent)
540 
541 #if defined(SQLITE_WIN32_HAS_ANSI)
542   { "CreateFileA",             (SYSCALL)CreateFileA,             0 },
543 #else
544   { "CreateFileA",             (SYSCALL)0,                       0 },
545 #endif
546 
547 #define osCreateFileA ((HANDLE(WINAPI*)(LPCSTR,DWORD,DWORD, \
548         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[4].pCurrent)
549 
550 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
551   { "CreateFileW",             (SYSCALL)CreateFileW,             0 },
552 #else
553   { "CreateFileW",             (SYSCALL)0,                       0 },
554 #endif
555 
556 #define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \
557         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)
558 
559 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
560         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0) && \
561         SQLITE_WIN32_CREATEFILEMAPPINGA
562   { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },
563 #else
564   { "CreateFileMappingA",      (SYSCALL)0,                       0 },
565 #endif
566 
567 #define osCreateFileMappingA ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
568         DWORD,DWORD,DWORD,LPCSTR))aSyscall[6].pCurrent)
569 
570 #if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
571         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
572   { "CreateFileMappingW",      (SYSCALL)CreateFileMappingW,      0 },
573 #else
574   { "CreateFileMappingW",      (SYSCALL)0,                       0 },
575 #endif
576 
577 #define osCreateFileMappingW ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
578         DWORD,DWORD,DWORD,LPCWSTR))aSyscall[7].pCurrent)
579 
580 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
581   { "CreateMutexW",            (SYSCALL)CreateMutexW,            0 },
582 #else
583   { "CreateMutexW",            (SYSCALL)0,                       0 },
584 #endif
585 
586 #define osCreateMutexW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,BOOL, \
587         LPCWSTR))aSyscall[8].pCurrent)
588 
589 #if defined(SQLITE_WIN32_HAS_ANSI)
590   { "DeleteFileA",             (SYSCALL)DeleteFileA,             0 },
591 #else
592   { "DeleteFileA",             (SYSCALL)0,                       0 },
593 #endif
594 
595 #define osDeleteFileA ((BOOL(WINAPI*)(LPCSTR))aSyscall[9].pCurrent)
596 
597 #if defined(SQLITE_WIN32_HAS_WIDE)
598   { "DeleteFileW",             (SYSCALL)DeleteFileW,             0 },
599 #else
600   { "DeleteFileW",             (SYSCALL)0,                       0 },
601 #endif
602 
603 #define osDeleteFileW ((BOOL(WINAPI*)(LPCWSTR))aSyscall[10].pCurrent)
604 
605 #if SQLITE_OS_WINCE
606   { "FileTimeToLocalFileTime", (SYSCALL)FileTimeToLocalFileTime, 0 },
607 #else
608   { "FileTimeToLocalFileTime", (SYSCALL)0,                       0 },
609 #endif
610 
611 #define osFileTimeToLocalFileTime ((BOOL(WINAPI*)(CONST FILETIME*, \
612         LPFILETIME))aSyscall[11].pCurrent)
613 
614 #if SQLITE_OS_WINCE
615   { "FileTimeToSystemTime",    (SYSCALL)FileTimeToSystemTime,    0 },
616 #else
617   { "FileTimeToSystemTime",    (SYSCALL)0,                       0 },
618 #endif
619 
620 #define osFileTimeToSystemTime ((BOOL(WINAPI*)(CONST FILETIME*, \
621         LPSYSTEMTIME))aSyscall[12].pCurrent)
622 
623   { "FlushFileBuffers",        (SYSCALL)FlushFileBuffers,        0 },
624 
625 #define osFlushFileBuffers ((BOOL(WINAPI*)(HANDLE))aSyscall[13].pCurrent)
626 
627 #if defined(SQLITE_WIN32_HAS_ANSI)
628   { "FormatMessageA",          (SYSCALL)FormatMessageA,          0 },
629 #else
630   { "FormatMessageA",          (SYSCALL)0,                       0 },
631 #endif
632 
633 #define osFormatMessageA ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPSTR, \
634         DWORD,va_list*))aSyscall[14].pCurrent)
635 
636 #if defined(SQLITE_WIN32_HAS_WIDE)
637   { "FormatMessageW",          (SYSCALL)FormatMessageW,          0 },
638 #else
639   { "FormatMessageW",          (SYSCALL)0,                       0 },
640 #endif
641 
642 #define osFormatMessageW ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPWSTR, \
643         DWORD,va_list*))aSyscall[15].pCurrent)
644 
645 #if !defined(SQLITE_OMIT_LOAD_EXTENSION)
646   { "FreeLibrary",             (SYSCALL)FreeLibrary,             0 },
647 #else
648   { "FreeLibrary",             (SYSCALL)0,                       0 },
649 #endif
650 
651 #define osFreeLibrary ((BOOL(WINAPI*)(HMODULE))aSyscall[16].pCurrent)
652 
653   { "GetCurrentProcessId",     (SYSCALL)GetCurrentProcessId,     0 },
654 
655 #define osGetCurrentProcessId ((DWORD(WINAPI*)(VOID))aSyscall[17].pCurrent)
656 
657 #if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)
658   { "GetDiskFreeSpaceA",       (SYSCALL)GetDiskFreeSpaceA,       0 },
659 #else
660   { "GetDiskFreeSpaceA",       (SYSCALL)0,                       0 },
661 #endif
662 
663 #define osGetDiskFreeSpaceA ((BOOL(WINAPI*)(LPCSTR,LPDWORD,LPDWORD,LPDWORD, \
664         LPDWORD))aSyscall[18].pCurrent)
665 
666 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
667   { "GetDiskFreeSpaceW",       (SYSCALL)GetDiskFreeSpaceW,       0 },
668 #else
669   { "GetDiskFreeSpaceW",       (SYSCALL)0,                       0 },
670 #endif
671 
672 #define osGetDiskFreeSpaceW ((BOOL(WINAPI*)(LPCWSTR,LPDWORD,LPDWORD,LPDWORD, \
673         LPDWORD))aSyscall[19].pCurrent)
674 
675 #if defined(SQLITE_WIN32_HAS_ANSI)
676   { "GetFileAttributesA",      (SYSCALL)GetFileAttributesA,      0 },
677 #else
678   { "GetFileAttributesA",      (SYSCALL)0,                       0 },
679 #endif
680 
681 #define osGetFileAttributesA ((DWORD(WINAPI*)(LPCSTR))aSyscall[20].pCurrent)
682 
683 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
684   { "GetFileAttributesW",      (SYSCALL)GetFileAttributesW,      0 },
685 #else
686   { "GetFileAttributesW",      (SYSCALL)0,                       0 },
687 #endif
688 
689 #define osGetFileAttributesW ((DWORD(WINAPI*)(LPCWSTR))aSyscall[21].pCurrent)
690 
691 #if defined(SQLITE_WIN32_HAS_WIDE)
692   { "GetFileAttributesExW",    (SYSCALL)GetFileAttributesExW,    0 },
693 #else
694   { "GetFileAttributesExW",    (SYSCALL)0,                       0 },
695 #endif
696 
697 #define osGetFileAttributesExW ((BOOL(WINAPI*)(LPCWSTR,GET_FILEEX_INFO_LEVELS, \
698         LPVOID))aSyscall[22].pCurrent)
699 
700 #if !SQLITE_OS_WINRT
701   { "GetFileSize",             (SYSCALL)GetFileSize,             0 },
702 #else
703   { "GetFileSize",             (SYSCALL)0,                       0 },
704 #endif
705 
706 #define osGetFileSize ((DWORD(WINAPI*)(HANDLE,LPDWORD))aSyscall[23].pCurrent)
707 
708 #if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)
709   { "GetFullPathNameA",        (SYSCALL)GetFullPathNameA,        0 },
710 #else
711   { "GetFullPathNameA",        (SYSCALL)0,                       0 },
712 #endif
713 
714 #define osGetFullPathNameA ((DWORD(WINAPI*)(LPCSTR,DWORD,LPSTR, \
715         LPSTR*))aSyscall[24].pCurrent)
716 
717 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
718   { "GetFullPathNameW",        (SYSCALL)GetFullPathNameW,        0 },
719 #else
720   { "GetFullPathNameW",        (SYSCALL)0,                       0 },
721 #endif
722 
723 #define osGetFullPathNameW ((DWORD(WINAPI*)(LPCWSTR,DWORD,LPWSTR, \
724         LPWSTR*))aSyscall[25].pCurrent)
725 
726   { "GetLastError",            (SYSCALL)GetLastError,            0 },
727 
728 #define osGetLastError ((DWORD(WINAPI*)(VOID))aSyscall[26].pCurrent)
729 
730 #if !defined(SQLITE_OMIT_LOAD_EXTENSION)
731 #if SQLITE_OS_WINCE
732   /* The GetProcAddressA() routine is only available on Windows CE. */
733   { "GetProcAddressA",         (SYSCALL)GetProcAddressA,         0 },
734 #else
735   /* All other Windows platforms expect GetProcAddress() to take
736   ** an ANSI string regardless of the _UNICODE setting */
737   { "GetProcAddressA",         (SYSCALL)GetProcAddress,          0 },
738 #endif
739 #else
740   { "GetProcAddressA",         (SYSCALL)0,                       0 },
741 #endif
742 
743 #define osGetProcAddressA ((FARPROC(WINAPI*)(HMODULE, \
744         LPCSTR))aSyscall[27].pCurrent)
745 
746 #if !SQLITE_OS_WINRT
747   { "GetSystemInfo",           (SYSCALL)GetSystemInfo,           0 },
748 #else
749   { "GetSystemInfo",           (SYSCALL)0,                       0 },
750 #endif
751 
752 #define osGetSystemInfo ((VOID(WINAPI*)(LPSYSTEM_INFO))aSyscall[28].pCurrent)
753 
754   { "GetSystemTime",           (SYSCALL)GetSystemTime,           0 },
755 
756 #define osGetSystemTime ((VOID(WINAPI*)(LPSYSTEMTIME))aSyscall[29].pCurrent)
757 
758 #if !SQLITE_OS_WINCE
759   { "GetSystemTimeAsFileTime", (SYSCALL)GetSystemTimeAsFileTime, 0 },
760 #else
761   { "GetSystemTimeAsFileTime", (SYSCALL)0,                       0 },
762 #endif
763 
764 #define osGetSystemTimeAsFileTime ((VOID(WINAPI*)( \
765         LPFILETIME))aSyscall[30].pCurrent)
766 
767 #if defined(SQLITE_WIN32_HAS_ANSI)
768   { "GetTempPathA",            (SYSCALL)GetTempPathA,            0 },
769 #else
770   { "GetTempPathA",            (SYSCALL)0,                       0 },
771 #endif
772 
773 #define osGetTempPathA ((DWORD(WINAPI*)(DWORD,LPSTR))aSyscall[31].pCurrent)
774 
775 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
776   { "GetTempPathW",            (SYSCALL)GetTempPathW,            0 },
777 #else
778   { "GetTempPathW",            (SYSCALL)0,                       0 },
779 #endif
780 
781 #define osGetTempPathW ((DWORD(WINAPI*)(DWORD,LPWSTR))aSyscall[32].pCurrent)
782 
783 #if !SQLITE_OS_WINRT
784   { "GetTickCount",            (SYSCALL)GetTickCount,            0 },
785 #else
786   { "GetTickCount",            (SYSCALL)0,                       0 },
787 #endif
788 
789 #define osGetTickCount ((DWORD(WINAPI*)(VOID))aSyscall[33].pCurrent)
790 
791 #if defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_GETVERSIONEX
792   { "GetVersionExA",           (SYSCALL)GetVersionExA,           0 },
793 #else
794   { "GetVersionExA",           (SYSCALL)0,                       0 },
795 #endif
796 
797 #define osGetVersionExA ((BOOL(WINAPI*)( \
798         LPOSVERSIONINFOA))aSyscall[34].pCurrent)
799 
800 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
801         SQLITE_WIN32_GETVERSIONEX
802   { "GetVersionExW",           (SYSCALL)GetVersionExW,           0 },
803 #else
804   { "GetVersionExW",           (SYSCALL)0,                       0 },
805 #endif
806 
807 #define osGetVersionExW ((BOOL(WINAPI*)( \
808         LPOSVERSIONINFOW))aSyscall[35].pCurrent)
809 
810   { "HeapAlloc",               (SYSCALL)HeapAlloc,               0 },
811 
812 #define osHeapAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD, \
813         SIZE_T))aSyscall[36].pCurrent)
814 
815 #if !SQLITE_OS_WINRT
816   { "HeapCreate",              (SYSCALL)HeapCreate,              0 },
817 #else
818   { "HeapCreate",              (SYSCALL)0,                       0 },
819 #endif
820 
821 #define osHeapCreate ((HANDLE(WINAPI*)(DWORD,SIZE_T, \
822         SIZE_T))aSyscall[37].pCurrent)
823 
824 #if !SQLITE_OS_WINRT
825   { "HeapDestroy",             (SYSCALL)HeapDestroy,             0 },
826 #else
827   { "HeapDestroy",             (SYSCALL)0,                       0 },
828 #endif
829 
830 #define osHeapDestroy ((BOOL(WINAPI*)(HANDLE))aSyscall[38].pCurrent)
831 
832   { "HeapFree",                (SYSCALL)HeapFree,                0 },
833 
834 #define osHeapFree ((BOOL(WINAPI*)(HANDLE,DWORD,LPVOID))aSyscall[39].pCurrent)
835 
836   { "HeapReAlloc",             (SYSCALL)HeapReAlloc,             0 },
837 
838 #define osHeapReAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD,LPVOID, \
839         SIZE_T))aSyscall[40].pCurrent)
840 
841   { "HeapSize",                (SYSCALL)HeapSize,                0 },
842 
843 #define osHeapSize ((SIZE_T(WINAPI*)(HANDLE,DWORD, \
844         LPCVOID))aSyscall[41].pCurrent)
845 
846 #if !SQLITE_OS_WINRT
847   { "HeapValidate",            (SYSCALL)HeapValidate,            0 },
848 #else
849   { "HeapValidate",            (SYSCALL)0,                       0 },
850 #endif
851 
852 #define osHeapValidate ((BOOL(WINAPI*)(HANDLE,DWORD, \
853         LPCVOID))aSyscall[42].pCurrent)
854 
855 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
856   { "HeapCompact",             (SYSCALL)HeapCompact,             0 },
857 #else
858   { "HeapCompact",             (SYSCALL)0,                       0 },
859 #endif
860 
861 #define osHeapCompact ((UINT(WINAPI*)(HANDLE,DWORD))aSyscall[43].pCurrent)
862 
863 #if defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
864   { "LoadLibraryA",            (SYSCALL)LoadLibraryA,            0 },
865 #else
866   { "LoadLibraryA",            (SYSCALL)0,                       0 },
867 #endif
868 
869 #define osLoadLibraryA ((HMODULE(WINAPI*)(LPCSTR))aSyscall[44].pCurrent)
870 
871 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
872         !defined(SQLITE_OMIT_LOAD_EXTENSION)
873   { "LoadLibraryW",            (SYSCALL)LoadLibraryW,            0 },
874 #else
875   { "LoadLibraryW",            (SYSCALL)0,                       0 },
876 #endif
877 
878 #define osLoadLibraryW ((HMODULE(WINAPI*)(LPCWSTR))aSyscall[45].pCurrent)
879 
880 #if !SQLITE_OS_WINRT
881   { "LocalFree",               (SYSCALL)LocalFree,               0 },
882 #else
883   { "LocalFree",               (SYSCALL)0,                       0 },
884 #endif
885 
886 #define osLocalFree ((HLOCAL(WINAPI*)(HLOCAL))aSyscall[46].pCurrent)
887 
888 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
889   { "LockFile",                (SYSCALL)LockFile,                0 },
890 #else
891   { "LockFile",                (SYSCALL)0,                       0 },
892 #endif
893 
894 #ifndef osLockFile
895 #define osLockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
896         DWORD))aSyscall[47].pCurrent)
897 #endif
898 
899 #if !SQLITE_OS_WINCE
900   { "LockFileEx",              (SYSCALL)LockFileEx,              0 },
901 #else
902   { "LockFileEx",              (SYSCALL)0,                       0 },
903 #endif
904 
905 #ifndef osLockFileEx
906 #define osLockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD,DWORD, \
907         LPOVERLAPPED))aSyscall[48].pCurrent)
908 #endif
909 
910 #if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && \
911         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
912   { "MapViewOfFile",           (SYSCALL)MapViewOfFile,           0 },
913 #else
914   { "MapViewOfFile",           (SYSCALL)0,                       0 },
915 #endif
916 
917 #define osMapViewOfFile ((LPVOID(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
918         SIZE_T))aSyscall[49].pCurrent)
919 
920   { "MultiByteToWideChar",     (SYSCALL)MultiByteToWideChar,     0 },
921 
922 #define osMultiByteToWideChar ((int(WINAPI*)(UINT,DWORD,LPCSTR,int,LPWSTR, \
923         int))aSyscall[50].pCurrent)
924 
925   { "QueryPerformanceCounter", (SYSCALL)QueryPerformanceCounter, 0 },
926 
927 #define osQueryPerformanceCounter ((BOOL(WINAPI*)( \
928         LARGE_INTEGER*))aSyscall[51].pCurrent)
929 
930   { "ReadFile",                (SYSCALL)ReadFile,                0 },
931 
932 #define osReadFile ((BOOL(WINAPI*)(HANDLE,LPVOID,DWORD,LPDWORD, \
933         LPOVERLAPPED))aSyscall[52].pCurrent)
934 
935   { "SetEndOfFile",            (SYSCALL)SetEndOfFile,            0 },
936 
937 #define osSetEndOfFile ((BOOL(WINAPI*)(HANDLE))aSyscall[53].pCurrent)
938 
939 #if !SQLITE_OS_WINRT
940   { "SetFilePointer",          (SYSCALL)SetFilePointer,          0 },
941 #else
942   { "SetFilePointer",          (SYSCALL)0,                       0 },
943 #endif
944 
945 #define osSetFilePointer ((DWORD(WINAPI*)(HANDLE,LONG,PLONG, \
946         DWORD))aSyscall[54].pCurrent)
947 
948 #if !SQLITE_OS_WINRT
949   { "Sleep",                   (SYSCALL)Sleep,                   0 },
950 #else
951   { "Sleep",                   (SYSCALL)0,                       0 },
952 #endif
953 
954 #define osSleep ((VOID(WINAPI*)(DWORD))aSyscall[55].pCurrent)
955 
956   { "SystemTimeToFileTime",    (SYSCALL)SystemTimeToFileTime,    0 },
957 
958 #define osSystemTimeToFileTime ((BOOL(WINAPI*)(CONST SYSTEMTIME*, \
959         LPFILETIME))aSyscall[56].pCurrent)
960 
961 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
962   { "UnlockFile",              (SYSCALL)UnlockFile,              0 },
963 #else
964   { "UnlockFile",              (SYSCALL)0,                       0 },
965 #endif
966 
967 #ifndef osUnlockFile
968 #define osUnlockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
969         DWORD))aSyscall[57].pCurrent)
970 #endif
971 
972 #if !SQLITE_OS_WINCE
973   { "UnlockFileEx",            (SYSCALL)UnlockFileEx,            0 },
974 #else
975   { "UnlockFileEx",            (SYSCALL)0,                       0 },
976 #endif
977 
978 #define osUnlockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
979         LPOVERLAPPED))aSyscall[58].pCurrent)
980 
981 #if SQLITE_OS_WINCE || !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
982   { "UnmapViewOfFile",         (SYSCALL)UnmapViewOfFile,         0 },
983 #else
984   { "UnmapViewOfFile",         (SYSCALL)0,                       0 },
985 #endif
986 
987 #define osUnmapViewOfFile ((BOOL(WINAPI*)(LPCVOID))aSyscall[59].pCurrent)
988 
989   { "WideCharToMultiByte",     (SYSCALL)WideCharToMultiByte,     0 },
990 
991 #define osWideCharToMultiByte ((int(WINAPI*)(UINT,DWORD,LPCWSTR,int,LPSTR,int, \
992         LPCSTR,LPBOOL))aSyscall[60].pCurrent)
993 
994   { "WriteFile",               (SYSCALL)WriteFile,               0 },
995 
996 #define osWriteFile ((BOOL(WINAPI*)(HANDLE,LPCVOID,DWORD,LPDWORD, \
997         LPOVERLAPPED))aSyscall[61].pCurrent)
998 
999 #if SQLITE_OS_WINRT
1000   { "CreateEventExW",          (SYSCALL)CreateEventExW,          0 },
1001 #else
1002   { "CreateEventExW",          (SYSCALL)0,                       0 },
1003 #endif
1004 
1005 #define osCreateEventExW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,LPCWSTR, \
1006         DWORD,DWORD))aSyscall[62].pCurrent)
1007 
1008 #if !SQLITE_OS_WINRT
1009   { "WaitForSingleObject",     (SYSCALL)WaitForSingleObject,     0 },
1010 #else
1011   { "WaitForSingleObject",     (SYSCALL)0,                       0 },
1012 #endif
1013 
1014 #define osWaitForSingleObject ((DWORD(WINAPI*)(HANDLE, \
1015         DWORD))aSyscall[63].pCurrent)
1016 
1017 #if !SQLITE_OS_WINCE
1018   { "WaitForSingleObjectEx",   (SYSCALL)WaitForSingleObjectEx,   0 },
1019 #else
1020   { "WaitForSingleObjectEx",   (SYSCALL)0,                       0 },
1021 #endif
1022 
1023 #define osWaitForSingleObjectEx ((DWORD(WINAPI*)(HANDLE,DWORD, \
1024         BOOL))aSyscall[64].pCurrent)
1025 
1026 #if SQLITE_OS_WINRT
1027   { "SetFilePointerEx",        (SYSCALL)SetFilePointerEx,        0 },
1028 #else
1029   { "SetFilePointerEx",        (SYSCALL)0,                       0 },
1030 #endif
1031 
1032 #define osSetFilePointerEx ((BOOL(WINAPI*)(HANDLE,LARGE_INTEGER, \
1033         PLARGE_INTEGER,DWORD))aSyscall[65].pCurrent)
1034 
1035 #if SQLITE_OS_WINRT
1036   { "GetFileInformationByHandleEx", (SYSCALL)GetFileInformationByHandleEx, 0 },
1037 #else
1038   { "GetFileInformationByHandleEx", (SYSCALL)0,                  0 },
1039 #endif
1040 
1041 #define osGetFileInformationByHandleEx ((BOOL(WINAPI*)(HANDLE, \
1042         FILE_INFO_BY_HANDLE_CLASS,LPVOID,DWORD))aSyscall[66].pCurrent)
1043 
1044 #if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
1045   { "MapViewOfFileFromApp",    (SYSCALL)MapViewOfFileFromApp,    0 },
1046 #else
1047   { "MapViewOfFileFromApp",    (SYSCALL)0,                       0 },
1048 #endif
1049 
1050 #define osMapViewOfFileFromApp ((LPVOID(WINAPI*)(HANDLE,ULONG,ULONG64, \
1051         SIZE_T))aSyscall[67].pCurrent)
1052 
1053 #if SQLITE_OS_WINRT
1054   { "CreateFile2",             (SYSCALL)CreateFile2,             0 },
1055 #else
1056   { "CreateFile2",             (SYSCALL)0,                       0 },
1057 #endif
1058 
1059 #define osCreateFile2 ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD,DWORD, \
1060         LPCREATEFILE2_EXTENDED_PARAMETERS))aSyscall[68].pCurrent)
1061 
1062 #if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_LOAD_EXTENSION)
1063   { "LoadPackagedLibrary",     (SYSCALL)LoadPackagedLibrary,     0 },
1064 #else
1065   { "LoadPackagedLibrary",     (SYSCALL)0,                       0 },
1066 #endif
1067 
1068 #define osLoadPackagedLibrary ((HMODULE(WINAPI*)(LPCWSTR, \
1069         DWORD))aSyscall[69].pCurrent)
1070 
1071 #if SQLITE_OS_WINRT
1072   { "GetTickCount64",          (SYSCALL)GetTickCount64,          0 },
1073 #else
1074   { "GetTickCount64",          (SYSCALL)0,                       0 },
1075 #endif
1076 
1077 #define osGetTickCount64 ((ULONGLONG(WINAPI*)(VOID))aSyscall[70].pCurrent)
1078 
1079 #if SQLITE_OS_WINRT
1080   { "GetNativeSystemInfo",     (SYSCALL)GetNativeSystemInfo,     0 },
1081 #else
1082   { "GetNativeSystemInfo",     (SYSCALL)0,                       0 },
1083 #endif
1084 
1085 #define osGetNativeSystemInfo ((VOID(WINAPI*)( \
1086         LPSYSTEM_INFO))aSyscall[71].pCurrent)
1087 
1088 #if defined(SQLITE_WIN32_HAS_ANSI)
1089   { "OutputDebugStringA",      (SYSCALL)OutputDebugStringA,      0 },
1090 #else
1091   { "OutputDebugStringA",      (SYSCALL)0,                       0 },
1092 #endif
1093 
1094 #define osOutputDebugStringA ((VOID(WINAPI*)(LPCSTR))aSyscall[72].pCurrent)
1095 
1096 #if defined(SQLITE_WIN32_HAS_WIDE)
1097   { "OutputDebugStringW",      (SYSCALL)OutputDebugStringW,      0 },
1098 #else
1099   { "OutputDebugStringW",      (SYSCALL)0,                       0 },
1100 #endif
1101 
1102 #define osOutputDebugStringW ((VOID(WINAPI*)(LPCWSTR))aSyscall[73].pCurrent)
1103 
1104   { "GetProcessHeap",          (SYSCALL)GetProcessHeap,          0 },
1105 
1106 #define osGetProcessHeap ((HANDLE(WINAPI*)(VOID))aSyscall[74].pCurrent)
1107 
1108 #if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
1109   { "CreateFileMappingFromApp", (SYSCALL)CreateFileMappingFromApp, 0 },
1110 #else
1111   { "CreateFileMappingFromApp", (SYSCALL)0,                      0 },
1112 #endif
1113 
1114 #define osCreateFileMappingFromApp ((HANDLE(WINAPI*)(HANDLE, \
1115         LPSECURITY_ATTRIBUTES,ULONG,ULONG64,LPCWSTR))aSyscall[75].pCurrent)
1116 
1117 /*
1118 ** NOTE: On some sub-platforms, the InterlockedCompareExchange "function"
1119 **       is really just a macro that uses a compiler intrinsic (e.g. x64).
1120 **       So do not try to make this is into a redefinable interface.
