xref: /sqlite-3.40.0/src/os_win.c (revision 3f09beda)
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 /*
80 ** Check to see if the GetVersionEx[AW] functions are deprecated on the
81 ** target system.  GetVersionEx was first deprecated in Win8.1.
82 */
83 #ifndef SQLITE_WIN32_GETVERSIONEX
84 #  if defined(NTDDI_VERSION) && NTDDI_VERSION >= NTDDI_WINBLUE
85 #    define SQLITE_WIN32_GETVERSIONEX   0   /* GetVersionEx() is deprecated */
86 #  else
87 #    define SQLITE_WIN32_GETVERSIONEX   1   /* GetVersionEx() is current */
88 #  endif
89 #endif
90 
91 /*
92 ** This constant should already be defined (in the "WinDef.h" SDK file).
93 */
94 #ifndef MAX_PATH
95 #  define MAX_PATH                      (260)
96 #endif
97 
98 /*
99 ** Maximum pathname length (in chars) for Win32.  This should normally be
100 ** MAX_PATH.
101 */
102 #ifndef SQLITE_WIN32_MAX_PATH_CHARS
103 #  define SQLITE_WIN32_MAX_PATH_CHARS   (MAX_PATH)
104 #endif
105 
106 /*
107 ** This constant should already be defined (in the "WinNT.h" SDK file).
108 */
109 #ifndef UNICODE_STRING_MAX_CHARS
110 #  define UNICODE_STRING_MAX_CHARS      (32767)
111 #endif
112 
113 /*
114 ** Maximum pathname length (in chars) for WinNT.  This should normally be
115 ** UNICODE_STRING_MAX_CHARS.
116 */
117 #ifndef SQLITE_WINNT_MAX_PATH_CHARS
118 #  define SQLITE_WINNT_MAX_PATH_CHARS   (UNICODE_STRING_MAX_CHARS)
119 #endif
120 
121 /*
122 ** Maximum pathname length (in bytes) for Win32.  The MAX_PATH macro is in
123 ** characters, so we allocate 4 bytes per character assuming worst-case of
124 ** 4-bytes-per-character for UTF8.
125 */
126 #ifndef SQLITE_WIN32_MAX_PATH_BYTES
127 #  define SQLITE_WIN32_MAX_PATH_BYTES   (SQLITE_WIN32_MAX_PATH_CHARS*4)
128 #endif
129 
130 /*
131 ** Maximum pathname length (in bytes) for WinNT.  This should normally be
132 ** UNICODE_STRING_MAX_CHARS * sizeof(WCHAR).
133 */
134 #ifndef SQLITE_WINNT_MAX_PATH_BYTES
135 #  define SQLITE_WINNT_MAX_PATH_BYTES   \
136                             (sizeof(WCHAR) * SQLITE_WINNT_MAX_PATH_CHARS)
137 #endif
138 
139 /*
140 ** Maximum error message length (in chars) for WinRT.
141 */
142 #ifndef SQLITE_WIN32_MAX_ERRMSG_CHARS
143 #  define SQLITE_WIN32_MAX_ERRMSG_CHARS (1024)
144 #endif
145 
146 /*
147 ** Returns non-zero if the character should be treated as a directory
148 ** separator.
149 */
150 #ifndef winIsDirSep
151 #  define winIsDirSep(a)                (((a) == '/') || ((a) == '\\'))
152 #endif
153 
154 /*
155 ** This macro is used when a local variable is set to a value that is
156 ** [sometimes] not used by the code (e.g. via conditional compilation).
157 */
158 #ifndef UNUSED_VARIABLE_VALUE
159 #  define UNUSED_VARIABLE_VALUE(x)      (void)(x)
160 #endif
161 
162 /*
163 ** Returns the character that should be used as the directory separator.
164 */
165 #ifndef winGetDirSep
166 #  define winGetDirSep()                '\\'
167 #endif
168 
169 /*
170 ** Do we need to manually define the Win32 file mapping APIs for use with WAL
171 ** mode or memory mapped files (e.g. these APIs are available in the Windows
172 ** CE SDK; however, they are not present in the header file)?
173 */
174 #if SQLITE_WIN32_FILEMAPPING_API && \
175         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
176 /*
177 ** Two of the file mapping APIs are different under WinRT.  Figure out which
178 ** set we need.
179 */
180 #if SQLITE_OS_WINRT
181 WINBASEAPI HANDLE WINAPI CreateFileMappingFromApp(HANDLE, \
182         LPSECURITY_ATTRIBUTES, ULONG, ULONG64, LPCWSTR);
183 
184 WINBASEAPI LPVOID WINAPI MapViewOfFileFromApp(HANDLE, ULONG, ULONG64, SIZE_T);
185 #else
186 #if defined(SQLITE_WIN32_HAS_ANSI)
187 WINBASEAPI HANDLE WINAPI CreateFileMappingA(HANDLE, LPSECURITY_ATTRIBUTES, \
188         DWORD, DWORD, DWORD, LPCSTR);
189 #endif /* defined(SQLITE_WIN32_HAS_ANSI) */
190 
191 #if defined(SQLITE_WIN32_HAS_WIDE)
192 WINBASEAPI HANDLE WINAPI CreateFileMappingW(HANDLE, LPSECURITY_ATTRIBUTES, \
193         DWORD, DWORD, DWORD, LPCWSTR);
194 #endif /* defined(SQLITE_WIN32_HAS_WIDE) */
195 
196 WINBASEAPI LPVOID WINAPI MapViewOfFile(HANDLE, DWORD, DWORD, DWORD, SIZE_T);
197 #endif /* SQLITE_OS_WINRT */
198 
199 /*
200 ** These file mapping APIs are common to both Win32 and WinRT.
201 */
202 
203 WINBASEAPI BOOL WINAPI FlushViewOfFile(LPCVOID, SIZE_T);
204 WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);
205 #endif /* SQLITE_WIN32_FILEMAPPING_API */
206 
207 /*
208 ** Some Microsoft compilers lack this definition.
209 */
210 #ifndef INVALID_FILE_ATTRIBUTES
211 # define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
212 #endif
213 
214 #ifndef FILE_FLAG_MASK
215 # define FILE_FLAG_MASK          (0xFF3C0000)
216 #endif
217 
218 #ifndef FILE_ATTRIBUTE_MASK
219 # define FILE_ATTRIBUTE_MASK     (0x0003FFF7)
220 #endif
221 
222 #ifndef SQLITE_OMIT_WAL
223 /* Forward references to structures used for WAL */
224 typedef struct winShm winShm;           /* A connection to shared-memory */
225 typedef struct winShmNode winShmNode;   /* A region of shared-memory */
226 #endif
227 
228 /*
229 ** WinCE lacks native support for file locking so we have to fake it
230 ** with some code of our own.
231 */
232 #if SQLITE_OS_WINCE
233 typedef struct winceLock {
234   int nReaders;       /* Number of reader locks obtained */
235   BOOL bPending;      /* Indicates a pending lock has been obtained */
236   BOOL bReserved;     /* Indicates a reserved lock has been obtained */
237   BOOL bExclusive;    /* Indicates an exclusive lock has been obtained */
238 } winceLock;
239 #endif
240 
241 /*
242 ** The winFile structure is a subclass of sqlite3_file* specific to the win32
243 ** portability layer.
244 */
245 typedef struct winFile winFile;
246 struct winFile {
247   const sqlite3_io_methods *pMethod; /*** Must be first ***/
248   sqlite3_vfs *pVfs;      /* The VFS used to open this file */
249   HANDLE h;               /* Handle for accessing the file */
250   u8 locktype;            /* Type of lock currently held on this file */
251   short sharedLockByte;   /* Randomly chosen byte used as a shared lock */
252   u8 ctrlFlags;           /* Flags.  See WINFILE_* below */
253   DWORD lastErrno;        /* The Windows errno from the last I/O error */
254 #ifndef SQLITE_OMIT_WAL
255   winShm *pShm;           /* Instance of shared memory on this file */
256 #endif
257   const char *zPath;      /* Full pathname of this file */
258   int szChunk;            /* Chunk size configured by FCNTL_CHUNK_SIZE */
259 #if SQLITE_OS_WINCE
260   LPWSTR zDeleteOnClose;  /* Name of file to delete when closing */
261   HANDLE hMutex;          /* Mutex used to control access to shared lock */
262   HANDLE hShared;         /* Shared memory segment used for locking */
263   winceLock local;        /* Locks obtained by this instance of winFile */
264   winceLock *shared;      /* Global shared lock memory for the file  */
265 #endif
266 #if SQLITE_MAX_MMAP_SIZE>0
267   int nFetchOut;                /* Number of outstanding xFetch references */
268   HANDLE hMap;                  /* Handle for accessing memory mapping */
269   void *pMapRegion;             /* Area memory mapped */
270   sqlite3_int64 mmapSize;       /* Usable size of mapped region */
271   sqlite3_int64 mmapSizeActual; /* Actual size of mapped region */
272   sqlite3_int64 mmapSizeMax;    /* Configured FCNTL_MMAP_SIZE value */
273 #endif
274 };
275 
276 /*
277 ** Allowed values for winFile.ctrlFlags
278 */
279 #define WINFILE_RDONLY          0x02   /* Connection is read only */
280 #define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */
281 #define WINFILE_PSOW            0x10   /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
282 
283 /*
284  * The size of the buffer used by sqlite3_win32_write_debug().
285  */
286 #ifndef SQLITE_WIN32_DBG_BUF_SIZE
287 #  define SQLITE_WIN32_DBG_BUF_SIZE   ((int)(4096-sizeof(DWORD)))
288 #endif
289 
290 /*
291  * The value used with sqlite3_win32_set_directory() to specify that
292  * the data directory should be changed.
293  */
294 #ifndef SQLITE_WIN32_DATA_DIRECTORY_TYPE
295 #  define SQLITE_WIN32_DATA_DIRECTORY_TYPE (1)
296 #endif
297 
298 /*
299  * The value used with sqlite3_win32_set_directory() to specify that
300  * the temporary directory should be changed.
301  */
302 #ifndef SQLITE_WIN32_TEMP_DIRECTORY_TYPE
303 #  define SQLITE_WIN32_TEMP_DIRECTORY_TYPE (2)
304 #endif
305 
306 /*
307  * If compiled with SQLITE_WIN32_MALLOC on Windows, we will use the
308  * various Win32 API heap functions instead of our own.
309  */
310 #ifdef SQLITE_WIN32_MALLOC
311 
312 /*
313  * If this is non-zero, an isolated heap will be created by the native Win32
314  * allocator subsystem; otherwise, the default process heap will be used.  This
315  * setting has no effect when compiling for WinRT.  By default, this is enabled
316  * and an isolated heap will be created to store all allocated data.
317  *
318  ******************************************************************************
319  * WARNING: It is important to note that when this setting is non-zero and the
320  *          winMemShutdown function is called (e.g. by the sqlite3_shutdown
321  *          function), all data that was allocated using the isolated heap will
322  *          be freed immediately and any attempt to access any of that freed
323  *          data will almost certainly result in an immediate access violation.
324  ******************************************************************************
325  */
326 #ifndef SQLITE_WIN32_HEAP_CREATE
327 #  define SQLITE_WIN32_HEAP_CREATE    (TRUE)
328 #endif
329 
330 /*
331  * The initial size of the Win32-specific heap.  This value may be zero.
332  */
333 #ifndef SQLITE_WIN32_HEAP_INIT_SIZE
334 #  define SQLITE_WIN32_HEAP_INIT_SIZE ((SQLITE_DEFAULT_CACHE_SIZE) * \
335                                        (SQLITE_DEFAULT_PAGE_SIZE) + 4194304)
336 #endif
337 
338 /*
339  * The maximum size of the Win32-specific heap.  This value may be zero.
340  */
341 #ifndef SQLITE_WIN32_HEAP_MAX_SIZE
342 #  define SQLITE_WIN32_HEAP_MAX_SIZE  (0)
343 #endif
344 
345 /*
346  * The extra flags to use in calls to the Win32 heap APIs.  This value may be
347  * zero for the default behavior.
348  */
349 #ifndef SQLITE_WIN32_HEAP_FLAGS
350 #  define SQLITE_WIN32_HEAP_FLAGS     (0)
351 #endif
352 
353 
354 /*
355 ** The winMemData structure stores information required by the Win32-specific
356 ** sqlite3_mem_methods implementation.
357 */
358 typedef struct winMemData winMemData;
359 struct winMemData {
360 #ifndef NDEBUG
361   u32 magic1;   /* Magic number to detect structure corruption. */
362 #endif
363   HANDLE hHeap; /* The handle to our heap. */
364   BOOL bOwned;  /* Do we own the heap (i.e. destroy it on shutdown)? */
365 #ifndef NDEBUG
366   u32 magic2;   /* Magic number to detect structure corruption. */
367 #endif
368 };
369 
370 #ifndef NDEBUG
371 #define WINMEM_MAGIC1     0x42b2830b
372 #define WINMEM_MAGIC2     0xbd4d7cf4
373 #endif
374 
375 static struct winMemData win_mem_data = {
376 #ifndef NDEBUG
377   WINMEM_MAGIC1,
378 #endif
379   NULL, FALSE
380 #ifndef NDEBUG
381   ,WINMEM_MAGIC2
382 #endif
383 };
384 
385 #ifndef NDEBUG
386 #define winMemAssertMagic1() assert( win_mem_data.magic1==WINMEM_MAGIC1 )
387 #define winMemAssertMagic2() assert( win_mem_data.magic2==WINMEM_MAGIC2 )
388 #define winMemAssertMagic()  winMemAssertMagic1(); winMemAssertMagic2();
389 #else
390 #define winMemAssertMagic()
391 #endif
392 
393 #define winMemGetDataPtr()  &win_mem_data
394 #define winMemGetHeap()     win_mem_data.hHeap
395 #define winMemGetOwned()    win_mem_data.bOwned
396 
397 static void *winMemMalloc(int nBytes);
398 static void winMemFree(void *pPrior);
399 static void *winMemRealloc(void *pPrior, int nBytes);
400 static int winMemSize(void *p);
401 static int winMemRoundup(int n);
402 static int winMemInit(void *pAppData);
403 static void winMemShutdown(void *pAppData);
404 
405 const sqlite3_mem_methods *sqlite3MemGetWin32(void);
406 #endif /* SQLITE_WIN32_MALLOC */
407 
408 /*
409 ** The following variable is (normally) set once and never changes
410 ** thereafter.  It records whether the operating system is Win9x
411 ** or WinNT.
412 **
413 ** 0:   Operating system unknown.
414 ** 1:   Operating system is Win9x.
415 ** 2:   Operating system is WinNT.
416 **
417 ** In order to facilitate testing on a WinNT system, the test fixture
418 ** can manually set this value to 1 to emulate Win98 behavior.
419 */
420 #ifdef SQLITE_TEST
421 LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;
422 #else
423 static LONG SQLITE_WIN32_VOLATILE sqlite3_os_type = 0;
424 #endif
425 
426 #ifndef SYSCALL
427 #  define SYSCALL sqlite3_syscall_ptr
428 #endif
429 
430 /*
431 ** This function is not available on Windows CE or WinRT.
432  */
433 
434 #if SQLITE_OS_WINCE || SQLITE_OS_WINRT
435 #  define osAreFileApisANSI()       1
436 #endif
437 
438 /*
439 ** Many system calls are accessed through pointer-to-functions so that
440 ** they may be overridden at runtime to facilitate fault injection during
441 ** testing and sandboxing.  The following array holds the names and pointers
442 ** to all overrideable system calls.