1121 */
1122 #if defined(InterlockedCompareExchange)
1123   { "InterlockedCompareExchange", (SYSCALL)0,                    0 },
1124 
1125 #define osInterlockedCompareExchange InterlockedCompareExchange
1126 #else
1127   { "InterlockedCompareExchange", (SYSCALL)InterlockedCompareExchange, 0 },
1128 
1129 #define osInterlockedCompareExchange ((LONG(WINAPI*)(LONG \
1130         SQLITE_WIN32_VOLATILE*, LONG,LONG))aSyscall[76].pCurrent)
1131 #endif /* defined(InterlockedCompareExchange) */
1132 
1133 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
1134   { "UuidCreate",               (SYSCALL)UuidCreate,             0 },
1135 #else
1136   { "UuidCreate",               (SYSCALL)0,                      0 },
1137 #endif
1138 
1139 #define osUuidCreate ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[77].pCurrent)
1140 
1141 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
1142   { "UuidCreateSequential",     (SYSCALL)UuidCreateSequential,   0 },
1143 #else
1144   { "UuidCreateSequential",     (SYSCALL)0,                      0 },
1145 #endif
1146 
1147 #define osUuidCreateSequential \
1148         ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[78].pCurrent)
1149 
1150 #if !defined(SQLITE_NO_SYNC) && SQLITE_MAX_MMAP_SIZE>0
1151   { "FlushViewOfFile",          (SYSCALL)FlushViewOfFile,        0 },
1152 #else
1153   { "FlushViewOfFile",          (SYSCALL)0,                      0 },
1154 #endif
1155 
1156 #define osFlushViewOfFile \
1157         ((BOOL(WINAPI*)(LPCVOID,SIZE_T))aSyscall[79].pCurrent)
1158 
1159 }; /* End of the overrideable system calls */
1160 
1161 /*
1162 ** This is the xSetSystemCall() method of sqlite3_vfs for all of the
1163 ** "win32" VFSes.  Return SQLITE_OK opon successfully updating the
1164 ** system call pointer, or SQLITE_NOTFOUND if there is no configurable
1165 ** system call named zName.
1166 */
1167 static int winSetSystemCall(
1168   sqlite3_vfs *pNotUsed,        /* The VFS pointer.  Not used */
1169   const char *zName,            /* Name of system call to override */
1170   sqlite3_syscall_ptr pNewFunc  /* Pointer to new system call value */
1171 ){
1172   unsigned int i;
1173   int rc = SQLITE_NOTFOUND;
1174 
1175   UNUSED_PARAMETER(pNotUsed);
1176   if( zName==0 ){
1177     /* If no zName is given, restore all system calls to their default
1178     ** settings and return NULL
1179     */
1180     rc = SQLITE_OK;
1181     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1182       if( aSyscall[i].pDefault ){
1183         aSyscall[i].pCurrent = aSyscall[i].pDefault;
1184       }
1185     }
1186   }else{
1187     /* If zName is specified, operate on only the one system call
1188     ** specified.
1189     */
1190     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1191       if( strcmp(zName, aSyscall[i].zName)==0 ){
1192         if( aSyscall[i].pDefault==0 ){
1193           aSyscall[i].pDefault = aSyscall[i].pCurrent;
1194         }
1195         rc = SQLITE_OK;
1196         if( pNewFunc==0 ) pNewFunc = aSyscall[i].pDefault;
1197         aSyscall[i].pCurrent = pNewFunc;
1198         break;
1199       }
1200     }
1201   }
1202   return rc;
1203 }
1204 
1205 /*
1206 ** Return the value of a system call.  Return NULL if zName is not a
1207 ** recognized system call name.  NULL is also returned if the system call
1208 ** is currently undefined.
1209 */
1210 static sqlite3_syscall_ptr winGetSystemCall(
1211   sqlite3_vfs *pNotUsed,
1212   const char *zName
1213 ){
1214   unsigned int i;
1215 
1216   UNUSED_PARAMETER(pNotUsed);
1217   for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1218     if( strcmp(zName, aSyscall[i].zName)==0 ) return aSyscall[i].pCurrent;
1219   }
1220   return 0;
1221 }
1222 
1223 /*
1224 ** Return the name of the first system call after zName.  If zName==NULL
1225 ** then return the name of the first system call.  Return NULL if zName
1226 ** is the last system call or if zName is not the name of a valid
1227 ** system call.
1228 */
1229 static const char *winNextSystemCall(sqlite3_vfs *p, const char *zName){
1230   int i = -1;
1231 
1232   UNUSED_PARAMETER(p);
1233   if( zName ){
1234     for(i=0; i<ArraySize(aSyscall)-1; i++){
1235       if( strcmp(zName, aSyscall[i].zName)==0 ) break;
1236     }
1237   }
1238   for(i++; i<ArraySize(aSyscall); i++){
1239     if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;
1240   }
1241   return 0;
1242 }
1243 
1244 #ifdef SQLITE_WIN32_MALLOC
1245 /*
1246 ** If a Win32 native heap has been configured, this function will attempt to
1247 ** compact it.  Upon success, SQLITE_OK will be returned.  Upon failure, one
1248 ** of SQLITE_NOMEM, SQLITE_ERROR, or SQLITE_NOTFOUND will be returned.  The
1249 ** "pnLargest" argument, if non-zero, will be used to return the size of the
1250 ** largest committed free block in the heap, in bytes.
1251 */
1252 int sqlite3_win32_compact_heap(LPUINT pnLargest){
1253   int rc = SQLITE_OK;
1254   UINT nLargest = 0;
1255   HANDLE hHeap;
1256 
1257   winMemAssertMagic();
1258   hHeap = winMemGetHeap();
1259   assert( hHeap!=0 );
1260   assert( hHeap!=INVALID_HANDLE_VALUE );
1261 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1262   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1263 #endif
1264 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
1265   if( (nLargest=osHeapCompact(hHeap, SQLITE_WIN32_HEAP_FLAGS))==0 ){
1266     DWORD lastErrno = osGetLastError();
1267     if( lastErrno==NO_ERROR ){
1268       sqlite3_log(SQLITE_NOMEM, "failed to HeapCompact (no space), heap=%p",
1269                   (void*)hHeap);
1270       rc = SQLITE_NOMEM_BKPT;
1271     }else{
1272       sqlite3_log(SQLITE_ERROR, "failed to HeapCompact (%lu), heap=%p",
1273                   osGetLastError(), (void*)hHeap);
1274       rc = SQLITE_ERROR;
1275     }
1276   }
1277 #else
1278   sqlite3_log(SQLITE_NOTFOUND, "failed to HeapCompact, heap=%p",
1279               (void*)hHeap);
1280   rc = SQLITE_NOTFOUND;
1281 #endif
1282   if( pnLargest ) *pnLargest = nLargest;
1283   return rc;
1284 }
1285 
1286 /*
1287 ** If a Win32 native heap has been configured, this function will attempt to
1288 ** destroy and recreate it.  If the Win32 native heap is not isolated and/or
1289 ** the sqlite3_memory_used() function does not return zero, SQLITE_BUSY will
1290 ** be returned and no changes will be made to the Win32 native heap.
1291 */
1292 int sqlite3_win32_reset_heap(){
1293   int rc;
1294   MUTEX_LOGIC( sqlite3_mutex *pMaster; ) /* The main static mutex */
1295   MUTEX_LOGIC( sqlite3_mutex *pMem; )    /* The memsys static mutex */
1296   MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
1297   MUTEX_LOGIC( pMem = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM); )
1298   sqlite3_mutex_enter(pMaster);
1299   sqlite3_mutex_enter(pMem);
1300   winMemAssertMagic();
1301   if( winMemGetHeap()!=NULL && winMemGetOwned() && sqlite3_memory_used()==0 ){
1302     /*
1303     ** At this point, there should be no outstanding memory allocations on
1304     ** the heap.  Also, since both the master and memsys locks are currently
1305     ** being held by us, no other function (i.e. from another thread) should
1306     ** be able to even access the heap.  Attempt to destroy and recreate our
1307     ** isolated Win32 native heap now.
1308     */
1309     assert( winMemGetHeap()!=NULL );
1310     assert( winMemGetOwned() );
1311     assert( sqlite3_memory_used()==0 );
1312     winMemShutdown(winMemGetDataPtr());
1313     assert( winMemGetHeap()==NULL );
1314     assert( !winMemGetOwned() );
1315     assert( sqlite3_memory_used()==0 );
1316     rc = winMemInit(winMemGetDataPtr());
1317     assert( rc!=SQLITE_OK || winMemGetHeap()!=NULL );
1318     assert( rc!=SQLITE_OK || winMemGetOwned() );
1319     assert( rc!=SQLITE_OK || sqlite3_memory_used()==0 );
1320   }else{
1321     /*
1322     ** The Win32 native heap cannot be modified because it may be in use.
1323     */
1324     rc = SQLITE_BUSY;
1325   }
1326   sqlite3_mutex_leave(pMem);
1327   sqlite3_mutex_leave(pMaster);
1328   return rc;
1329 }
1330 #endif /* SQLITE_WIN32_MALLOC */
1331 
1332 /*
1333 ** This function outputs the specified (ANSI) string to the Win32 debugger
1334 ** (if available).
1335 */
1336 
1337 void sqlite3_win32_write_debug(const char *zBuf, int nBuf){
1338   char zDbgBuf[SQLITE_WIN32_DBG_BUF_SIZE];
1339   int nMin = MIN(nBuf, (SQLITE_WIN32_DBG_BUF_SIZE - 1)); /* may be negative. */
1340   if( nMin<-1 ) nMin = -1; /* all negative values become -1. */
1341   assert( nMin==-1 || nMin==0 || nMin<SQLITE_WIN32_DBG_BUF_SIZE );
1342 #ifdef SQLITE_ENABLE_API_ARMOR
1343   if( !zBuf ){
1344     (void)SQLITE_MISUSE_BKPT;
1345     return;
1346   }
1347 #endif
1348 #if defined(SQLITE_WIN32_HAS_ANSI)
1349   if( nMin>0 ){
1350     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1351     memcpy(zDbgBuf, zBuf, nMin);
1352     osOutputDebugStringA(zDbgBuf);
1353   }else{
1354     osOutputDebugStringA(zBuf);
1355   }
1356 #elif defined(SQLITE_WIN32_HAS_WIDE)
1357   memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1358   if ( osMultiByteToWideChar(
1359           osAreFileApisANSI() ? CP_ACP : CP_OEMCP, 0, zBuf,
1360           nMin, (LPWSTR)zDbgBuf, SQLITE_WIN32_DBG_BUF_SIZE/sizeof(WCHAR))<=0 ){
1361     return;
1362   }
1363   osOutputDebugStringW((LPCWSTR)zDbgBuf);
1364 #else
1365   if( nMin>0 ){
1366     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1367     memcpy(zDbgBuf, zBuf, nMin);
1368     fprintf(stderr, "%s", zDbgBuf);
1369   }else{
1370     fprintf(stderr, "%s", zBuf);
1371   }
1372 #endif
1373 }
1374 
1375 /*
1376 ** The following routine suspends the current thread for at least ms
1377 ** milliseconds.  This is equivalent to the Win32 Sleep() interface.
1378 */
1379 #if SQLITE_OS_WINRT
1380 static HANDLE sleepObj = NULL;
1381 #endif
1382 
1383 void sqlite3_win32_sleep(DWORD milliseconds){
1384 #if SQLITE_OS_WINRT
1385   if ( sleepObj==NULL ){
1386     sleepObj = osCreateEventExW(NULL, NULL, CREATE_EVENT_MANUAL_RESET,
1387                                 SYNCHRONIZE);
1388   }
1389   assert( sleepObj!=NULL );
1390   osWaitForSingleObjectEx(sleepObj, milliseconds, FALSE);
1391 #else
1392   osSleep(milliseconds);
1393 #endif
1394 }
1395 
1396 #if SQLITE_MAX_WORKER_THREADS>0 && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \
1397         SQLITE_THREADSAFE>0
1398 DWORD sqlite3Win32Wait(HANDLE hObject){
1399   DWORD rc;
1400   while( (rc = osWaitForSingleObjectEx(hObject, INFINITE,
1401                                        TRUE))==WAIT_IO_COMPLETION ){}
1402   return rc;
1403 }
1404 #endif
1405 
1406 /*
1407 ** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
1408 ** or WinCE.  Return false (zero) for Win95, Win98, or WinME.
1409 **
1410 ** Here is an interesting observation:  Win95, Win98, and WinME lack
1411 ** the LockFileEx() API.  But we can still statically link against that
1412 ** API as long as we don't call it when running Win95/98/ME.  A call to
1413 ** this routine is used to determine if the host is Win95/98/ME or
1414 ** WinNT/2K/XP so that we will know whether or not we can safely call
1415 ** the LockFileEx() API.
1416 */
1417 
1418 #if !SQLITE_WIN32_GETVERSIONEX
1419 # define osIsNT()  (1)
1420 #elif SQLITE_OS_WINCE || SQLITE_OS_WINRT || !defined(SQLITE_WIN32_HAS_ANSI)
1421 # define osIsNT()  (1)
1422 #elif !defined(SQLITE_WIN32_HAS_WIDE)
1423 # define osIsNT()  (0)
1424 #else
1425 # define osIsNT()  ((sqlite3_os_type==2) || sqlite3_win32_is_nt())
1426 #endif
1427 
1428 /*
1429 ** This function determines if the machine is running a version of Windows
1430 ** based on the NT kernel.
1431 */
1432 int sqlite3_win32_is_nt(void){
1433 #if SQLITE_OS_WINRT
1434   /*
1435   ** NOTE: The WinRT sub-platform is always assumed to be based on the NT
1436   **       kernel.
1437   */
1438   return 1;
1439 #elif SQLITE_WIN32_GETVERSIONEX
1440   if( osInterlockedCompareExchange(&sqlite3_os_type, 0, 0)==0 ){
1441 #if defined(SQLITE_WIN32_HAS_ANSI)
1442     OSVERSIONINFOA sInfo;
1443     sInfo.dwOSVersionInfoSize = sizeof(sInfo);
1444     osGetVersionExA(&sInfo);
1445     osInterlockedCompareExchange(&sqlite3_os_type,
1446         (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
1447 #elif defined(SQLITE_WIN32_HAS_WIDE)
1448     OSVERSIONINFOW sInfo;
1449     sInfo.dwOSVersionInfoSize = sizeof(sInfo);
1450     osGetVersionExW(&sInfo);
1451     osInterlockedCompareExchange(&sqlite3_os_type,
1452         (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
1453 #endif
1454   }
1455   return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;
1456 #elif SQLITE_TEST
1457   return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;
1458 #else
1459   /*
1460   ** NOTE: All sub-platforms where the GetVersionEx[AW] functions are
1461   **       deprecated are always assumed to be based on the NT kernel.
1462   */
1463   return 1;
1464 #endif
1465 }
1466 
1467 #ifdef SQLITE_WIN32_MALLOC
1468 /*
1469 ** Allocate nBytes of memory.
1470 */
1471 static void *winMemMalloc(int nBytes){
1472   HANDLE hHeap;
1473   void *p;
1474 
1475   winMemAssertMagic();
1476   hHeap = winMemGetHeap();
1477   assert( hHeap!=0 );
1478   assert( hHeap!=INVALID_HANDLE_VALUE );
1479 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1480   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1481 #endif
1482   assert( nBytes>=0 );
1483   p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
1484   if( !p ){
1485     sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%lu), heap=%p",
1486                 nBytes, osGetLastError(), (void*)hHeap);
1487   }
1488   return p;
1489 }
1490 
1491 /*
1492 ** Free memory.
1493 */
1494 static void winMemFree(void *pPrior){
1495   HANDLE hHeap;
1496 
1497   winMemAssertMagic();
1498   hHeap = winMemGetHeap();
1499   assert( hHeap!=0 );
1500   assert( hHeap!=INVALID_HANDLE_VALUE );
1501 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1502   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
1503 #endif
1504   if( !pPrior ) return; /* Passing NULL to HeapFree is undefined. */
1505   if( !osHeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){
1506     sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%lu), heap=%p",
1507                 pPrior, osGetLastError(), (void*)hHeap);
1508   }
1509 }
1510 
1511 /*
1512 ** Change the size of an existing memory allocation
1513 */
1514 static void *winMemRealloc(void *pPrior, int nBytes){
1515   HANDLE hHeap;
1516   void *p;
1517 
1518   winMemAssertMagic();
1519   hHeap = winMemGetHeap();
1520   assert( hHeap!=0 );
1521   assert( hHeap!=INVALID_HANDLE_VALUE );
1522 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1523   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
1524 #endif
1525   assert( nBytes>=0 );
1526   if( !pPrior ){
1527     p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
1528   }else{
1529     p = osHeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);
1530   }
1531   if( !p ){
1532     sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%lu), heap=%p",
1533                 pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, osGetLastError(),
1534                 (void*)hHeap);
1535   }
1536   return p;
1537 }
1538 
1539 /*
1540 ** Return the size of an outstanding allocation, in bytes.
1541 */
1542 static int winMemSize(void *p){
1543   HANDLE hHeap;
1544   SIZE_T n;
1545 
1546   winMemAssertMagic();
1547   hHeap = winMemGetHeap();
1548   assert( hHeap!=0 );
1549   assert( hHeap!=INVALID_HANDLE_VALUE );
1550 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1551   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, p) );
1552 #endif
1553   if( !p ) return 0;
1554   n = osHeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);
1555   if( n==(SIZE_T)-1 ){
1556     sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%lu), heap=%p",
1557                 p, osGetLastError(), (void*)hHeap);
1558     return 0;
1559   }
1560   return (int)n;
1561 }
1562 
1563 /*
1564 ** Round up a request size to the next valid allocation size.
1565 */
1566 static int winMemRoundup(int n){
1567   return n;
1568 }
1569 
1570 /*
1571 ** Initialize this module.
1572 */
1573 static int winMemInit(void *pAppData){
1574   winMemData *pWinMemData = (winMemData *)pAppData;
1575 
1576   if( !pWinMemData ) return SQLITE_ERROR;
1577   assert( pWinMemData->magic1==WINMEM_MAGIC1 );
1578   assert( pWinMemData->magic2==WINMEM_MAGIC2 );
1579 
1580 #if !SQLITE_OS_WINRT && SQLITE_WIN32_HEAP_CREATE
1581   if( !pWinMemData->hHeap ){
1582     DWORD dwInitialSize = SQLITE_WIN32_HEAP_INIT_SIZE;
1583     DWORD dwMaximumSize = (DWORD)sqlite3GlobalConfig.nHeap;
1584     if( dwMaximumSize==0 ){
1585       dwMaximumSize = SQLITE_WIN32_HEAP_MAX_SIZE;
1586     }else if( dwInitialSize>dwMaximumSize ){
1587       dwInitialSize = dwMaximumSize;
1588     }
1589     pWinMemData->hHeap = osHeapCreate(SQLITE_WIN32_HEAP_FLAGS,
1590                                       dwInitialSize, dwMaximumSize);
1591     if( !pWinMemData->hHeap ){
1592       sqlite3_log(SQLITE_NOMEM,
1593           "failed to HeapCreate (%lu), flags=%u, initSize=%lu, maxSize=%lu",
1594           osGetLastError(), SQLITE_WIN32_HEAP_FLAGS, dwInitialSize,
1595           dwMaximumSize);
1596       return SQLITE_NOMEM_BKPT;
1597     }
1598     pWinMemData->bOwned = TRUE;
1599     assert( pWinMemData->bOwned );
1600   }
1601 #else
1602   pWinMemData->hHeap = osGetProcessHeap();
1603   if( !pWinMemData->hHeap ){
1604     sqlite3_log(SQLITE_NOMEM,
1605         "failed to GetProcessHeap (%lu)", osGetLastError());
1606     return SQLITE_NOMEM_BKPT;
1607   }
1608   pWinMemData->bOwned = FALSE;
1609   assert( !pWinMemData->bOwned );
1610 #endif
1611   assert( pWinMemData->hHeap!=0 );
1612   assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
1613 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1614   assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1615 #endif
1616   return SQLITE_OK;
1617 }
1618 
1619 /*
1620 ** Deinitialize this module.
1621 */
1622 static void winMemShutdown(void *pAppData){
1623   winMemData *pWinMemData = (winMemData *)pAppData;
1624 
1625   if( !pWinMemData ) return;
1626   assert( pWinMemData->magic1==WINMEM_MAGIC1 );
1627   assert( pWinMemData->magic2==WINMEM_MAGIC2 );
1628 
1629   if( pWinMemData->hHeap ){
1630     assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
1631 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1632     assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1633 #endif
1634     if( pWinMemData->bOwned ){
1635       if( !osHeapDestroy(pWinMemData->hHeap) ){
1636         sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%lu), heap=%p",
1637                     osGetLastError(), (void*)pWinMemData->hHeap);
1638       }
1639       pWinMemData->bOwned = FALSE;
1640     }
1641     pWinMemData->hHeap = NULL;
1642   }
1643 }
1644 
1645 /*
1646 ** Populate the low-level memory allocation function pointers in
1647 ** sqlite3GlobalConfig.m with pointers to the routines in this file. The
1648 ** arguments specify the block of memory to manage.
1649 **
1650 ** This routine is only called by sqlite3_config(), and therefore
1651 ** is not required to be threadsafe (it is not).
1652 */
1653 const sqlite3_mem_methods *sqlite3MemGetWin32(void){
1654   static const sqlite3_mem_methods winMemMethods = {
1655     winMemMalloc,
1656     winMemFree,
1657     winMemRealloc,
1658     winMemSize,
1659     winMemRoundup,
1660     winMemInit,
1661     winMemShutdown,
1662     &win_mem_data
1663   };
1664   return &winMemMethods;
1665 }
1666 
1667 void sqlite3MemSetDefault(void){
1668   sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetWin32());
1669 }
1670 #endif /* SQLITE_WIN32_MALLOC */
1671 
1672 /*
1673 ** Convert a UTF-8 string to Microsoft Unicode.
1674 **
1675 ** Space to hold the returned string is obtained from sqlite3_malloc().
1676 */
1677 static LPWSTR winUtf8ToUnicode(const char *zText){
1678   int nChar;
1679   LPWSTR zWideText;
1680 
1681   nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, NULL, 0);
1682   if( nChar==0 ){
1683     return 0;
1684   }
1685   zWideText = sqlite3MallocZero( nChar*sizeof(WCHAR) );
1686   if( zWideText==0 ){
1687     return 0;
1688   }
1689   nChar = osMultiByteToWideChar(CP_UTF8, 0, zText, -1, zWideText,
1690                                 nChar);
1691   if( nChar==0 ){
1692     sqlite3_free(zWideText);
1693     zWideText = 0;
1694   }
1695   return zWideText;
1696 }
1697 
1698 /*
1699 ** Convert a Microsoft Unicode string to UTF-8.
1700 **
1701 ** Space to hold the returned string is obtained from sqlite3_malloc().
1702 */
1703 static char *winUnicodeToUtf8(LPCWSTR zWideText){
1704   int nByte;
1705   char *zText;
1706 
1707   nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, 0, 0, 0, 0);
1708   if( nByte == 0 ){
1709     return 0;
1710   }
1711   zText = sqlite3MallocZero( nByte );
1712   if( zText==0 ){
1713     return 0;
1714   }
1715   nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideText, -1, zText, nByte,
1716                                 0, 0);
1717   if( nByte == 0 ){
1718     sqlite3_free(zText);
1719     zText = 0;
1720   }
1721   return zText;
1722 }
1723 
1724 /*
1725 ** Convert an ANSI string to Microsoft Unicode, using the ANSI or OEM
1726 ** code page.
1727 **
1728 ** Space to hold the returned string is obtained from sqlite3_malloc().
1729 */
1730 static LPWSTR winMbcsToUnicode(const char *zText, int useAnsi){
1731   int nByte;
1732   LPWSTR zMbcsText;
1733   int codepage = useAnsi ? CP_ACP : CP_OEMCP;
1734 
1735   nByte = osMultiByteToWideChar(codepage, 0, zText, -1, NULL,
1736                                 0)*sizeof(WCHAR);
1737   if( nByte==0 ){
1738     return 0;
1739   }
1740   zMbcsText = sqlite3MallocZero( nByte*sizeof(WCHAR) );
1741   if( zMbcsText==0 ){
1742     return 0;
1743   }
1744   nByte = osMultiByteToWideChar(codepage, 0, zText, -1, zMbcsText,
1745                                 nByte);
1746   if( nByte==0 ){
1747     sqlite3_free(zMbcsText);
1748     zMbcsText = 0;
1749   }
1750   return zMbcsText;
1751 }
1752 
1753 /*
1754 ** Convert a Microsoft Unicode string to a multi-byte character string,
1755 ** using the ANSI or OEM code page.
1756 **
1757 ** Space to hold the returned string is obtained from sqlite3_malloc().
1758 */
1759 static char *winUnicodeToMbcs(LPCWSTR zWideText, int useAnsi){
1760   int nByte;
1761   char *zText;
1762   int codepage = useAnsi ? CP_ACP : CP_OEMCP;
1763 
1764   nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, 0, 0, 0, 0);
1765   if( nByte == 0 ){
1766     return 0;
1767   }
1768   zText = sqlite3MallocZero( nByte );
1769   if( zText==0 ){
1770     return 0;
1771   }
1772   nByte = osWideCharToMultiByte(codepage, 0, zWideText, -1, zText,
1773                                 nByte, 0, 0);
1774   if( nByte == 0 ){
1775     sqlite3_free(zText);
1776     zText = 0;
1777   }
1778   return zText;
1779 }
1780 
1781 /*
1782 ** Convert a multi-byte character string to UTF-8.
1783 **
1784 ** Space to hold the returned string is obtained from sqlite3_malloc().
1785 */
1786 static char *winMbcsToUtf8(const char *zText, int useAnsi){
1787   char *zTextUtf8;
1788   LPWSTR zTmpWide;
1789 
1790   zTmpWide = winMbcsToUnicode(zText, useAnsi);
1791   if( zTmpWide==0 ){
1792     return 0;
1793   }
1794   zTextUtf8 = winUnicodeToUtf8(zTmpWide);
1795   sqlite3_free(zTmpWide);
1796   return zTextUtf8;
1797 }
1798 
1799 /*
1800 ** Convert a UTF-8 string to a multi-byte character string.
1801 **
1802 ** Space to hold the returned string is obtained from sqlite3_malloc().
1803 */
1804 static char *winUtf8ToMbcs(const char *zText, int useAnsi){
1805   char *zTextMbcs;
1806   LPWSTR zTmpWide;
1807 
1808   zTmpWide = winUtf8ToUnicode(zText);
1809   if( zTmpWide==0 ){
1810     return 0;
1811   }
1812   zTextMbcs = winUnicodeToMbcs(zTmpWide, useAnsi);
1813   sqlite3_free(zTmpWide);
1814   return zTextMbcs;
1815 }
1816 
1817 /*
1818 ** This is a public wrapper for the winUtf8ToUnicode() function.
1819 */
1820 LPWSTR sqlite3_win32_utf8_to_unicode(const char *zText){
1821 #ifdef SQLITE_ENABLE_API_ARMOR
1822   if( !zText ){
1823     (void)SQLITE_MISUSE_BKPT;
1824     return 0;
1825   }
1826 #endif
1827 #ifndef SQLITE_OMIT_AUTOINIT
1828   if( sqlite3_initialize() ) return 0;
1829 #endif
1830   return winUtf8ToUnicode(zText);
1831 }
1832 
1833 /*
1834 ** This is a public wrapper for the winUnicodeToUtf8() function.
1835 */
1836 char *sqlite3_win32_unicode_to_utf8(LPCWSTR zWideText){
1837 #ifdef SQLITE_ENABLE_API_ARMOR
1838   if( !zWideText ){
1839     (void)SQLITE_MISUSE_BKPT;
1840     return 0;
1841   }
1842 #endif
1843 #ifndef SQLITE_OMIT_AUTOINIT
1844   if( sqlite3_initialize() ) return 0;
1845 #endif
1846   return winUnicodeToUtf8(zWideText);
1847 }
1848 
1849 /*
1850 ** This is a public wrapper for the winMbcsToUtf8() function.
1851 */
1852 char *sqlite3_win32_mbcs_to_utf8(const char *zText){
1853 #ifdef SQLITE_ENABLE_API_ARMOR
1854   if( !zText ){
1855     (void)SQLITE_MISUSE_BKPT;
1856     return 0;
1857   }
1858 #endif
1859 #ifndef SQLITE_OMIT_AUTOINIT
1860   if( sqlite3_initialize() ) return 0;
1861 #endif
1862   return winMbcsToUtf8(zText, osAreFileApisANSI());
1863 }
1864 
1865 /*
1866 ** This is a public wrapper for the winMbcsToUtf8() function.
1867 */
1868 char *sqlite3_win32_mbcs_to_utf8_v2(const char *zText, int useAnsi){
1869 #ifdef SQLITE_ENABLE_API_ARMOR
1870   if( !zText ){
1871     (void)SQLITE_MISUSE_BKPT;
1872     return 0;
1873   }
1874 #endif
1875 #ifndef SQLITE_OMIT_AUTOINIT
1876   if( sqlite3_initialize() ) return 0;
1877 #endif
1878   return winMbcsToUtf8(zText, useAnsi);
1879 }
1880 
1881 /*
1882 ** This is a public wrapper for the winUtf8ToMbcs() function.
1883 */
1884 char *sqlite3_win32_utf8_to_mbcs(const char *zText){
1885 #ifdef SQLITE_ENABLE_API_ARMOR
1886   if( !zText ){
1887     (void)SQLITE_MISUSE_BKPT;
1888     return 0;
1889   }
1890 #endif
1891 #ifndef SQLITE_OMIT_AUTOINIT
1892   if( sqlite3_initialize() ) return 0;
1893 #endif
1894   return winUtf8ToMbcs(zText, osAreFileApisANSI());
1895 }
1896 
1897 /*
1898 ** This is a public wrapper for the winUtf8ToMbcs() function.
1899 */
1900 char *sqlite3_win32_utf8_to_mbcs_v2(const char *zText, int useAnsi){
1901 #ifdef SQLITE_ENABLE_API_ARMOR
1902   if( !zText ){
1903     (void)SQLITE_MISUSE_BKPT;
1904     return 0;
1905   }
1906 #endif
1907 #ifndef SQLITE_OMIT_AUTOINIT
1908   if( sqlite3_initialize() ) return 0;
1909 #endif
1910   return winUtf8ToMbcs(zText, useAnsi);
1911 }
1912 
1913 /*
1914 ** This function is the same as sqlite3_win32_set_directory (below); however,
1915 ** it accepts a UTF-8 string.
1916 */
1917 int sqlite3_win32_set_directory8(
1918   unsigned long type, /* Identifier for directory being set or reset */
1919   const char *zValue  /* New value for directory being set or reset */
1920 ){
1921   char **ppDirectory = 0;
1922 #ifndef SQLITE_OMIT_AUTOINIT
1923   int rc = sqlite3_initialize();
1924   if( rc ) return rc;
1925 #endif
1926   if( type==SQLITE_WIN32_DATA_DIRECTORY_TYPE ){
1927     ppDirectory = &sqlite3_data_directory;
1928   }else if( type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE ){
1929     ppDirectory = &sqlite3_temp_directory;
1930   }
1931   assert( !ppDirectory || type==SQLITE_WIN32_DATA_DIRECTORY_TYPE
1932           || type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE
1933   );
1934   assert( !ppDirectory || sqlite3MemdebugHasType(*ppDirectory, MEMTYPE_HEAP) );
1935   if( ppDirectory ){
1936     char *zCopy = 0;
1937     if( zValue && zValue[0] ){
1938       zCopy = sqlite3_mprintf("%s", zValue);
1939       if ( zCopy==0 ){
1940         return SQLITE_NOMEM_BKPT;
1941       }
1942     }
1943     sqlite3_free(*ppDirectory);
1944     *ppDirectory = zCopy;
1945     return SQLITE_OK;
1946   }
1947   return SQLITE_ERROR;
1948 }
1949 
1950 /*
1951 ** This function is the same as sqlite3_win32_set_directory (below); however,
1952 ** it accepts a UTF-16 string.
1953 */
1954 int sqlite3_win32_set_directory16(
1955   unsigned long type, /* Identifier for directory being set or reset */
1956   const void *zValue  /* New value for directory being set or reset */
1957 ){
1958   int rc;
1959   char *zUtf8 = 0;
1960   if( zValue ){
1961     zUtf8 = sqlite3_win32_unicode_to_utf8(zValue);
1962     if( zUtf8==0 ) return SQLITE_NOMEM_BKPT;
1963   }
1964   rc = sqlite3_win32_set_directory8(type, zUtf8);
1965   if( zUtf8 ) sqlite3_free(zUtf8);
1966   return rc;
1967 }
1968 
1969 /*
1970 ** This function sets the data directory or the temporary directory based on
1971 ** the provided arguments.  The type argument must be 1 in order to set the
1972 ** data directory or 2 in order to set the temporary directory.  The zValue
1973 ** argument is the name of the directory to use.  The return value will be
1974 ** SQLITE_OK if successful.
1975 */
1976 int sqlite3_win32_set_directory(
1977   unsigned long type, /* Identifier for directory being set or reset */
1978   void *zValue        /* New value for directory being set or reset */
1979 ){
1980   return sqlite3_win32_set_directory16(type, zValue);
1981 }
1982 
1983 /*
1984 ** The return value of winGetLastErrorMsg
1985 ** is zero if the error message fits in the buffer, or non-zero
1986 ** otherwise (if the message was truncated).
1987 */
1988 static int winGetLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){
1989   /* FormatMessage returns 0 on failure.  Otherwise it
1990   ** returns the number of TCHARs written to the output
1991   ** buffer, excluding the terminating null char.
1992   */
1993   DWORD dwLen = 0;
1994   char *zOut = 0;
1995 
1996   if( osIsNT() ){
1997 #if SQLITE_OS_WINRT
1998     WCHAR zTempWide[SQLITE_WIN32_MAX_ERRMSG_CHARS+1];
1999     dwLen = osFormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
2000                              FORMAT_MESSAGE_IGNORE_INSERTS,
2001                              NULL,
2002                              lastErrno,
2003                              0,
2004                              zTempWide,
2005                              SQLITE_WIN32_MAX_ERRMSG_CHARS,
2006                              0);
2007 #else
2008     LPWSTR zTempWide = NULL;
2009     dwLen = osFormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
2010                              FORMAT_MESSAGE_FROM_SYSTEM |
2011                              FORMAT_MESSAGE_IGNORE_INSERTS,
2012                              NULL,
2013                              lastErrno,
2014                              0,
2015                              (LPWSTR) &zTempWide,
2016                              0,
2017                              0);
2018 #endif
2019     if( dwLen > 0 ){
2020       /* allocate a buffer and convert to UTF8 */
2021       sqlite3BeginBenignMalloc();
2022       zOut = winUnicodeToUtf8(zTempWide);
2023       sqlite3EndBenignMalloc();
2024 #if !SQLITE_OS_WINRT
2025       /* free the system buffer allocated by FormatMessage */
2026       osLocalFree(zTempWide);
2027 #endif
2028     }
2029   }
2030 #ifdef SQLITE_WIN32_HAS_ANSI
2031   else{
2032     char *zTemp = NULL;
2033     dwLen = osFormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
2034                              FORMAT_MESSAGE_FROM_SYSTEM |
2035                              FORMAT_MESSAGE_IGNORE_INSERTS,
2036                              NULL,
2037                              lastErrno,
2038                              0,
2039                              (LPSTR) &zTemp,
2040                              0,
2041                              0);
2042     if( dwLen > 0 ){
2043       /* allocate a buffer and convert to UTF8 */
2044       sqlite3BeginBenignMalloc();
2045       zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
2046       sqlite3EndBenignMalloc();
2047       /* free the system buffer allocated by FormatMessage */
2048       osLocalFree(zTemp);
2049     }
2050   }
2051 #endif
2052   if( 0 == dwLen ){
2053     sqlite3_snprintf(nBuf, zBuf, "OsError 0x%lx (%lu)", lastErrno, lastErrno);
2054   }else{
2055     /* copy a maximum of nBuf chars to output buffer */
2056     sqlite3_snprintf(nBuf, zBuf, "%s", zOut);
2057     /* free the UTF8 buffer */
2058     sqlite3_free(zOut);
2059   }
2060   return 0;
2061 }
2062 
2063 /*
2064 **
2065 ** This function - winLogErrorAtLine() - is only ever called via the macro
2066 ** winLogError().
2067 **
2068 ** This routine is invoked after an error occurs in an OS function.
2069 ** It logs a message using sqlite3_log() containing the current value of
2070 ** error code and, if possible, the human-readable equivalent from
2071 ** FormatMessage.
2072 **
2073 ** The first argument passed to the macro should be the error code that
2074 ** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN).
2075 ** The two subsequent arguments should be the name of the OS function that
2076 ** failed and the associated file-system path, if any.
2077 */
2078 #define winLogError(a,b,c,d)   winLogErrorAtLine(a,b,c,d,__LINE__)
2079 static int winLogErrorAtLine(
2080   int errcode,                    /* SQLite error code */
2081   DWORD lastErrno,                /* Win32 last error */
2082   const char *zFunc,              /* Name of OS function that failed */
2083   const char *zPath,              /* File path associated with error */
2084   int iLine                       /* Source line number where error occurred */
2085 ){
2086   char zMsg[500];                 /* Human readable error text */
2087   int i;                          /* Loop counter */
2088 
2089   zMsg[0] = 0;
2090   winGetLastErrorMsg(lastErrno, sizeof(zMsg), zMsg);
2091   assert( errcode!=SQLITE_OK );
2092   if( zPath==0 ) zPath = "";
2093   for(i=0; zMsg[i] && zMsg[i]!='\r' && zMsg[i]!='\n'; i++){}
2094   zMsg[i] = 0;
2095   sqlite3_log(errcode,
2096       "os_win.c:%d: (%lu) %s(%s) - %s",
2097       iLine, lastErrno, zFunc, zPath, zMsg
2098   );
2099 
2100   return errcode;
2101 }
2102 
2103 /*
2104 ** The number of times that a ReadFile(), WriteFile(), and DeleteFile()
2105 ** will be retried following a locking error - probably caused by
2106 ** antivirus software.  Also the initial delay before the first retry.
2107 ** The delay increases linearly with each retry.
2108 */
2109 #ifndef SQLITE_WIN32_IOERR_RETRY
2110 # define SQLITE_WIN32_IOERR_RETRY 10
2111 #endif
2112 #ifndef SQLITE_WIN32_IOERR_RETRY_DELAY
2113 # define SQLITE_WIN32_IOERR_RETRY_DELAY 25
2114 #endif
2115 static int winIoerrRetry = SQLITE_WIN32_IOERR_RETRY;
2116 static int winIoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;
2117 
2118 /*
2119 ** The "winIoerrCanRetry1" macro is used to determine if a particular I/O
2120 ** error code obtained via GetLastError() is eligible to be retried.  It
2121 ** must accept the error code DWORD as its only argument and should return
2122 ** non-zero if the error code is transient in nature and the operation
2123 ** responsible for generating the original error might succeed upon being
2124 ** retried.  The argument to this macro should be a variable.
2125 **
2126 ** Additionally, a macro named "winIoerrCanRetry2" may be defined.  If it
2127 ** is defined, it will be consulted only when the macro "winIoerrCanRetry1"
2128 ** returns zero.  The "winIoerrCanRetry2" macro is completely optional and
2129 ** may be used to include additional error codes in the set that should
2130 ** result in the failing I/O operation being retried by the caller.  If
2131 ** defined, the "winIoerrCanRetry2" macro must exhibit external semantics
2132 ** identical to those of the "winIoerrCanRetry1" macro.
2133 */
2134 #if !defined(winIoerrCanRetry1)
2135 #define winIoerrCanRetry1(a) (((a)==ERROR_ACCESS_DENIED)        || \
2136                               ((a)==ERROR_SHARING_VIOLATION)    || \
2137                               ((a)==ERROR_LOCK_VIOLATION)       || \
2138                               ((a)==ERROR_DEV_NOT_EXIST)        || \
2139                               ((a)==ERROR_NETNAME_DELETED)      || \
2140                               ((a)==ERROR_SEM_TIMEOUT)          || \
2141                               ((a)==ERROR_NETWORK_UNREACHABLE))
2142 #endif
2143 
2144 /*
2145 ** If a ReadFile() or WriteFile() error occurs, invoke this routine
2146 ** to see if it should be retried.  Return TRUE to retry.  Return FALSE
2147 ** to give up with an error.
2148 */
2149 static int winRetryIoerr(int *pnRetry, DWORD *pError){
2150   DWORD e = osGetLastError();
2151   if( *pnRetry>=winIoerrRetry ){
2152     if( pError ){
2153       *pError = e;
2154     }
2155     return 0;
2156   }
2157   if( winIoerrCanRetry1(e) ){
2158     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
2159     ++*pnRetry;
2160     return 1;
2161   }
2162 #if defined(winIoerrCanRetry2)
2163   else if( winIoerrCanRetry2(e) ){
2164     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
2165     ++*pnRetry;
2166     return 1;
2167   }
2168 #endif
2169   if( pError ){
2170     *pError = e;
2171   }
2172   return 0;
2173 }
2174 
2175 /*
2176 ** Log a I/O error retry episode.
2177 */
2178 static void winLogIoerr(int nRetry, int lineno){
2179   if( nRetry ){
2180     sqlite3_log(SQLITE_NOTICE,
2181       "delayed %dms for lock/sharing conflict at line %d",
2182       winIoerrRetryDelay*nRetry*(nRetry+1)/2, lineno
2183     );
2184   }
2185 }
2186 
2187 /*
2188 ** This #if does not rely on the SQLITE_OS_WINCE define because the
2189 ** corresponding section in "date.c" cannot use it.
2190 */
2191 #if !defined(SQLITE_OMIT_LOCALTIME) && defined(_WIN32_WCE) && \
2192     (!defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API)
2193 /*
2194 ** The MSVC CRT on Windows CE may not have a localtime() function.
2195 ** So define a substitute.
2196 */
2197 #  include <time.h>
2198 struct tm *__cdecl localtime(const time_t *t)
2199 {
2200   static struct tm y;
2201   FILETIME uTm, lTm;
2202   SYSTEMTIME pTm;
2203   sqlite3_int64 t64;
2204   t64 = *t;
2205   t64 = (t64 + 11644473600)*10000000;
2206   uTm.dwLowDateTime = (DWORD)(t64 & 0xFFFFFFFF);
2207   uTm.dwHighDateTime= (DWORD)(t64 >> 32);
2208   osFileTimeToLocalFileTime(&uTm,&lTm);
2209   osFileTimeToSystemTime(&lTm,&pTm);
2210   y.tm_year = pTm.wYear - 1900;
2211   y.tm_mon = pTm.wMonth - 1;
2212   y.tm_wday = pTm.wDayOfWeek;
2213   y.tm_mday = pTm.wDay;
2214   y.tm_hour = pTm.wHour;
2215   y.tm_min = pTm.wMinute;
2216   y.tm_sec = pTm.wSecond;
2217   return &y;
2218 }
2219 #endif
2220 
2221 #if SQLITE_OS_WINCE
2222 /*************************************************************************
2223 ** This section contains code for WinCE only.
2224 */
2225 #define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]
2226 
2227 /*
2228 ** Acquire a lock on the handle h
2229 */
2230 static void winceMutexAcquire(HANDLE h){
2231    DWORD dwErr;
2232    do {
2233      dwErr = osWaitForSingleObject(h, INFINITE);
2234    } while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);
2235 }
2236 /*
2237 ** Release a lock acquired by winceMutexAcquire()
2238 */
2239 #define winceMutexRelease(h) ReleaseMutex(h)
2240 
2241 /*
2242 ** Create the mutex and shared memory used for locking in the file
2243 ** descriptor pFile
2244 */
2245 static int winceCreateLock(const char *zFilename, winFile *pFile){
2246   LPWSTR zTok;
2247   LPWSTR zName;
2248   DWORD lastErrno;
2249   BOOL bLogged = FALSE;
2250   BOOL bInit = TRUE;
2251 
2252   zName = winUtf8ToUnicode(zFilename);
2253   if( zName==0 ){
2254     /* out of memory */
2255     return SQLITE_IOERR_NOMEM_BKPT;
2256   }
2257 
2258   /* Initialize the local lockdata */
2259   memset(&pFile->local, 0, sizeof(pFile->local));
2260 
2261   /* Replace the backslashes from the filename and lowercase it
2262   ** to derive a mutex name. */
2263   zTok = osCharLowerW(zName);
2264   for (;*zTok;zTok++){
2265     if (*zTok == '\\') *zTok = '_';
2266   }
2267 
2268   /* Create/open the named mutex */
2269   pFile->hMutex = osCreateMutexW(NULL, FALSE, zName);
2270   if (!pFile->hMutex){
2271     pFile->lastErrno = osGetLastError();
2272     sqlite3_free(zName);
2273     return winLogError(SQLITE_IOERR, pFile->lastErrno,
2274                        "winceCreateLock1", zFilename);
2275   }
2276 
2277   /* Acquire the mutex before continuing */
2278   winceMutexAcquire(pFile->hMutex);
2279 
2280   /* Since the names of named mutexes, semaphores, file mappings etc are
2281   ** case-sensitive, take advantage of that by uppercasing the mutex name
2282   ** and using that as the shared filemapping name.
2283   */
2284   osCharUpperW(zName);
2285   pFile->hShared = osCreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
2286                                         PAGE_READWRITE, 0, sizeof(winceLock),
2287                                         zName);
2288 
2289   /* Set a flag that indicates we're the first to create the memory so it
2290   ** must be zero-initialized */
2291   lastErrno = osGetLastError();
2292   if (lastErrno == ERROR_ALREADY_EXISTS){
2293     bInit = FALSE;
2294   }
2295 
2296   sqlite3_free(zName);
2297 
2298   /* If we succeeded in making the shared memory handle, map it. */
2299   if( pFile->hShared ){
2300     pFile->shared = (winceLock*)osMapViewOfFile(pFile->hShared,
2301              FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
2302     /* If mapping failed, close the shared memory handle and erase it */
2303     if( !pFile->shared ){
2304       pFile->lastErrno = osGetLastError();
2305       winLogError(SQLITE_IOERR, pFile->lastErrno,
2306                   "winceCreateLock2", zFilename);
2307       bLogged = TRUE;
2308       osCloseHandle(pFile->hShared);
2309       pFile->hShared = NULL;
2310     }
2311   }
2312 
2313   /* If shared memory could not be created, then close the mutex and fail */
2314   if( pFile->hShared==NULL ){
2315     if( !bLogged ){
2316       pFile->lastErrno = lastErrno;
2317       winLogError(SQLITE_IOERR, pFile->lastErrno,
2318                   "winceCreateLock3", zFilename);
2319       bLogged = TRUE;
2320     }
2321     winceMutexRelease(pFile->hMutex);
2322     osCloseHandle(pFile->hMutex);
2323     pFile->hMutex = NULL;
2324     return SQLITE_IOERR;
2325   }
2326 
2327   /* Initialize the shared memory if we're supposed to */
2328   if( bInit ){
2329     memset(pFile->shared, 0, sizeof(winceLock));
2330   }
2331 
2332   winceMutexRelease(pFile->hMutex);
2333   return SQLITE_OK;
2334 }
2335 
2336 /*
2337 ** Destroy the part of winFile that deals with wince locks
2338 */
2339 static void winceDestroyLock(winFile *pFile){
2340   if (pFile->hMutex){
2341     /* Acquire the mutex */
2342     winceMutexAcquire(pFile->hMutex);
2343 
2344     /* The following blocks should probably assert in debug mode, but they
2345        are to cleanup in case any locks remained open */
2346     if (pFile->local.nReaders){
2347       pFile->shared->nReaders --;
2348     }
2349     if (pFile->local.bReserved){
2350       pFile->shared->bReserved = FALSE;
2351     }
2352     if (pFile->local.bPending){
2353       pFile->shared->bPending = FALSE;
2354     }
2355     if (pFile->local.bExclusive){
2356       pFile->shared->bExclusive = FALSE;
2357     }
2358 
2359     /* De-reference and close our copy of the shared memory handle */
2360     osUnmapViewOfFile(pFile->shared);
2361     osCloseHandle(pFile->hShared);
2362 
2363     /* Done with the mutex */
2364     winceMutexRelease(pFile->hMutex);
2365     osCloseHandle(pFile->hMutex);
2366     pFile->hMutex = NULL;
2367   }
2368 }
2369 
2370 /*
2371 ** An implementation of the LockFile() API of Windows for CE
2372 */
2373 static BOOL winceLockFile(
2374   LPHANDLE phFile,
2375   DWORD dwFileOffsetLow,
2376   DWORD dwFileOffsetHigh,
2377   DWORD nNumberOfBytesToLockLow,
2378   DWORD nNumberOfBytesToLockHigh
2379 ){
2380   winFile *pFile = HANDLE_TO_WINFILE(phFile);
2381   BOOL bReturn = FALSE;
2382 
2383   UNUSED_PARAMETER(dwFileOffsetHigh);
2384   UNUSED_PARAMETER(nNumberOfBytesToLockHigh);
2385 
2386   if (!pFile->hMutex) return TRUE;
2387   winceMutexAcquire(pFile->hMutex);
2388 
2389   /* Wanting an exclusive lock? */
2390   if (dwFileOffsetLow == (DWORD)SHARED_FIRST
2391        && nNumberOfBytesToLockLow == (DWORD)SHARED_SIZE){
2392     if (pFile->shared->nReaders == 0 && pFile->shared->bExclusive == 0){
2393        pFile->shared->bExclusive = TRUE;
2394        pFile->local.bExclusive = TRUE;
2395        bReturn = TRUE;
2396     }
2397   }
2398 
2399   /* Want a read-only lock? */
2400   else if (dwFileOffsetLow == (DWORD)SHARED_FIRST &&
2401            nNumberOfBytesToLockLow == 1){
2402     if (pFile->shared->bExclusive == 0){
2403       pFile->local.nReaders ++;
2404       if (pFile->local.nReaders == 1){
2405         pFile->shared->nReaders ++;
2406       }
2407       bReturn = TRUE;
2408     }
2409   }
2410 
2411   /* Want a pending lock? */
2412   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
2413            && nNumberOfBytesToLockLow == 1){
2414     /* If no pending lock has been acquired, then acquire it */
2415     if (pFile->shared->bPending == 0) {
2416       pFile->shared->bPending = TRUE;
2417       pFile->local.bPending = TRUE;
2418       bReturn = TRUE;
2419     }
2420   }
2421 
2422   /* Want a reserved lock? */
2423   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
2424            && nNumberOfBytesToLockLow == 1){
2425     if (pFile->shared->bReserved == 0) {
2426       pFile->shared->bReserved = TRUE;
2427       pFile->local.bReserved = TRUE;
2428       bReturn = TRUE;
2429     }
2430   }
2431 
2432   winceMutexRelease(pFile->hMutex);
2433   return bReturn;
2434 }
2435 
2436 /*
2437 ** An implementation of the UnlockFile API of Windows for CE
2438 */
2439 static BOOL winceUnlockFile(
2440   LPHANDLE phFile,
2441   DWORD dwFileOffsetLow,
2442   DWORD dwFileOffsetHigh,
2443   DWORD nNumberOfBytesToUnlockLow,
2444   DWORD nNumberOfBytesToUnlockHigh
2445 ){
2446   winFile *pFile = HANDLE_TO_WINFILE(phFile);
2447   BOOL bReturn = FALSE;
2448 
2449   UNUSED_PARAMETER(dwFileOffsetHigh);
2450   UNUSED_PARAMETER(nNumberOfBytesToUnlockHigh);
2451 
2452   if (!pFile->hMutex) return TRUE;
2453   winceMutexAcquire(pFile->hMutex);
2454 
2455   /* Releasing a reader lock or an exclusive lock */
2456   if (dwFileOffsetLow == (DWORD)SHARED_FIRST){
2457     /* Did we have an exclusive lock? */
2458     if (pFile->local.bExclusive){
2459       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE);
2460       pFile->local.bExclusive = FALSE;
2461       pFile->shared->bExclusive = FALSE;
2462       bReturn = TRUE;
2463     }
2464 
2465     /* Did we just have a reader lock? */
2466     else if (pFile->local.nReaders){
2467       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE
2468              || nNumberOfBytesToUnlockLow == 1);
2469       pFile->local.nReaders --;
2470       if (pFile->local.nReaders == 0)
2471       {
2472         pFile->shared->nReaders --;
2473       }
2474       bReturn = TRUE;
2475     }
2476   }
2477 
2478   /* Releasing a pending lock */
2479   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
2480            && nNumberOfBytesToUnlockLow == 1){
2481     if (pFile->local.bPending){
2482       pFile->local.bPending = FALSE;
2483       pFile->shared->bPending = FALSE;
2484       bReturn = TRUE;
2485     }
2486   }
2487   /* Releasing a reserved lock */
2488   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
2489            && nNumberOfBytesToUnlockLow == 1){
2490     if (pFile->local.bReserved) {
2491       pFile->local.bReserved = FALSE;
2492       pFile->shared->bReserved = FALSE;
2493       bReturn = TRUE;
2494     }
2495   }
2496 
2497   winceMutexRelease(pFile->hMutex);
2498   return bReturn;
2499 }
2500 /*
2501 ** End of the special code for wince
2502 *****************************************************************************/
2503 #endif /* SQLITE_OS_WINCE */
2504 
2505 /*
2506 ** Lock a file region.
2507 */
2508 static BOOL winLockFile(
2509   LPHANDLE phFile,
2510   DWORD flags,
2511   DWORD offsetLow,
2512   DWORD offsetHigh,
2513   DWORD numBytesLow,
2514   DWORD numBytesHigh
2515 ){
2516 #if SQLITE_OS_WINCE
2517   /*
2518   ** NOTE: Windows CE is handled differently here due its lack of the Win32
2519   **       API LockFile.
2520   */
2521   return winceLockFile(phFile, offsetLow, offsetHigh,
2522                        numBytesLow, numBytesHigh);
2523 #else
2524   if( osIsNT() ){
2525     OVERLAPPED ovlp;
2526     memset(&ovlp, 0, sizeof(OVERLAPPED));
2527     ovlp.Offset = offsetLow;
2528     ovlp.OffsetHigh = offsetHigh;
2529     return osLockFileEx(*phFile, flags, 0, numBytesLow, numBytesHigh, &ovlp);
2530   }else{
2531     return osLockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
2532                       numBytesHigh);
2533   }
2534 #endif
2535 }
2536 
2537 /*
2538 ** Unlock a file region.
2539  */
2540 static BOOL winUnlockFile(
2541   LPHANDLE phFile,
2542   DWORD offsetLow,
2543   DWORD offsetHigh,
2544   DWORD numBytesLow,
2545   DWORD numBytesHigh
2546 ){
2547 #if SQLITE_OS_WINCE
2548   /*
2549   ** NOTE: Windows CE is handled differently here due its lack of the Win32
2550   **       API UnlockFile.
2551   */
2552   return winceUnlockFile(phFile, offsetLow, offsetHigh,
2553                          numBytesLow, numBytesHigh);
2554 #else
2555   if( osIsNT() ){
2556     OVERLAPPED ovlp;
2557     memset(&ovlp, 0, sizeof(OVERLAPPED));
2558     ovlp.Offset = offsetLow;
2559     ovlp.OffsetHigh = offsetHigh;
2560     return osUnlockFileEx(*phFile, 0, numBytesLow, numBytesHigh, &ovlp);
2561   }else{
2562     return osUnlockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
2563                         numBytesHigh);
2564   }
2565 #endif
2566 }
2567 
2568 /*****************************************************************************
2569 ** The next group of routines implement the I/O methods specified
2570 ** by the sqlite3_io_methods object.