443 */
444 static struct win_syscall {
445   const char *zName;            /* Name of the system call */
446   sqlite3_syscall_ptr pCurrent; /* Current value of the system call */
447   sqlite3_syscall_ptr pDefault; /* Default value */
448 } aSyscall[] = {
449 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
450   { "AreFileApisANSI",         (SYSCALL)AreFileApisANSI,         0 },
451 #else
452   { "AreFileApisANSI",         (SYSCALL)0,                       0 },
453 #endif
454 
455 #ifndef osAreFileApisANSI
456 #define osAreFileApisANSI ((BOOL(WINAPI*)(VOID))aSyscall[0].pCurrent)
457 #endif
458 
459 #if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)
460   { "CharLowerW",              (SYSCALL)CharLowerW,              0 },
461 #else
462   { "CharLowerW",              (SYSCALL)0,                       0 },
463 #endif
464 
465 #define osCharLowerW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[1].pCurrent)
466 
467 #if SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_WIDE)
468   { "CharUpperW",              (SYSCALL)CharUpperW,              0 },
469 #else
470   { "CharUpperW",              (SYSCALL)0,                       0 },
471 #endif
472 
473 #define osCharUpperW ((LPWSTR(WINAPI*)(LPWSTR))aSyscall[2].pCurrent)
474 
475   { "CloseHandle",             (SYSCALL)CloseHandle,             0 },
476 
477 #define osCloseHandle ((BOOL(WINAPI*)(HANDLE))aSyscall[3].pCurrent)
478 
479 #if defined(SQLITE_WIN32_HAS_ANSI)
480   { "CreateFileA",             (SYSCALL)CreateFileA,             0 },
481 #else
482   { "CreateFileA",             (SYSCALL)0,                       0 },
483 #endif
484 
485 #define osCreateFileA ((HANDLE(WINAPI*)(LPCSTR,DWORD,DWORD, \
486         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[4].pCurrent)
487 
488 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
489   { "CreateFileW",             (SYSCALL)CreateFileW,             0 },
490 #else
491   { "CreateFileW",             (SYSCALL)0,                       0 },
492 #endif
493 
494 #define osCreateFileW ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD, \
495         LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE))aSyscall[5].pCurrent)
496 
497 #if (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_ANSI) && \
498         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
499   { "CreateFileMappingA",      (SYSCALL)CreateFileMappingA,      0 },
500 #else
501   { "CreateFileMappingA",      (SYSCALL)0,                       0 },
502 #endif
503 
504 #define osCreateFileMappingA ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
505         DWORD,DWORD,DWORD,LPCSTR))aSyscall[6].pCurrent)
506 
507 #if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
508         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
509   { "CreateFileMappingW",      (SYSCALL)CreateFileMappingW,      0 },
510 #else
511   { "CreateFileMappingW",      (SYSCALL)0,                       0 },
512 #endif
513 
514 #define osCreateFileMappingW ((HANDLE(WINAPI*)(HANDLE,LPSECURITY_ATTRIBUTES, \
515         DWORD,DWORD,DWORD,LPCWSTR))aSyscall[7].pCurrent)
516 
517 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
518   { "CreateMutexW",            (SYSCALL)CreateMutexW,            0 },
519 #else
520   { "CreateMutexW",            (SYSCALL)0,                       0 },
521 #endif
522 
523 #define osCreateMutexW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,BOOL, \
524         LPCWSTR))aSyscall[8].pCurrent)
525 
526 #if defined(SQLITE_WIN32_HAS_ANSI)
527   { "DeleteFileA",             (SYSCALL)DeleteFileA,             0 },
528 #else
529   { "DeleteFileA",             (SYSCALL)0,                       0 },
530 #endif
531 
532 #define osDeleteFileA ((BOOL(WINAPI*)(LPCSTR))aSyscall[9].pCurrent)
533 
534 #if defined(SQLITE_WIN32_HAS_WIDE)
535   { "DeleteFileW",             (SYSCALL)DeleteFileW,             0 },
536 #else
537   { "DeleteFileW",             (SYSCALL)0,                       0 },
538 #endif
539 
540 #define osDeleteFileW ((BOOL(WINAPI*)(LPCWSTR))aSyscall[10].pCurrent)
541 
542 #if SQLITE_OS_WINCE
543   { "FileTimeToLocalFileTime", (SYSCALL)FileTimeToLocalFileTime, 0 },
544 #else
545   { "FileTimeToLocalFileTime", (SYSCALL)0,                       0 },
546 #endif
547 
548 #define osFileTimeToLocalFileTime ((BOOL(WINAPI*)(CONST FILETIME*, \
549         LPFILETIME))aSyscall[11].pCurrent)
550 
551 #if SQLITE_OS_WINCE
552   { "FileTimeToSystemTime",    (SYSCALL)FileTimeToSystemTime,    0 },
553 #else
554   { "FileTimeToSystemTime",    (SYSCALL)0,                       0 },
555 #endif
556 
557 #define osFileTimeToSystemTime ((BOOL(WINAPI*)(CONST FILETIME*, \
558         LPSYSTEMTIME))aSyscall[12].pCurrent)
559 
560   { "FlushFileBuffers",        (SYSCALL)FlushFileBuffers,        0 },
561 
562 #define osFlushFileBuffers ((BOOL(WINAPI*)(HANDLE))aSyscall[13].pCurrent)
563 
564 #if defined(SQLITE_WIN32_HAS_ANSI)
565   { "FormatMessageA",          (SYSCALL)FormatMessageA,          0 },
566 #else
567   { "FormatMessageA",          (SYSCALL)0,                       0 },
568 #endif
569 
570 #define osFormatMessageA ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPSTR, \
571         DWORD,va_list*))aSyscall[14].pCurrent)
572 
573 #if defined(SQLITE_WIN32_HAS_WIDE)
574   { "FormatMessageW",          (SYSCALL)FormatMessageW,          0 },
575 #else
576   { "FormatMessageW",          (SYSCALL)0,                       0 },
577 #endif
578 
579 #define osFormatMessageW ((DWORD(WINAPI*)(DWORD,LPCVOID,DWORD,DWORD,LPWSTR, \
580         DWORD,va_list*))aSyscall[15].pCurrent)
581 
582 #if !defined(SQLITE_OMIT_LOAD_EXTENSION)
583   { "FreeLibrary",             (SYSCALL)FreeLibrary,             0 },
584 #else
585   { "FreeLibrary",             (SYSCALL)0,                       0 },
586 #endif
587 
588 #define osFreeLibrary ((BOOL(WINAPI*)(HMODULE))aSyscall[16].pCurrent)
589 
590   { "GetCurrentProcessId",     (SYSCALL)GetCurrentProcessId,     0 },
591 
592 #define osGetCurrentProcessId ((DWORD(WINAPI*)(VOID))aSyscall[17].pCurrent)
593 
594 #if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)
595   { "GetDiskFreeSpaceA",       (SYSCALL)GetDiskFreeSpaceA,       0 },
596 #else
597   { "GetDiskFreeSpaceA",       (SYSCALL)0,                       0 },
598 #endif
599 
600 #define osGetDiskFreeSpaceA ((BOOL(WINAPI*)(LPCSTR,LPDWORD,LPDWORD,LPDWORD, \
601         LPDWORD))aSyscall[18].pCurrent)
602 
603 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
604   { "GetDiskFreeSpaceW",       (SYSCALL)GetDiskFreeSpaceW,       0 },
605 #else
606   { "GetDiskFreeSpaceW",       (SYSCALL)0,                       0 },
607 #endif
608 
609 #define osGetDiskFreeSpaceW ((BOOL(WINAPI*)(LPCWSTR,LPDWORD,LPDWORD,LPDWORD, \
610         LPDWORD))aSyscall[19].pCurrent)
611 
612 #if defined(SQLITE_WIN32_HAS_ANSI)
613   { "GetFileAttributesA",      (SYSCALL)GetFileAttributesA,      0 },
614 #else
615   { "GetFileAttributesA",      (SYSCALL)0,                       0 },
616 #endif
617 
618 #define osGetFileAttributesA ((DWORD(WINAPI*)(LPCSTR))aSyscall[20].pCurrent)
619 
620 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
621   { "GetFileAttributesW",      (SYSCALL)GetFileAttributesW,      0 },
622 #else
623   { "GetFileAttributesW",      (SYSCALL)0,                       0 },
624 #endif
625 
626 #define osGetFileAttributesW ((DWORD(WINAPI*)(LPCWSTR))aSyscall[21].pCurrent)
627 
628 #if defined(SQLITE_WIN32_HAS_WIDE)
629   { "GetFileAttributesExW",    (SYSCALL)GetFileAttributesExW,    0 },
630 #else
631   { "GetFileAttributesExW",    (SYSCALL)0,                       0 },
632 #endif
633 
634 #define osGetFileAttributesExW ((BOOL(WINAPI*)(LPCWSTR,GET_FILEEX_INFO_LEVELS, \
635         LPVOID))aSyscall[22].pCurrent)
636 
637 #if !SQLITE_OS_WINRT
638   { "GetFileSize",             (SYSCALL)GetFileSize,             0 },
639 #else
640   { "GetFileSize",             (SYSCALL)0,                       0 },
641 #endif
642 
643 #define osGetFileSize ((DWORD(WINAPI*)(HANDLE,LPDWORD))aSyscall[23].pCurrent)
644 
645 #if !SQLITE_OS_WINCE && defined(SQLITE_WIN32_HAS_ANSI)
646   { "GetFullPathNameA",        (SYSCALL)GetFullPathNameA,        0 },
647 #else
648   { "GetFullPathNameA",        (SYSCALL)0,                       0 },
649 #endif
650 
651 #define osGetFullPathNameA ((DWORD(WINAPI*)(LPCSTR,DWORD,LPSTR, \
652         LPSTR*))aSyscall[24].pCurrent)
653 
654 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
655   { "GetFullPathNameW",        (SYSCALL)GetFullPathNameW,        0 },
656 #else
657   { "GetFullPathNameW",        (SYSCALL)0,                       0 },
658 #endif
659 
660 #define osGetFullPathNameW ((DWORD(WINAPI*)(LPCWSTR,DWORD,LPWSTR, \
661         LPWSTR*))aSyscall[25].pCurrent)
662 
663   { "GetLastError",            (SYSCALL)GetLastError,            0 },
664 
665 #define osGetLastError ((DWORD(WINAPI*)(VOID))aSyscall[26].pCurrent)
666 
667 #if !defined(SQLITE_OMIT_LOAD_EXTENSION)
668 #if SQLITE_OS_WINCE
669   /* The GetProcAddressA() routine is only available on Windows CE. */
670   { "GetProcAddressA",         (SYSCALL)GetProcAddressA,         0 },
671 #else
672   /* All other Windows platforms expect GetProcAddress() to take
673   ** an ANSI string regardless of the _UNICODE setting */
674   { "GetProcAddressA",         (SYSCALL)GetProcAddress,          0 },
675 #endif
676 #else
677   { "GetProcAddressA",         (SYSCALL)0,                       0 },
678 #endif
679 
680 #define osGetProcAddressA ((FARPROC(WINAPI*)(HMODULE, \
681         LPCSTR))aSyscall[27].pCurrent)
682 
683 #if !SQLITE_OS_WINRT
684   { "GetSystemInfo",           (SYSCALL)GetSystemInfo,           0 },
685 #else
686   { "GetSystemInfo",           (SYSCALL)0,                       0 },
687 #endif
688 
689 #define osGetSystemInfo ((VOID(WINAPI*)(LPSYSTEM_INFO))aSyscall[28].pCurrent)
690 
691   { "GetSystemTime",           (SYSCALL)GetSystemTime,           0 },
692 
693 #define osGetSystemTime ((VOID(WINAPI*)(LPSYSTEMTIME))aSyscall[29].pCurrent)
694 
695 #if !SQLITE_OS_WINCE
696   { "GetSystemTimeAsFileTime", (SYSCALL)GetSystemTimeAsFileTime, 0 },
697 #else
698   { "GetSystemTimeAsFileTime", (SYSCALL)0,                       0 },
699 #endif
700 
701 #define osGetSystemTimeAsFileTime ((VOID(WINAPI*)( \
702         LPFILETIME))aSyscall[30].pCurrent)
703 
704 #if defined(SQLITE_WIN32_HAS_ANSI)
705   { "GetTempPathA",            (SYSCALL)GetTempPathA,            0 },
706 #else
707   { "GetTempPathA",            (SYSCALL)0,                       0 },
708 #endif
709 
710 #define osGetTempPathA ((DWORD(WINAPI*)(DWORD,LPSTR))aSyscall[31].pCurrent)
711 
712 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE)
713   { "GetTempPathW",            (SYSCALL)GetTempPathW,            0 },
714 #else
715   { "GetTempPathW",            (SYSCALL)0,                       0 },
716 #endif
717 
718 #define osGetTempPathW ((DWORD(WINAPI*)(DWORD,LPWSTR))aSyscall[32].pCurrent)
719 
720 #if !SQLITE_OS_WINRT
721   { "GetTickCount",            (SYSCALL)GetTickCount,            0 },
722 #else
723   { "GetTickCount",            (SYSCALL)0,                       0 },
724 #endif
725 
726 #define osGetTickCount ((DWORD(WINAPI*)(VOID))aSyscall[33].pCurrent)
727 
728 #if defined(SQLITE_WIN32_HAS_ANSI) && defined(SQLITE_WIN32_GETVERSIONEX) && \
729         SQLITE_WIN32_GETVERSIONEX
730   { "GetVersionExA",           (SYSCALL)GetVersionExA,           0 },
731 #else
732   { "GetVersionExA",           (SYSCALL)0,                       0 },
733 #endif
734 
735 #define osGetVersionExA ((BOOL(WINAPI*)( \
736         LPOSVERSIONINFOA))aSyscall[34].pCurrent)
737 
738 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
739         defined(SQLITE_WIN32_GETVERSIONEX) && SQLITE_WIN32_GETVERSIONEX
740   { "GetVersionExW",           (SYSCALL)GetVersionExW,           0 },
741 #else
742   { "GetVersionExW",           (SYSCALL)0,                       0 },
743 #endif
744 
745 #define osGetVersionExW ((BOOL(WINAPI*)( \
746         LPOSVERSIONINFOW))aSyscall[35].pCurrent)
747 
748   { "HeapAlloc",               (SYSCALL)HeapAlloc,               0 },
749 
750 #define osHeapAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD, \
751         SIZE_T))aSyscall[36].pCurrent)
752 
753 #if !SQLITE_OS_WINRT
754   { "HeapCreate",              (SYSCALL)HeapCreate,              0 },
755 #else
756   { "HeapCreate",              (SYSCALL)0,                       0 },
757 #endif
758 
759 #define osHeapCreate ((HANDLE(WINAPI*)(DWORD,SIZE_T, \
760         SIZE_T))aSyscall[37].pCurrent)
761 
762 #if !SQLITE_OS_WINRT
763   { "HeapDestroy",             (SYSCALL)HeapDestroy,             0 },
764 #else
765   { "HeapDestroy",             (SYSCALL)0,                       0 },
766 #endif
767 
768 #define osHeapDestroy ((BOOL(WINAPI*)(HANDLE))aSyscall[38].pCurrent)
769 
770   { "HeapFree",                (SYSCALL)HeapFree,                0 },
771 
772 #define osHeapFree ((BOOL(WINAPI*)(HANDLE,DWORD,LPVOID))aSyscall[39].pCurrent)
773 
774   { "HeapReAlloc",             (SYSCALL)HeapReAlloc,             0 },
775 
776 #define osHeapReAlloc ((LPVOID(WINAPI*)(HANDLE,DWORD,LPVOID, \
777         SIZE_T))aSyscall[40].pCurrent)
778 
779   { "HeapSize",                (SYSCALL)HeapSize,                0 },
780 
781 #define osHeapSize ((SIZE_T(WINAPI*)(HANDLE,DWORD, \
782         LPCVOID))aSyscall[41].pCurrent)
783 
784 #if !SQLITE_OS_WINRT
785   { "HeapValidate",            (SYSCALL)HeapValidate,            0 },
786 #else
787   { "HeapValidate",            (SYSCALL)0,                       0 },
788 #endif
789 
790 #define osHeapValidate ((BOOL(WINAPI*)(HANDLE,DWORD, \
791         LPCVOID))aSyscall[42].pCurrent)
792 
793 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
794   { "HeapCompact",             (SYSCALL)HeapCompact,             0 },
795 #else
796   { "HeapCompact",             (SYSCALL)0,                       0 },
797 #endif
798 
799 #define osHeapCompact ((UINT(WINAPI*)(HANDLE,DWORD))aSyscall[43].pCurrent)
800 
801 #if defined(SQLITE_WIN32_HAS_ANSI) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
802   { "LoadLibraryA",            (SYSCALL)LoadLibraryA,            0 },
803 #else
804   { "LoadLibraryA",            (SYSCALL)0,                       0 },
805 #endif
806 
807 #define osLoadLibraryA ((HMODULE(WINAPI*)(LPCSTR))aSyscall[44].pCurrent)
808 
809 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_HAS_WIDE) && \
810         !defined(SQLITE_OMIT_LOAD_EXTENSION)
811   { "LoadLibraryW",            (SYSCALL)LoadLibraryW,            0 },
812 #else
813   { "LoadLibraryW",            (SYSCALL)0,                       0 },
814 #endif
815 
816 #define osLoadLibraryW ((HMODULE(WINAPI*)(LPCWSTR))aSyscall[45].pCurrent)
817 
818 #if !SQLITE_OS_WINRT
819   { "LocalFree",               (SYSCALL)LocalFree,               0 },
820 #else
821   { "LocalFree",               (SYSCALL)0,                       0 },
822 #endif
823 
824 #define osLocalFree ((HLOCAL(WINAPI*)(HLOCAL))aSyscall[46].pCurrent)
825 
826 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
827   { "LockFile",                (SYSCALL)LockFile,                0 },
828 #else
829   { "LockFile",                (SYSCALL)0,                       0 },
830 #endif
831 
832 #ifndef osLockFile
833 #define osLockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
834         DWORD))aSyscall[47].pCurrent)
835 #endif
836 
837 #if !SQLITE_OS_WINCE
838   { "LockFileEx",              (SYSCALL)LockFileEx,              0 },
839 #else
840   { "LockFileEx",              (SYSCALL)0,                       0 },
841 #endif
842 
843 #ifndef osLockFileEx
844 #define osLockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD,DWORD, \
845         LPOVERLAPPED))aSyscall[48].pCurrent)
846 #endif
847 
848 #if SQLITE_OS_WINCE || (!SQLITE_OS_WINRT && \
849         (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0))
850   { "MapViewOfFile",           (SYSCALL)MapViewOfFile,           0 },
851 #else
852   { "MapViewOfFile",           (SYSCALL)0,                       0 },
853 #endif
854 
855 #define osMapViewOfFile ((LPVOID(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
856         SIZE_T))aSyscall[49].pCurrent)
857 
858   { "MultiByteToWideChar",     (SYSCALL)MultiByteToWideChar,     0 },
859 
860 #define osMultiByteToWideChar ((int(WINAPI*)(UINT,DWORD,LPCSTR,int,LPWSTR, \
861         int))aSyscall[50].pCurrent)
862 
863   { "QueryPerformanceCounter", (SYSCALL)QueryPerformanceCounter, 0 },
864 
865 #define osQueryPerformanceCounter ((BOOL(WINAPI*)( \
866         LARGE_INTEGER*))aSyscall[51].pCurrent)
867 
868   { "ReadFile",                (SYSCALL)ReadFile,                0 },
869 
870 #define osReadFile ((BOOL(WINAPI*)(HANDLE,LPVOID,DWORD,LPDWORD, \
871         LPOVERLAPPED))aSyscall[52].pCurrent)
872 
873   { "SetEndOfFile",            (SYSCALL)SetEndOfFile,            0 },
874 
875 #define osSetEndOfFile ((BOOL(WINAPI*)(HANDLE))aSyscall[53].pCurrent)
876 
877 #if !SQLITE_OS_WINRT
878   { "SetFilePointer",          (SYSCALL)SetFilePointer,          0 },
879 #else
880   { "SetFilePointer",          (SYSCALL)0,                       0 },
881 #endif
882 
883 #define osSetFilePointer ((DWORD(WINAPI*)(HANDLE,LONG,PLONG, \
884         DWORD))aSyscall[54].pCurrent)
885 
886 #if !SQLITE_OS_WINRT
887   { "Sleep",                   (SYSCALL)Sleep,                   0 },
888 #else
889   { "Sleep",                   (SYSCALL)0,                       0 },
890 #endif
891 
892 #define osSleep ((VOID(WINAPI*)(DWORD))aSyscall[55].pCurrent)
893 
894   { "SystemTimeToFileTime",    (SYSCALL)SystemTimeToFileTime,    0 },
895 
896 #define osSystemTimeToFileTime ((BOOL(WINAPI*)(CONST SYSTEMTIME*, \
897         LPFILETIME))aSyscall[56].pCurrent)
898 
899 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
900   { "UnlockFile",              (SYSCALL)UnlockFile,              0 },
901 #else
902   { "UnlockFile",              (SYSCALL)0,                       0 },
903 #endif
904 
905 #ifndef osUnlockFile
906 #define osUnlockFile ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
907         DWORD))aSyscall[57].pCurrent)
908 #endif
909 
910 #if !SQLITE_OS_WINCE
911   { "UnlockFileEx",            (SYSCALL)UnlockFileEx,            0 },
912 #else
913   { "UnlockFileEx",            (SYSCALL)0,                       0 },
914 #endif
915 
916 #define osUnlockFileEx ((BOOL(WINAPI*)(HANDLE,DWORD,DWORD,DWORD, \
917         LPOVERLAPPED))aSyscall[58].pCurrent)
918 
919 #if SQLITE_OS_WINCE || !defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0
920   { "UnmapViewOfFile",         (SYSCALL)UnmapViewOfFile,         0 },
921 #else
922   { "UnmapViewOfFile",         (SYSCALL)0,                       0 },
923 #endif
924 
925 #define osUnmapViewOfFile ((BOOL(WINAPI*)(LPCVOID))aSyscall[59].pCurrent)
926 
927   { "WideCharToMultiByte",     (SYSCALL)WideCharToMultiByte,     0 },
928 
929 #define osWideCharToMultiByte ((int(WINAPI*)(UINT,DWORD,LPCWSTR,int,LPSTR,int, \
930         LPCSTR,LPBOOL))aSyscall[60].pCurrent)
931 
932   { "WriteFile",               (SYSCALL)WriteFile,               0 },
933 
934 #define osWriteFile ((BOOL(WINAPI*)(HANDLE,LPCVOID,DWORD,LPDWORD, \
935         LPOVERLAPPED))aSyscall[61].pCurrent)
936 
937 #if SQLITE_OS_WINRT
938   { "CreateEventExW",          (SYSCALL)CreateEventExW,          0 },
939 #else
940   { "CreateEventExW",          (SYSCALL)0,                       0 },
941 #endif
942 
943 #define osCreateEventExW ((HANDLE(WINAPI*)(LPSECURITY_ATTRIBUTES,LPCWSTR, \
944         DWORD,DWORD))aSyscall[62].pCurrent)
945 
946 #if !SQLITE_OS_WINRT
947   { "WaitForSingleObject",     (SYSCALL)WaitForSingleObject,     0 },
948 #else
949   { "WaitForSingleObject",     (SYSCALL)0,                       0 },
950 #endif
951 
952 #define osWaitForSingleObject ((DWORD(WINAPI*)(HANDLE, \
953         DWORD))aSyscall[63].pCurrent)
954 
955 #if !SQLITE_OS_WINCE
956   { "WaitForSingleObjectEx",   (SYSCALL)WaitForSingleObjectEx,   0 },
957 #else
958   { "WaitForSingleObjectEx",   (SYSCALL)0,                       0 },
959 #endif
960 
961 #define osWaitForSingleObjectEx ((DWORD(WINAPI*)(HANDLE,DWORD, \
962         BOOL))aSyscall[64].pCurrent)
963 
964 #if SQLITE_OS_WINRT
965   { "SetFilePointerEx",        (SYSCALL)SetFilePointerEx,        0 },
966 #else
967   { "SetFilePointerEx",        (SYSCALL)0,                       0 },
968 #endif
969 
970 #define osSetFilePointerEx ((BOOL(WINAPI*)(HANDLE,LARGE_INTEGER, \
971         PLARGE_INTEGER,DWORD))aSyscall[65].pCurrent)
972 
973 #if SQLITE_OS_WINRT
974   { "GetFileInformationByHandleEx", (SYSCALL)GetFileInformationByHandleEx, 0 },
975 #else
976   { "GetFileInformationByHandleEx", (SYSCALL)0,                  0 },
977 #endif
978 
979 #define osGetFileInformationByHandleEx ((BOOL(WINAPI*)(HANDLE, \
980         FILE_INFO_BY_HANDLE_CLASS,LPVOID,DWORD))aSyscall[66].pCurrent)
981 
982 #if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
983   { "MapViewOfFileFromApp",    (SYSCALL)MapViewOfFileFromApp,    0 },
984 #else
985   { "MapViewOfFileFromApp",    (SYSCALL)0,                       0 },
986 #endif
987 
988 #define osMapViewOfFileFromApp ((LPVOID(WINAPI*)(HANDLE,ULONG,ULONG64, \
989         SIZE_T))aSyscall[67].pCurrent)
990 
991 #if SQLITE_OS_WINRT
992   { "CreateFile2",             (SYSCALL)CreateFile2,             0 },
993 #else
994   { "CreateFile2",             (SYSCALL)0,                       0 },
995 #endif
996 
997 #define osCreateFile2 ((HANDLE(WINAPI*)(LPCWSTR,DWORD,DWORD,DWORD, \
998         LPCREATEFILE2_EXTENDED_PARAMETERS))aSyscall[68].pCurrent)
999 
1000 #if SQLITE_OS_WINRT && !defined(SQLITE_OMIT_LOAD_EXTENSION)
1001   { "LoadPackagedLibrary",     (SYSCALL)LoadPackagedLibrary,     0 },
1002 #else
1003   { "LoadPackagedLibrary",     (SYSCALL)0,                       0 },
1004 #endif
1005 
1006 #define osLoadPackagedLibrary ((HMODULE(WINAPI*)(LPCWSTR, \
1007         DWORD))aSyscall[69].pCurrent)
1008 
1009 #if SQLITE_OS_WINRT
1010   { "GetTickCount64",          (SYSCALL)GetTickCount64,          0 },
1011 #else
1012   { "GetTickCount64",          (SYSCALL)0,                       0 },
1013 #endif
1014 
1015 #define osGetTickCount64 ((ULONGLONG(WINAPI*)(VOID))aSyscall[70].pCurrent)
1016 
1017 #if SQLITE_OS_WINRT
1018   { "GetNativeSystemInfo",     (SYSCALL)GetNativeSystemInfo,     0 },
1019 #else
1020   { "GetNativeSystemInfo",     (SYSCALL)0,                       0 },
1021 #endif
1022 
1023 #define osGetNativeSystemInfo ((VOID(WINAPI*)( \
1024         LPSYSTEM_INFO))aSyscall[71].pCurrent)
1025 
1026 #if defined(SQLITE_WIN32_HAS_ANSI)
1027   { "OutputDebugStringA",      (SYSCALL)OutputDebugStringA,      0 },
1028 #else
1029   { "OutputDebugStringA",      (SYSCALL)0,                       0 },
1030 #endif
1031 
1032 #define osOutputDebugStringA ((VOID(WINAPI*)(LPCSTR))aSyscall[72].pCurrent)
1033 
1034 #if defined(SQLITE_WIN32_HAS_WIDE)
1035   { "OutputDebugStringW",      (SYSCALL)OutputDebugStringW,      0 },
1036 #else
1037   { "OutputDebugStringW",      (SYSCALL)0,                       0 },
1038 #endif
1039 
1040 #define osOutputDebugStringW ((VOID(WINAPI*)(LPCWSTR))aSyscall[73].pCurrent)
1041 
1042   { "GetProcessHeap",          (SYSCALL)GetProcessHeap,          0 },
1043 
1044 #define osGetProcessHeap ((HANDLE(WINAPI*)(VOID))aSyscall[74].pCurrent)
1045 
1046 #if SQLITE_OS_WINRT && (!defined(SQLITE_OMIT_WAL) || SQLITE_MAX_MMAP_SIZE>0)
1047   { "CreateFileMappingFromApp", (SYSCALL)CreateFileMappingFromApp, 0 },
1048 #else
1049   { "CreateFileMappingFromApp", (SYSCALL)0,                      0 },
1050 #endif
1051 
1052 #define osCreateFileMappingFromApp ((HANDLE(WINAPI*)(HANDLE, \
1053         LPSECURITY_ATTRIBUTES,ULONG,ULONG64,LPCWSTR))aSyscall[75].pCurrent)
1054 
1055 /*
1056 ** NOTE: On some sub-platforms, the InterlockedCompareExchange "function"
1057 **       is really just a macro that uses a compiler intrinsic (e.g. x64).
1058 **       So do not try to make this is into a redefinable interface.
1059 */
1060 #if defined(InterlockedCompareExchange)
1061   { "InterlockedCompareExchange", (SYSCALL)0,                    0 },
1062 
1063 #define osInterlockedCompareExchange InterlockedCompareExchange
1064 #else
1065   { "InterlockedCompareExchange", (SYSCALL)InterlockedCompareExchange, 0 },
1066 
1067 #define osInterlockedCompareExchange ((LONG(WINAPI*)(LONG \
1068         SQLITE_WIN32_VOLATILE*, LONG,LONG))aSyscall[76].pCurrent)
1069 #endif /* defined(InterlockedCompareExchange) */
1070 
1071 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
1072   { "UuidCreate",               (SYSCALL)UuidCreate,             0 },
1073 #else
1074   { "UuidCreate",               (SYSCALL)0,                      0 },
1075 #endif
1076 
1077 #define osUuidCreate ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[77].pCurrent)
1078 
1079 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
1080   { "UuidCreateSequential",     (SYSCALL)UuidCreateSequential,   0 },
1081 #else
1082   { "UuidCreateSequential",     (SYSCALL)0,                      0 },
1083 #endif
1084 
1085 #define osUuidCreateSequential \
1086         ((RPC_STATUS(RPC_ENTRY*)(UUID*))aSyscall[78].pCurrent)
1087 
1088 #if !defined(SQLITE_NO_SYNC) && SQLITE_MAX_MMAP_SIZE>0
1089   { "FlushViewOfFile",          (SYSCALL)FlushViewOfFile,        0 },
1090 #else
1091   { "FlushViewOfFile",          (SYSCALL)0,                      0 },
1092 #endif
1093 
1094 #define osFlushViewOfFile \
1095         ((BOOL(WINAPI*)(LPCVOID,SIZE_T))aSyscall[79].pCurrent)
1096 
1097 }; /* End of the overrideable system calls */
1098 
1099 /*
1100 ** This is the xSetSystemCall() method of sqlite3_vfs for all of the
1101 ** "win32" VFSes.  Return SQLITE_OK opon successfully updating the
1102 ** system call pointer, or SQLITE_NOTFOUND if there is no configurable
1103 ** system call named zName.