2571 ******************************************************************************/
2572 
2573 /*
2574 ** Some Microsoft compilers lack this definition.
2575 */
2576 #ifndef INVALID_SET_FILE_POINTER
2577 # define INVALID_SET_FILE_POINTER ((DWORD)-1)
2578 #endif
2579 
2580 /*
2581 ** Move the current position of the file handle passed as the first
2582 ** argument to offset iOffset within the file. If successful, return 0.
2583 ** Otherwise, set pFile->lastErrno and return non-zero.
2584 */
2585 static int winSeekFile(winFile *pFile, sqlite3_int64 iOffset){
2586 #if !SQLITE_OS_WINRT
2587   LONG upperBits;                 /* Most sig. 32 bits of new offset */
2588   LONG lowerBits;                 /* Least sig. 32 bits of new offset */
2589   DWORD dwRet;                    /* Value returned by SetFilePointer() */
2590   DWORD lastErrno;                /* Value returned by GetLastError() */
2591 
2592   OSTRACE(("SEEK file=%p, offset=%lld\n", pFile->h, iOffset));
2593 
2594   upperBits = (LONG)((iOffset>>32) & 0x7fffffff);
2595   lowerBits = (LONG)(iOffset & 0xffffffff);
2596 
2597   /* API oddity: If successful, SetFilePointer() returns a dword
2598   ** containing the lower 32-bits of the new file-offset. Or, if it fails,
2599   ** it returns INVALID_SET_FILE_POINTER. However according to MSDN,
2600   ** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine
2601   ** whether an error has actually occurred, it is also necessary to call
2602   ** GetLastError().
2603   */
2604   dwRet = osSetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
2605 
2606   if( (dwRet==INVALID_SET_FILE_POINTER
2607       && ((lastErrno = osGetLastError())!=NO_ERROR)) ){
2608     pFile->lastErrno = lastErrno;
2609     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
2610                 "winSeekFile", pFile->zPath);
2611     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
2612     return 1;
2613   }
2614 
2615   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
2616   return 0;
2617 #else
2618   /*
2619   ** Same as above, except that this implementation works for WinRT.
2620   */
2621 
2622   LARGE_INTEGER x;                /* The new offset */
2623   BOOL bRet;                      /* Value returned by SetFilePointerEx() */
2624 
2625   x.QuadPart = iOffset;
2626   bRet = osSetFilePointerEx(pFile->h, x, 0, FILE_BEGIN);
2627 
2628   if(!bRet){
2629     pFile->lastErrno = osGetLastError();
2630     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
2631                 "winSeekFile", pFile->zPath);
2632     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
2633     return 1;
2634   }
2635 
2636   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
2637   return 0;
2638 #endif
2639 }
2640 
2641 #if SQLITE_MAX_MMAP_SIZE>0
2642 /* Forward references to VFS helper methods used for memory mapped files */
2643 static int winMapfile(winFile*, sqlite3_int64);
2644 static int winUnmapfile(winFile*);
2645 #endif
2646 
2647 /*
2648 ** Close a file.
2649 **
2650 ** It is reported that an attempt to close a handle might sometimes
2651 ** fail.  This is a very unreasonable result, but Windows is notorious
2652 ** for being unreasonable so I do not doubt that it might happen.  If
2653 ** the close fails, we pause for 100 milliseconds and try again.  As
2654 ** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before
2655 ** giving up and returning an error.
2656 */
2657 #define MX_CLOSE_ATTEMPT 3
2658 static int winClose(sqlite3_file *id){
2659   int rc, cnt = 0;
2660   winFile *pFile = (winFile*)id;
2661 
2662   assert( id!=0 );
2663 #ifndef SQLITE_OMIT_WAL
2664   assert( pFile->pShm==0 );
2665 #endif
2666   assert( pFile->h!=NULL && pFile->h!=INVALID_HANDLE_VALUE );
2667   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p\n",
2668            osGetCurrentProcessId(), pFile, pFile->h));
2669 
2670 #if SQLITE_MAX_MMAP_SIZE>0
2671   winUnmapfile(pFile);
2672 #endif
2673 
2674   do{
2675     rc = osCloseHandle(pFile->h);
2676     /* SimulateIOError( rc=0; cnt=MX_CLOSE_ATTEMPT; ); */
2677   }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (sqlite3_win32_sleep(100), 1) );
2678 #if SQLITE_OS_WINCE
2679 #define WINCE_DELETION_ATTEMPTS 3
2680   {
2681     winVfsAppData *pAppData = (winVfsAppData*)pFile->pVfs->pAppData;
2682     if( pAppData==NULL || !pAppData->bNoLock ){
2683       winceDestroyLock(pFile);
2684     }
2685   }
2686   if( pFile->zDeleteOnClose ){
2687     int cnt = 0;
2688     while(
2689            osDeleteFileW(pFile->zDeleteOnClose)==0
2690         && osGetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff
2691         && cnt++ < WINCE_DELETION_ATTEMPTS
2692     ){
2693        sqlite3_win32_sleep(100);  /* Wait a little before trying again */
2694     }
2695     sqlite3_free(pFile->zDeleteOnClose);
2696   }
2697 #endif
2698   if( rc ){
2699     pFile->h = NULL;
2700   }
2701   OpenCounter(-1);
2702   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p, rc=%s\n",
2703            osGetCurrentProcessId(), pFile, pFile->h, rc ? "ok" : "failed"));
2704   return rc ? SQLITE_OK
2705             : winLogError(SQLITE_IOERR_CLOSE, osGetLastError(),
2706                           "winClose", pFile->zPath);
2707 }
2708 
2709 /*
2710 ** Read data from a file into a buffer.  Return SQLITE_OK if all
2711 ** bytes were read successfully and SQLITE_IOERR if anything goes
2712 ** wrong.
2713 */
2714 static int winRead(
2715   sqlite3_file *id,          /* File to read from */
2716   void *pBuf,                /* Write content into this buffer */
2717   int amt,                   /* Number of bytes to read */
2718   sqlite3_int64 offset       /* Begin reading at this offset */
2719 ){
2720 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2721   OVERLAPPED overlapped;          /* The offset for ReadFile. */
2722 #endif
2723   winFile *pFile = (winFile*)id;  /* file handle */
2724   DWORD nRead;                    /* Number of bytes actually read from file */
2725   int nRetry = 0;                 /* Number of retrys */
2726 
2727   assert( id!=0 );
2728   assert( amt>0 );
2729   assert( offset>=0 );
2730   SimulateIOError(return SQLITE_IOERR_READ);
2731   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
2732            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
2733            pFile->h, pBuf, amt, offset, pFile->locktype));
2734 
2735 #if SQLITE_MAX_MMAP_SIZE>0
2736   /* Deal with as much of this read request as possible by transfering
2737   ** data from the memory mapping using memcpy().  */
2738   if( offset<pFile->mmapSize ){
2739     if( offset+amt <= pFile->mmapSize ){
2740       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
2741       OSTRACE(("READ-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2742                osGetCurrentProcessId(), pFile, pFile->h));
2743       return SQLITE_OK;
2744     }else{
2745       int nCopy = (int)(pFile->mmapSize - offset);
2746       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);
2747       pBuf = &((u8 *)pBuf)[nCopy];
2748       amt -= nCopy;
2749       offset += nCopy;
2750     }
2751   }
2752 #endif
2753 
2754 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2755   if( winSeekFile(pFile, offset) ){
2756     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
2757              osGetCurrentProcessId(), pFile, pFile->h));
2758     return SQLITE_FULL;
2759   }
2760   while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
2761 #else
2762   memset(&overlapped, 0, sizeof(OVERLAPPED));
2763   overlapped.Offset = (LONG)(offset & 0xffffffff);
2764   overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2765   while( !osReadFile(pFile->h, pBuf, amt, &nRead, &overlapped) &&
2766          osGetLastError()!=ERROR_HANDLE_EOF ){
2767 #endif
2768     DWORD lastErrno;
2769     if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
2770     pFile->lastErrno = lastErrno;
2771     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_READ\n",
2772              osGetCurrentProcessId(), pFile, pFile->h));
2773     return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,
2774                        "winRead", pFile->zPath);
2775   }
2776   winLogIoerr(nRetry, __LINE__);
2777   if( nRead<(DWORD)amt ){
2778     /* Unread parts of the buffer must be zero-filled */
2779     memset(&((char*)pBuf)[nRead], 0, amt-nRead);
2780     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_SHORT_READ\n",
2781              osGetCurrentProcessId(), pFile, pFile->h));
2782     return SQLITE_IOERR_SHORT_READ;
2783   }
2784 
2785   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2786            osGetCurrentProcessId(), pFile, pFile->h));
2787   return SQLITE_OK;
2788 }
2789 
2790 /*
2791 ** Write data from a buffer into a file.  Return SQLITE_OK on success
2792 ** or some other error code on failure.
2793 */
2794 static int winWrite(
2795   sqlite3_file *id,               /* File to write into */
2796   const void *pBuf,               /* The bytes to be written */
2797   int amt,                        /* Number of bytes to write */
2798   sqlite3_int64 offset            /* Offset into the file to begin writing at */
2799 ){
2800   int rc = 0;                     /* True if error has occurred, else false */
2801   winFile *pFile = (winFile*)id;  /* File handle */
2802   int nRetry = 0;                 /* Number of retries */
2803 
2804   assert( amt>0 );
2805   assert( pFile );
2806   SimulateIOError(return SQLITE_IOERR_WRITE);
2807   SimulateDiskfullError(return SQLITE_FULL);
2808 
2809   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
2810            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
2811            pFile->h, pBuf, amt, offset, pFile->locktype));
2812 
2813 #if defined(SQLITE_MMAP_READWRITE) && SQLITE_MAX_MMAP_SIZE>0
2814   /* Deal with as much of this write request as possible by transfering
2815   ** data from the memory mapping using memcpy().  */
2816   if( offset<pFile->mmapSize ){
2817     if( offset+amt <= pFile->mmapSize ){
2818       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
2819       OSTRACE(("WRITE-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2820                osGetCurrentProcessId(), pFile, pFile->h));
2821       return SQLITE_OK;
2822     }else{
2823       int nCopy = (int)(pFile->mmapSize - offset);
2824       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);
2825       pBuf = &((u8 *)pBuf)[nCopy];
2826       amt -= nCopy;
2827       offset += nCopy;
2828     }
2829   }
2830 #endif
2831 
2832 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2833   rc = winSeekFile(pFile, offset);
2834   if( rc==0 ){
2835 #else
2836   {
2837 #endif
2838 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2839     OVERLAPPED overlapped;        /* The offset for WriteFile. */
2840 #endif
2841     u8 *aRem = (u8 *)pBuf;        /* Data yet to be written */
2842     int nRem = amt;               /* Number of bytes yet to be written */
2843     DWORD nWrite;                 /* Bytes written by each WriteFile() call */
2844     DWORD lastErrno = NO_ERROR;   /* Value returned by GetLastError() */
2845 
2846 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2847     memset(&overlapped, 0, sizeof(OVERLAPPED));
2848     overlapped.Offset = (LONG)(offset & 0xffffffff);
2849     overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2850 #endif
2851 
2852     while( nRem>0 ){
2853 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2854       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, 0) ){
2855 #else
2856       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, &overlapped) ){
2857 #endif
2858         if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
2859         break;
2860       }
2861       assert( nWrite==0 || nWrite<=(DWORD)nRem );
2862       if( nWrite==0 || nWrite>(DWORD)nRem ){
2863         lastErrno = osGetLastError();
2864         break;
2865       }
2866 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2867       offset += nWrite;
2868       overlapped.Offset = (LONG)(offset & 0xffffffff);
2869       overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2870 #endif
2871       aRem += nWrite;
2872       nRem -= nWrite;
2873     }
2874     if( nRem>0 ){
2875       pFile->lastErrno = lastErrno;
2876       rc = 1;
2877     }
2878   }
2879 
2880   if( rc ){
2881     if(   ( pFile->lastErrno==ERROR_HANDLE_DISK_FULL )
2882        || ( pFile->lastErrno==ERROR_DISK_FULL )){
2883       OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
2884                osGetCurrentProcessId(), pFile, pFile->h));
2885       return winLogError(SQLITE_FULL, pFile->lastErrno,
2886                          "winWrite1", pFile->zPath);
2887     }
2888     OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_WRITE\n",
2889              osGetCurrentProcessId(), pFile, pFile->h));
2890     return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,
2891                        "winWrite2", pFile->zPath);
2892   }else{
2893     winLogIoerr(nRetry, __LINE__);
2894   }
2895   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2896            osGetCurrentProcessId(), pFile, pFile->h));
2897   return SQLITE_OK;
2898 }
2899 
2900 /*
2901 ** Truncate an open file to a specified size
2902 */
2903 static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
2904   winFile *pFile = (winFile*)id;  /* File handle object */
2905   int rc = SQLITE_OK;             /* Return code for this function */
2906   DWORD lastErrno;
2907 
2908   assert( pFile );
2909   SimulateIOError(return SQLITE_IOERR_TRUNCATE);
2910   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, size=%lld, lock=%d\n",
2911            osGetCurrentProcessId(), pFile, pFile->h, nByte, pFile->locktype));
2912 
2913   /* If the user has configured a chunk-size for this file, truncate the
2914   ** file so that it consists of an integer number of chunks (i.e. the
2915   ** actual file size after the operation may be larger than the requested
2916   ** size).
2917   */
2918   if( pFile->szChunk>0 ){
2919     nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
2920   }
2921 
2922   /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
2923   if( winSeekFile(pFile, nByte) ){
2924     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
2925                      "winTruncate1", pFile->zPath);
2926   }else if( 0==osSetEndOfFile(pFile->h) &&
2927             ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){
2928     pFile->lastErrno = lastErrno;
2929     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
2930                      "winTruncate2", pFile->zPath);
2931   }
2932 
2933 #if SQLITE_MAX_MMAP_SIZE>0
2934   /* If the file was truncated to a size smaller than the currently
2935   ** mapped region, reduce the effective mapping size as well. SQLite will
2936   ** use read() and write() to access data beyond this point from now on.
2937   */
2938   if( pFile->pMapRegion && nByte<pFile->mmapSize ){
2939     pFile->mmapSize = nByte;
2940   }
2941 #endif
2942 
2943   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, rc=%s\n",
2944            osGetCurrentProcessId(), pFile, pFile->h, sqlite3ErrName(rc)));
2945   return rc;
2946 }
2947 
2948 #ifdef SQLITE_TEST
2949 /*
2950 ** Count the number of fullsyncs and normal syncs.  This is used to test
2951 ** that syncs and fullsyncs are occuring at the right times.
2952 */
2953 int sqlite3_sync_count = 0;
2954 int sqlite3_fullsync_count = 0;
2955 #endif
2956 
2957 /*
2958 ** Make sure all writes to a particular file are committed to disk.
2959 */
2960 static int winSync(sqlite3_file *id, int flags){
2961 #ifndef SQLITE_NO_SYNC
2962   /*
2963   ** Used only when SQLITE_NO_SYNC is not defined.
2964    */
2965   BOOL rc;
2966 #endif
2967 #if !defined(NDEBUG) || !defined(SQLITE_NO_SYNC) || \
2968     defined(SQLITE_HAVE_OS_TRACE)
2969   /*
2970   ** Used when SQLITE_NO_SYNC is not defined and by the assert() and/or
2971   ** OSTRACE() macros.
2972    */
2973   winFile *pFile = (winFile*)id;
2974 #else
2975   UNUSED_PARAMETER(id);
2976 #endif
2977 
2978   assert( pFile );
2979   /* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */
2980   assert((flags&0x0F)==SQLITE_SYNC_NORMAL
2981       || (flags&0x0F)==SQLITE_SYNC_FULL
2982   );
2983 
2984   /* Unix cannot, but some systems may return SQLITE_FULL from here. This
2985   ** line is to test that doing so does not cause any problems.
2986   */
2987   SimulateDiskfullError( return SQLITE_FULL );
2988 
2989   OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, flags=%x, lock=%d\n",
2990            osGetCurrentProcessId(), pFile, pFile->h, flags,
2991            pFile->locktype));
2992 
2993 #ifndef SQLITE_TEST
2994   UNUSED_PARAMETER(flags);
2995 #else
2996   if( (flags&0x0F)==SQLITE_SYNC_FULL ){
2997     sqlite3_fullsync_count++;
2998   }
2999   sqlite3_sync_count++;
3000 #endif
3001 
3002   /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
3003   ** no-op
3004   */
3005 #ifdef SQLITE_NO_SYNC
3006   OSTRACE(("SYNC-NOP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
3007            osGetCurrentProcessId(), pFile, pFile->h));
3008   return SQLITE_OK;
3009 #else
3010 #if SQLITE_MAX_MMAP_SIZE>0
3011   if( pFile->pMapRegion ){
3012     if( osFlushViewOfFile(pFile->pMapRegion, 0) ){
3013       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
3014                "rc=SQLITE_OK\n", osGetCurrentProcessId(),
3015                pFile, pFile->pMapRegion));
3016     }else{
3017       pFile->lastErrno = osGetLastError();
3018       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
3019                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(),
3020                pFile, pFile->pMapRegion));
3021       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
3022                          "winSync1", pFile->zPath);
3023     }
3024   }
3025 #endif
3026   rc = osFlushFileBuffers(pFile->h);
3027   SimulateIOError( rc=FALSE );
3028   if( rc ){
3029     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
3030              osGetCurrentProcessId(), pFile, pFile->h));
3031     return SQLITE_OK;
3032   }else{
3033     pFile->lastErrno = osGetLastError();
3034     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_FSYNC\n",
3035              osGetCurrentProcessId(), pFile, pFile->h));
3036     return winLogError(SQLITE_IOERR_FSYNC, pFile->lastErrno,
3037                        "winSync2", pFile->zPath);
3038   }
3039 #endif
3040 }
3041 
3042 /*
3043 ** Determine the current size of a file in bytes
3044 */
3045 static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
3046   winFile *pFile = (winFile*)id;
3047   int rc = SQLITE_OK;
3048 
3049   assert( id!=0 );
3050   assert( pSize!=0 );
3051   SimulateIOError(return SQLITE_IOERR_FSTAT);
3052   OSTRACE(("SIZE file=%p, pSize=%p\n", pFile->h, pSize));
3053 
3054 #if SQLITE_OS_WINRT
3055   {
3056     FILE_STANDARD_INFO info;
3057     if( osGetFileInformationByHandleEx(pFile->h, FileStandardInfo,
3058                                      &info, sizeof(info)) ){
3059       *pSize = info.EndOfFile.QuadPart;
3060     }else{
3061       pFile->lastErrno = osGetLastError();
3062       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
3063                        "winFileSize", pFile->zPath);
3064     }
3065   }
3066 #else
3067   {
3068     DWORD upperBits;
3069     DWORD lowerBits;
3070     DWORD lastErrno;
3071 
3072     lowerBits = osGetFileSize(pFile->h, &upperBits);
3073     *pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;
3074     if(   (lowerBits == INVALID_FILE_SIZE)
3075        && ((lastErrno = osGetLastError())!=NO_ERROR) ){
3076       pFile->lastErrno = lastErrno;
3077       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
3078                        "winFileSize", pFile->zPath);
3079     }
3080   }
3081 #endif
3082   OSTRACE(("SIZE file=%p, pSize=%p, *pSize=%lld, rc=%s\n",
3083            pFile->h, pSize, *pSize, sqlite3ErrName(rc)));
3084   return rc;
3085 }
3086 
3087 /*
3088 ** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.
3089 */
3090 #ifndef LOCKFILE_FAIL_IMMEDIATELY
3091 # define LOCKFILE_FAIL_IMMEDIATELY 1
3092 #endif
3093 
3094 #ifndef LOCKFILE_EXCLUSIVE_LOCK
3095 # define LOCKFILE_EXCLUSIVE_LOCK 2
3096 #endif
3097 
3098 /*
3099 ** Historically, SQLite has used both the LockFile and LockFileEx functions.
3100 ** When the LockFile function was used, it was always expected to fail
3101 ** immediately if the lock could not be obtained.  Also, it always expected to
3102 ** obtain an exclusive lock.  These flags are used with the LockFileEx function
3103 ** and reflect those expectations; therefore, they should not be changed.
3104 */
3105 #ifndef SQLITE_LOCKFILE_FLAGS
3106 # define SQLITE_LOCKFILE_FLAGS   (LOCKFILE_FAIL_IMMEDIATELY | \
3107                                   LOCKFILE_EXCLUSIVE_LOCK)
3108 #endif
3109 
3110 /*
3111 ** Currently, SQLite never calls the LockFileEx function without wanting the
3112 ** call to fail immediately if the lock cannot be obtained.
3113 */
3114 #ifndef SQLITE_LOCKFILEEX_FLAGS
3115 # define SQLITE_LOCKFILEEX_FLAGS (LOCKFILE_FAIL_IMMEDIATELY)
3116 #endif
3117 
3118 /*
3119 ** Acquire a reader lock.
3120 ** Different API routines are called depending on whether or not this
3121 ** is Win9x or WinNT.
3122 */
3123 static int winGetReadLock(winFile *pFile){
3124   int res;
3125   OSTRACE(("READ-LOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
3126   if( osIsNT() ){
3127 #if SQLITE_OS_WINCE
3128     /*
3129     ** NOTE: Windows CE is handled differently here due its lack of the Win32
3130     **       API LockFileEx.
3131     */
3132     res = winceLockFile(&pFile->h, SHARED_FIRST, 0, 1, 0);
3133 #else
3134     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS, SHARED_FIRST, 0,
3135                       SHARED_SIZE, 0);
3136 #endif
3137   }
3138 #ifdef SQLITE_WIN32_HAS_ANSI
3139   else{
3140     int lk;
3141     sqlite3_randomness(sizeof(lk), &lk);
3142     pFile->sharedLockByte = (short)((lk & 0x7fffffff)%(SHARED_SIZE - 1));
3143     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
3144                       SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
3145   }
3146 #endif
3147   if( res == 0 ){
3148     pFile->lastErrno = osGetLastError();
3149     /* No need to log a failure to lock */
3150   }
3151   OSTRACE(("READ-LOCK file=%p, result=%d\n", pFile->h, res));
3152   return res;
3153 }
3154 
3155 /*
3156 ** Undo a readlock
3157 */
3158 static int winUnlockReadLock(winFile *pFile){
3159   int res;
3160   DWORD lastErrno;
3161   OSTRACE(("READ-UNLOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
3162   if( osIsNT() ){
3163     res = winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
3164   }
3165 #ifdef SQLITE_WIN32_HAS_ANSI
3166   else{
3167     res = winUnlockFile(&pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
3168   }
3169 #endif
3170   if( res==0 && ((lastErrno = osGetLastError())!=ERROR_NOT_LOCKED) ){
3171     pFile->lastErrno = lastErrno;
3172     winLogError(SQLITE_IOERR_UNLOCK, pFile->lastErrno,
3173                 "winUnlockReadLock", pFile->zPath);
3174   }
3175   OSTRACE(("READ-UNLOCK file=%p, result=%d\n", pFile->h, res));
3176   return res;
3177 }
3178 
3179 /*
3180 ** Lock the file with the lock specified by parameter locktype - one
3181 ** of the following:
3182 **
3183 **     (1) SHARED_LOCK
3184 **     (2) RESERVED_LOCK
3185 **     (3) PENDING_LOCK
3186 **     (4) EXCLUSIVE_LOCK
3187 **
3188 ** Sometimes when requesting one lock state, additional lock states
3189 ** are inserted in between.  The locking might fail on one of the later
3190 ** transitions leaving the lock state different from what it started but
3191 ** still short of its goal.  The following chart shows the allowed
3192 ** transitions and the inserted intermediate states:
3193 **
3194 **    UNLOCKED -> SHARED
3195 **    SHARED -> RESERVED
3196 **    SHARED -> (PENDING) -> EXCLUSIVE
3197 **    RESERVED -> (PENDING) -> EXCLUSIVE
3198 **    PENDING -> EXCLUSIVE
3199 **
3200 ** This routine will only increase a lock.  The winUnlock() routine
3201 ** erases all locks at once and returns us immediately to locking level 0.
3202 ** It is not possible to lower the locking level one step at a time.  You
3203 ** must go straight to locking level 0.
3204 */
3205 static int winLock(sqlite3_file *id, int locktype){
3206   int rc = SQLITE_OK;    /* Return code from subroutines */
3207   int res = 1;           /* Result of a Windows lock call */
3208   int newLocktype;       /* Set pFile->locktype to this value before exiting */
3209   int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
3210   winFile *pFile = (winFile*)id;
3211   DWORD lastErrno = NO_ERROR;
3212 
3213   assert( id!=0 );
3214   OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",
3215            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
3216 
3217   /* If there is already a lock of this type or more restrictive on the
3218   ** OsFile, do nothing. Don't use the end_lock: exit path, as
3219   ** sqlite3OsEnterMutex() hasn't been called yet.
3220   */
3221   if( pFile->locktype>=locktype ){
3222     OSTRACE(("LOCK-HELD file=%p, rc=SQLITE_OK\n", pFile->h));
3223     return SQLITE_OK;
3224   }
3225 
3226   /* Do not allow any kind of write-lock on a read-only database
3227   */
3228   if( (pFile->ctrlFlags & WINFILE_RDONLY)!=0 && locktype>=RESERVED_LOCK ){
3229     return SQLITE_IOERR_LOCK;
3230   }
3231 
3232   /* Make sure the locking sequence is correct
3233   */
3234   assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
3235   assert( locktype!=PENDING_LOCK );
3236   assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
3237 
3238   /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
3239   ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
3240   ** the PENDING_LOCK byte is temporary.
3241   */
3242   newLocktype = pFile->locktype;
3243   if( pFile->locktype==NO_LOCK
3244    || (locktype==EXCLUSIVE_LOCK && pFile->locktype<=RESERVED_LOCK)
3245   ){
3246     int cnt = 3;
3247     while( cnt-->0 && (res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
3248                                          PENDING_BYTE, 0, 1, 0))==0 ){
3249       /* Try 3 times to get the pending lock.  This is needed to work
3250       ** around problems caused by indexing and/or anti-virus software on
3251       ** Windows systems.
3252       ** If you are using this code as a model for alternative VFSes, do not
3253       ** copy this retry logic.  It is a hack intended for Windows only.