1104 */
1105 static int winSetSystemCall(
1106   sqlite3_vfs *pNotUsed,        /* The VFS pointer.  Not used */
1107   const char *zName,            /* Name of system call to override */
1108   sqlite3_syscall_ptr pNewFunc  /* Pointer to new system call value */
1109 ){
1110   unsigned int i;
1111   int rc = SQLITE_NOTFOUND;
1112 
1113   UNUSED_PARAMETER(pNotUsed);
1114   if( zName==0 ){
1115     /* If no zName is given, restore all system calls to their default
1116     ** settings and return NULL
1117     */
1118     rc = SQLITE_OK;
1119     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1120       if( aSyscall[i].pDefault ){
1121         aSyscall[i].pCurrent = aSyscall[i].pDefault;
1122       }
1123     }
1124   }else{
1125     /* If zName is specified, operate on only the one system call
1126     ** specified.
1127     */
1128     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1129       if( strcmp(zName, aSyscall[i].zName)==0 ){
1130         if( aSyscall[i].pDefault==0 ){
1131           aSyscall[i].pDefault = aSyscall[i].pCurrent;
1132         }
1133         rc = SQLITE_OK;
1134         if( pNewFunc==0 ) pNewFunc = aSyscall[i].pDefault;
1135         aSyscall[i].pCurrent = pNewFunc;
1136         break;
1137       }
1138     }
1139   }
1140   return rc;
1141 }
1142 
1143 /*
1144 ** Return the value of a system call.  Return NULL if zName is not a
1145 ** recognized system call name.  NULL is also returned if the system call
1146 ** is currently undefined.
1147 */
1148 static sqlite3_syscall_ptr winGetSystemCall(
1149   sqlite3_vfs *pNotUsed,
1150   const char *zName
1151 ){
1152   unsigned int i;
1153 
1154   UNUSED_PARAMETER(pNotUsed);
1155   for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
1156     if( strcmp(zName, aSyscall[i].zName)==0 ) return aSyscall[i].pCurrent;
1157   }
1158   return 0;
1159 }
1160 
1161 /*
1162 ** Return the name of the first system call after zName.  If zName==NULL
1163 ** then return the name of the first system call.  Return NULL if zName
1164 ** is the last system call or if zName is not the name of a valid
1165 ** system call.
1166 */
1167 static const char *winNextSystemCall(sqlite3_vfs *p, const char *zName){
1168   int i = -1;
1169 
1170   UNUSED_PARAMETER(p);
1171   if( zName ){
1172     for(i=0; i<ArraySize(aSyscall)-1; i++){
1173       if( strcmp(zName, aSyscall[i].zName)==0 ) break;
1174     }
1175   }
1176   for(i++; i<ArraySize(aSyscall); i++){
1177     if( aSyscall[i].pCurrent!=0 ) return aSyscall[i].zName;
1178   }
1179   return 0;
1180 }
1181 
1182 #ifdef SQLITE_WIN32_MALLOC
1183 /*
1184 ** If a Win32 native heap has been configured, this function will attempt to
1185 ** compact it.  Upon success, SQLITE_OK will be returned.  Upon failure, one
1186 ** of SQLITE_NOMEM, SQLITE_ERROR, or SQLITE_NOTFOUND will be returned.  The
1187 ** "pnLargest" argument, if non-zero, will be used to return the size of the
1188 ** largest committed free block in the heap, in bytes.
1189 */
1190 int sqlite3_win32_compact_heap(LPUINT pnLargest){
1191   int rc = SQLITE_OK;
1192   UINT nLargest = 0;
1193   HANDLE hHeap;
1194 
1195   winMemAssertMagic();
1196   hHeap = winMemGetHeap();
1197   assert( hHeap!=0 );
1198   assert( hHeap!=INVALID_HANDLE_VALUE );
1199 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1200   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1201 #endif
1202 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT
1203   if( (nLargest=osHeapCompact(hHeap, SQLITE_WIN32_HEAP_FLAGS))==0 ){
1204     DWORD lastErrno = osGetLastError();
1205     if( lastErrno==NO_ERROR ){
1206       sqlite3_log(SQLITE_NOMEM, "failed to HeapCompact (no space), heap=%p",
1207                   (void*)hHeap);
1208       rc = SQLITE_NOMEM;
1209     }else{
1210       sqlite3_log(SQLITE_ERROR, "failed to HeapCompact (%lu), heap=%p",
1211                   osGetLastError(), (void*)hHeap);
1212       rc = SQLITE_ERROR;
1213     }
1214   }
1215 #else
1216   sqlite3_log(SQLITE_NOTFOUND, "failed to HeapCompact, heap=%p",
1217               (void*)hHeap);
1218   rc = SQLITE_NOTFOUND;
1219 #endif
1220   if( pnLargest ) *pnLargest = nLargest;
1221   return rc;
1222 }
1223 
1224 /*
1225 ** If a Win32 native heap has been configured, this function will attempt to
1226 ** destroy and recreate it.  If the Win32 native heap is not isolated and/or
1227 ** the sqlite3_memory_used() function does not return zero, SQLITE_BUSY will
1228 ** be returned and no changes will be made to the Win32 native heap.
1229 */
1230 int sqlite3_win32_reset_heap(){
1231   int rc;
1232   MUTEX_LOGIC( sqlite3_mutex *pMaster; ) /* The main static mutex */
1233   MUTEX_LOGIC( sqlite3_mutex *pMem; )    /* The memsys static mutex */
1234   MUTEX_LOGIC( pMaster = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER); )
1235   MUTEX_LOGIC( pMem = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM); )
1236   sqlite3_mutex_enter(pMaster);
1237   sqlite3_mutex_enter(pMem);
1238   winMemAssertMagic();
1239   if( winMemGetHeap()!=NULL && winMemGetOwned() && sqlite3_memory_used()==0 ){
1240     /*
1241     ** At this point, there should be no outstanding memory allocations on
1242     ** the heap.  Also, since both the master and memsys locks are currently
1243     ** being held by us, no other function (i.e. from another thread) should
1244     ** be able to even access the heap.  Attempt to destroy and recreate our
1245     ** isolated Win32 native heap now.
1246     */
1247     assert( winMemGetHeap()!=NULL );
1248     assert( winMemGetOwned() );
1249     assert( sqlite3_memory_used()==0 );
1250     winMemShutdown(winMemGetDataPtr());
1251     assert( winMemGetHeap()==NULL );
1252     assert( !winMemGetOwned() );
1253     assert( sqlite3_memory_used()==0 );
1254     rc = winMemInit(winMemGetDataPtr());
1255     assert( rc!=SQLITE_OK || winMemGetHeap()!=NULL );
1256     assert( rc!=SQLITE_OK || winMemGetOwned() );
1257     assert( rc!=SQLITE_OK || sqlite3_memory_used()==0 );
1258   }else{
1259     /*
1260     ** The Win32 native heap cannot be modified because it may be in use.
1261     */
1262     rc = SQLITE_BUSY;
1263   }
1264   sqlite3_mutex_leave(pMem);
1265   sqlite3_mutex_leave(pMaster);
1266   return rc;
1267 }
1268 #endif /* SQLITE_WIN32_MALLOC */
1269 
1270 /*
1271 ** This function outputs the specified (ANSI) string to the Win32 debugger
1272 ** (if available).
1273 */
1274 
1275 void sqlite3_win32_write_debug(const char *zBuf, int nBuf){
1276   char zDbgBuf[SQLITE_WIN32_DBG_BUF_SIZE];
1277   int nMin = MIN(nBuf, (SQLITE_WIN32_DBG_BUF_SIZE - 1)); /* may be negative. */
1278   if( nMin<-1 ) nMin = -1; /* all negative values become -1. */
1279   assert( nMin==-1 || nMin==0 || nMin<SQLITE_WIN32_DBG_BUF_SIZE );
1280 #if defined(SQLITE_WIN32_HAS_ANSI)
1281   if( nMin>0 ){
1282     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1283     memcpy(zDbgBuf, zBuf, nMin);
1284     osOutputDebugStringA(zDbgBuf);
1285   }else{
1286     osOutputDebugStringA(zBuf);
1287   }
1288 #elif defined(SQLITE_WIN32_HAS_WIDE)
1289   memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1290   if ( osMultiByteToWideChar(
1291           osAreFileApisANSI() ? CP_ACP : CP_OEMCP, 0, zBuf,
1292           nMin, (LPWSTR)zDbgBuf, SQLITE_WIN32_DBG_BUF_SIZE/sizeof(WCHAR))<=0 ){
1293     return;
1294   }
1295   osOutputDebugStringW((LPCWSTR)zDbgBuf);
1296 #else
1297   if( nMin>0 ){
1298     memset(zDbgBuf, 0, SQLITE_WIN32_DBG_BUF_SIZE);
1299     memcpy(zDbgBuf, zBuf, nMin);
1300     fprintf(stderr, "%s", zDbgBuf);
1301   }else{
1302     fprintf(stderr, "%s", zBuf);
1303   }
1304 #endif
1305 }
1306 
1307 /*
1308 ** The following routine suspends the current thread for at least ms
1309 ** milliseconds.  This is equivalent to the Win32 Sleep() interface.
1310 */
1311 #if SQLITE_OS_WINRT
1312 static HANDLE sleepObj = NULL;
1313 #endif
1314 
1315 void sqlite3_win32_sleep(DWORD milliseconds){
1316 #if SQLITE_OS_WINRT
1317   if ( sleepObj==NULL ){
1318     sleepObj = osCreateEventExW(NULL, NULL, CREATE_EVENT_MANUAL_RESET,
1319                                 SYNCHRONIZE);
1320   }
1321   assert( sleepObj!=NULL );
1322   osWaitForSingleObjectEx(sleepObj, milliseconds, FALSE);
1323 #else
1324   osSleep(milliseconds);
1325 #endif
1326 }
1327 
1328 #if SQLITE_MAX_WORKER_THREADS>0 && !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && \
1329         SQLITE_THREADSAFE>0
1330 DWORD sqlite3Win32Wait(HANDLE hObject){
1331   DWORD rc;
1332   while( (rc = osWaitForSingleObjectEx(hObject, INFINITE,
1333                                        TRUE))==WAIT_IO_COMPLETION ){}
1334   return rc;
1335 }
1336 #endif
1337 
1338 /*
1339 ** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
1340 ** or WinCE.  Return false (zero) for Win95, Win98, or WinME.
1341 **
1342 ** Here is an interesting observation:  Win95, Win98, and WinME lack
1343 ** the LockFileEx() API.  But we can still statically link against that
1344 ** API as long as we don't call it when running Win95/98/ME.  A call to
1345 ** this routine is used to determine if the host is Win95/98/ME or
1346 ** WinNT/2K/XP so that we will know whether or not we can safely call
1347 ** the LockFileEx() API.
1348 */
1349 
1350 #if !defined(SQLITE_WIN32_GETVERSIONEX) || !SQLITE_WIN32_GETVERSIONEX
1351 # define osIsNT()  (1)
1352 #elif SQLITE_OS_WINCE || SQLITE_OS_WINRT || !defined(SQLITE_WIN32_HAS_ANSI)
1353 # define osIsNT()  (1)
1354 #elif !defined(SQLITE_WIN32_HAS_WIDE)
1355 # define osIsNT()  (0)
1356 #else
1357 # define osIsNT()  ((sqlite3_os_type==2) || sqlite3_win32_is_nt())
1358 #endif
1359 
1360 /*
1361 ** This function determines if the machine is running a version of Windows
1362 ** based on the NT kernel.
1363 */
1364 int sqlite3_win32_is_nt(void){
1365 #if SQLITE_OS_WINRT
1366   /*
1367   ** NOTE: The WinRT sub-platform is always assumed to be based on the NT
1368   **       kernel.
1369   */
1370   return 1;
1371 #elif defined(SQLITE_WIN32_GETVERSIONEX) && SQLITE_WIN32_GETVERSIONEX
1372   if( osInterlockedCompareExchange(&sqlite3_os_type, 0, 0)==0 ){
1373 #if defined(SQLITE_WIN32_HAS_ANSI)
1374     OSVERSIONINFOA sInfo;
1375     sInfo.dwOSVersionInfoSize = sizeof(sInfo);
1376     osGetVersionExA(&sInfo);
1377     osInterlockedCompareExchange(&sqlite3_os_type,
1378         (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
1379 #elif defined(SQLITE_WIN32_HAS_WIDE)
1380     OSVERSIONINFOW sInfo;
1381     sInfo.dwOSVersionInfoSize = sizeof(sInfo);
1382     osGetVersionExW(&sInfo);
1383     osInterlockedCompareExchange(&sqlite3_os_type,
1384         (sInfo.dwPlatformId == VER_PLATFORM_WIN32_NT) ? 2 : 1, 0);
1385 #endif
1386   }
1387   return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;
1388 #elif SQLITE_TEST
1389   return osInterlockedCompareExchange(&sqlite3_os_type, 2, 2)==2;
1390 #else
1391   /*
1392   ** NOTE: All sub-platforms where the GetVersionEx[AW] functions are
1393   **       deprecated are always assumed to be based on the NT kernel.
1394   */
1395   return 1;
1396 #endif
1397 }
1398 
1399 #ifdef SQLITE_WIN32_MALLOC
1400 /*
1401 ** Allocate nBytes of memory.
1402 */
1403 static void *winMemMalloc(int nBytes){
1404   HANDLE hHeap;
1405   void *p;
1406 
1407   winMemAssertMagic();
1408   hHeap = winMemGetHeap();
1409   assert( hHeap!=0 );
1410   assert( hHeap!=INVALID_HANDLE_VALUE );
1411 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1412   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1413 #endif
1414   assert( nBytes>=0 );
1415   p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
1416   if( !p ){
1417     sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%lu), heap=%p",
1418                 nBytes, osGetLastError(), (void*)hHeap);
1419   }
1420   return p;
1421 }
1422 
1423 /*
1424 ** Free memory.
1425 */
1426 static void winMemFree(void *pPrior){
1427   HANDLE hHeap;
1428 
1429   winMemAssertMagic();
1430   hHeap = winMemGetHeap();
1431   assert( hHeap!=0 );
1432   assert( hHeap!=INVALID_HANDLE_VALUE );
1433 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1434   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
1435 #endif
1436   if( !pPrior ) return; /* Passing NULL to HeapFree is undefined. */
1437   if( !osHeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){
1438     sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%lu), heap=%p",
1439                 pPrior, osGetLastError(), (void*)hHeap);
1440   }
1441 }
1442 
1443 /*
1444 ** Change the size of an existing memory allocation
1445 */
1446 static void *winMemRealloc(void *pPrior, int nBytes){
1447   HANDLE hHeap;
1448   void *p;
1449 
1450   winMemAssertMagic();
1451   hHeap = winMemGetHeap();
1452   assert( hHeap!=0 );
1453   assert( hHeap!=INVALID_HANDLE_VALUE );
1454 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1455   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
1456 #endif
1457   assert( nBytes>=0 );
1458   if( !pPrior ){
1459     p = osHeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
1460   }else{
1461     p = osHeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);
1462   }
1463   if( !p ){
1464     sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%lu), heap=%p",
1465                 pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, osGetLastError(),
1466                 (void*)hHeap);
1467   }
1468   return p;
1469 }
1470 
1471 /*
1472 ** Return the size of an outstanding allocation, in bytes.
1473 */
1474 static int winMemSize(void *p){
1475   HANDLE hHeap;
1476   SIZE_T n;
1477 
1478   winMemAssertMagic();
1479   hHeap = winMemGetHeap();
1480   assert( hHeap!=0 );
1481   assert( hHeap!=INVALID_HANDLE_VALUE );
1482 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1483   assert( osHeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, p) );
1484 #endif
1485   if( !p ) return 0;
1486   n = osHeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);
1487   if( n==(SIZE_T)-1 ){
1488     sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%lu), heap=%p",
1489                 p, osGetLastError(), (void*)hHeap);
1490     return 0;
1491   }
1492   return (int)n;
1493 }
1494 
1495 /*
1496 ** Round up a request size to the next valid allocation size.
1497 */
1498 static int winMemRoundup(int n){
1499   return n;
1500 }
1501 
1502 /*
1503 ** Initialize this module.
1504 */
1505 static int winMemInit(void *pAppData){
1506   winMemData *pWinMemData = (winMemData *)pAppData;
1507 
1508   if( !pWinMemData ) return SQLITE_ERROR;
1509   assert( pWinMemData->magic1==WINMEM_MAGIC1 );
1510   assert( pWinMemData->magic2==WINMEM_MAGIC2 );
1511 
1512 #if !SQLITE_OS_WINRT && SQLITE_WIN32_HEAP_CREATE
1513   if( !pWinMemData->hHeap ){
1514     DWORD dwInitialSize = SQLITE_WIN32_HEAP_INIT_SIZE;
1515     DWORD dwMaximumSize = (DWORD)sqlite3GlobalConfig.nHeap;
1516     if( dwMaximumSize==0 ){
1517       dwMaximumSize = SQLITE_WIN32_HEAP_MAX_SIZE;
1518     }else if( dwInitialSize>dwMaximumSize ){
1519       dwInitialSize = dwMaximumSize;
1520     }
1521     pWinMemData->hHeap = osHeapCreate(SQLITE_WIN32_HEAP_FLAGS,
1522                                       dwInitialSize, dwMaximumSize);
1523     if( !pWinMemData->hHeap ){
1524       sqlite3_log(SQLITE_NOMEM,
1525           "failed to HeapCreate (%lu), flags=%u, initSize=%lu, maxSize=%lu",
1526           osGetLastError(), SQLITE_WIN32_HEAP_FLAGS, dwInitialSize,
1527           dwMaximumSize);
1528       return SQLITE_NOMEM;
1529     }
1530     pWinMemData->bOwned = TRUE;
1531     assert( pWinMemData->bOwned );
1532   }
1533 #else
1534   pWinMemData->hHeap = osGetProcessHeap();
1535   if( !pWinMemData->hHeap ){
1536     sqlite3_log(SQLITE_NOMEM,
1537         "failed to GetProcessHeap (%lu)", osGetLastError());
1538     return SQLITE_NOMEM;
1539   }
1540   pWinMemData->bOwned = FALSE;
1541   assert( !pWinMemData->bOwned );
1542 #endif
1543   assert( pWinMemData->hHeap!=0 );
1544   assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
1545 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1546   assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1547 #endif
1548   return SQLITE_OK;
1549 }
1550 
1551 /*
1552 ** Deinitialize this module.
1553 */
1554 static void winMemShutdown(void *pAppData){
1555   winMemData *pWinMemData = (winMemData *)pAppData;
1556 
1557   if( !pWinMemData ) return;
1558   assert( pWinMemData->magic1==WINMEM_MAGIC1 );
1559   assert( pWinMemData->magic2==WINMEM_MAGIC2 );
1560 
1561   if( pWinMemData->hHeap ){
1562     assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
1563 #if !SQLITE_OS_WINRT && defined(SQLITE_WIN32_MALLOC_VALIDATE)
1564     assert( osHeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
1565 #endif
1566     if( pWinMemData->bOwned ){
1567       if( !osHeapDestroy(pWinMemData->hHeap) ){
1568         sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%lu), heap=%p",
1569                     osGetLastError(), (void*)pWinMemData->hHeap);
1570       }
1571       pWinMemData->bOwned = FALSE;
1572     }
1573     pWinMemData->hHeap = NULL;
1574   }
1575 }
1576 
1577 /*
1578 ** Populate the low-level memory allocation function pointers in
1579 ** sqlite3GlobalConfig.m with pointers to the routines in this file. The
1580 ** arguments specify the block of memory to manage.
1581 **
1582 ** This routine is only called by sqlite3_config(), and therefore
1583 ** is not required to be threadsafe (it is not).
1584 */
1585 const sqlite3_mem_methods *sqlite3MemGetWin32(void){
1586   static const sqlite3_mem_methods winMemMethods = {
1587     winMemMalloc,
1588     winMemFree,
1589     winMemRealloc,
1590     winMemSize,
1591     winMemRoundup,
1592     winMemInit,
1593     winMemShutdown,
1594     &win_mem_data
1595   };
1596   return &winMemMethods;
1597 }
1598 
1599 void sqlite3MemSetDefault(void){
1600   sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetWin32());
1601 }
1602 #endif /* SQLITE_WIN32_MALLOC */
1603 
1604 /*
1605 ** Convert a UTF-8 string to Microsoft Unicode (UTF-16?).
1606 **
1607 ** Space to hold the returned string is obtained from malloc.
1608 */
1609 static LPWSTR winUtf8ToUnicode(const char *zFilename){
1610   int nChar;
1611   LPWSTR zWideFilename;
1612 
1613   nChar = osMultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
1614   if( nChar==0 ){
1615     return 0;
1616   }
1617   zWideFilename = sqlite3MallocZero( nChar*sizeof(zWideFilename[0]) );
1618   if( zWideFilename==0 ){
1619     return 0;
1620   }
1621   nChar = osMultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename,
1622                                 nChar);
1623   if( nChar==0 ){
1624     sqlite3_free(zWideFilename);
1625     zWideFilename = 0;
1626   }
1627   return zWideFilename;
1628 }
1629 
1630 /*
1631 ** Convert Microsoft Unicode to UTF-8.  Space to hold the returned string is
1632 ** obtained from sqlite3_malloc().
1633 */
1634 static char *winUnicodeToUtf8(LPCWSTR zWideFilename){
1635   int nByte;
1636   char *zFilename;
1637 
1638   nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, 0, 0, 0, 0);
1639   if( nByte == 0 ){
1640     return 0;
1641   }
1642   zFilename = sqlite3MallocZero( nByte );
1643   if( zFilename==0 ){
1644     return 0;
1645   }
1646   nByte = osWideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, zFilename, nByte,
1647                                 0, 0);
1648   if( nByte == 0 ){
1649     sqlite3_free(zFilename);
1650     zFilename = 0;
1651   }
1652   return zFilename;
1653 }
1654 
1655 /*
1656 ** Convert an ANSI string to Microsoft Unicode, based on the
1657 ** current codepage settings for file apis.
1658 **
1659 ** Space to hold the returned string is obtained
1660 ** from sqlite3_malloc.
1661 */
1662 static LPWSTR winMbcsToUnicode(const char *zFilename){
1663   int nByte;
1664   LPWSTR zMbcsFilename;
1665   int codepage = osAreFileApisANSI() ? CP_ACP : CP_OEMCP;
1666 
1667   nByte = osMultiByteToWideChar(codepage, 0, zFilename, -1, NULL,
1668                                 0)*sizeof(WCHAR);
1669   if( nByte==0 ){
1670     return 0;
1671   }
1672   zMbcsFilename = sqlite3MallocZero( nByte*sizeof(zMbcsFilename[0]) );
1673   if( zMbcsFilename==0 ){
1674     return 0;
1675   }
1676   nByte = osMultiByteToWideChar(codepage, 0, zFilename, -1, zMbcsFilename,
1677                                 nByte);
1678   if( nByte==0 ){
1679     sqlite3_free(zMbcsFilename);
1680     zMbcsFilename = 0;
1681   }
1682   return zMbcsFilename;
1683 }
1684 
1685 /*
1686 ** Convert Microsoft Unicode to multi-byte character string, based on the
1687 ** user's ANSI codepage.
1688 **
1689 ** Space to hold the returned string is obtained from
1690 ** sqlite3_malloc().
1691 */
1692 static char *winUnicodeToMbcs(LPCWSTR zWideFilename){
1693   int nByte;
1694   char *zFilename;
1695   int codepage = osAreFileApisANSI() ? CP_ACP : CP_OEMCP;
1696 
1697   nByte = osWideCharToMultiByte(codepage, 0, zWideFilename, -1, 0, 0, 0, 0);
1698   if( nByte == 0 ){
1699     return 0;
1700   }
1701   zFilename = sqlite3MallocZero( nByte );
1702   if( zFilename==0 ){
1703     return 0;
1704   }
1705   nByte = osWideCharToMultiByte(codepage, 0, zWideFilename, -1, zFilename,
1706                                 nByte, 0, 0);
1707   if( nByte == 0 ){
1708     sqlite3_free(zFilename);
1709     zFilename = 0;
1710   }
1711   return zFilename;
1712 }
1713 
1714 /*
1715 ** Convert multibyte character string to UTF-8.  Space to hold the
1716 ** returned string is obtained from sqlite3_malloc().
1717 */
1718 char *sqlite3_win32_mbcs_to_utf8(const char *zFilename){
1719   char *zFilenameUtf8;
1720   LPWSTR zTmpWide;
1721 
1722   zTmpWide = winMbcsToUnicode(zFilename);
1723   if( zTmpWide==0 ){
1724     return 0;
1725   }
1726   zFilenameUtf8 = winUnicodeToUtf8(zTmpWide);
1727   sqlite3_free(zTmpWide);
1728   return zFilenameUtf8;
1729 }
1730 
1731 /*
1732 ** Convert UTF-8 to multibyte character string.  Space to hold the
1733 ** returned string is obtained from sqlite3_malloc().
1734 */
1735 char *sqlite3_win32_utf8_to_mbcs(const char *zFilename){
1736   char *zFilenameMbcs;
1737   LPWSTR zTmpWide;
1738 
1739   zTmpWide = winUtf8ToUnicode(zFilename);
1740   if( zTmpWide==0 ){
1741     return 0;
1742   }
1743   zFilenameMbcs = winUnicodeToMbcs(zTmpWide);
1744   sqlite3_free(zTmpWide);
1745   return zFilenameMbcs;
1746 }
1747 
1748 /*
1749 ** This function sets the data directory or the temporary directory based on
1750 ** the provided arguments.  The type argument must be 1 in order to set the
1751 ** data directory or 2 in order to set the temporary directory.  The zValue
1752 ** argument is the name of the directory to use.  The return value will be
1753 ** SQLITE_OK if successful.
1754 */
1755 int sqlite3_win32_set_directory(DWORD type, LPCWSTR zValue){
1756   char **ppDirectory = 0;
1757 #ifndef SQLITE_OMIT_AUTOINIT
1758   int rc = sqlite3_initialize();
1759   if( rc ) return rc;
1760 #endif
1761   if( type==SQLITE_WIN32_DATA_DIRECTORY_TYPE ){
1762     ppDirectory = &sqlite3_data_directory;
1763   }else if( type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE ){
1764     ppDirectory = &sqlite3_temp_directory;
1765   }
1766   assert( !ppDirectory || type==SQLITE_WIN32_DATA_DIRECTORY_TYPE
1767           || type==SQLITE_WIN32_TEMP_DIRECTORY_TYPE
1768   );
1769   assert( !ppDirectory || sqlite3MemdebugHasType(*ppDirectory, MEMTYPE_HEAP) );
1770   if( ppDirectory ){
1771     char *zValueUtf8 = 0;
1772     if( zValue && zValue[0] ){
1773       zValueUtf8 = winUnicodeToUtf8(zValue);
1774       if ( zValueUtf8==0 ){
1775         return SQLITE_NOMEM;
1776       }
1777     }
1778     sqlite3_free(*ppDirectory);
1779     *ppDirectory = zValueUtf8;
1780     return SQLITE_OK;
1781   }
1782   return SQLITE_ERROR;
1783 }
1784 
1785 /*
1786 ** The return value of winGetLastErrorMsg
1787 ** is zero if the error message fits in the buffer, or non-zero
1788 ** otherwise (if the message was truncated).
1789 */
1790 static int winGetLastErrorMsg(DWORD lastErrno, int nBuf, char *zBuf){
1791   /* FormatMessage returns 0 on failure.  Otherwise it
1792   ** returns the number of TCHARs written to the output
1793   ** buffer, excluding the terminating null char.
1794   */
1795   DWORD dwLen = 0;
1796   char *zOut = 0;
1797 
1798   if( osIsNT() ){
1799 #if SQLITE_OS_WINRT
1800     WCHAR zTempWide[SQLITE_WIN32_MAX_ERRMSG_CHARS+1];
1801     dwLen = osFormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
1802                              FORMAT_MESSAGE_IGNORE_INSERTS,
1803                              NULL,
1804                              lastErrno,
1805                              0,
1806                              zTempWide,
1807                              SQLITE_WIN32_MAX_ERRMSG_CHARS,
1808                              0);
1809 #else
1810     LPWSTR zTempWide = NULL;
1811     dwLen = osFormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
1812                              FORMAT_MESSAGE_FROM_SYSTEM |
1813                              FORMAT_MESSAGE_IGNORE_INSERTS,
1814                              NULL,
1815                              lastErrno,
1816                              0,
1817                              (LPWSTR) &zTempWide,
1818                              0,
1819                              0);
1820 #endif
1821     if( dwLen > 0 ){
1822       /* allocate a buffer and convert to UTF8 */
1823       sqlite3BeginBenignMalloc();
1824       zOut = winUnicodeToUtf8(zTempWide);
1825       sqlite3EndBenignMalloc();
1826 #if !SQLITE_OS_WINRT
1827       /* free the system buffer allocated by FormatMessage */
1828       osLocalFree(zTempWide);
1829 #endif
1830     }
1831   }
1832 #ifdef SQLITE_WIN32_HAS_ANSI
1833   else{
1834     char *zTemp = NULL;
1835     dwLen = osFormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER |
1836                              FORMAT_MESSAGE_FROM_SYSTEM |
1837                              FORMAT_MESSAGE_IGNORE_INSERTS,
1838                              NULL,
1839                              lastErrno,
1840                              0,
1841                              (LPSTR) &zTemp,
1842                              0,
1843                              0);
1844     if( dwLen > 0 ){
1845       /* allocate a buffer and convert to UTF8 */
1846       sqlite3BeginBenignMalloc();
1847       zOut = sqlite3_win32_mbcs_to_utf8(zTemp);
1848       sqlite3EndBenignMalloc();
1849       /* free the system buffer allocated by FormatMessage */
1850       osLocalFree(zTemp);
1851     }
1852   }
1853 #endif
1854   if( 0 == dwLen ){
1855     sqlite3_snprintf(nBuf, zBuf, "OsError 0x%lx (%lu)", lastErrno, lastErrno);
1856   }else{
1857     /* copy a maximum of nBuf chars to output buffer */
1858     sqlite3_snprintf(nBuf, zBuf, "%s", zOut);
1859     /* free the UTF8 buffer */
1860     sqlite3_free(zOut);
1861   }
1862   return 0;
1863 }
1864 
1865 /*
1866 **
1867 ** This function - winLogErrorAtLine() - is only ever called via the macro
1868 ** winLogError().
1869 **
1870 ** This routine is invoked after an error occurs in an OS function.
1871 ** It logs a message using sqlite3_log() containing the current value of
1872 ** error code and, if possible, the human-readable equivalent from
1873 ** FormatMessage.