3254       */
3255       lastErrno = osGetLastError();
3256       OSTRACE(("LOCK-PENDING-FAIL file=%p, count=%d, result=%d\n",
3257                pFile->h, cnt, res));
3258       if( lastErrno==ERROR_INVALID_HANDLE ){
3259         pFile->lastErrno = lastErrno;
3260         rc = SQLITE_IOERR_LOCK;
3261         OSTRACE(("LOCK-FAIL file=%p, count=%d, rc=%s\n",
3262                  pFile->h, cnt, sqlite3ErrName(rc)));
3263         return rc;
3264       }
3265       if( cnt ) sqlite3_win32_sleep(1);
3266     }
3267     gotPendingLock = res;
3268     if( !res ){
3269       lastErrno = osGetLastError();
3270     }
3271   }
3272 
3273   /* Acquire a shared lock
3274   */
3275   if( locktype==SHARED_LOCK && res ){
3276     assert( pFile->locktype==NO_LOCK );
3277     res = winGetReadLock(pFile);
3278     if( res ){
3279       newLocktype = SHARED_LOCK;
3280     }else{
3281       lastErrno = osGetLastError();
3282     }
3283   }
3284 
3285   /* Acquire a RESERVED lock
3286   */
3287   if( locktype==RESERVED_LOCK && res ){
3288     assert( pFile->locktype==SHARED_LOCK );
3289     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, RESERVED_BYTE, 0, 1, 0);
3290     if( res ){
3291       newLocktype = RESERVED_LOCK;
3292     }else{
3293       lastErrno = osGetLastError();
3294     }
3295   }
3296 
3297   /* Acquire a PENDING lock
3298   */
3299   if( locktype==EXCLUSIVE_LOCK && res ){
3300     newLocktype = PENDING_LOCK;
3301     gotPendingLock = 0;
3302   }
3303 
3304   /* Acquire an EXCLUSIVE lock
3305   */
3306   if( locktype==EXCLUSIVE_LOCK && res ){
3307     assert( pFile->locktype>=SHARED_LOCK );
3308     res = winUnlockReadLock(pFile);
3309     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, SHARED_FIRST, 0,
3310                       SHARED_SIZE, 0);
3311     if( res ){
3312       newLocktype = EXCLUSIVE_LOCK;
3313     }else{
3314       lastErrno = osGetLastError();
3315       winGetReadLock(pFile);
3316     }
3317   }
3318 
3319   /* If we are holding a PENDING lock that ought to be released, then
3320   ** release it now.
3321   */
3322   if( gotPendingLock && locktype==SHARED_LOCK ){
3323     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
3324   }
3325 
3326   /* Update the state of the lock has held in the file descriptor then
3327   ** return the appropriate result code.
3328   */
3329   if( res ){
3330     rc = SQLITE_OK;
3331   }else{
3332     pFile->lastErrno = lastErrno;
3333     rc = SQLITE_BUSY;
3334     OSTRACE(("LOCK-FAIL file=%p, wanted=%d, got=%d\n",
3335              pFile->h, locktype, newLocktype));
3336   }
3337   pFile->locktype = (u8)newLocktype;
3338   OSTRACE(("LOCK file=%p, lock=%d, rc=%s\n",
3339            pFile->h, pFile->locktype, sqlite3ErrName(rc)));
3340   return rc;
3341 }
3342 
3343 /*
3344 ** This routine checks if there is a RESERVED lock held on the specified
3345 ** file by this or any other process. If such a lock is held, return
3346 ** non-zero, otherwise zero.
3347 */
3348 static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
3349   int res;
3350   winFile *pFile = (winFile*)id;
3351 
3352   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
3353   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));
3354 
3355   assert( id!=0 );
3356   if( pFile->locktype>=RESERVED_LOCK ){
3357     res = 1;
3358     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (local)\n", pFile->h, res));
3359   }else{
3360     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE,0,1,0);
3361     if( res ){
3362       winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
3363     }
3364     res = !res;
3365     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (remote)\n", pFile->h, res));
3366   }
3367   *pResOut = res;
3368   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
3369            pFile->h, pResOut, *pResOut));
3370   return SQLITE_OK;
3371 }
3372 
3373 /*
3374 ** Lower the locking level on file descriptor id to locktype.  locktype
3375 ** must be either NO_LOCK or SHARED_LOCK.
3376 **
3377 ** If the locking level of the file descriptor is already at or below
3378 ** the requested locking level, this routine is a no-op.
3379 **
3380 ** It is not possible for this routine to fail if the second argument
3381 ** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
3382 ** might return SQLITE_IOERR;
3383 */
3384 static int winUnlock(sqlite3_file *id, int locktype){
3385   int type;
3386   winFile *pFile = (winFile*)id;
3387   int rc = SQLITE_OK;
3388   assert( pFile!=0 );
3389   assert( locktype<=SHARED_LOCK );
3390   OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
3391            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
3392   type = pFile->locktype;
3393   if( type>=EXCLUSIVE_LOCK ){
3394     winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
3395     if( locktype==SHARED_LOCK && !winGetReadLock(pFile) ){
3396       /* This should never happen.  We should always be able to
3397       ** reacquire the read lock */
3398       rc = winLogError(SQLITE_IOERR_UNLOCK, osGetLastError(),
3399                        "winUnlock", pFile->zPath);
3400     }
3401   }
3402   if( type>=RESERVED_LOCK ){
3403     winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
3404   }
3405   if( locktype==NO_LOCK && type>=SHARED_LOCK ){
3406     winUnlockReadLock(pFile);
3407   }
3408   if( type>=PENDING_LOCK ){
3409     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
3410   }
3411   pFile->locktype = (u8)locktype;
3412   OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",
3413            pFile->h, pFile->locktype, sqlite3ErrName(rc)));
3414   return rc;
3415 }
3416 
3417 /******************************************************************************
3418 ****************************** No-op Locking **********************************
3419 **
3420 ** Of the various locking implementations available, this is by far the
3421 ** simplest:  locking is ignored.  No attempt is made to lock the database
3422 ** file for reading or writing.
3423 **
3424 ** This locking mode is appropriate for use on read-only databases
3425 ** (ex: databases that are burned into CD-ROM, for example.)  It can
3426 ** also be used if the application employs some external mechanism to
3427 ** prevent simultaneous access of the same database by two or more
3428 ** database connections.  But there is a serious risk of database
3429 ** corruption if this locking mode is used in situations where multiple
3430 ** database connections are accessing the same database file at the same
3431 ** time and one or more of those connections are writing.
3432 */
3433 
3434 static int winNolockLock(sqlite3_file *id, int locktype){
3435   UNUSED_PARAMETER(id);
3436   UNUSED_PARAMETER(locktype);
3437   return SQLITE_OK;
3438 }
3439 
3440 static int winNolockCheckReservedLock(sqlite3_file *id, int *pResOut){
3441   UNUSED_PARAMETER(id);
3442   UNUSED_PARAMETER(pResOut);
3443   return SQLITE_OK;
3444 }
3445 
3446 static int winNolockUnlock(sqlite3_file *id, int locktype){
3447   UNUSED_PARAMETER(id);
3448   UNUSED_PARAMETER(locktype);
3449   return SQLITE_OK;
3450 }
3451 
3452 /******************* End of the no-op lock implementation *********************
3453 ******************************************************************************/
3454 
3455 /*
3456 ** If *pArg is initially negative then this is a query.  Set *pArg to
3457 ** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
3458 **
3459 ** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.
3460 */
3461 static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){
3462   if( *pArg<0 ){
3463     *pArg = (pFile->ctrlFlags & mask)!=0;
3464   }else if( (*pArg)==0 ){
3465     pFile->ctrlFlags &= ~mask;
3466   }else{
3467     pFile->ctrlFlags |= mask;
3468   }
3469 }
3470 
3471 /* Forward references to VFS helper methods used for temporary files */
3472 static int winGetTempname(sqlite3_vfs *, char **);
3473 static int winIsDir(const void *);
3474 static BOOL winIsDriveLetterAndColon(const char *);
3475 
3476 /*
3477 ** Control and query of the open file handle.
3478 */
3479 static int winFileControl(sqlite3_file *id, int op, void *pArg){
3480   winFile *pFile = (winFile*)id;
3481   OSTRACE(("FCNTL file=%p, op=%d, pArg=%p\n", pFile->h, op, pArg));
3482   switch( op ){
3483     case SQLITE_FCNTL_LOCKSTATE: {
3484       *(int*)pArg = pFile->locktype;
3485       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3486       return SQLITE_OK;
3487     }
3488     case SQLITE_FCNTL_LAST_ERRNO: {
3489       *(int*)pArg = (int)pFile->lastErrno;
3490       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3491       return SQLITE_OK;
3492     }
3493     case SQLITE_FCNTL_CHUNK_SIZE: {
3494       pFile->szChunk = *(int *)pArg;
3495       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3496       return SQLITE_OK;
3497     }
3498     case SQLITE_FCNTL_SIZE_HINT: {
3499       if( pFile->szChunk>0 ){
3500         sqlite3_int64 oldSz;
3501         int rc = winFileSize(id, &oldSz);
3502         if( rc==SQLITE_OK ){
3503           sqlite3_int64 newSz = *(sqlite3_int64*)pArg;
3504           if( newSz>oldSz ){
3505             SimulateIOErrorBenign(1);
3506             rc = winTruncate(id, newSz);
3507             SimulateIOErrorBenign(0);
3508           }
3509         }
3510         OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3511         return rc;
3512       }
3513       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3514       return SQLITE_OK;
3515     }
3516     case SQLITE_FCNTL_PERSIST_WAL: {
3517       winModeBit(pFile, WINFILE_PERSIST_WAL, (int*)pArg);
3518       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3519       return SQLITE_OK;
3520     }
3521     case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
3522       winModeBit(pFile, WINFILE_PSOW, (int*)pArg);
3523       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3524       return SQLITE_OK;
3525     }
3526     case SQLITE_FCNTL_VFSNAME: {
3527       *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
3528       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3529       return SQLITE_OK;
3530     }
3531     case SQLITE_FCNTL_WIN32_AV_RETRY: {
3532       int *a = (int*)pArg;
3533       if( a[0]>0 ){
3534         winIoerrRetry = a[0];
3535       }else{
3536         a[0] = winIoerrRetry;
3537       }
3538       if( a[1]>0 ){
3539         winIoerrRetryDelay = a[1];
3540       }else{
3541         a[1] = winIoerrRetryDelay;
3542       }
3543       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3544       return SQLITE_OK;
3545     }
3546     case SQLITE_FCNTL_WIN32_GET_HANDLE: {
3547       LPHANDLE phFile = (LPHANDLE)pArg;
3548       *phFile = pFile->h;
3549       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3550       return SQLITE_OK;
3551     }
3552 #ifdef SQLITE_TEST
3553     case SQLITE_FCNTL_WIN32_SET_HANDLE: {
3554       LPHANDLE phFile = (LPHANDLE)pArg;
3555       HANDLE hOldFile = pFile->h;
3556       pFile->h = *phFile;
3557       *phFile = hOldFile;
3558       OSTRACE(("FCNTL oldFile=%p, newFile=%p, rc=SQLITE_OK\n",
3559                hOldFile, pFile->h));
3560       return SQLITE_OK;
3561     }
3562 #endif
3563     case SQLITE_FCNTL_TEMPFILENAME: {
3564       char *zTFile = 0;
3565       int rc = winGetTempname(pFile->pVfs, &zTFile);
3566       if( rc==SQLITE_OK ){
3567         *(char**)pArg = zTFile;
3568       }
3569       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3570       return rc;
3571     }
3572 #if SQLITE_MAX_MMAP_SIZE>0
3573     case SQLITE_FCNTL_MMAP_SIZE: {
3574       i64 newLimit = *(i64*)pArg;
3575       int rc = SQLITE_OK;
3576       if( newLimit>sqlite3GlobalConfig.mxMmap ){
3577         newLimit = sqlite3GlobalConfig.mxMmap;
3578       }
3579 
3580       /* The value of newLimit may be eventually cast to (SIZE_T) and passed
3581       ** to MapViewOfFile(). Restrict its value to 2GB if (SIZE_T) is not at
3582       ** least a 64-bit type. */
3583       if( newLimit>0 && sizeof(SIZE_T)<8 ){
3584         newLimit = (newLimit & 0x7FFFFFFF);
3585       }
3586 
3587       *(i64*)pArg = pFile->mmapSizeMax;
3588       if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
3589         pFile->mmapSizeMax = newLimit;
3590         if( pFile->mmapSize>0 ){
3591           winUnmapfile(pFile);
3592           rc = winMapfile(pFile, -1);
3593         }
3594       }
3595       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3596       return rc;
3597     }
3598 #endif
3599   }
3600   OSTRACE(("FCNTL file=%p, rc=SQLITE_NOTFOUND\n", pFile->h));
3601   return SQLITE_NOTFOUND;
3602 }
3603 
3604 /*
3605 ** Return the sector size in bytes of the underlying block device for
3606 ** the specified file. This is almost always 512 bytes, but may be
3607 ** larger for some devices.
3608 **
3609 ** SQLite code assumes this function cannot fail. It also assumes that
3610 ** if two files are created in the same file-system directory (i.e.
3611 ** a database and its journal file) that the sector size will be the
3612 ** same for both.
3613 */
3614 static int winSectorSize(sqlite3_file *id){
3615   (void)id;
3616   return SQLITE_DEFAULT_SECTOR_SIZE;
3617 }
3618 
3619 /*
3620 ** Return a vector of device characteristics.
3621 */
3622 static int winDeviceCharacteristics(sqlite3_file *id){
3623   winFile *p = (winFile*)id;
3624   return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |
3625          ((p->ctrlFlags & WINFILE_PSOW)?SQLITE_IOCAP_POWERSAFE_OVERWRITE:0);
3626 }
3627 
3628 /*
3629 ** Windows will only let you create file view mappings
3630 ** on allocation size granularity boundaries.
3631 ** During sqlite3_os_init() we do a GetSystemInfo()
3632 ** to get the granularity size.
3633 */
3634 static SYSTEM_INFO winSysInfo;
3635 
3636 #ifndef SQLITE_OMIT_WAL
3637 
3638 /*
3639 ** Helper functions to obtain and relinquish the global mutex. The
3640 ** global mutex is used to protect the winLockInfo objects used by
3641 ** this file, all of which may be shared by multiple threads.
3642 **
3643 ** Function winShmMutexHeld() is used to assert() that the global mutex
3644 ** is held when required. This function is only used as part of assert()
3645 ** statements. e.g.
3646 **
3647 **   winShmEnterMutex()
3648 **     assert( winShmMutexHeld() );
3649 **   winShmLeaveMutex()
3650 */
3651 static sqlite3_mutex *winBigLock = 0;
3652 static void winShmEnterMutex(void){
3653   sqlite3_mutex_enter(winBigLock);
3654 }
3655 static void winShmLeaveMutex(void){
3656   sqlite3_mutex_leave(winBigLock);
3657 }
3658 #ifndef NDEBUG
3659 static int winShmMutexHeld(void) {
3660   return sqlite3_mutex_held(winBigLock);
3661 }
3662 #endif
3663 
3664 /*
3665 ** Object used to represent a single file opened and mmapped to provide
3666 ** shared memory.  When multiple threads all reference the same
3667 ** log-summary, each thread has its own winFile object, but they all
3668 ** point to a single instance of this object.  In other words, each
3669 ** log-summary is opened only once per process.
3670 **
3671 ** winShmMutexHeld() must be true when creating or destroying
3672 ** this object or while reading or writing the following fields:
3673 **
3674 **      nRef
3675 **      pNext
3676 **
3677 ** The following fields are read-only after the object is created:
3678 **
3679 **      fid
3680 **      zFilename
3681 **
3682 ** Either winShmNode.mutex must be held or winShmNode.nRef==0 and
3683 ** winShmMutexHeld() is true when reading or writing any other field
3684 ** in this structure.
3685 **
3686 */
3687 struct winShmNode {
3688   sqlite3_mutex *mutex;      /* Mutex to access this object */
3689   char *zFilename;           /* Name of the file */
3690   winFile hFile;             /* File handle from winOpen */
3691 
3692   int szRegion;              /* Size of shared-memory regions */
3693   int nRegion;               /* Size of array apRegion */
3694   u8 isReadonly;             /* True if read-only */
3695   u8 isUnlocked;             /* True if no DMS lock held */
3696 
3697   struct ShmRegion {
3698     HANDLE hMap;             /* File handle from CreateFileMapping */
3699     void *pMap;
3700   } *aRegion;
3701   DWORD lastErrno;           /* The Windows errno from the last I/O error */
3702 
3703   int nRef;                  /* Number of winShm objects pointing to this */
3704   winShm *pFirst;            /* All winShm objects pointing to this */
3705   winShmNode *pNext;         /* Next in list of all winShmNode objects */
3706 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3707   u8 nextShmId;              /* Next available winShm.id value */
3708 #endif
3709 };
3710 
3711 /*
3712 ** A global array of all winShmNode objects.
3713 **
3714 ** The winShmMutexHeld() must be true while reading or writing this list.
3715 */
3716 static winShmNode *winShmNodeList = 0;
3717 
3718 /*
3719 ** Structure used internally by this VFS to record the state of an
3720 ** open shared memory connection.
3721 **
3722 ** The following fields are initialized when this object is created and
3723 ** are read-only thereafter:
3724 **
3725 **    winShm.pShmNode
3726 **    winShm.id
3727 **
3728 ** All other fields are read/write.  The winShm.pShmNode->mutex must be held
3729 ** while accessing any read/write fields.
3730 */
3731 struct winShm {
3732   winShmNode *pShmNode;      /* The underlying winShmNode object */
3733   winShm *pNext;             /* Next winShm with the same winShmNode */
3734   u8 hasMutex;               /* True if holding the winShmNode mutex */
3735   u16 sharedMask;            /* Mask of shared locks held */
3736   u16 exclMask;              /* Mask of exclusive locks held */
3737 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3738   u8 id;                     /* Id of this connection with its winShmNode */
3739 #endif
3740 };
3741 
3742 /*
3743 ** Constants used for locking
3744 */
3745 #define WIN_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)        /* first lock byte */
3746 #define WIN_SHM_DMS    (WIN_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */
3747 
3748 /*
3749 ** Apply advisory locks for all n bytes beginning at ofst.
3750 */
3751 #define WINSHM_UNLCK  1
3752 #define WINSHM_RDLCK  2
3753 #define WINSHM_WRLCK  3
3754 static int winShmSystemLock(
3755   winShmNode *pFile,    /* Apply locks to this open shared-memory segment */
3756   int lockType,         /* WINSHM_UNLCK, WINSHM_RDLCK, or WINSHM_WRLCK */
3757   int ofst,             /* Offset to first byte to be locked/unlocked */
3758   int nByte             /* Number of bytes to lock or unlock */
3759 ){
3760   int rc = 0;           /* Result code form Lock/UnlockFileEx() */
3761 
3762   /* Access to the winShmNode object is serialized by the caller */
3763   assert( pFile->nRef==0 || sqlite3_mutex_held(pFile->mutex) );
3764 
3765   OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",
3766            pFile->hFile.h, lockType, ofst, nByte));
3767 
3768   /* Release/Acquire the system-level lock */
3769   if( lockType==WINSHM_UNLCK ){
3770     rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);
3771   }else{
3772     /* Initialize the locking parameters */
3773     DWORD dwFlags = LOCKFILE_FAIL_IMMEDIATELY;
3774     if( lockType == WINSHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
3775     rc = winLockFile(&pFile->hFile.h, dwFlags, ofst, 0, nByte, 0);
3776   }
3777 
3778   if( rc!= 0 ){
3779     rc = SQLITE_OK;
3780   }else{
3781     pFile->lastErrno =  osGetLastError();
3782     rc = SQLITE_BUSY;
3783   }
3784 
3785   OSTRACE(("SHM-LOCK file=%p, func=%s, errno=%lu, rc=%s\n",
3786            pFile->hFile.h, (lockType == WINSHM_UNLCK) ? "winUnlockFile" :
3787            "winLockFile", pFile->lastErrno, sqlite3ErrName(rc)));
3788 
3789   return rc;
3790 }
3791 
3792 /* Forward references to VFS methods */
3793 static int winOpen(sqlite3_vfs*,const char*,sqlite3_file*,int,int*);
3794 static int winDelete(sqlite3_vfs *,const char*,int);
3795 
3796 /*
3797 ** Purge the winShmNodeList list of all entries with winShmNode.nRef==0.
3798 **
3799 ** This is not a VFS shared-memory method; it is a utility function called
3800 ** by VFS shared-memory methods.
3801 */
3802 static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){
3803   winShmNode **pp;
3804   winShmNode *p;
3805   assert( winShmMutexHeld() );
3806   OSTRACE(("SHM-PURGE pid=%lu, deleteFlag=%d\n",
3807            osGetCurrentProcessId(), deleteFlag));
3808   pp = &winShmNodeList;
3809   while( (p = *pp)!=0 ){
3810     if( p->nRef==0 ){
3811       int i;
3812       if( p->mutex ){ sqlite3_mutex_free(p->mutex); }
3813       for(i=0; i<p->nRegion; i++){
3814         BOOL bRc = osUnmapViewOfFile(p->aRegion[i].pMap);
3815         OSTRACE(("SHM-PURGE-UNMAP pid=%lu, region=%d, rc=%s\n",
3816                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
3817         UNUSED_VARIABLE_VALUE(bRc);
3818         bRc = osCloseHandle(p->aRegion[i].hMap);
3819         OSTRACE(("SHM-PURGE-CLOSE pid=%lu, region=%d, rc=%s\n",
3820                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
3821         UNUSED_VARIABLE_VALUE(bRc);
3822       }
3823       if( p->hFile.h!=NULL && p->hFile.h!=INVALID_HANDLE_VALUE ){
3824         SimulateIOErrorBenign(1);
3825         winClose((sqlite3_file *)&p->hFile);
3826         SimulateIOErrorBenign(0);
3827       }
3828       if( deleteFlag ){
3829         SimulateIOErrorBenign(1);
3830         sqlite3BeginBenignMalloc();
3831         winDelete(pVfs, p->zFilename, 0);
3832         sqlite3EndBenignMalloc();
3833         SimulateIOErrorBenign(0);
3834       }
3835       *pp = p->pNext;
3836       sqlite3_free(p->aRegion);
3837       sqlite3_free(p);
3838     }else{
3839       pp = &p->pNext;
3840     }
3841   }
3842 }
3843 
3844 /*
3845 ** The DMS lock has not yet been taken on shm file pShmNode. Attempt to
3846 ** take it now. Return SQLITE_OK if successful, or an SQLite error
3847 ** code otherwise.
3848 **
3849 ** If the DMS cannot be locked because this is a readonly_shm=1
3850 ** connection and no other process already holds a lock, return
3851 ** SQLITE_READONLY_CANTINIT and set pShmNode->isUnlocked=1.
3852 */
3853 static int winLockSharedMemory(winShmNode *pShmNode){
3854   int rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, WIN_SHM_DMS, 1);
3855 
3856   if( rc==SQLITE_OK ){
3857     if( pShmNode->isReadonly ){
3858       pShmNode->isUnlocked = 1;
3859       winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3860       return SQLITE_READONLY_CANTINIT;
3861     }else if( winTruncate((sqlite3_file*)&pShmNode->hFile, 0) ){
3862       winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3863       return winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),
3864                          "winLockSharedMemory", pShmNode->zFilename);
3865     }
3866   }
3867 
3868   if( rc==SQLITE_OK ){
3869     winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3870   }
3871 
3872   return winShmSystemLock(pShmNode, WINSHM_RDLCK, WIN_SHM_DMS, 1);
3873 }
3874 
3875 /*
3876 ** Open the shared-memory area associated with database file pDbFd.
3877 **
3878 ** When opening a new shared-memory file, if no other instances of that
3879 ** file are currently open, in this process or in other processes, then
3880 ** the file must be truncated to zero length or have its header cleared.
3881 */
3882 static int winOpenSharedMemory(winFile *pDbFd){
3883   struct winShm *p;                  /* The connection to be opened */
3884   winShmNode *pShmNode = 0;          /* The underlying mmapped file */
3885   int rc = SQLITE_OK;                /* Result code */
3886   winShmNode *pNew;                  /* Newly allocated winShmNode */
3887   int nName;                         /* Size of zName in bytes */
3888 
3889   assert( pDbFd->pShm==0 );    /* Not previously opened */
3890 
3891   /* Allocate space for the new sqlite3_shm object.  Also speculatively
3892   ** allocate space for a new winShmNode and filename.
3893   */
3894   p = sqlite3MallocZero( sizeof(*p) );
3895   if( p==0 ) return SQLITE_IOERR_NOMEM_BKPT;
3896   nName = sqlite3Strlen30(pDbFd->zPath);
3897   pNew = sqlite3MallocZero( sizeof(*pShmNode) + nName + 17 );
3898   if( pNew==0 ){
3899     sqlite3_free(p);
3900     return SQLITE_IOERR_NOMEM_BKPT;
3901   }
3902   pNew->zFilename = (char*)&pNew[1];
3903   sqlite3_snprintf(nName+15, pNew->zFilename, "%s-shm", pDbFd->zPath);
3904   sqlite3FileSuffix3(pDbFd->zPath, pNew->zFilename);
3905 
3906   /* Look to see if there is an existing winShmNode that can be used.
3907   ** If no matching winShmNode currently exists, create a new one.
3908   */
3909   winShmEnterMutex();
3910   for(pShmNode = winShmNodeList; pShmNode; pShmNode=pShmNode->pNext){
3911     /* TBD need to come up with better match here.  Perhaps
3912     ** use FILE_ID_BOTH_DIR_INFO Structure.
3913     */
3914     if( sqlite3StrICmp(pShmNode->zFilename, pNew->zFilename)==0 ) break;
3915   }
3916   if( pShmNode ){
3917     sqlite3_free(pNew);
3918   }else{
3919     int inFlags = SQLITE_OPEN_WAL;
3920     int outFlags = 0;
3921 
3922     pShmNode = pNew;
3923     pNew = 0;
3924     ((winFile*)(&pShmNode->hFile))->h = INVALID_HANDLE_VALUE;
3925     pShmNode->pNext = winShmNodeList;
3926     winShmNodeList = pShmNode;
3927 
3928     if( sqlite3GlobalConfig.bCoreMutex ){
3929       pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
3930       if( pShmNode->mutex==0 ){
3931         rc = SQLITE_IOERR_NOMEM_BKPT;
3932         goto shm_open_err;
3933       }
3934     }
3935 
3936     if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
3937       inFlags |= SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
3938     }else{
3939       inFlags |= SQLITE_OPEN_READONLY;
3940     }
3941     rc = winOpen(pDbFd->pVfs, pShmNode->zFilename,
3942                  (sqlite3_file*)&pShmNode->hFile,
3943                  inFlags, &outFlags);
3944     if( rc!=SQLITE_OK ){
3945       rc = winLogError(rc, osGetLastError(), "winOpenShm",
3946                        pShmNode->zFilename);
3947       goto shm_open_err;
3948     }
3949     if( outFlags==SQLITE_OPEN_READONLY ) pShmNode->isReadonly = 1;
3950 
3951     rc = winLockSharedMemory(pShmNode);
3952     if( rc!=SQLITE_OK && rc!=SQLITE_READONLY_CANTINIT ) goto shm_open_err;
3953   }
3954 
3955   /* Make the new connection a child of the winShmNode */
3956   p->pShmNode = pShmNode;
3957 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3958   p->id = pShmNode->nextShmId++;
3959 #endif
3960   pShmNode->nRef++;
3961   pDbFd->pShm = p;
3962   winShmLeaveMutex();
3963 
3964   /* The reference count on pShmNode has already been incremented under
3965   ** the cover of the winShmEnterMutex() mutex and the pointer from the
3966   ** new (struct winShm) object to the pShmNode has been set. All that is
3967   ** left to do is to link the new object into the linked list starting
3968   ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex
3969   ** mutex.
3970   */
3971   sqlite3_mutex_enter(pShmNode->mutex);
3972   p->pNext = pShmNode->pFirst;
3973   pShmNode->pFirst = p;
3974   sqlite3_mutex_leave(pShmNode->mutex);
3975   return rc;
3976 
3977   /* Jump here on any error */
3978 shm_open_err:
3979   winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
3980   winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */
3981   sqlite3_free(p);
3982   sqlite3_free(pNew);
3983   winShmLeaveMutex();
3984   return rc;
3985 }
3986 
3987 /*
3988 ** Close a connection to shared-memory.  Delete the underlying
3989 ** storage if deleteFlag is true.