1874 **
1875 ** The first argument passed to the macro should be the error code that
1876 ** will be returned to SQLite (e.g. SQLITE_IOERR_DELETE, SQLITE_CANTOPEN).
1877 ** The two subsequent arguments should be the name of the OS function that
1878 ** failed and the associated file-system path, if any.
1879 */
1880 #define winLogError(a,b,c,d)   winLogErrorAtLine(a,b,c,d,__LINE__)
1881 static int winLogErrorAtLine(
1882   int errcode,                    /* SQLite error code */
1883   DWORD lastErrno,                /* Win32 last error */
1884   const char *zFunc,              /* Name of OS function that failed */
1885   const char *zPath,              /* File path associated with error */
1886   int iLine                       /* Source line number where error occurred */
1887 ){
1888   char zMsg[500];                 /* Human readable error text */
1889   int i;                          /* Loop counter */
1890 
1891   zMsg[0] = 0;
1892   winGetLastErrorMsg(lastErrno, sizeof(zMsg), zMsg);
1893   assert( errcode!=SQLITE_OK );
1894   if( zPath==0 ) zPath = "";
1895   for(i=0; zMsg[i] && zMsg[i]!='\r' && zMsg[i]!='\n'; i++){}
1896   zMsg[i] = 0;
1897   sqlite3_log(errcode,
1898       "os_win.c:%d: (%lu) %s(%s) - %s",
1899       iLine, lastErrno, zFunc, zPath, zMsg
1900   );
1901 
1902   return errcode;
1903 }
1904 
1905 /*
1906 ** The number of times that a ReadFile(), WriteFile(), and DeleteFile()
1907 ** will be retried following a locking error - probably caused by
1908 ** antivirus software.  Also the initial delay before the first retry.
1909 ** The delay increases linearly with each retry.
1910 */
1911 #ifndef SQLITE_WIN32_IOERR_RETRY
1912 # define SQLITE_WIN32_IOERR_RETRY 10
1913 #endif
1914 #ifndef SQLITE_WIN32_IOERR_RETRY_DELAY
1915 # define SQLITE_WIN32_IOERR_RETRY_DELAY 25
1916 #endif
1917 static int winIoerrRetry = SQLITE_WIN32_IOERR_RETRY;
1918 static int winIoerrRetryDelay = SQLITE_WIN32_IOERR_RETRY_DELAY;
1919 
1920 /*
1921 ** The "winIoerrCanRetry1" macro is used to determine if a particular I/O
1922 ** error code obtained via GetLastError() is eligible to be retried.  It
1923 ** must accept the error code DWORD as its only argument and should return
1924 ** non-zero if the error code is transient in nature and the operation
1925 ** responsible for generating the original error might succeed upon being
1926 ** retried.  The argument to this macro should be a variable.
1927 **
1928 ** Additionally, a macro named "winIoerrCanRetry2" may be defined.  If it
1929 ** is defined, it will be consulted only when the macro "winIoerrCanRetry1"
1930 ** returns zero.  The "winIoerrCanRetry2" macro is completely optional and
1931 ** may be used to include additional error codes in the set that should
1932 ** result in the failing I/O operation being retried by the caller.  If
1933 ** defined, the "winIoerrCanRetry2" macro must exhibit external semantics
1934 ** identical to those of the "winIoerrCanRetry1" macro.
1935 */
1936 #if !defined(winIoerrCanRetry1)
1937 #define winIoerrCanRetry1(a) (((a)==ERROR_ACCESS_DENIED)        || \
1938                               ((a)==ERROR_SHARING_VIOLATION)    || \
1939                               ((a)==ERROR_LOCK_VIOLATION)       || \
1940                               ((a)==ERROR_DEV_NOT_EXIST)        || \
1941                               ((a)==ERROR_NETNAME_DELETED)      || \
1942                               ((a)==ERROR_SEM_TIMEOUT)          || \
1943                               ((a)==ERROR_NETWORK_UNREACHABLE))
1944 #endif
1945 
1946 /*
1947 ** If a ReadFile() or WriteFile() error occurs, invoke this routine
1948 ** to see if it should be retried.  Return TRUE to retry.  Return FALSE
1949 ** to give up with an error.
1950 */
1951 static int winRetryIoerr(int *pnRetry, DWORD *pError){
1952   DWORD e = osGetLastError();
1953   if( *pnRetry>=winIoerrRetry ){
1954     if( pError ){
1955       *pError = e;
1956     }
1957     return 0;
1958   }
1959   if( winIoerrCanRetry1(e) ){
1960     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
1961     ++*pnRetry;
1962     return 1;
1963   }
1964 #if defined(winIoerrCanRetry2)
1965   else if( winIoerrCanRetry2(e) ){
1966     sqlite3_win32_sleep(winIoerrRetryDelay*(1+*pnRetry));
1967     ++*pnRetry;
1968     return 1;
1969   }
1970 #endif
1971   if( pError ){
1972     *pError = e;
1973   }
1974   return 0;
1975 }
1976 
1977 /*
1978 ** Log a I/O error retry episode.
1979 */
1980 static void winLogIoerr(int nRetry, int lineno){
1981   if( nRetry ){
1982     sqlite3_log(SQLITE_NOTICE,
1983       "delayed %dms for lock/sharing conflict at line %d",
1984       winIoerrRetryDelay*nRetry*(nRetry+1)/2, lineno
1985     );
1986   }
1987 }
1988 
1989 #if SQLITE_OS_WINCE
1990 /*************************************************************************
1991 ** This section contains code for WinCE only.
1992 */
1993 #if !defined(SQLITE_MSVC_LOCALTIME_API) || !SQLITE_MSVC_LOCALTIME_API
1994 /*
1995 ** The MSVC CRT on Windows CE may not have a localtime() function.  So
1996 ** create a substitute.
1997 */
1998 #include <time.h>
1999 struct tm *__cdecl localtime(const time_t *t)
2000 {
2001   static struct tm y;
2002   FILETIME uTm, lTm;
2003   SYSTEMTIME pTm;
2004   sqlite3_int64 t64;
2005   t64 = *t;
2006   t64 = (t64 + 11644473600)*10000000;
2007   uTm.dwLowDateTime = (DWORD)(t64 & 0xFFFFFFFF);
2008   uTm.dwHighDateTime= (DWORD)(t64 >> 32);
2009   osFileTimeToLocalFileTime(&uTm,&lTm);
2010   osFileTimeToSystemTime(&lTm,&pTm);
2011   y.tm_year = pTm.wYear - 1900;
2012   y.tm_mon = pTm.wMonth - 1;
2013   y.tm_wday = pTm.wDayOfWeek;
2014   y.tm_mday = pTm.wDay;
2015   y.tm_hour = pTm.wHour;
2016   y.tm_min = pTm.wMinute;
2017   y.tm_sec = pTm.wSecond;
2018   return &y;
2019 }
2020 #endif
2021 
2022 #define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]
2023 
2024 /*
2025 ** Acquire a lock on the handle h
2026 */
2027 static void winceMutexAcquire(HANDLE h){
2028    DWORD dwErr;
2029    do {
2030      dwErr = osWaitForSingleObject(h, INFINITE);
2031    } while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);
2032 }
2033 /*
2034 ** Release a lock acquired by winceMutexAcquire()
2035 */
2036 #define winceMutexRelease(h) ReleaseMutex(h)
2037 
2038 /*
2039 ** Create the mutex and shared memory used for locking in the file
2040 ** descriptor pFile
2041 */
2042 static int winceCreateLock(const char *zFilename, winFile *pFile){
2043   LPWSTR zTok;
2044   LPWSTR zName;
2045   DWORD lastErrno;
2046   BOOL bLogged = FALSE;
2047   BOOL bInit = TRUE;
2048 
2049   zName = winUtf8ToUnicode(zFilename);
2050   if( zName==0 ){
2051     /* out of memory */
2052     return SQLITE_IOERR_NOMEM;
2053   }
2054 
2055   /* Initialize the local lockdata */
2056   memset(&pFile->local, 0, sizeof(pFile->local));
2057 
2058   /* Replace the backslashes from the filename and lowercase it
2059   ** to derive a mutex name. */
2060   zTok = osCharLowerW(zName);
2061   for (;*zTok;zTok++){
2062     if (*zTok == '\\') *zTok = '_';
2063   }
2064 
2065   /* Create/open the named mutex */
2066   pFile->hMutex = osCreateMutexW(NULL, FALSE, zName);
2067   if (!pFile->hMutex){
2068     pFile->lastErrno = osGetLastError();
2069     sqlite3_free(zName);
2070     return winLogError(SQLITE_IOERR, pFile->lastErrno,
2071                        "winceCreateLock1", zFilename);
2072   }
2073 
2074   /* Acquire the mutex before continuing */
2075   winceMutexAcquire(pFile->hMutex);
2076 
2077   /* Since the names of named mutexes, semaphores, file mappings etc are
2078   ** case-sensitive, take advantage of that by uppercasing the mutex name
2079   ** and using that as the shared filemapping name.
2080   */
2081   osCharUpperW(zName);
2082   pFile->hShared = osCreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
2083                                         PAGE_READWRITE, 0, sizeof(winceLock),
2084                                         zName);
2085 
2086   /* Set a flag that indicates we're the first to create the memory so it
2087   ** must be zero-initialized */
2088   lastErrno = osGetLastError();
2089   if (lastErrno == ERROR_ALREADY_EXISTS){
2090     bInit = FALSE;
2091   }
2092 
2093   sqlite3_free(zName);
2094 
2095   /* If we succeeded in making the shared memory handle, map it. */
2096   if( pFile->hShared ){
2097     pFile->shared = (winceLock*)osMapViewOfFile(pFile->hShared,
2098              FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
2099     /* If mapping failed, close the shared memory handle and erase it */
2100     if( !pFile->shared ){
2101       pFile->lastErrno = osGetLastError();
2102       winLogError(SQLITE_IOERR, pFile->lastErrno,
2103                   "winceCreateLock2", zFilename);
2104       bLogged = TRUE;
2105       osCloseHandle(pFile->hShared);
2106       pFile->hShared = NULL;
2107     }
2108   }
2109 
2110   /* If shared memory could not be created, then close the mutex and fail */
2111   if( pFile->hShared==NULL ){
2112     if( !bLogged ){
2113       pFile->lastErrno = lastErrno;
2114       winLogError(SQLITE_IOERR, pFile->lastErrno,
2115                   "winceCreateLock3", zFilename);
2116       bLogged = TRUE;
2117     }
2118     winceMutexRelease(pFile->hMutex);
2119     osCloseHandle(pFile->hMutex);
2120     pFile->hMutex = NULL;
2121     return SQLITE_IOERR;
2122   }
2123 
2124   /* Initialize the shared memory if we're supposed to */
2125   if( bInit ){
2126     memset(pFile->shared, 0, sizeof(winceLock));
2127   }
2128 
2129   winceMutexRelease(pFile->hMutex);
2130   return SQLITE_OK;
2131 }
2132 
2133 /*
2134 ** Destroy the part of winFile that deals with wince locks
2135 */
2136 static void winceDestroyLock(winFile *pFile){
2137   if (pFile->hMutex){
2138     /* Acquire the mutex */
2139     winceMutexAcquire(pFile->hMutex);
2140 
2141     /* The following blocks should probably assert in debug mode, but they
2142        are to cleanup in case any locks remained open */
2143     if (pFile->local.nReaders){
2144       pFile->shared->nReaders --;
2145     }
2146     if (pFile->local.bReserved){
2147       pFile->shared->bReserved = FALSE;
2148     }
2149     if (pFile->local.bPending){
2150       pFile->shared->bPending = FALSE;
2151     }
2152     if (pFile->local.bExclusive){
2153       pFile->shared->bExclusive = FALSE;
2154     }
2155 
2156     /* De-reference and close our copy of the shared memory handle */
2157     osUnmapViewOfFile(pFile->shared);
2158     osCloseHandle(pFile->hShared);
2159 
2160     /* Done with the mutex */
2161     winceMutexRelease(pFile->hMutex);
2162     osCloseHandle(pFile->hMutex);
2163     pFile->hMutex = NULL;
2164   }
2165 }
2166 
2167 /*
2168 ** An implementation of the LockFile() API of Windows for CE
2169 */
2170 static BOOL winceLockFile(
2171   LPHANDLE phFile,
2172   DWORD dwFileOffsetLow,
2173   DWORD dwFileOffsetHigh,
2174   DWORD nNumberOfBytesToLockLow,
2175   DWORD nNumberOfBytesToLockHigh
2176 ){
2177   winFile *pFile = HANDLE_TO_WINFILE(phFile);
2178   BOOL bReturn = FALSE;
2179 
2180   UNUSED_PARAMETER(dwFileOffsetHigh);
2181   UNUSED_PARAMETER(nNumberOfBytesToLockHigh);
2182 
2183   if (!pFile->hMutex) return TRUE;
2184   winceMutexAcquire(pFile->hMutex);
2185 
2186   /* Wanting an exclusive lock? */
2187   if (dwFileOffsetLow == (DWORD)SHARED_FIRST
2188        && nNumberOfBytesToLockLow == (DWORD)SHARED_SIZE){
2189     if (pFile->shared->nReaders == 0 && pFile->shared->bExclusive == 0){
2190        pFile->shared->bExclusive = TRUE;
2191        pFile->local.bExclusive = TRUE;
2192        bReturn = TRUE;
2193     }
2194   }
2195 
2196   /* Want a read-only lock? */
2197   else if (dwFileOffsetLow == (DWORD)SHARED_FIRST &&
2198            nNumberOfBytesToLockLow == 1){
2199     if (pFile->shared->bExclusive == 0){
2200       pFile->local.nReaders ++;
2201       if (pFile->local.nReaders == 1){
2202         pFile->shared->nReaders ++;
2203       }
2204       bReturn = TRUE;
2205     }
2206   }
2207 
2208   /* Want a pending lock? */
2209   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
2210            && nNumberOfBytesToLockLow == 1){
2211     /* If no pending lock has been acquired, then acquire it */
2212     if (pFile->shared->bPending == 0) {
2213       pFile->shared->bPending = TRUE;
2214       pFile->local.bPending = TRUE;
2215       bReturn = TRUE;
2216     }
2217   }
2218 
2219   /* Want a reserved lock? */
2220   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
2221            && nNumberOfBytesToLockLow == 1){
2222     if (pFile->shared->bReserved == 0) {
2223       pFile->shared->bReserved = TRUE;
2224       pFile->local.bReserved = TRUE;
2225       bReturn = TRUE;
2226     }
2227   }
2228 
2229   winceMutexRelease(pFile->hMutex);
2230   return bReturn;
2231 }
2232 
2233 /*
2234 ** An implementation of the UnlockFile API of Windows for CE
2235 */
2236 static BOOL winceUnlockFile(
2237   LPHANDLE phFile,
2238   DWORD dwFileOffsetLow,
2239   DWORD dwFileOffsetHigh,
2240   DWORD nNumberOfBytesToUnlockLow,
2241   DWORD nNumberOfBytesToUnlockHigh
2242 ){
2243   winFile *pFile = HANDLE_TO_WINFILE(phFile);
2244   BOOL bReturn = FALSE;
2245 
2246   UNUSED_PARAMETER(dwFileOffsetHigh);
2247   UNUSED_PARAMETER(nNumberOfBytesToUnlockHigh);
2248 
2249   if (!pFile->hMutex) return TRUE;
2250   winceMutexAcquire(pFile->hMutex);
2251 
2252   /* Releasing a reader lock or an exclusive lock */
2253   if (dwFileOffsetLow == (DWORD)SHARED_FIRST){
2254     /* Did we have an exclusive lock? */
2255     if (pFile->local.bExclusive){
2256       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE);
2257       pFile->local.bExclusive = FALSE;
2258       pFile->shared->bExclusive = FALSE;
2259       bReturn = TRUE;
2260     }
2261 
2262     /* Did we just have a reader lock? */
2263     else if (pFile->local.nReaders){
2264       assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE
2265              || nNumberOfBytesToUnlockLow == 1);
2266       pFile->local.nReaders --;
2267       if (pFile->local.nReaders == 0)
2268       {
2269         pFile->shared->nReaders --;
2270       }
2271       bReturn = TRUE;
2272     }
2273   }
2274 
2275   /* Releasing a pending lock */
2276   else if (dwFileOffsetLow == (DWORD)PENDING_BYTE
2277            && nNumberOfBytesToUnlockLow == 1){
2278     if (pFile->local.bPending){
2279       pFile->local.bPending = FALSE;
2280       pFile->shared->bPending = FALSE;
2281       bReturn = TRUE;
2282     }
2283   }
2284   /* Releasing a reserved lock */
2285   else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE
2286            && nNumberOfBytesToUnlockLow == 1){
2287     if (pFile->local.bReserved) {
2288       pFile->local.bReserved = FALSE;
2289       pFile->shared->bReserved = FALSE;
2290       bReturn = TRUE;
2291     }
2292   }
2293 
2294   winceMutexRelease(pFile->hMutex);
2295   return bReturn;
2296 }
2297 /*
2298 ** End of the special code for wince
2299 *****************************************************************************/
2300 #endif /* SQLITE_OS_WINCE */
2301 
2302 /*
2303 ** Lock a file region.