3990 */
3991 static int winShmUnmap(
3992   sqlite3_file *fd,          /* Database holding shared memory */
3993   int deleteFlag             /* Delete after closing if true */
3994 ){
3995   winFile *pDbFd;       /* Database holding shared-memory */
3996   winShm *p;            /* The connection to be closed */
3997   winShmNode *pShmNode; /* The underlying shared-memory file */
3998   winShm **pp;          /* For looping over sibling connections */
3999 
4000   pDbFd = (winFile*)fd;
4001   p = pDbFd->pShm;
4002   if( p==0 ) return SQLITE_OK;
4003   pShmNode = p->pShmNode;
4004 
4005   /* Remove connection p from the set of connections associated
4006   ** with pShmNode */
4007   sqlite3_mutex_enter(pShmNode->mutex);
4008   for(pp=&pShmNode->pFirst; (*pp)!=p; pp = &(*pp)->pNext){}
4009   *pp = p->pNext;
4010 
4011   /* Free the connection p */
4012   sqlite3_free(p);
4013   pDbFd->pShm = 0;
4014   sqlite3_mutex_leave(pShmNode->mutex);
4015 
4016   /* If pShmNode->nRef has reached 0, then close the underlying
4017   ** shared-memory file, too */
4018   winShmEnterMutex();
4019   assert( pShmNode->nRef>0 );
4020   pShmNode->nRef--;
4021   if( pShmNode->nRef==0 ){
4022     winShmPurge(pDbFd->pVfs, deleteFlag);
4023   }
4024   winShmLeaveMutex();
4025 
4026   return SQLITE_OK;
4027 }
4028 
4029 /*
4030 ** Change the lock state for a shared-memory segment.
4031 */
4032 static int winShmLock(
4033   sqlite3_file *fd,          /* Database file holding the shared memory */
4034   int ofst,                  /* First lock to acquire or release */
4035   int n,                     /* Number of locks to acquire or release */
4036   int flags                  /* What to do with the lock */
4037 ){
4038   winFile *pDbFd = (winFile*)fd;        /* Connection holding shared memory */
4039   winShm *p = pDbFd->pShm;              /* The shared memory being locked */
4040   winShm *pX;                           /* For looping over all siblings */
4041   winShmNode *pShmNode = p->pShmNode;
4042   int rc = SQLITE_OK;                   /* Result code */
4043   u16 mask;                             /* Mask of locks to take or release */
4044 
4045   assert( ofst>=0 && ofst+n<=SQLITE_SHM_NLOCK );
4046   assert( n>=1 );
4047   assert( flags==(SQLITE_SHM_LOCK | SQLITE_SHM_SHARED)
4048        || flags==(SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE)
4049        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED)
4050        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE) );
4051   assert( n==1 || (flags & SQLITE_SHM_EXCLUSIVE)!=0 );
4052 
4053   mask = (u16)((1U<<(ofst+n)) - (1U<<ofst));
4054   assert( n>1 || mask==(1<<ofst) );
4055   sqlite3_mutex_enter(pShmNode->mutex);
4056   if( flags & SQLITE_SHM_UNLOCK ){
4057     u16 allMask = 0; /* Mask of locks held by siblings */
4058 
4059     /* See if any siblings hold this same lock */
4060     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4061       if( pX==p ) continue;
4062       assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );
4063       allMask |= pX->sharedMask;
4064     }
4065 
4066     /* Unlock the system-level locks */
4067     if( (mask & allMask)==0 ){
4068       rc = winShmSystemLock(pShmNode, WINSHM_UNLCK, ofst+WIN_SHM_BASE, n);
4069     }else{
4070       rc = SQLITE_OK;
4071     }
4072 
4073     /* Undo the local locks */
4074     if( rc==SQLITE_OK ){
4075       p->exclMask &= ~mask;
4076       p->sharedMask &= ~mask;
4077     }
4078   }else if( flags & SQLITE_SHM_SHARED ){
4079     u16 allShared = 0;  /* Union of locks held by connections other than "p" */
4080 
4081     /* Find out which shared locks are already held by sibling connections.
4082     ** If any sibling already holds an exclusive lock, go ahead and return
4083     ** SQLITE_BUSY.
4084     */
4085     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4086       if( (pX->exclMask & mask)!=0 ){
4087         rc = SQLITE_BUSY;
4088         break;
4089       }
4090       allShared |= pX->sharedMask;
4091     }
4092 
4093     /* Get shared locks at the system level, if necessary */
4094     if( rc==SQLITE_OK ){
4095       if( (allShared & mask)==0 ){
4096         rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, ofst+WIN_SHM_BASE, n);
4097       }else{
4098         rc = SQLITE_OK;
4099       }
4100     }
4101 
4102     /* Get the local shared locks */
4103     if( rc==SQLITE_OK ){
4104       p->sharedMask |= mask;
4105     }
4106   }else{
4107     /* Make sure no sibling connections hold locks that will block this
4108     ** lock.  If any do, return SQLITE_BUSY right away.
4109     */
4110     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
4111       if( (pX->exclMask & mask)!=0 || (pX->sharedMask & mask)!=0 ){
4112         rc = SQLITE_BUSY;
4113         break;
4114       }
4115     }
4116 
4117     /* Get the exclusive locks at the system level.  Then if successful
4118     ** also mark the local connection as being locked.
4119     */
4120     if( rc==SQLITE_OK ){
4121       rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, ofst+WIN_SHM_BASE, n);
4122       if( rc==SQLITE_OK ){
4123         assert( (p->sharedMask & mask)==0 );
4124         p->exclMask |= mask;
4125       }
4126     }
4127   }
4128   sqlite3_mutex_leave(pShmNode->mutex);
4129   OSTRACE(("SHM-LOCK pid=%lu, id=%d, sharedMask=%03x, exclMask=%03x, rc=%s\n",
4130            osGetCurrentProcessId(), p->id, p->sharedMask, p->exclMask,
4131            sqlite3ErrName(rc)));
4132   return rc;
4133 }
4134 
4135 /*
4136 ** Implement a memory barrier or memory fence on shared memory.
4137 **
4138 ** All loads and stores begun before the barrier must complete before
4139 ** any load or store begun after the barrier.
4140 */
4141 static void winShmBarrier(
4142   sqlite3_file *fd          /* Database holding the shared memory */
4143 ){
4144   UNUSED_PARAMETER(fd);
4145   sqlite3MemoryBarrier();   /* compiler-defined memory barrier */
4146   winShmEnterMutex();       /* Also mutex, for redundancy */
4147   winShmLeaveMutex();
4148 }
4149 
4150 /*
4151 ** This function is called to obtain a pointer to region iRegion of the
4152 ** shared-memory associated with the database file fd. Shared-memory regions
4153 ** are numbered starting from zero. Each shared-memory region is szRegion
4154 ** bytes in size.
4155 **
4156 ** If an error occurs, an error code is returned and *pp is set to NULL.
4157 **
4158 ** Otherwise, if the isWrite parameter is 0 and the requested shared-memory
4159 ** region has not been allocated (by any client, including one running in a
4160 ** separate process), then *pp is set to NULL and SQLITE_OK returned. If
4161 ** isWrite is non-zero and the requested shared-memory region has not yet
4162 ** been allocated, it is allocated by this function.
4163 **
4164 ** If the shared-memory region has already been allocated or is allocated by
4165 ** this call as described above, then it is mapped into this processes
4166 ** address space (if it is not already), *pp is set to point to the mapped
4167 ** memory and SQLITE_OK returned.
4168 */
4169 static int winShmMap(
4170   sqlite3_file *fd,               /* Handle open on database file */
4171   int iRegion,                    /* Region to retrieve */
4172   int szRegion,                   /* Size of regions */
4173   int isWrite,                    /* True to extend file if necessary */
4174   void volatile **pp              /* OUT: Mapped memory */
4175 ){
4176   winFile *pDbFd = (winFile*)fd;
4177   winShm *pShm = pDbFd->pShm;
4178   winShmNode *pShmNode;
4179   DWORD protect = PAGE_READWRITE;
4180   DWORD flags = FILE_MAP_WRITE | FILE_MAP_READ;
4181   int rc = SQLITE_OK;
4182 
4183   if( !pShm ){
4184     rc = winOpenSharedMemory(pDbFd);
4185     if( rc!=SQLITE_OK ) return rc;
4186     pShm = pDbFd->pShm;
4187   }
4188   pShmNode = pShm->pShmNode;
4189 
4190   sqlite3_mutex_enter(pShmNode->mutex);
4191   if( pShmNode->isUnlocked ){
4192     rc = winLockSharedMemory(pShmNode);
4193     if( rc!=SQLITE_OK ) goto shmpage_out;
4194     pShmNode->isUnlocked = 0;
4195   }
4196   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
4197 
4198   if( pShmNode->nRegion<=iRegion ){
4199     struct ShmRegion *apNew;           /* New aRegion[] array */
4200     int nByte = (iRegion+1)*szRegion;  /* Minimum required file size */
4201     sqlite3_int64 sz;                  /* Current size of wal-index file */
4202 
4203     pShmNode->szRegion = szRegion;
4204 
4205     /* The requested region is not mapped into this processes address space.
4206     ** Check to see if it has been allocated (i.e. if the wal-index file is
4207     ** large enough to contain the requested region).
4208     */
4209     rc = winFileSize((sqlite3_file *)&pShmNode->hFile, &sz);
4210     if( rc!=SQLITE_OK ){
4211       rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
4212                        "winShmMap1", pDbFd->zPath);
4213       goto shmpage_out;
4214     }
4215 
4216     if( sz<nByte ){
4217       /* The requested memory region does not exist. If isWrite is set to
4218       ** zero, exit early. *pp will be set to NULL and SQLITE_OK returned.
4219       **
4220       ** Alternatively, if isWrite is non-zero, use ftruncate() to allocate
4221       ** the requested memory region.
4222       */
4223       if( !isWrite ) goto shmpage_out;
4224       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, nByte);
4225       if( rc!=SQLITE_OK ){
4226         rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
4227                          "winShmMap2", pDbFd->zPath);
4228         goto shmpage_out;
4229       }
4230     }
4231 
4232     /* Map the requested memory region into this processes address space. */
4233     apNew = (struct ShmRegion *)sqlite3_realloc64(
4234         pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])
4235     );
4236     if( !apNew ){
4237       rc = SQLITE_IOERR_NOMEM_BKPT;
4238       goto shmpage_out;
4239     }
4240     pShmNode->aRegion = apNew;
4241 
4242     if( pShmNode->isReadonly ){
4243       protect = PAGE_READONLY;
4244       flags = FILE_MAP_READ;
4245     }
4246 
4247     while( pShmNode->nRegion<=iRegion ){
4248       HANDLE hMap = NULL;         /* file-mapping handle */
4249       void *pMap = 0;             /* Mapped memory region */
4250 
4251 #if SQLITE_OS_WINRT
4252       hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,
4253           NULL, protect, nByte, NULL
4254       );
4255 #elif defined(SQLITE_WIN32_HAS_WIDE)
4256       hMap = osCreateFileMappingW(pShmNode->hFile.h,
4257           NULL, protect, 0, nByte, NULL
4258       );
4259 #elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
4260       hMap = osCreateFileMappingA(pShmNode->hFile.h,
4261           NULL, protect, 0, nByte, NULL
4262       );
4263 #endif
4264       OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
4265                osGetCurrentProcessId(), pShmNode->nRegion, nByte,
4266                hMap ? "ok" : "failed"));
4267       if( hMap ){
4268         int iOffset = pShmNode->nRegion*szRegion;
4269         int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
4270 #if SQLITE_OS_WINRT
4271         pMap = osMapViewOfFileFromApp(hMap, flags,
4272             iOffset - iOffsetShift, szRegion + iOffsetShift
4273         );
4274 #else
4275         pMap = osMapViewOfFile(hMap, flags,
4276             0, iOffset - iOffsetShift, szRegion + iOffsetShift
4277         );
4278 #endif
4279         OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",
4280                  osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
4281                  szRegion, pMap ? "ok" : "failed"));
4282       }
4283       if( !pMap ){
4284         pShmNode->lastErrno = osGetLastError();
4285         rc = winLogError(SQLITE_IOERR_SHMMAP, pShmNode->lastErrno,
4286                          "winShmMap3", pDbFd->zPath);
4287         if( hMap ) osCloseHandle(hMap);
4288         goto shmpage_out;
4289       }
4290 
4291       pShmNode->aRegion[pShmNode->nRegion].pMap = pMap;
4292       pShmNode->aRegion[pShmNode->nRegion].hMap = hMap;
4293       pShmNode->nRegion++;
4294     }
4295   }
4296 
4297 shmpage_out:
4298   if( pShmNode->nRegion>iRegion ){
4299     int iOffset = iRegion*szRegion;
4300     int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
4301     char *p = (char *)pShmNode->aRegion[iRegion].pMap;
4302     *pp = (void *)&p[iOffsetShift];
4303   }else{
4304     *pp = 0;
4305   }
4306   if( pShmNode->isReadonly && rc==SQLITE_OK ) rc = SQLITE_READONLY;
4307   sqlite3_mutex_leave(pShmNode->mutex);
4308   return rc;
4309 }
4310 
4311 #else
4312 # define winShmMap     0
4313 # define winShmLock    0
4314 # define winShmBarrier 0
4315 # define winShmUnmap   0
4316 #endif /* #ifndef SQLITE_OMIT_WAL */
4317 
4318 /*
4319 ** Cleans up the mapped region of the specified file, if any.
4320 */
4321 #if SQLITE_MAX_MMAP_SIZE>0
4322 static int winUnmapfile(winFile *pFile){
4323   assert( pFile!=0 );
4324   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, pMapRegion=%p, "
4325            "mmapSize=%lld, mmapSizeActual=%lld, mmapSizeMax=%lld\n",
4326            osGetCurrentProcessId(), pFile, pFile->hMap, pFile->pMapRegion,
4327            pFile->mmapSize, pFile->mmapSizeActual, pFile->mmapSizeMax));
4328   if( pFile->pMapRegion ){
4329     if( !osUnmapViewOfFile(pFile->pMapRegion) ){
4330       pFile->lastErrno = osGetLastError();
4331       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, pMapRegion=%p, "
4332                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(), pFile,
4333                pFile->pMapRegion));
4334       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
4335                          "winUnmapfile1", pFile->zPath);
4336     }
4337     pFile->pMapRegion = 0;
4338     pFile->mmapSize = 0;
4339     pFile->mmapSizeActual = 0;
4340   }
4341   if( pFile->hMap!=NULL ){
4342     if( !osCloseHandle(pFile->hMap) ){
4343       pFile->lastErrno = osGetLastError();
4344       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, rc=SQLITE_IOERR_MMAP\n",
4345                osGetCurrentProcessId(), pFile, pFile->hMap));
4346       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
4347                          "winUnmapfile2", pFile->zPath);
4348     }
4349     pFile->hMap = NULL;
4350   }
4351   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4352            osGetCurrentProcessId(), pFile));
4353   return SQLITE_OK;
4354 }
4355 
4356 /*
4357 ** Memory map or remap the file opened by file-descriptor pFd (if the file
4358 ** is already mapped, the existing mapping is replaced by the new). Or, if
4359 ** there already exists a mapping for this file, and there are still
4360 ** outstanding xFetch() references to it, this function is a no-op.
4361 **
4362 ** If parameter nByte is non-negative, then it is the requested size of
4363 ** the mapping to create. Otherwise, if nByte is less than zero, then the
4364 ** requested size is the size of the file on disk. The actual size of the
4365 ** created mapping is either the requested size or the value configured
4366 ** using SQLITE_FCNTL_MMAP_SIZE, whichever is smaller.
4367 **
4368 ** SQLITE_OK is returned if no error occurs (even if the mapping is not
4369 ** recreated as a result of outstanding references) or an SQLite error
4370 ** code otherwise.
4371 */
4372 static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
4373   sqlite3_int64 nMap = nByte;
4374   int rc;
4375 
4376   assert( nMap>=0 || pFd->nFetchOut==0 );
4377   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, size=%lld\n",
4378            osGetCurrentProcessId(), pFd, nByte));
4379 
4380   if( pFd->nFetchOut>0 ) return SQLITE_OK;
4381 
4382   if( nMap<0 ){
4383     rc = winFileSize((sqlite3_file*)pFd, &nMap);
4384     if( rc ){
4385       OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_IOERR_FSTAT\n",
4386                osGetCurrentProcessId(), pFd));
4387       return SQLITE_IOERR_FSTAT;
4388     }
4389   }
4390   if( nMap>pFd->mmapSizeMax ){
4391     nMap = pFd->mmapSizeMax;
4392   }
4393   nMap &= ~(sqlite3_int64)(winSysInfo.dwPageSize - 1);
4394 
4395   if( nMap==0 && pFd->mmapSize>0 ){
4396     winUnmapfile(pFd);
4397   }
4398   if( nMap!=pFd->mmapSize ){
4399     void *pNew = 0;
4400     DWORD protect = PAGE_READONLY;
4401     DWORD flags = FILE_MAP_READ;
4402 
4403     winUnmapfile(pFd);
4404 #ifdef SQLITE_MMAP_READWRITE
4405     if( (pFd->ctrlFlags & WINFILE_RDONLY)==0 ){
4406       protect = PAGE_READWRITE;
4407       flags |= FILE_MAP_WRITE;
4408     }
4409 #endif
4410 #if SQLITE_OS_WINRT
4411     pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);
4412 #elif defined(SQLITE_WIN32_HAS_WIDE)
4413     pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,
4414                                 (DWORD)((nMap>>32) & 0xffffffff),
4415                                 (DWORD)(nMap & 0xffffffff), NULL);
4416 #elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
4417     pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,
4418                                 (DWORD)((nMap>>32) & 0xffffffff),
4419                                 (DWORD)(nMap & 0xffffffff), NULL);
4420 #endif
4421     if( pFd->hMap==NULL ){
4422       pFd->lastErrno = osGetLastError();
4423       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
4424                        "winMapfile1", pFd->zPath);
4425       /* Log the error, but continue normal operation using xRead/xWrite */
4426       OSTRACE(("MAP-FILE-CREATE pid=%lu, pFile=%p, rc=%s\n",
4427                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4428       return SQLITE_OK;
4429     }
4430     assert( (nMap % winSysInfo.dwPageSize)==0 );
4431     assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );
4432 #if SQLITE_OS_WINRT
4433     pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, (SIZE_T)nMap);
4434 #else
4435     pNew = osMapViewOfFile(pFd->hMap, flags, 0, 0, (SIZE_T)nMap);
4436 #endif
4437     if( pNew==NULL ){
4438       osCloseHandle(pFd->hMap);
4439       pFd->hMap = NULL;
4440       pFd->lastErrno = osGetLastError();
4441       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
4442                        "winMapfile2", pFd->zPath);
4443       /* Log the error, but continue normal operation using xRead/xWrite */
4444       OSTRACE(("MAP-FILE-MAP pid=%lu, pFile=%p, rc=%s\n",
4445                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4446       return SQLITE_OK;
4447     }
4448     pFd->pMapRegion = pNew;
4449     pFd->mmapSize = nMap;
4450     pFd->mmapSizeActual = nMap;
4451   }
4452 
4453   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4454            osGetCurrentProcessId(), pFd));
4455   return SQLITE_OK;
4456 }
4457 #endif /* SQLITE_MAX_MMAP_SIZE>0 */
4458 
4459 /*
4460 ** If possible, return a pointer to a mapping of file fd starting at offset
4461 ** iOff. The mapping must be valid for at least nAmt bytes.
4462 **
4463 ** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
4464 ** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
4465 ** Finally, if an error does occur, return an SQLite error code. The final
4466 ** value of *pp is undefined in this case.
4467 **
4468 ** If this function does return a pointer, the caller must eventually
4469 ** release the reference by calling winUnfetch().
4470 */
4471 static int winFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
4472 #if SQLITE_MAX_MMAP_SIZE>0
4473   winFile *pFd = (winFile*)fd;   /* The underlying database file */
4474 #endif
4475   *pp = 0;
4476 
4477   OSTRACE(("FETCH pid=%lu, pFile=%p, offset=%lld, amount=%d, pp=%p\n",
4478            osGetCurrentProcessId(), fd, iOff, nAmt, pp));
4479 
4480 #if SQLITE_MAX_MMAP_SIZE>0
4481   if( pFd->mmapSizeMax>0 ){
4482     if( pFd->pMapRegion==0 ){
4483       int rc = winMapfile(pFd, -1);
4484       if( rc!=SQLITE_OK ){
4485         OSTRACE(("FETCH pid=%lu, pFile=%p, rc=%s\n",
4486                  osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4487         return rc;
4488       }
4489     }
4490     if( pFd->mmapSize >= iOff+nAmt ){
4491       *pp = &((u8 *)pFd->pMapRegion)[iOff];
4492       pFd->nFetchOut++;
4493     }
4494   }
4495 #endif
4496 
4497   OSTRACE(("FETCH pid=%lu, pFile=%p, pp=%p, *pp=%p, rc=SQLITE_OK\n",
4498            osGetCurrentProcessId(), fd, pp, *pp));
4499   return SQLITE_OK;
4500 }
4501 
4502 /*
4503 ** If the third argument is non-NULL, then this function releases a
4504 ** reference obtained by an earlier call to winFetch(). The second
4505 ** argument passed to this function must be the same as the corresponding
4506 ** argument that was passed to the winFetch() invocation.
4507 **
4508 ** Or, if the third argument is NULL, then this function is being called
4509 ** to inform the VFS layer that, according to POSIX, any existing mapping
4510 ** may now be invalid and should be unmapped.
4511 */
4512 static int winUnfetch(sqlite3_file *fd, i64 iOff, void *p){
4513 #if SQLITE_MAX_MMAP_SIZE>0
4514   winFile *pFd = (winFile*)fd;   /* The underlying database file */
4515 
4516   /* If p==0 (unmap the entire file) then there must be no outstanding
4517   ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
4518   ** then there must be at least one outstanding.  */
4519   assert( (p==0)==(pFd->nFetchOut==0) );
4520 
4521   /* If p!=0, it must match the iOff value. */
4522   assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );
4523 
4524   OSTRACE(("UNFETCH pid=%lu, pFile=%p, offset=%lld, p=%p\n",
4525            osGetCurrentProcessId(), pFd, iOff, p));
4526 
4527   if( p ){
4528     pFd->nFetchOut--;
4529   }else{
4530     /* FIXME:  If Windows truly always prevents truncating or deleting a
4531     ** file while a mapping is held, then the following winUnmapfile() call
4532     ** is unnecessary can be omitted - potentially improving
4533     ** performance.  */
4534     winUnmapfile(pFd);
4535   }
4536 
4537   assert( pFd->nFetchOut>=0 );
4538 #endif
4539 
4540   OSTRACE(("UNFETCH pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4541            osGetCurrentProcessId(), fd));
4542   return SQLITE_OK;
4543 }
4544 
4545 /*
4546 ** Here ends the implementation of all sqlite3_file methods.
4547 **
4548 ********************** End sqlite3_file Methods *******************************
4549 ******************************************************************************/
4550 
4551 /*
4552 ** This vector defines all the methods that can operate on an
4553 ** sqlite3_file for win32.
4554 */
4555 static const sqlite3_io_methods winIoMethod = {
4556   3,                              /* iVersion */
4557   winClose,                       /* xClose */
4558   winRead,                        /* xRead */
4559   winWrite,                       /* xWrite */
4560   winTruncate,                    /* xTruncate */
4561   winSync,                        /* xSync */
4562   winFileSize,                    /* xFileSize */
4563   winLock,                        /* xLock */
4564   winUnlock,                      /* xUnlock */
4565   winCheckReservedLock,           /* xCheckReservedLock */
4566   winFileControl,                 /* xFileControl */
4567   winSectorSize,                  /* xSectorSize */
4568   winDeviceCharacteristics,       /* xDeviceCharacteristics */
4569   winShmMap,                      /* xShmMap */
4570   winShmLock,                     /* xShmLock */
4571   winShmBarrier,                  /* xShmBarrier */
4572   winShmUnmap,                    /* xShmUnmap */
4573   winFetch,                       /* xFetch */
4574   winUnfetch                      /* xUnfetch */
4575 };
4576 
4577 /*
4578 ** This vector defines all the methods that can operate on an
4579 ** sqlite3_file for win32 without performing any locking.
4580 */
4581 static const sqlite3_io_methods winIoNolockMethod = {
4582   3,                              /* iVersion */
4583   winClose,                       /* xClose */
4584   winRead,                        /* xRead */
4585   winWrite,                       /* xWrite */
4586   winTruncate,                    /* xTruncate */
4587   winSync,                        /* xSync */
4588   winFileSize,                    /* xFileSize */
4589   winNolockLock,                  /* xLock */
4590   winNolockUnlock,                /* xUnlock */
4591   winNolockCheckReservedLock,     /* xCheckReservedLock */
4592   winFileControl,                 /* xFileControl */
4593   winSectorSize,                  /* xSectorSize */
4594   winDeviceCharacteristics,       /* xDeviceCharacteristics */
4595   winShmMap,                      /* xShmMap */
4596   winShmLock,                     /* xShmLock */
4597   winShmBarrier,                  /* xShmBarrier */
4598   winShmUnmap,                    /* xShmUnmap */
4599   winFetch,                       /* xFetch */
4600   winUnfetch                      /* xUnfetch */
4601 };
4602 
4603 static winVfsAppData winAppData = {
4604   &winIoMethod,       /* pMethod */
4605   0,                  /* pAppData */
4606   0                   /* bNoLock */
4607 };
4608 
4609 static winVfsAppData winNolockAppData = {
4610   &winIoNolockMethod, /* pMethod */
4611   0,                  /* pAppData */
4612   1                   /* bNoLock */
4613 };
4614 
4615 /****************************************************************************
4616 **************************** sqlite3_vfs methods ****************************
4617 **
4618 ** This division contains the implementation of methods on the
4619 ** sqlite3_vfs object.
4620 */
4621 
4622 #if defined(__CYGWIN__)
4623 /*
4624 ** Convert a filename from whatever the underlying operating system
4625 ** supports for filenames into UTF-8.  Space to hold the result is
4626 ** obtained from malloc and must be freed by the calling function.
4627 */
4628 static char *winConvertToUtf8Filename(const void *zFilename){
4629   char *zConverted = 0;
4630   if( osIsNT() ){
4631     zConverted = winUnicodeToUtf8(zFilename);
4632   }
4633 #ifdef SQLITE_WIN32_HAS_ANSI
4634   else{
4635     zConverted = winMbcsToUtf8(zFilename, osAreFileApisANSI());
4636   }
4637 #endif
4638   /* caller will handle out of memory */
4639   return zConverted;
4640 }
4641 #endif
4642 
4643 /*
4644 ** Convert a UTF-8 filename into whatever form the underlying
4645 ** operating system wants filenames in.  Space to hold the result
4646 ** is obtained from malloc and must be freed by the calling
4647 ** function.
4648 */
4649 static void *winConvertFromUtf8Filename(const char *zFilename){
4650   void *zConverted = 0;
4651   if( osIsNT() ){
4652     zConverted = winUtf8ToUnicode(zFilename);
4653   }
4654 #ifdef SQLITE_WIN32_HAS_ANSI
4655   else{
4656     zConverted = winUtf8ToMbcs(zFilename, osAreFileApisANSI());
4657   }
4658 #endif
4659   /* caller will handle out of memory */
4660   return zConverted;
4661 }
4662 
4663 /*
4664 ** This function returns non-zero if the specified UTF-8 string buffer
4665 ** ends with a directory separator character or one was successfully
4666 ** added to it.
4667 */
4668 static int winMakeEndInDirSep(int nBuf, char *zBuf){
4669   if( zBuf ){
4670     int nLen = sqlite3Strlen30(zBuf);
4671     if( nLen>0 ){
4672       if( winIsDirSep(zBuf[nLen-1]) ){
4673         return 1;
4674       }else if( nLen+1<nBuf ){
4675         zBuf[nLen] = winGetDirSep();
4676         zBuf[nLen+1] = '\0';
4677         return 1;
4678       }
4679     }
4680   }
4681   return 0;
4682 }
4683 
4684 /*
4685 ** Create a temporary file name and store the resulting pointer into pzBuf.
4686 ** The pointer returned in pzBuf must be freed via sqlite3_free().
4687 */
4688 static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
4689   static char zChars[] =
4690     "abcdefghijklmnopqrstuvwxyz"
4691     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
4692     "0123456789";
4693   size_t i, j;
4694   int nPre = sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX);
4695   int nMax, nBuf, nDir, nLen;
4696   char *zBuf;
4697 
4698   /* It's odd to simulate an io-error here, but really this is just
4699   ** using the io-error infrastructure to test that SQLite handles this
4700   ** function failing.
4701   */
4702   SimulateIOError( return SQLITE_IOERR );
4703 
4704   /* Allocate a temporary buffer to store the fully qualified file
4705   ** name for the temporary file.  If this fails, we cannot continue.
4706   */
4707   nMax = pVfs->mxPathname; nBuf = nMax + 2;
4708   zBuf = sqlite3MallocZero( nBuf );
4709   if( !zBuf ){
4710     OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4711     return SQLITE_IOERR_NOMEM_BKPT;
4712   }
4713 
4714   /* Figure out the effective temporary directory.  First, check if one
4715   ** has been explicitly set by the application; otherwise, use the one
4716   ** configured by the operating system.
4717   */
4718   nDir = nMax - (nPre + 15);
4719   assert( nDir>0 );
4720   if( sqlite3_temp_directory ){
4721     int nDirLen = sqlite3Strlen30(sqlite3_temp_directory);
4722     if( nDirLen>0 ){
4723       if( !winIsDirSep(sqlite3_temp_directory[nDirLen-1]) ){
4724         nDirLen++;
4725       }
4726       if( nDirLen>nDir ){
4727         sqlite3_free(zBuf);
4728         OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4729         return winLogError(SQLITE_ERROR, 0, "winGetTempname1", 0);
4730       }
4731       sqlite3_snprintf(nMax, zBuf, "%s", sqlite3_temp_directory);
4732     }
4733   }
4734 #if defined(__CYGWIN__)
4735   else{
4736     static const char *azDirs[] = {
4737        0, /* getenv("SQLITE_TMPDIR") */
4738        0, /* getenv("TMPDIR") */
4739        0, /* getenv("TMP") */
4740        0, /* getenv("TEMP") */
4741        0, /* getenv("USERPROFILE") */
4742        "/var/tmp",
4743        "/usr/tmp",
4744        "/tmp",
4745        ".",
4746        0        /* List terminator */
4747     };
4748     unsigned int i;
4749     const char *zDir = 0;
4750 
4751     if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");
4752     if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");
4753     if( !azDirs[2] ) azDirs[2] = getenv("TMP");
4754     if( !azDirs[3] ) azDirs[3] = getenv("TEMP");
4755     if( !azDirs[4] ) azDirs[4] = getenv("USERPROFILE");
4756     for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); zDir=azDirs[i++]){
4757       void *zConverted;
4758       if( zDir==0 ) continue;
4759       /* If the path starts with a drive letter followed by the colon
4760       ** character, assume it is already a native Win32 path; otherwise,
4761       ** it must be converted to a native Win32 path via the Cygwin API
4762       ** prior to using it.
4763       */
4764       if( winIsDriveLetterAndColon(zDir) ){
4765         zConverted = winConvertFromUtf8Filename(zDir);
4766         if( !zConverted ){
4767           sqlite3_free(zBuf);
4768           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4769           return SQLITE_IOERR_NOMEM_BKPT;
4770         }
4771         if( winIsDir(zConverted) ){
4772           sqlite3_snprintf(nMax, zBuf, "%s", zDir);
4773           sqlite3_free(zConverted);
4774           break;
4775         }
4776         sqlite3_free(zConverted);
4777       }else{
4778         zConverted = sqlite3MallocZero( nMax+1 );
4779         if( !zConverted ){
4780           sqlite3_free(zBuf);
4781           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4782           return SQLITE_IOERR_NOMEM_BKPT;
4783         }
4784         if( cygwin_conv_path(
4785                 osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A, zDir,
4786                 zConverted, nMax+1)<0 ){
4787           sqlite3_free(zConverted);
4788           sqlite3_free(zBuf);
4789           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_CONVPATH\n"));
4790           return winLogError(SQLITE_IOERR_CONVPATH, (DWORD)errno,
4791                              "winGetTempname2", zDir);
4792         }
4793         if( winIsDir(zConverted) ){
4794           /* At this point, we know the candidate directory exists and should
4795           ** be used.  However, we may need to convert the string containing
4796           ** its name into UTF-8 (i.e. if it is UTF-16 right now).
4797           */
4798           char *zUtf8 = winConvertToUtf8Filename(zConverted);
4799           if( !zUtf8 ){
4800             sqlite3_free(zConverted);
4801             sqlite3_free(zBuf);
4802             OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4803             return SQLITE_IOERR_NOMEM_BKPT;
4804           }
4805           sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
4806           sqlite3_free(zUtf8);
4807           sqlite3_free(zConverted);
4808           break;
4809         }
4810         sqlite3_free(zConverted);
4811       }
4812     }
4813   }
4814 #elif !SQLITE_OS_WINRT && !defined(__CYGWIN__)
4815   else if( osIsNT() ){
4816     char *zMulti;
4817     LPWSTR zWidePath = sqlite3MallocZero( nMax*sizeof(WCHAR) );
4818     if( !zWidePath ){
4819       sqlite3_free(zBuf);
4820       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4821       return SQLITE_IOERR_NOMEM_BKPT;
4822     }
4823     if( osGetTempPathW(nMax, zWidePath)==0 ){
4824       sqlite3_free(zWidePath);
4825       sqlite3_free(zBuf);
4826       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
4827       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
4828                          "winGetTempname2", 0);
4829     }
4830     zMulti = winUnicodeToUtf8(zWidePath);
4831     if( zMulti ){
4832       sqlite3_snprintf(nMax, zBuf, "%s", zMulti);
4833       sqlite3_free(zMulti);
4834       sqlite3_free(zWidePath);
4835     }else{
4836       sqlite3_free(zWidePath);
4837       sqlite3_free(zBuf);
4838       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4839       return SQLITE_IOERR_NOMEM_BKPT;
4840     }
4841   }
4842 #ifdef SQLITE_WIN32_HAS_ANSI
4843   else{
4844     char *zUtf8;
4845     char *zMbcsPath = sqlite3MallocZero( nMax );
4846     if( !zMbcsPath ){
4847       sqlite3_free(zBuf);
4848       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4849       return SQLITE_IOERR_NOMEM_BKPT;
4850     }
4851     if( osGetTempPathA(nMax, zMbcsPath)==0 ){
4852       sqlite3_free(zBuf);
4853       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
4854       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
4855                          "winGetTempname3", 0);
4856     }
4857     zUtf8 = winMbcsToUtf8(zMbcsPath, osAreFileApisANSI());
4858     if( zUtf8 ){
4859       sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
4860       sqlite3_free(zUtf8);
4861     }else{
4862       sqlite3_free(zBuf);
4863       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4864       return SQLITE_IOERR_NOMEM_BKPT;
4865     }
4866   }
4867 #endif /* SQLITE_WIN32_HAS_ANSI */
4868 #endif /* !SQLITE_OS_WINRT */
4869 
4870   /*
4871   ** Check to make sure the temporary directory ends with an appropriate
4872   ** separator.  If it does not and there is not enough space left to add
4873   ** one, fail.
4874   */
4875   if( !winMakeEndInDirSep(nDir+1, zBuf) ){
4876     sqlite3_free(zBuf);
4877     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4878     return winLogError(SQLITE_ERROR, 0, "winGetTempname4", 0);
4879   }
4880 
4881   /*
4882   ** Check that the output buffer is large enough for the temporary file
4883   ** name in the following format:
4884   **
4885   **   "<temporary_directory>/etilqs_XXXXXXXXXXXXXXX\0\0"
4886   **
4887   ** If not, return SQLITE_ERROR.  The number 17 is used here in order to
4888   ** account for the space used by the 15 character random suffix and the
4889   ** two trailing NUL characters.  The final directory separator character
4890   ** has already added if it was not already present.
4891   */
4892   nLen = sqlite3Strlen30(zBuf);
4893   if( (nLen + nPre + 17) > nBuf ){
4894     sqlite3_free(zBuf);
4895     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4896     return winLogError(SQLITE_ERROR, 0, "winGetTempname5", 0);
4897   }
4898 
4899   sqlite3_snprintf(nBuf-16-nLen, zBuf+nLen, SQLITE_TEMP_FILE_PREFIX);
4900 
4901   j = sqlite3Strlen30(zBuf);
4902   sqlite3_randomness(15, &zBuf[j]);
4903   for(i=0; i<15; i++, j++){
4904     zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
4905   }
4906   zBuf[j] = 0;
4907   zBuf[j+1] = 0;
4908   *pzBuf = zBuf;
4909 
4910   OSTRACE(("TEMP-FILENAME name=%s, rc=SQLITE_OK\n", zBuf));
4911   return SQLITE_OK;
4912 }
4913 
4914 /*
4915 ** Return TRUE if the named file is really a directory.  Return false if
4916 ** it is something other than a directory, or if there is any kind of memory
4917 ** allocation failure.
4918 */
4919 static int winIsDir(const void *zConverted){
4920   DWORD attr;
4921   int rc = 0;
4922   DWORD lastErrno;
4923 
4924   if( osIsNT() ){
4925     int cnt = 0;
4926     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
4927     memset(&sAttrData, 0, sizeof(sAttrData));
4928     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
4929                              GetFileExInfoStandard,
4930                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
4931     if( !rc ){
4932       return 0; /* Invalid name? */
4933     }
4934     attr = sAttrData.dwFileAttributes;
4935 #if SQLITE_OS_WINCE==0
4936   }else{
4937     attr = osGetFileAttributesA((char*)zConverted);
4938 #endif
4939   }
4940   return (attr!=INVALID_FILE_ATTRIBUTES) && (attr&FILE_ATTRIBUTE_DIRECTORY);
4941 }
4942 
4943 /* forward reference */
4944 static int winAccess(
4945   sqlite3_vfs *pVfs,         /* Not used on win32 */
4946   const char *zFilename,     /* Name of file to check */
4947   int flags,                 /* Type of test to make on this file */
4948   int *pResOut               /* OUT: Result */
4949 );
4950 
4951 /*
4952 ** Open a file.
4953 */
4954 static int winOpen(
4955   sqlite3_vfs *pVfs,        /* Used to get maximum path length and AppData */
4956   const char *zName,        /* Name of the file (UTF-8) */
4957   sqlite3_file *id,         /* Write the SQLite file handle here */
4958   int flags,                /* Open mode flags */
4959   int *pOutFlags            /* Status return flags */
4960 ){
4961   HANDLE h;
4962   DWORD lastErrno = 0;
4963   DWORD dwDesiredAccess;
4964   DWORD dwShareMode;
4965   DWORD dwCreationDisposition;
4966   DWORD dwFlagsAndAttributes = 0;
4967 #if SQLITE_OS_WINCE
4968   int isTemp = 0;
4969 #endif
4970   winVfsAppData *pAppData;
4971   winFile *pFile = (winFile*)id;
4972   void *zConverted;              /* Filename in OS encoding */
4973   const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */
4974   int cnt = 0;
4975 
4976   /* If argument zPath is a NULL pointer, this function is required to open
4977   ** a temporary file. Use this buffer to store the file name in.
4978   */
4979   char *zTmpname = 0; /* For temporary filename, if necessary. */
4980 
4981   int rc = SQLITE_OK;            /* Function Return Code */
4982 #if !defined(NDEBUG) || SQLITE_OS_WINCE
4983   int eType = flags&0xFFFFFF00;  /* Type of file to open */
4984 #endif
4985 
4986   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
4987   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
4988   int isCreate     = (flags & SQLITE_OPEN_CREATE);
4989   int isReadonly   = (flags & SQLITE_OPEN_READONLY);
4990   int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
4991 
4992 #ifndef NDEBUG
4993   int isOpenJournal = (isCreate && (
4994         eType==SQLITE_OPEN_MASTER_JOURNAL
4995      || eType==SQLITE_OPEN_MAIN_JOURNAL
4996      || eType==SQLITE_OPEN_WAL
4997   ));
4998 #endif
4999 
5000   OSTRACE(("OPEN name=%s, pFile=%p, flags=%x, pOutFlags=%p\n",
5001            zUtf8Name, id, flags, pOutFlags));
5002 
5003   /* Check the following statements are true:
5004   **
5005   **   (a) Exactly one of the READWRITE and READONLY flags must be set, and
5006   **   (b) if CREATE is set, then READWRITE must also be set, and
5007   **   (c) if EXCLUSIVE is set, then CREATE must also be set.
5008   **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
5009   */
5010   assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
5011   assert(isCreate==0 || isReadWrite);
5012   assert(isExclusive==0 || isCreate);
5013   assert(isDelete==0 || isCreate);
5014 
5015   /* The main DB, main journal, WAL file and master journal are never
5016   ** automatically deleted. Nor are they ever temporary files.  */
5017   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
5018   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
5019   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MASTER_JOURNAL );
5020   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );
5021 
5022   /* Assert that the upper layer has set one of the "file-type" flags. */
5023   assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB
5024        || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL
5025        || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL
5026        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
5027   );
5028 
5029   assert( pFile!=0 );
5030   memset(pFile, 0, sizeof(winFile));
5031   pFile->h = INVALID_HANDLE_VALUE;
5032 
5033 #if SQLITE_OS_WINRT
5034   if( !zUtf8Name && !sqlite3_temp_directory ){
5035     sqlite3_log(SQLITE_ERROR,
5036         "sqlite3_temp_directory variable should be set for WinRT");
5037   }
5038 #endif
5039 
5040   /* If the second argument to this function is NULL, generate a
5041   ** temporary file name to use
5042   */
5043   if( !zUtf8Name ){
5044     assert( isDelete && !isOpenJournal );
5045     rc = winGetTempname(pVfs, &zTmpname);
5046     if( rc!=SQLITE_OK ){
5047       OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));
5048       return rc;
5049     }
5050     zUtf8Name = zTmpname;
5051   }
5052 
5053   /* Database filenames are double-zero terminated if they are not
5054   ** URIs with parameters.  Hence, they can always be passed into
5055   ** sqlite3_uri_parameter().
5056   */
5057   assert( (eType!=SQLITE_OPEN_MAIN_DB) || (flags & SQLITE_OPEN_URI) ||
5058        zUtf8Name[sqlite3Strlen30(zUtf8Name)+1]==0 );
5059 
5060   /* Convert the filename to the system encoding. */
5061   zConverted = winConvertFromUtf8Filename(zUtf8Name);
5062   if( zConverted==0 ){
5063     sqlite3_free(zTmpname);
5064     OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));
5065     return SQLITE_IOERR_NOMEM_BKPT;
5066   }
5067 
5068   if( winIsDir(zConverted) ){
5069     sqlite3_free(zConverted);
5070     sqlite3_free(zTmpname);
5071     OSTRACE(("OPEN name=%s, rc=SQLITE_CANTOPEN_ISDIR", zUtf8Name));
5072     return SQLITE_CANTOPEN_ISDIR;
5073   }
5074 
5075   if( isReadWrite ){
5076     dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
5077   }else{
5078     dwDesiredAccess = GENERIC_READ;
5079   }
5080 
5081   /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is
5082   ** created. SQLite doesn't use it to indicate "exclusive access"
5083   ** as it is usually understood.
5084   */
5085   if( isExclusive ){
5086     /* Creates a new file, only if it does not already exist. */
5087     /* If the file exists, it fails. */
5088     dwCreationDisposition = CREATE_NEW;
5089   }else if( isCreate ){
5090     /* Open existing file, or create if it doesn't exist */
5091     dwCreationDisposition = OPEN_ALWAYS;
5092   }else{
5093     /* Opens a file, only if it exists. */
5094     dwCreationDisposition = OPEN_EXISTING;
5095   }
5096 
5097   dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
5098 
5099   if( isDelete ){
5100 #if SQLITE_OS_WINCE
5101     dwFlagsAndAttributes = FILE_ATTRIBUTE_HIDDEN;
5102     isTemp = 1;
5103 #else
5104     dwFlagsAndAttributes = FILE_ATTRIBUTE_TEMPORARY
5105                                | FILE_ATTRIBUTE_HIDDEN
5106                                | FILE_FLAG_DELETE_ON_CLOSE;
5107 #endif
5108   }else{
5109     dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
5110   }
5111   /* Reports from the internet are that performance is always
5112   ** better if FILE_FLAG_RANDOM_ACCESS is used.  Ticket #2699. */
5113 #if SQLITE_OS_WINCE
5114   dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
5115 #endif
5116 
5117   if( osIsNT() ){
5118 #if SQLITE_OS_WINRT
5119     CREATEFILE2_EXTENDED_PARAMETERS extendedParameters;
5120     extendedParameters.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
5121     extendedParameters.dwFileAttributes =
5122             dwFlagsAndAttributes & FILE_ATTRIBUTE_MASK;
5123     extendedParameters.dwFileFlags = dwFlagsAndAttributes & FILE_FLAG_MASK;
5124     extendedParameters.dwSecurityQosFlags = SECURITY_ANONYMOUS;
5125     extendedParameters.lpSecurityAttributes = NULL;
5126     extendedParameters.hTemplateFile = NULL;
5127     do{
5128       h = osCreateFile2((LPCWSTR)zConverted,
5129                         dwDesiredAccess,
5130                         dwShareMode,
5131                         dwCreationDisposition,
5132                         &extendedParameters);
5133       if( h!=INVALID_HANDLE_VALUE ) break;
5134       if( isReadWrite ){
5135         int rc2, isRO = 0;
5136         sqlite3BeginBenignMalloc();
5137         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5138         sqlite3EndBenignMalloc();
5139         if( rc2==SQLITE_OK && isRO ) break;
5140       }
5141     }while( winRetryIoerr(&cnt, &lastErrno) );
5142 #else
5143     do{
5144       h = osCreateFileW((LPCWSTR)zConverted,
5145                         dwDesiredAccess,
5146                         dwShareMode, NULL,
5147                         dwCreationDisposition,
5148                         dwFlagsAndAttributes,
5149                         NULL);
5150       if( h!=INVALID_HANDLE_VALUE ) break;
5151       if( isReadWrite ){
5152         int rc2, isRO = 0;
5153         sqlite3BeginBenignMalloc();
5154         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5155         sqlite3EndBenignMalloc();
5156         if( rc2==SQLITE_OK && isRO ) break;
5157       }
5158     }while( winRetryIoerr(&cnt, &lastErrno) );
5159 #endif
5160   }
5161 #ifdef SQLITE_WIN32_HAS_ANSI
5162   else{
5163     do{
5164       h = osCreateFileA((LPCSTR)zConverted,
5165                         dwDesiredAccess,
5166                         dwShareMode, NULL,
5167                         dwCreationDisposition,
5168                         dwFlagsAndAttributes,
5169                         NULL);
5170       if( h!=INVALID_HANDLE_VALUE ) break;
5171       if( isReadWrite ){
5172         int rc2, isRO = 0;
5173         sqlite3BeginBenignMalloc();
5174         rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
5175         sqlite3EndBenignMalloc();
5176         if( rc2==SQLITE_OK && isRO ) break;
5177       }
5178     }while( winRetryIoerr(&cnt, &lastErrno) );
5179   }
5180 #endif
5181   winLogIoerr(cnt, __LINE__);
5182 
5183   OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
5184            dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
5185 
5186   if( h==INVALID_HANDLE_VALUE ){
5187     sqlite3_free(zConverted);
5188     sqlite3_free(zTmpname);
5189     if( isReadWrite && !isExclusive ){
5190       return winOpen(pVfs, zName, id,
5191          ((flags|SQLITE_OPEN_READONLY) &
5192                      ~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
5193          pOutFlags);
5194     }else{
5195       pFile->lastErrno = lastErrno;
5196       winLogError(SQLITE_CANTOPEN, pFile->lastErrno, "winOpen", zUtf8Name);
5197       return SQLITE_CANTOPEN_BKPT;
5198     }
5199   }
5200 
5201   if( pOutFlags ){
5202     if( isReadWrite ){
5203       *pOutFlags = SQLITE_OPEN_READWRITE;
5204     }else{
5205       *pOutFlags = SQLITE_OPEN_READONLY;
5206     }
5207   }
5208 
5209   OSTRACE(("OPEN file=%p, name=%s, access=%lx, pOutFlags=%p, *pOutFlags=%d, "
5210            "rc=%s\n", h, zUtf8Name, dwDesiredAccess, pOutFlags, pOutFlags ?
5211            *pOutFlags : 0, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
5212 
5213   pAppData = (winVfsAppData*)pVfs->pAppData;
5214 
5215 #if SQLITE_OS_WINCE
5216   {
5217     if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
5218          && ((pAppData==NULL) || !pAppData->bNoLock)
5219          && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
5220     ){
5221       osCloseHandle(h);
5222       sqlite3_free(zConverted);
5223       sqlite3_free(zTmpname);
5224       OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
5225       return rc;
5226     }
5227   }
5228   if( isTemp ){
5229     pFile->zDeleteOnClose = zConverted;
5230   }else
5231 #endif
5232   {
5233     sqlite3_free(zConverted);
5234   }
5235 
5236   sqlite3_free(zTmpname);
5237   pFile->pMethod = pAppData ? pAppData->pMethod : &winIoMethod;
5238   pFile->pVfs = pVfs;
5239   pFile->h = h;
5240   if( isReadonly ){
5241     pFile->ctrlFlags |= WINFILE_RDONLY;
5242   }
5243   if( sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE) ){
5244     pFile->ctrlFlags |= WINFILE_PSOW;
5245   }
5246   pFile->lastErrno = NO_ERROR;
5247   pFile->zPath = zName;
5248 #if SQLITE_MAX_MMAP_SIZE>0
5249   pFile->hMap = NULL;
5250   pFile->pMapRegion = 0;
5251   pFile->mmapSize = 0;
5252   pFile->mmapSizeActual = 0;
5253   pFile->mmapSizeMax = sqlite3GlobalConfig.szMmap;
5254 #endif
5255 
5256   OpenCounter(+1);
5257   return rc;
5258 }
5259 
5260 /*
5261 ** Delete the named file.
5262 **
5263 ** Note that Windows does not allow a file to be deleted if some other
5264 ** process has it open.  Sometimes a virus scanner or indexing program
5265 ** will open a journal file shortly after it is created in order to do
5266 ** whatever it does.  While this other process is holding the
5267 ** file open, we will be unable to delete it.  To work around this
5268 ** problem, we delay 100 milliseconds and try to delete again.  Up
5269 ** to MX_DELETION_ATTEMPTs deletion attempts are run before giving
5270 ** up and returning an error.
5271 */
5272 static int winDelete(
5273   sqlite3_vfs *pVfs,          /* Not used on win32 */
5274   const char *zFilename,      /* Name of file to delete */
5275   int syncDir                 /* Not used on win32 */
5276 ){
5277   int cnt = 0;
5278   int rc;
5279   DWORD attr;
5280   DWORD lastErrno = 0;
5281   void *zConverted;
5282   UNUSED_PARAMETER(pVfs);
5283   UNUSED_PARAMETER(syncDir);
5284 
5285   SimulateIOError(return SQLITE_IOERR_DELETE);
5286   OSTRACE(("DELETE name=%s, syncDir=%d\n", zFilename, syncDir));
5287 
5288   zConverted = winConvertFromUtf8Filename(zFilename);
5289   if( zConverted==0 ){
5290     OSTRACE(("DELETE name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
5291     return SQLITE_IOERR_NOMEM_BKPT;
5292   }
5293   if( osIsNT() ){
5294     do {
5295 #if SQLITE_OS_WINRT
5296       WIN32_FILE_ATTRIBUTE_DATA sAttrData;
5297       memset(&sAttrData, 0, sizeof(sAttrData));
5298       if ( osGetFileAttributesExW(zConverted, GetFileExInfoStandard,
5299                                   &sAttrData) ){
5300         attr = sAttrData.dwFileAttributes;
5301       }else{
5302         lastErrno = osGetLastError();
5303         if( lastErrno==ERROR_FILE_NOT_FOUND
5304          || lastErrno==ERROR_PATH_NOT_FOUND ){
5305           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5306         }else{
5307           rc = SQLITE_ERROR;
5308         }
5309         break;
5310       }
5311 #else
5312       attr = osGetFileAttributesW(zConverted);
5313 #endif
5314       if ( attr==INVALID_FILE_ATTRIBUTES ){
5315         lastErrno = osGetLastError();
5316         if( lastErrno==ERROR_FILE_NOT_FOUND
5317          || lastErrno==ERROR_PATH_NOT_FOUND ){
5318           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5319         }else{
5320           rc = SQLITE_ERROR;
5321         }
5322         break;
5323       }
5324       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
5325         rc = SQLITE_ERROR; /* Files only. */
5326         break;
5327       }
5328       if ( osDeleteFileW(zConverted) ){
5329         rc = SQLITE_OK; /* Deleted OK. */
5330         break;
5331       }
5332       if ( !winRetryIoerr(&cnt, &lastErrno) ){
5333         rc = SQLITE_ERROR; /* No more retries. */
5334         break;
5335       }
5336     } while(1);
5337   }
5338 #ifdef SQLITE_WIN32_HAS_ANSI
5339   else{
5340     do {
5341       attr = osGetFileAttributesA(zConverted);
5342       if ( attr==INVALID_FILE_ATTRIBUTES ){
5343         lastErrno = osGetLastError();
5344         if( lastErrno==ERROR_FILE_NOT_FOUND
5345          || lastErrno==ERROR_PATH_NOT_FOUND ){
5346           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
5347         }else{
5348           rc = SQLITE_ERROR;
5349         }
5350         break;
5351       }
5352       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
5353         rc = SQLITE_ERROR; /* Files only. */
5354         break;
5355       }
5356       if ( osDeleteFileA(zConverted) ){
5357         rc = SQLITE_OK; /* Deleted OK. */
5358         break;
5359       }
5360       if ( !winRetryIoerr(&cnt, &lastErrno) ){
5361         rc = SQLITE_ERROR; /* No more retries. */
5362         break;
5363       }
5364     } while(1);
5365   }
5366 #endif
5367   if( rc && rc!=SQLITE_IOERR_DELETE_NOENT ){
5368     rc = winLogError(SQLITE_IOERR_DELETE, lastErrno, "winDelete", zFilename);
5369   }else{
5370     winLogIoerr(cnt, __LINE__);
5371   }
5372   sqlite3_free(zConverted);
5373   OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));
5374   return rc;
5375 }
5376 
5377 /*
5378 ** Check the existence and status of a file.