2304 */
2305 static BOOL winLockFile(
2306   LPHANDLE phFile,
2307   DWORD flags,
2308   DWORD offsetLow,
2309   DWORD offsetHigh,
2310   DWORD numBytesLow,
2311   DWORD numBytesHigh
2312 ){
2313 #if SQLITE_OS_WINCE
2314   /*
2315   ** NOTE: Windows CE is handled differently here due its lack of the Win32
2316   **       API LockFile.
2317   */
2318   return winceLockFile(phFile, offsetLow, offsetHigh,
2319                        numBytesLow, numBytesHigh);
2320 #else
2321   if( osIsNT() ){
2322     OVERLAPPED ovlp;
2323     memset(&ovlp, 0, sizeof(OVERLAPPED));
2324     ovlp.Offset = offsetLow;
2325     ovlp.OffsetHigh = offsetHigh;
2326     return osLockFileEx(*phFile, flags, 0, numBytesLow, numBytesHigh, &ovlp);
2327   }else{
2328     return osLockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
2329                       numBytesHigh);
2330   }
2331 #endif
2332 }
2333 
2334 /*
2335 ** Unlock a file region.
2336  */
2337 static BOOL winUnlockFile(
2338   LPHANDLE phFile,
2339   DWORD offsetLow,
2340   DWORD offsetHigh,
2341   DWORD numBytesLow,
2342   DWORD numBytesHigh
2343 ){
2344 #if SQLITE_OS_WINCE
2345   /*
2346   ** NOTE: Windows CE is handled differently here due its lack of the Win32
2347   **       API UnlockFile.
2348   */
2349   return winceUnlockFile(phFile, offsetLow, offsetHigh,
2350                          numBytesLow, numBytesHigh);
2351 #else
2352   if( osIsNT() ){
2353     OVERLAPPED ovlp;
2354     memset(&ovlp, 0, sizeof(OVERLAPPED));
2355     ovlp.Offset = offsetLow;
2356     ovlp.OffsetHigh = offsetHigh;
2357     return osUnlockFileEx(*phFile, 0, numBytesLow, numBytesHigh, &ovlp);
2358   }else{
2359     return osUnlockFile(*phFile, offsetLow, offsetHigh, numBytesLow,
2360                         numBytesHigh);
2361   }
2362 #endif
2363 }
2364 
2365 /*****************************************************************************
2366 ** The next group of routines implement the I/O methods specified
2367 ** by the sqlite3_io_methods object.
2368 ******************************************************************************/
2369 
2370 /*
2371 ** Some Microsoft compilers lack this definition.
2372 */
2373 #ifndef INVALID_SET_FILE_POINTER
2374 # define INVALID_SET_FILE_POINTER ((DWORD)-1)
2375 #endif
2376 
2377 /*
2378 ** Move the current position of the file handle passed as the first
2379 ** argument to offset iOffset within the file. If successful, return 0.
2380 ** Otherwise, set pFile->lastErrno and return non-zero.
2381 */
2382 static int winSeekFile(winFile *pFile, sqlite3_int64 iOffset){
2383 #if !SQLITE_OS_WINRT
2384   LONG upperBits;                 /* Most sig. 32 bits of new offset */
2385   LONG lowerBits;                 /* Least sig. 32 bits of new offset */
2386   DWORD dwRet;                    /* Value returned by SetFilePointer() */
2387   DWORD lastErrno;                /* Value returned by GetLastError() */
2388 
2389   OSTRACE(("SEEK file=%p, offset=%lld\n", pFile->h, iOffset));
2390 
2391   upperBits = (LONG)((iOffset>>32) & 0x7fffffff);
2392   lowerBits = (LONG)(iOffset & 0xffffffff);
2393 
2394   /* API oddity: If successful, SetFilePointer() returns a dword
2395   ** containing the lower 32-bits of the new file-offset. Or, if it fails,
2396   ** it returns INVALID_SET_FILE_POINTER. However according to MSDN,
2397   ** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine
2398   ** whether an error has actually occurred, it is also necessary to call
2399   ** GetLastError().
2400   */
2401   dwRet = osSetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
2402 
2403   if( (dwRet==INVALID_SET_FILE_POINTER
2404       && ((lastErrno = osGetLastError())!=NO_ERROR)) ){
2405     pFile->lastErrno = lastErrno;
2406     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
2407                 "winSeekFile", pFile->zPath);
2408     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
2409     return 1;
2410   }
2411 
2412   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
2413   return 0;
2414 #else
2415   /*
2416   ** Same as above, except that this implementation works for WinRT.
2417   */
2418 
2419   LARGE_INTEGER x;                /* The new offset */
2420   BOOL bRet;                      /* Value returned by SetFilePointerEx() */
2421 
2422   x.QuadPart = iOffset;
2423   bRet = osSetFilePointerEx(pFile->h, x, 0, FILE_BEGIN);
2424 
2425   if(!bRet){
2426     pFile->lastErrno = osGetLastError();
2427     winLogError(SQLITE_IOERR_SEEK, pFile->lastErrno,
2428                 "winSeekFile", pFile->zPath);
2429     OSTRACE(("SEEK file=%p, rc=SQLITE_IOERR_SEEK\n", pFile->h));
2430     return 1;
2431   }
2432 
2433   OSTRACE(("SEEK file=%p, rc=SQLITE_OK\n", pFile->h));
2434   return 0;
2435 #endif
2436 }
2437 
2438 #if SQLITE_MAX_MMAP_SIZE>0
2439 /* Forward references to VFS helper methods used for memory mapped files */
2440 static int winMapfile(winFile*, sqlite3_int64);
2441 static int winUnmapfile(winFile*);
2442 #endif
2443 
2444 /*
2445 ** Close a file.
2446 **
2447 ** It is reported that an attempt to close a handle might sometimes
2448 ** fail.  This is a very unreasonable result, but Windows is notorious
2449 ** for being unreasonable so I do not doubt that it might happen.  If
2450 ** the close fails, we pause for 100 milliseconds and try again.  As
2451 ** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before
2452 ** giving up and returning an error.
2453 */
2454 #define MX_CLOSE_ATTEMPT 3
2455 static int winClose(sqlite3_file *id){
2456   int rc, cnt = 0;
2457   winFile *pFile = (winFile*)id;
2458 
2459   assert( id!=0 );
2460 #ifndef SQLITE_OMIT_WAL
2461   assert( pFile->pShm==0 );
2462 #endif
2463   assert( pFile->h!=NULL && pFile->h!=INVALID_HANDLE_VALUE );
2464   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p\n",
2465            osGetCurrentProcessId(), pFile, pFile->h));
2466 
2467 #if SQLITE_MAX_MMAP_SIZE>0
2468   winUnmapfile(pFile);
2469 #endif
2470 
2471   do{
2472     rc = osCloseHandle(pFile->h);
2473     /* SimulateIOError( rc=0; cnt=MX_CLOSE_ATTEMPT; ); */
2474   }while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (sqlite3_win32_sleep(100), 1) );
2475 #if SQLITE_OS_WINCE
2476 #define WINCE_DELETION_ATTEMPTS 3
2477   winceDestroyLock(pFile);
2478   if( pFile->zDeleteOnClose ){
2479     int cnt = 0;
2480     while(
2481            osDeleteFileW(pFile->zDeleteOnClose)==0
2482         && osGetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff
2483         && cnt++ < WINCE_DELETION_ATTEMPTS
2484     ){
2485        sqlite3_win32_sleep(100);  /* Wait a little before trying again */
2486     }
2487     sqlite3_free(pFile->zDeleteOnClose);
2488   }
2489 #endif
2490   if( rc ){
2491     pFile->h = NULL;
2492   }
2493   OpenCounter(-1);
2494   OSTRACE(("CLOSE pid=%lu, pFile=%p, file=%p, rc=%s\n",
2495            osGetCurrentProcessId(), pFile, pFile->h, rc ? "ok" : "failed"));
2496   return rc ? SQLITE_OK
2497             : winLogError(SQLITE_IOERR_CLOSE, osGetLastError(),
2498                           "winClose", pFile->zPath);
2499 }
2500 
2501 /*
2502 ** Read data from a file into a buffer.  Return SQLITE_OK if all
2503 ** bytes were read successfully and SQLITE_IOERR if anything goes
2504 ** wrong.
2505 */
2506 static int winRead(
2507   sqlite3_file *id,          /* File to read from */
2508   void *pBuf,                /* Write content into this buffer */
2509   int amt,                   /* Number of bytes to read */
2510   sqlite3_int64 offset       /* Begin reading at this offset */
2511 ){
2512 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2513   OVERLAPPED overlapped;          /* The offset for ReadFile. */
2514 #endif
2515   winFile *pFile = (winFile*)id;  /* file handle */
2516   DWORD nRead;                    /* Number of bytes actually read from file */
2517   int nRetry = 0;                 /* Number of retrys */
2518 
2519   assert( id!=0 );
2520   assert( amt>0 );
2521   assert( offset>=0 );
2522   SimulateIOError(return SQLITE_IOERR_READ);
2523   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
2524            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
2525            pFile->h, pBuf, amt, offset, pFile->locktype));
2526 
2527 #if SQLITE_MAX_MMAP_SIZE>0
2528   /* Deal with as much of this read request as possible by transfering
2529   ** data from the memory mapping using memcpy().  */
2530   if( offset<pFile->mmapSize ){
2531     if( offset+amt <= pFile->mmapSize ){
2532       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], amt);
2533       OSTRACE(("READ-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2534                osGetCurrentProcessId(), pFile, pFile->h));
2535       return SQLITE_OK;
2536     }else{
2537       int nCopy = (int)(pFile->mmapSize - offset);
2538       memcpy(pBuf, &((u8 *)(pFile->pMapRegion))[offset], nCopy);
2539       pBuf = &((u8 *)pBuf)[nCopy];
2540       amt -= nCopy;
2541       offset += nCopy;
2542     }
2543   }
2544 #endif
2545 
2546 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2547   if( winSeekFile(pFile, offset) ){
2548     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
2549              osGetCurrentProcessId(), pFile, pFile->h));
2550     return SQLITE_FULL;
2551   }
2552   while( !osReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
2553 #else
2554   memset(&overlapped, 0, sizeof(OVERLAPPED));
2555   overlapped.Offset = (LONG)(offset & 0xffffffff);
2556   overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2557   while( !osReadFile(pFile->h, pBuf, amt, &nRead, &overlapped) &&
2558          osGetLastError()!=ERROR_HANDLE_EOF ){
2559 #endif
2560     DWORD lastErrno;
2561     if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
2562     pFile->lastErrno = lastErrno;
2563     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_READ\n",
2564              osGetCurrentProcessId(), pFile, pFile->h));
2565     return winLogError(SQLITE_IOERR_READ, pFile->lastErrno,
2566                        "winRead", pFile->zPath);
2567   }
2568   winLogIoerr(nRetry, __LINE__);
2569   if( nRead<(DWORD)amt ){
2570     /* Unread parts of the buffer must be zero-filled */
2571     memset(&((char*)pBuf)[nRead], 0, amt-nRead);
2572     OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_SHORT_READ\n",
2573              osGetCurrentProcessId(), pFile, pFile->h));
2574     return SQLITE_IOERR_SHORT_READ;
2575   }
2576 
2577   OSTRACE(("READ pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2578            osGetCurrentProcessId(), pFile, pFile->h));
2579   return SQLITE_OK;
2580 }
2581 
2582 /*
2583 ** Write data from a buffer into a file.  Return SQLITE_OK on success
2584 ** or some other error code on failure.