5379 */
5380 static int winAccess(
5381   sqlite3_vfs *pVfs,         /* Not used on win32 */
5382   const char *zFilename,     /* Name of file to check */
5383   int flags,                 /* Type of test to make on this file */
5384   int *pResOut               /* OUT: Result */
5385 ){
5386   DWORD attr;
5387   int rc = 0;
5388   DWORD lastErrno = 0;
5389   void *zConverted;
5390   UNUSED_PARAMETER(pVfs);
5391 
5392   SimulateIOError( return SQLITE_IOERR_ACCESS; );
5393   OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",
5394            zFilename, flags, pResOut));
5395 
5396   zConverted = winConvertFromUtf8Filename(zFilename);
5397   if( zConverted==0 ){
5398     OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
5399     return SQLITE_IOERR_NOMEM_BKPT;
5400   }
5401   if( osIsNT() ){
5402     int cnt = 0;
5403     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
5404     memset(&sAttrData, 0, sizeof(sAttrData));
5405     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
5406                              GetFileExInfoStandard,
5407                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
5408     if( rc ){
5409       /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
5410       ** as if it does not exist.
5411       */
5412       if(    flags==SQLITE_ACCESS_EXISTS
5413           && sAttrData.nFileSizeHigh==0
5414           && sAttrData.nFileSizeLow==0 ){
5415         attr = INVALID_FILE_ATTRIBUTES;
5416       }else{
5417         attr = sAttrData.dwFileAttributes;
5418       }
5419     }else{
5420       winLogIoerr(cnt, __LINE__);
5421       if( lastErrno!=ERROR_FILE_NOT_FOUND && lastErrno!=ERROR_PATH_NOT_FOUND ){
5422         sqlite3_free(zConverted);
5423         return winLogError(SQLITE_IOERR_ACCESS, lastErrno, "winAccess",
5424                            zFilename);
5425       }else{
5426         attr = INVALID_FILE_ATTRIBUTES;
5427       }
5428     }
5429   }
5430 #ifdef SQLITE_WIN32_HAS_ANSI
5431   else{
5432     attr = osGetFileAttributesA((char*)zConverted);
5433   }
5434 #endif
5435   sqlite3_free(zConverted);
5436   switch( flags ){
5437     case SQLITE_ACCESS_READ:
5438     case SQLITE_ACCESS_EXISTS:
5439       rc = attr!=INVALID_FILE_ATTRIBUTES;
5440       break;
5441     case SQLITE_ACCESS_READWRITE:
5442       rc = attr!=INVALID_FILE_ATTRIBUTES &&
5443              (attr & FILE_ATTRIBUTE_READONLY)==0;
5444       break;
5445     default:
5446       assert(!"Invalid flags argument");
5447   }
5448   *pResOut = rc;
5449   OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
5450            zFilename, pResOut, *pResOut));
5451   return SQLITE_OK;
5452 }
5453 
5454 /*
5455 ** Returns non-zero if the specified path name starts with a drive letter
5456 ** followed by a colon character.
5457 */
5458 static BOOL winIsDriveLetterAndColon(
5459   const char *zPathname
5460 ){
5461   return ( sqlite3Isalpha(zPathname[0]) && zPathname[1]==':' );
5462 }
5463 
5464 /*
5465 ** Returns non-zero if the specified path name should be used verbatim.  If
5466 ** non-zero is returned from this function, the calling function must simply
5467 ** use the provided path name verbatim -OR- resolve it into a full path name
5468 ** using the GetFullPathName Win32 API function (if available).
5469 */
5470 static BOOL winIsVerbatimPathname(
5471   const char *zPathname
5472 ){
5473   /*
5474   ** If the path name starts with a forward slash or a backslash, it is either
5475   ** a legal UNC name, a volume relative path, or an absolute path name in the
5476   ** "Unix" format on Windows.  There is no easy way to differentiate between
5477   ** the final two cases; therefore, we return the safer return value of TRUE
5478   ** so that callers of this function will simply use it verbatim.
5479   */
5480   if ( winIsDirSep(zPathname[0]) ){
5481     return TRUE;
5482   }
5483 
5484   /*
5485   ** If the path name starts with a letter and a colon it is either a volume
5486   ** relative path or an absolute path.  Callers of this function must not
5487   ** attempt to treat it as a relative path name (i.e. they should simply use
5488   ** it verbatim).
5489   */
5490   if ( winIsDriveLetterAndColon(zPathname) ){
5491     return TRUE;
5492   }
5493 
5494   /*
5495   ** If we get to this point, the path name should almost certainly be a purely
5496   ** relative one (i.e. not a UNC name, not absolute, and not volume relative).
5497   */
5498   return FALSE;
5499 }
5500 
5501 /*
5502 ** Turn a relative pathname into a full pathname.  Write the full
5503 ** pathname into zOut[].  zOut[] will be at least pVfs->mxPathname
5504 ** bytes in size.
5505 */
5506 static int winFullPathname(
5507   sqlite3_vfs *pVfs,            /* Pointer to vfs object */
5508   const char *zRelative,        /* Possibly relative input path */
5509   int nFull,                    /* Size of output buffer in bytes */
5510   char *zFull                   /* Output buffer */
5511 ){
5512 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
5513   DWORD nByte;
5514   void *zConverted;
5515   char *zOut;
5516 #endif
5517 
5518   /* If this path name begins with "/X:", where "X" is any alphabetic
5519   ** character, discard the initial "/" from the pathname.
5520   */
5521   if( zRelative[0]=='/' && winIsDriveLetterAndColon(zRelative+1) ){
5522     zRelative++;
5523   }
5524 
5525 #if defined(__CYGWIN__)
5526   SimulateIOError( return SQLITE_ERROR );
5527   UNUSED_PARAMETER(nFull);
5528   assert( nFull>=pVfs->mxPathname );
5529   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5530     /*
5531     ** NOTE: We are dealing with a relative path name and the data
5532     **       directory has been set.  Therefore, use it as the basis
5533     **       for converting the relative path name to an absolute
5534     **       one by prepending the data directory and a slash.
5535     */
5536     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
5537     if( !zOut ){
5538       return SQLITE_IOERR_NOMEM_BKPT;
5539     }
5540     if( cygwin_conv_path(
5541             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A) |
5542             CCP_RELATIVE, zRelative, zOut, pVfs->mxPathname+1)<0 ){
5543       sqlite3_free(zOut);
5544       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
5545                          "winFullPathname1", zRelative);
5546     }else{
5547       char *zUtf8 = winConvertToUtf8Filename(zOut);
5548       if( !zUtf8 ){
5549         sqlite3_free(zOut);
5550         return SQLITE_IOERR_NOMEM_BKPT;
5551       }
5552       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5553                        sqlite3_data_directory, winGetDirSep(), zUtf8);
5554       sqlite3_free(zUtf8);
5555       sqlite3_free(zOut);
5556     }
5557   }else{
5558     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
5559     if( !zOut ){
5560       return SQLITE_IOERR_NOMEM_BKPT;
5561     }
5562     if( cygwin_conv_path(
5563             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A),
5564             zRelative, zOut, pVfs->mxPathname+1)<0 ){
5565       sqlite3_free(zOut);
5566       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
5567                          "winFullPathname2", zRelative);
5568     }else{
5569       char *zUtf8 = winConvertToUtf8Filename(zOut);
5570       if( !zUtf8 ){
5571         sqlite3_free(zOut);
5572         return SQLITE_IOERR_NOMEM_BKPT;
5573       }
5574       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zUtf8);
5575       sqlite3_free(zUtf8);
5576       sqlite3_free(zOut);
5577     }
5578   }
5579   return SQLITE_OK;
5580 #endif
5581 
5582 #if (SQLITE_OS_WINCE || SQLITE_OS_WINRT) && !defined(__CYGWIN__)
5583   SimulateIOError( return SQLITE_ERROR );
5584   /* WinCE has no concept of a relative pathname, or so I am told. */
5585   /* WinRT has no way to convert a relative path to an absolute one. */
5586   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5587     /*
5588     ** NOTE: We are dealing with a relative path name and the data
5589     **       directory has been set.  Therefore, use it as the basis
5590     **       for converting the relative path name to an absolute
5591     **       one by prepending the data directory and a backslash.
5592     */
5593     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5594                      sqlite3_data_directory, winGetDirSep(), zRelative);
5595   }else{
5596     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zRelative);
5597   }
5598   return SQLITE_OK;
5599 #endif
5600 
5601 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
5602   /* It's odd to simulate an io-error here, but really this is just
5603   ** using the io-error infrastructure to test that SQLite handles this
5604   ** function failing. This function could fail if, for example, the
5605   ** current working directory has been unlinked.
5606   */
5607   SimulateIOError( return SQLITE_ERROR );
5608   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5609     /*
5610     ** NOTE: We are dealing with a relative path name and the data
5611     **       directory has been set.  Therefore, use it as the basis
5612     **       for converting the relative path name to an absolute
5613     **       one by prepending the data directory and a backslash.
5614     */
5615     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5616                      sqlite3_data_directory, winGetDirSep(), zRelative);
5617     return SQLITE_OK;
5618   }
5619   zConverted = winConvertFromUtf8Filename(zRelative);
5620   if( zConverted==0 ){
5621     return SQLITE_IOERR_NOMEM_BKPT;
5622   }
5623   if( osIsNT() ){
5624     LPWSTR zTemp;
5625     nByte = osGetFullPathNameW((LPCWSTR)zConverted, 0, 0, 0);
5626     if( nByte==0 ){
5627       sqlite3_free(zConverted);
5628       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5629                          "winFullPathname1", zRelative);
5630     }
5631     nByte += 3;
5632     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
5633     if( zTemp==0 ){
5634       sqlite3_free(zConverted);
5635       return SQLITE_IOERR_NOMEM_BKPT;
5636     }
5637     nByte = osGetFullPathNameW((LPCWSTR)zConverted, nByte, zTemp, 0);
5638     if( nByte==0 ){
5639       sqlite3_free(zConverted);
5640       sqlite3_free(zTemp);
5641       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5642                          "winFullPathname2", zRelative);
5643     }
5644     sqlite3_free(zConverted);
5645     zOut = winUnicodeToUtf8(zTemp);
5646     sqlite3_free(zTemp);
5647   }
5648 #ifdef SQLITE_WIN32_HAS_ANSI
5649   else{
5650     char *zTemp;
5651     nByte = osGetFullPathNameA((char*)zConverted, 0, 0, 0);
5652     if( nByte==0 ){
5653       sqlite3_free(zConverted);
5654       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5655                          "winFullPathname3", zRelative);
5656     }
5657     nByte += 3;
5658     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
5659     if( zTemp==0 ){
5660       sqlite3_free(zConverted);
5661       return SQLITE_IOERR_NOMEM_BKPT;
5662     }
5663     nByte = osGetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
5664     if( nByte==0 ){
5665       sqlite3_free(zConverted);
5666       sqlite3_free(zTemp);
5667       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5668                          "winFullPathname4", zRelative);
5669     }
5670     sqlite3_free(zConverted);
5671     zOut = winMbcsToUtf8(zTemp, osAreFileApisANSI());
5672     sqlite3_free(zTemp);
5673   }
5674 #endif
5675   if( zOut ){
5676     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zOut);
5677     sqlite3_free(zOut);
5678     return SQLITE_OK;
5679   }else{
5680     return SQLITE_IOERR_NOMEM_BKPT;
5681   }
5682 #endif
5683 }
5684 
5685 #ifndef SQLITE_OMIT_LOAD_EXTENSION
5686 /*
5687 ** Interfaces for opening a shared library, finding entry points
5688 ** within the shared library, and closing the shared library.
5689 */
5690 static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
5691   HANDLE h;
5692 #if defined(__CYGWIN__)
5693   int nFull = pVfs->mxPathname+1;
5694   char *zFull = sqlite3MallocZero( nFull );
5695   void *zConverted = 0;
5696   if( zFull==0 ){
5697     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5698     return 0;
5699   }
5700   if( winFullPathname(pVfs, zFilename, nFull, zFull)!=SQLITE_OK ){
5701     sqlite3_free(zFull);
5702     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5703     return 0;
5704   }
5705   zConverted = winConvertFromUtf8Filename(zFull);
5706   sqlite3_free(zFull);
5707 #else
5708   void *zConverted = winConvertFromUtf8Filename(zFilename);
5709   UNUSED_PARAMETER(pVfs);
5710 #endif
5711   if( zConverted==0 ){
5712     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5713     return 0;
5714   }
5715   if( osIsNT() ){
5716 #if SQLITE_OS_WINRT
5717     h = osLoadPackagedLibrary((LPCWSTR)zConverted, 0);
5718 #else
5719     h = osLoadLibraryW((LPCWSTR)zConverted);
5720 #endif
5721   }
5722 #ifdef SQLITE_WIN32_HAS_ANSI
5723   else{
5724     h = osLoadLibraryA((char*)zConverted);
5725   }
5726 #endif
5727   OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)h));
5728   sqlite3_free(zConverted);
5729   return (void*)h;
5730 }
5731 static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
5732   UNUSED_PARAMETER(pVfs);
5733   winGetLastErrorMsg(osGetLastError(), nBuf, zBufOut);
5734 }
5735 static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){
5736   FARPROC proc;
5737   UNUSED_PARAMETER(pVfs);
5738   proc = osGetProcAddressA((HANDLE)pH, zSym);
5739   OSTRACE(("DLSYM handle=%p, symbol=%s, address=%p\n",
5740            (void*)pH, zSym, (void*)proc));
5741   return (void(*)(void))proc;
5742 }
5743 static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
5744   UNUSED_PARAMETER(pVfs);
5745   osFreeLibrary((HANDLE)pHandle);
5746   OSTRACE(("DLCLOSE handle=%p\n", (void*)pHandle));
5747 }
5748 #else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
5749   #define winDlOpen  0
5750   #define winDlError 0
5751   #define winDlSym   0
5752   #define winDlClose 0
5753 #endif
5754 
5755 /* State information for the randomness gatherer. */
5756 typedef struct EntropyGatherer EntropyGatherer;
5757 struct EntropyGatherer {
5758   unsigned char *a;   /* Gather entropy into this buffer */
5759   int na;             /* Size of a[] in bytes */
5760   int i;              /* XOR next input into a[i] */
5761   int nXor;           /* Number of XOR operations done */
5762 };
5763 
5764 #if !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS)
5765 /* Mix sz bytes of entropy into p. */
5766 static void xorMemory(EntropyGatherer *p, unsigned char *x, int sz){
5767   int j, k;
5768   for(j=0, k=p->i; j<sz; j++){
5769     p->a[k++] ^= x[j];
5770     if( k>=p->na ) k = 0;
5771   }
5772   p->i = k;
5773   p->nXor += sz;
5774 }
5775 #endif /* !defined(SQLITE_TEST) && !defined(SQLITE_OMIT_RANDOMNESS) */
5776 
5777 /*
5778 ** Write up to nBuf bytes of randomness into zBuf.
5779 */
5780 static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5781 #if defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS)
5782   UNUSED_PARAMETER(pVfs);
5783   memset(zBuf, 0, nBuf);
5784   return nBuf;
5785 #else
5786   EntropyGatherer e;
5787   UNUSED_PARAMETER(pVfs);
5788   memset(zBuf, 0, nBuf);
5789   e.a = (unsigned char*)zBuf;
5790   e.na = nBuf;
5791   e.nXor = 0;
5792   e.i = 0;
5793   {
5794     SYSTEMTIME x;
5795     osGetSystemTime(&x);
5796     xorMemory(&e, (unsigned char*)&x, sizeof(SYSTEMTIME));
5797   }
5798   {
5799     DWORD pid = osGetCurrentProcessId();
5800     xorMemory(&e, (unsigned char*)&pid, sizeof(DWORD));
5801   }
5802 #if SQLITE_OS_WINRT
5803   {
5804     ULONGLONG cnt = osGetTickCount64();
5805     xorMemory(&e, (unsigned char*)&cnt, sizeof(ULONGLONG));
5806   }
5807 #else
5808   {
5809     DWORD cnt = osGetTickCount();
5810     xorMemory(&e, (unsigned char*)&cnt, sizeof(DWORD));
5811   }
5812 #endif /* SQLITE_OS_WINRT */
5813   {
5814     LARGE_INTEGER i;
5815     osQueryPerformanceCounter(&i);
5816     xorMemory(&e, (unsigned char*)&i, sizeof(LARGE_INTEGER));
5817   }
5818 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
5819   {
5820     UUID id;
5821     memset(&id, 0, sizeof(UUID));
5822     osUuidCreate(&id);
5823     xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
5824     memset(&id, 0, sizeof(UUID));
5825     osUuidCreateSequential(&id);
5826     xorMemory(&e, (unsigned char*)&id, sizeof(UUID));
5827   }
5828 #endif /* !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID */
5829   return e.nXor>nBuf ? nBuf : e.nXor;
5830 #endif /* defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS) */
5831 }
5832 
5833 
5834 /*
5835 ** Sleep for a little while.  Return the amount of time slept.
5836 */
5837 static int winSleep(sqlite3_vfs *pVfs, int microsec){
5838   sqlite3_win32_sleep((microsec+999)/1000);
5839   UNUSED_PARAMETER(pVfs);
5840   return ((microsec+999)/1000)*1000;
5841 }
5842 
5843 /*
5844 ** The following variable, if set to a non-zero value, is interpreted as
5845 ** the number of seconds since 1970 and is used to set the result of
5846 ** sqlite3OsCurrentTime() during testing.
5847 */
5848 #ifdef SQLITE_TEST
5849 int sqlite3_current_time = 0;  /* Fake system time in seconds since 1970. */
5850 #endif
5851 
5852 /*
5853 ** Find the current time (in Universal Coordinated Time).  Write into *piNow
5854 ** the current time and date as a Julian Day number times 86_400_000.  In
5855 ** other words, write into *piNow the number of milliseconds since the Julian
5856 ** epoch of noon in Greenwich on November 24, 4714 B.C according to the
5857 ** proleptic Gregorian calendar.
5858 **
5859 ** On success, return SQLITE_OK.  Return SQLITE_ERROR if the time and date
5860 ** cannot be found.
5861 */
5862 static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
5863   /* FILETIME structure is a 64-bit value representing the number of
5864      100-nanosecond intervals since January 1, 1601 (= JD 2305813.5).
5865   */
5866   FILETIME ft;
5867   static const sqlite3_int64 winFiletimeEpoch = 23058135*(sqlite3_int64)8640000;
5868 #ifdef SQLITE_TEST
5869   static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000;
5870 #endif
5871   /* 2^32 - to avoid use of LL and warnings in gcc */
5872   static const sqlite3_int64 max32BitValue =
5873       (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 +
5874       (sqlite3_int64)294967296;
5875 
5876 #if SQLITE_OS_WINCE
5877   SYSTEMTIME time;
5878   osGetSystemTime(&time);
5879   /* if SystemTimeToFileTime() fails, it returns zero. */
5880   if (!osSystemTimeToFileTime(&time,&ft)){
5881     return SQLITE_ERROR;
5882   }
5883 #else
5884   osGetSystemTimeAsFileTime( &ft );
5885 #endif
5886 
5887   *piNow = winFiletimeEpoch +
5888             ((((sqlite3_int64)ft.dwHighDateTime)*max32BitValue) +
5889                (sqlite3_int64)ft.dwLowDateTime)/(sqlite3_int64)10000;
5890 
5891 #ifdef SQLITE_TEST
5892   if( sqlite3_current_time ){
5893     *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;
5894   }
5895 #endif
5896   UNUSED_PARAMETER(pVfs);
5897   return SQLITE_OK;
5898 }
5899 
5900 /*
5901 ** Find the current time (in Universal Coordinated Time).  Write the
5902 ** current time and date as a Julian Day number into *prNow and
5903 ** return 0.  Return 1 if the time and date cannot be found.
5904 */
5905 static int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){
5906   int rc;
5907   sqlite3_int64 i;
5908   rc = winCurrentTimeInt64(pVfs, &i);
5909   if( !rc ){
5910     *prNow = i/86400000.0;
5911   }
5912   return rc;
5913 }
5914 
5915 /*
5916 ** The idea is that this function works like a combination of
5917 ** GetLastError() and FormatMessage() on Windows (or errno and
5918 ** strerror_r() on Unix). After an error is returned by an OS
5919 ** function, SQLite calls this function with zBuf pointing to
5920 ** a buffer of nBuf bytes. The OS layer should populate the
5921 ** buffer with a nul-terminated UTF-8 encoded error message
5922 ** describing the last IO error to have occurred within the calling
5923 ** thread.
5924 **
5925 ** If the error message is too large for the supplied buffer,
5926 ** it should be truncated. The return value of xGetLastError
5927 ** is zero if the error message fits in the buffer, or non-zero
5928 ** otherwise (if the message was truncated). If non-zero is returned,
5929 ** then it is not necessary to include the nul-terminator character
5930 ** in the output buffer.
5931 **
5932 ** Not supplying an error message will have no adverse effect
5933 ** on SQLite. It is fine to have an implementation that never
5934 ** returns an error message:
5935 **
5936 **   int xGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5937 **     assert(zBuf[0]=='\0');
5938 **     return 0;
5939 **   }
5940 **
5941 ** However if an error message is supplied, it will be incorporated
5942 ** by sqlite into the error message available to the user using
5943 ** sqlite3_errmsg(), possibly making IO errors easier to debug.
5944 */
5945 static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5946   DWORD e = osGetLastError();
5947   UNUSED_PARAMETER(pVfs);
5948   if( nBuf>0 ) winGetLastErrorMsg(e, nBuf, zBuf);
5949   return e;
5950 }
5951 
5952 /*
5953 ** Initialize and deinitialize the operating system interface.
5954 */
5955 int sqlite3_os_init(void){
5956   static sqlite3_vfs winVfs = {
5957     3,                     /* iVersion */
5958     sizeof(winFile),       /* szOsFile */
5959     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
5960     0,                     /* pNext */
5961     "win32",               /* zName */
5962     &winAppData,           /* pAppData */
5963     winOpen,               /* xOpen */
5964     winDelete,             /* xDelete */
5965     winAccess,             /* xAccess */
5966     winFullPathname,       /* xFullPathname */
5967     winDlOpen,             /* xDlOpen */
5968     winDlError,            /* xDlError */
5969     winDlSym,              /* xDlSym */
5970     winDlClose,            /* xDlClose */
5971     winRandomness,         /* xRandomness */
5972     winSleep,              /* xSleep */
5973     winCurrentTime,        /* xCurrentTime */
5974     winGetLastError,       /* xGetLastError */
5975     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
5976     winSetSystemCall,      /* xSetSystemCall */
5977     winGetSystemCall,      /* xGetSystemCall */
5978     winNextSystemCall,     /* xNextSystemCall */
5979   };
5980 #if defined(SQLITE_WIN32_HAS_WIDE)
5981   static sqlite3_vfs winLongPathVfs = {
5982     3,                     /* iVersion */
5983     sizeof(winFile),       /* szOsFile */
5984     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
5985     0,                     /* pNext */
5986     "win32-longpath",      /* zName */
5987     &winAppData,           /* pAppData */
5988     winOpen,               /* xOpen */
5989     winDelete,             /* xDelete */
5990     winAccess,             /* xAccess */
5991     winFullPathname,       /* xFullPathname */
5992     winDlOpen,             /* xDlOpen */
5993     winDlError,            /* xDlError */
5994     winDlSym,              /* xDlSym */
5995     winDlClose,            /* xDlClose */
5996     winRandomness,         /* xRandomness */
5997     winSleep,              /* xSleep */
5998     winCurrentTime,        /* xCurrentTime */
5999     winGetLastError,       /* xGetLastError */
6000     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6001     winSetSystemCall,      /* xSetSystemCall */
6002     winGetSystemCall,      /* xGetSystemCall */
6003     winNextSystemCall,     /* xNextSystemCall */
6004   };
6005 #endif
6006   static sqlite3_vfs winNolockVfs = {
6007     3,                     /* iVersion */
6008     sizeof(winFile),       /* szOsFile */
6009     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
6010     0,                     /* pNext */
6011     "win32-none",          /* zName */
6012     &winNolockAppData,     /* pAppData */
6013     winOpen,               /* xOpen */
6014     winDelete,             /* xDelete */
6015     winAccess,             /* xAccess */
6016     winFullPathname,       /* xFullPathname */
6017     winDlOpen,             /* xDlOpen */
6018     winDlError,            /* xDlError */
6019     winDlSym,              /* xDlSym */
6020     winDlClose,            /* xDlClose */
6021     winRandomness,         /* xRandomness */
6022     winSleep,              /* xSleep */
6023     winCurrentTime,        /* xCurrentTime */
6024     winGetLastError,       /* xGetLastError */
6025     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6026     winSetSystemCall,      /* xSetSystemCall */
6027     winGetSystemCall,      /* xGetSystemCall */
6028     winNextSystemCall,     /* xNextSystemCall */
6029   };
6030 #if defined(SQLITE_WIN32_HAS_WIDE)
6031   static sqlite3_vfs winLongPathNolockVfs = {
6032     3,                     /* iVersion */
6033     sizeof(winFile),       /* szOsFile */
6034     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
6035     0,                     /* pNext */
6036     "win32-longpath-none", /* zName */
6037     &winNolockAppData,     /* pAppData */
6038     winOpen,               /* xOpen */
6039     winDelete,             /* xDelete */
6040     winAccess,             /* xAccess */
6041     winFullPathname,       /* xFullPathname */
6042     winDlOpen,             /* xDlOpen */
6043     winDlError,            /* xDlError */
6044     winDlSym,              /* xDlSym */
6045     winDlClose,            /* xDlClose */
6046     winRandomness,         /* xRandomness */
6047     winSleep,              /* xSleep */
6048     winCurrentTime,        /* xCurrentTime */
6049     winGetLastError,       /* xGetLastError */
6050     winCurrentTimeInt64,   /* xCurrentTimeInt64 */
6051     winSetSystemCall,      /* xSetSystemCall */
6052     winGetSystemCall,      /* xGetSystemCall */
6053     winNextSystemCall,     /* xNextSystemCall */
6054   };
6055 #endif
6056 
6057   /* Double-check that the aSyscall[] array has been constructed
6058   ** correctly.  See ticket [bb3a86e890c8e96ab] */
6059   assert( ArraySize(aSyscall)==80 );
6060 
6061   /* get memory map allocation granularity */
6062   memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
6063 #if SQLITE_OS_WINRT
6064   osGetNativeSystemInfo(&winSysInfo);
6065 #else
6066   osGetSystemInfo(&winSysInfo);
6067 #endif
6068   assert( winSysInfo.dwAllocationGranularity>0 );
6069   assert( winSysInfo.dwPageSize>0 );
6070 
6071   sqlite3_vfs_register(&winVfs, 1);
6072 
6073 #if defined(SQLITE_WIN32_HAS_WIDE)
6074   sqlite3_vfs_register(&winLongPathVfs, 0);
6075 #endif
6076 
6077   sqlite3_vfs_register(&winNolockVfs, 0);
6078 
6079 #if defined(SQLITE_WIN32_HAS_WIDE)
6080   sqlite3_vfs_register(&winLongPathNolockVfs, 0);
6081 #endif
6082 
6083 #ifndef SQLITE_OMIT_WAL
6084   winBigLock = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1);
6085 #endif
6086 
6087   return SQLITE_OK;
6088 }
6089 
6090 int sqlite3_os_end(void){
6091 #if SQLITE_OS_WINRT
6092   if( sleepObj!=NULL ){
6093     osCloseHandle(sleepObj);
6094     sleepObj = NULL;
6095   }
6096 #endif
6097 
6098 #ifndef SQLITE_OMIT_WAL
6099   winBigLock = 0;
6100 #endif
6101 
6102   return SQLITE_OK;
6103 }
6104 
6105 #endif /* SQLITE_OS_WIN */
6106