2585 */
2586 static int winWrite(
2587   sqlite3_file *id,               /* File to write into */
2588   const void *pBuf,               /* The bytes to be written */
2589   int amt,                        /* Number of bytes to write */
2590   sqlite3_int64 offset            /* Offset into the file to begin writing at */
2591 ){
2592   int rc = 0;                     /* True if error has occurred, else false */
2593   winFile *pFile = (winFile*)id;  /* File handle */
2594   int nRetry = 0;                 /* Number of retries */
2595 
2596   assert( amt>0 );
2597   assert( pFile );
2598   SimulateIOError(return SQLITE_IOERR_WRITE);
2599   SimulateDiskfullError(return SQLITE_FULL);
2600 
2601   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, buffer=%p, amount=%d, "
2602            "offset=%lld, lock=%d\n", osGetCurrentProcessId(), pFile,
2603            pFile->h, pBuf, amt, offset, pFile->locktype));
2604 
2605 #if SQLITE_MAX_MMAP_SIZE>0
2606   /* Deal with as much of this write request as possible by transfering
2607   ** data from the memory mapping using memcpy().  */
2608   if( offset<pFile->mmapSize ){
2609     if( offset+amt <= pFile->mmapSize ){
2610       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, amt);
2611       OSTRACE(("WRITE-MMAP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2612                osGetCurrentProcessId(), pFile, pFile->h));
2613       return SQLITE_OK;
2614     }else{
2615       int nCopy = (int)(pFile->mmapSize - offset);
2616       memcpy(&((u8 *)(pFile->pMapRegion))[offset], pBuf, nCopy);
2617       pBuf = &((u8 *)pBuf)[nCopy];
2618       amt -= nCopy;
2619       offset += nCopy;
2620     }
2621   }
2622 #endif
2623 
2624 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2625   rc = winSeekFile(pFile, offset);
2626   if( rc==0 ){
2627 #else
2628   {
2629 #endif
2630 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2631     OVERLAPPED overlapped;        /* The offset for WriteFile. */
2632 #endif
2633     u8 *aRem = (u8 *)pBuf;        /* Data yet to be written */
2634     int nRem = amt;               /* Number of bytes yet to be written */
2635     DWORD nWrite;                 /* Bytes written by each WriteFile() call */
2636     DWORD lastErrno = NO_ERROR;   /* Value returned by GetLastError() */
2637 
2638 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2639     memset(&overlapped, 0, sizeof(OVERLAPPED));
2640     overlapped.Offset = (LONG)(offset & 0xffffffff);
2641     overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2642 #endif
2643 
2644     while( nRem>0 ){
2645 #if SQLITE_OS_WINCE || defined(SQLITE_WIN32_NO_OVERLAPPED)
2646       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, 0) ){
2647 #else
2648       if( !osWriteFile(pFile->h, aRem, nRem, &nWrite, &overlapped) ){
2649 #endif
2650         if( winRetryIoerr(&nRetry, &lastErrno) ) continue;
2651         break;
2652       }
2653       assert( nWrite==0 || nWrite<=(DWORD)nRem );
2654       if( nWrite==0 || nWrite>(DWORD)nRem ){
2655         lastErrno = osGetLastError();
2656         break;
2657       }
2658 #if !SQLITE_OS_WINCE && !defined(SQLITE_WIN32_NO_OVERLAPPED)
2659       offset += nWrite;
2660       overlapped.Offset = (LONG)(offset & 0xffffffff);
2661       overlapped.OffsetHigh = (LONG)((offset>>32) & 0x7fffffff);
2662 #endif
2663       aRem += nWrite;
2664       nRem -= nWrite;
2665     }
2666     if( nRem>0 ){
2667       pFile->lastErrno = lastErrno;
2668       rc = 1;
2669     }
2670   }
2671 
2672   if( rc ){
2673     if(   ( pFile->lastErrno==ERROR_HANDLE_DISK_FULL )
2674        || ( pFile->lastErrno==ERROR_DISK_FULL )){
2675       OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_FULL\n",
2676                osGetCurrentProcessId(), pFile, pFile->h));
2677       return winLogError(SQLITE_FULL, pFile->lastErrno,
2678                          "winWrite1", pFile->zPath);
2679     }
2680     OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_WRITE\n",
2681              osGetCurrentProcessId(), pFile, pFile->h));
2682     return winLogError(SQLITE_IOERR_WRITE, pFile->lastErrno,
2683                        "winWrite2", pFile->zPath);
2684   }else{
2685     winLogIoerr(nRetry, __LINE__);
2686   }
2687   OSTRACE(("WRITE pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2688            osGetCurrentProcessId(), pFile, pFile->h));
2689   return SQLITE_OK;
2690 }
2691 
2692 /*
2693 ** Truncate an open file to a specified size
2694 */
2695 static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
2696   winFile *pFile = (winFile*)id;  /* File handle object */
2697   int rc = SQLITE_OK;             /* Return code for this function */
2698   DWORD lastErrno;
2699 
2700   assert( pFile );
2701   SimulateIOError(return SQLITE_IOERR_TRUNCATE);
2702   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, size=%lld, lock=%d\n",
2703            osGetCurrentProcessId(), pFile, pFile->h, nByte, pFile->locktype));
2704 
2705   /* If the user has configured a chunk-size for this file, truncate the
2706   ** file so that it consists of an integer number of chunks (i.e. the
2707   ** actual file size after the operation may be larger than the requested
2708   ** size).
2709   */
2710   if( pFile->szChunk>0 ){
2711     nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
2712   }
2713 
2714   /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
2715   if( winSeekFile(pFile, nByte) ){
2716     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
2717                      "winTruncate1", pFile->zPath);
2718   }else if( 0==osSetEndOfFile(pFile->h) &&
2719             ((lastErrno = osGetLastError())!=ERROR_USER_MAPPED_FILE) ){
2720     pFile->lastErrno = lastErrno;
2721     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
2722                      "winTruncate2", pFile->zPath);
2723   }
2724 
2725 #if SQLITE_MAX_MMAP_SIZE>0
2726   /* If the file was truncated to a size smaller than the currently
2727   ** mapped region, reduce the effective mapping size as well. SQLite will
2728   ** use read() and write() to access data beyond this point from now on.
2729   */
2730   if( pFile->pMapRegion && nByte<pFile->mmapSize ){
2731     pFile->mmapSize = nByte;
2732   }
2733 #endif
2734 
2735   OSTRACE(("TRUNCATE pid=%lu, pFile=%p, file=%p, rc=%s\n",
2736            osGetCurrentProcessId(), pFile, pFile->h, sqlite3ErrName(rc)));
2737   return rc;
2738 }
2739 
2740 #ifdef SQLITE_TEST
2741 /*
2742 ** Count the number of fullsyncs and normal syncs.  This is used to test
2743 ** that syncs and fullsyncs are occuring at the right times.
2744 */
2745 int sqlite3_sync_count = 0;
2746 int sqlite3_fullsync_count = 0;
2747 #endif
2748 
2749 /*
2750 ** Make sure all writes to a particular file are committed to disk.
2751 */
2752 static int winSync(sqlite3_file *id, int flags){
2753 #ifndef SQLITE_NO_SYNC
2754   /*
2755   ** Used only when SQLITE_NO_SYNC is not defined.
2756    */
2757   BOOL rc;
2758 #endif
2759 #if !defined(NDEBUG) || !defined(SQLITE_NO_SYNC) || \
2760     defined(SQLITE_HAVE_OS_TRACE)
2761   /*
2762   ** Used when SQLITE_NO_SYNC is not defined and by the assert() and/or
2763   ** OSTRACE() macros.
2764    */
2765   winFile *pFile = (winFile*)id;
2766 #else
2767   UNUSED_PARAMETER(id);
2768 #endif
2769 
2770   assert( pFile );
2771   /* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */
2772   assert((flags&0x0F)==SQLITE_SYNC_NORMAL
2773       || (flags&0x0F)==SQLITE_SYNC_FULL
2774   );
2775 
2776   /* Unix cannot, but some systems may return SQLITE_FULL from here. This
2777   ** line is to test that doing so does not cause any problems.
2778   */
2779   SimulateDiskfullError( return SQLITE_FULL );
2780 
2781   OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, flags=%x, lock=%d\n",
2782            osGetCurrentProcessId(), pFile, pFile->h, flags,
2783            pFile->locktype));
2784 
2785 #ifndef SQLITE_TEST
2786   UNUSED_PARAMETER(flags);
2787 #else
2788   if( (flags&0x0F)==SQLITE_SYNC_FULL ){
2789     sqlite3_fullsync_count++;
2790   }
2791   sqlite3_sync_count++;
2792 #endif
2793 
2794   /* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
2795   ** no-op
2796   */
2797 #ifdef SQLITE_NO_SYNC
2798   OSTRACE(("SYNC-NOP pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2799            osGetCurrentProcessId(), pFile, pFile->h));
2800   return SQLITE_OK;
2801 #else
2802 #if SQLITE_MAX_MMAP_SIZE>0
2803   if( pFile->pMapRegion ){
2804     if( osFlushViewOfFile(pFile->pMapRegion, 0) ){
2805       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
2806                "rc=SQLITE_OK\n", osGetCurrentProcessId(),
2807                pFile, pFile->pMapRegion));
2808     }else{
2809       pFile->lastErrno = osGetLastError();
2810       OSTRACE(("SYNC-MMAP pid=%lu, pFile=%p, pMapRegion=%p, "
2811                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(),
2812                pFile, pFile->pMapRegion));
2813       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
2814                          "winSync1", pFile->zPath);
2815     }
2816   }
2817 #endif
2818   rc = osFlushFileBuffers(pFile->h);
2819   SimulateIOError( rc=FALSE );
2820   if( rc ){
2821     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_OK\n",
2822              osGetCurrentProcessId(), pFile, pFile->h));
2823     return SQLITE_OK;
2824   }else{
2825     pFile->lastErrno = osGetLastError();
2826     OSTRACE(("SYNC pid=%lu, pFile=%p, file=%p, rc=SQLITE_IOERR_FSYNC\n",
2827              osGetCurrentProcessId(), pFile, pFile->h));
2828     return winLogError(SQLITE_IOERR_FSYNC, pFile->lastErrno,
2829                        "winSync2", pFile->zPath);
2830   }
2831 #endif
2832 }
2833 
2834 /*
2835 ** Determine the current size of a file in bytes
2836 */
2837 static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
2838   winFile *pFile = (winFile*)id;
2839   int rc = SQLITE_OK;
2840 
2841   assert( id!=0 );
2842   assert( pSize!=0 );
2843   SimulateIOError(return SQLITE_IOERR_FSTAT);
2844   OSTRACE(("SIZE file=%p, pSize=%p\n", pFile->h, pSize));
2845 
2846 #if SQLITE_OS_WINRT
2847   {
2848     FILE_STANDARD_INFO info;
2849     if( osGetFileInformationByHandleEx(pFile->h, FileStandardInfo,
2850                                      &info, sizeof(info)) ){
2851       *pSize = info.EndOfFile.QuadPart;
2852     }else{
2853       pFile->lastErrno = osGetLastError();
2854       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
2855                        "winFileSize", pFile->zPath);
2856     }
2857   }
2858 #else
2859   {
2860     DWORD upperBits;
2861     DWORD lowerBits;
2862     DWORD lastErrno;
2863 
2864     lowerBits = osGetFileSize(pFile->h, &upperBits);
2865     *pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;
2866     if(   (lowerBits == INVALID_FILE_SIZE)
2867        && ((lastErrno = osGetLastError())!=NO_ERROR) ){
2868       pFile->lastErrno = lastErrno;
2869       rc = winLogError(SQLITE_IOERR_FSTAT, pFile->lastErrno,
2870                        "winFileSize", pFile->zPath);
2871     }
2872   }
2873 #endif
2874   OSTRACE(("SIZE file=%p, pSize=%p, *pSize=%lld, rc=%s\n",
2875            pFile->h, pSize, *pSize, sqlite3ErrName(rc)));
2876   return rc;
2877 }
2878 
2879 /*
2880 ** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.
2881 */
2882 #ifndef LOCKFILE_FAIL_IMMEDIATELY
2883 # define LOCKFILE_FAIL_IMMEDIATELY 1
2884 #endif
2885 
2886 #ifndef LOCKFILE_EXCLUSIVE_LOCK
2887 # define LOCKFILE_EXCLUSIVE_LOCK 2
2888 #endif
2889 
2890 /*
2891 ** Historically, SQLite has used both the LockFile and LockFileEx functions.
2892 ** When the LockFile function was used, it was always expected to fail
2893 ** immediately if the lock could not be obtained.  Also, it always expected to
2894 ** obtain an exclusive lock.  These flags are used with the LockFileEx function
2895 ** and reflect those expectations; therefore, they should not be changed.
2896 */
2897 #ifndef SQLITE_LOCKFILE_FLAGS
2898 # define SQLITE_LOCKFILE_FLAGS   (LOCKFILE_FAIL_IMMEDIATELY | \
2899                                   LOCKFILE_EXCLUSIVE_LOCK)
2900 #endif
2901 
2902 /*
2903 ** Currently, SQLite never calls the LockFileEx function without wanting the
2904 ** call to fail immediately if the lock cannot be obtained.
2905 */
2906 #ifndef SQLITE_LOCKFILEEX_FLAGS
2907 # define SQLITE_LOCKFILEEX_FLAGS (LOCKFILE_FAIL_IMMEDIATELY)
2908 #endif
2909 
2910 /*
2911 ** Acquire a reader lock.
2912 ** Different API routines are called depending on whether or not this
2913 ** is Win9x or WinNT.
2914 */
2915 static int winGetReadLock(winFile *pFile){
2916   int res;
2917   OSTRACE(("READ-LOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
2918   if( osIsNT() ){
2919 #if SQLITE_OS_WINCE
2920     /*
2921     ** NOTE: Windows CE is handled differently here due its lack of the Win32
2922     **       API LockFileEx.
2923     */
2924     res = winceLockFile(&pFile->h, SHARED_FIRST, 0, 1, 0);
2925 #else
2926     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS, SHARED_FIRST, 0,
2927                       SHARED_SIZE, 0);
2928 #endif
2929   }
2930 #ifdef SQLITE_WIN32_HAS_ANSI
2931   else{
2932     int lk;
2933     sqlite3_randomness(sizeof(lk), &lk);
2934     pFile->sharedLockByte = (short)((lk & 0x7fffffff)%(SHARED_SIZE - 1));
2935     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
2936                       SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
2937   }
2938 #endif
2939   if( res == 0 ){
2940     pFile->lastErrno = osGetLastError();
2941     /* No need to log a failure to lock */
2942   }
2943   OSTRACE(("READ-LOCK file=%p, result=%d\n", pFile->h, res));
2944   return res;
2945 }
2946 
2947 /*
2948 ** Undo a readlock
2949 */
2950 static int winUnlockReadLock(winFile *pFile){
2951   int res;
2952   DWORD lastErrno;
2953   OSTRACE(("READ-UNLOCK file=%p, lock=%d\n", pFile->h, pFile->locktype));
2954   if( osIsNT() ){
2955     res = winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
2956   }
2957 #ifdef SQLITE_WIN32_HAS_ANSI
2958   else{
2959     res = winUnlockFile(&pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
2960   }
2961 #endif
2962   if( res==0 && ((lastErrno = osGetLastError())!=ERROR_NOT_LOCKED) ){
2963     pFile->lastErrno = lastErrno;
2964     winLogError(SQLITE_IOERR_UNLOCK, pFile->lastErrno,
2965                 "winUnlockReadLock", pFile->zPath);
2966   }
2967   OSTRACE(("READ-UNLOCK file=%p, result=%d\n", pFile->h, res));
2968   return res;
2969 }
2970 
2971 /*
2972 ** Lock the file with the lock specified by parameter locktype - one
2973 ** of the following:
2974 **
2975 **     (1) SHARED_LOCK
2976 **     (2) RESERVED_LOCK
2977 **     (3) PENDING_LOCK
2978 **     (4) EXCLUSIVE_LOCK
2979 **
2980 ** Sometimes when requesting one lock state, additional lock states
2981 ** are inserted in between.  The locking might fail on one of the later
2982 ** transitions leaving the lock state different from what it started but
2983 ** still short of its goal.  The following chart shows the allowed
2984 ** transitions and the inserted intermediate states:
2985 **
2986 **    UNLOCKED -> SHARED
2987 **    SHARED -> RESERVED
2988 **    SHARED -> (PENDING) -> EXCLUSIVE
2989 **    RESERVED -> (PENDING) -> EXCLUSIVE
2990 **    PENDING -> EXCLUSIVE
2991 **
2992 ** This routine will only increase a lock.  The winUnlock() routine
2993 ** erases all locks at once and returns us immediately to locking level 0.
2994 ** It is not possible to lower the locking level one step at a time.  You
2995 ** must go straight to locking level 0.
2996 */
2997 static int winLock(sqlite3_file *id, int locktype){
2998   int rc = SQLITE_OK;    /* Return code from subroutines */
2999   int res = 1;           /* Result of a Windows lock call */
3000   int newLocktype;       /* Set pFile->locktype to this value before exiting */
3001   int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
3002   winFile *pFile = (winFile*)id;
3003   DWORD lastErrno = NO_ERROR;
3004 
3005   assert( id!=0 );
3006   OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",
3007            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
3008 
3009   /* If there is already a lock of this type or more restrictive on the
3010   ** OsFile, do nothing. Don't use the end_lock: exit path, as
3011   ** sqlite3OsEnterMutex() hasn't been called yet.
3012   */
3013   if( pFile->locktype>=locktype ){
3014     OSTRACE(("LOCK-HELD file=%p, rc=SQLITE_OK\n", pFile->h));
3015     return SQLITE_OK;
3016   }
3017 
3018   /* Do not allow any kind of write-lock on a read-only database
3019   */
3020   if( (pFile->ctrlFlags & WINFILE_RDONLY)!=0 && locktype>=RESERVED_LOCK ){
3021     return SQLITE_IOERR_LOCK;
3022   }
3023 
3024   /* Make sure the locking sequence is correct
3025   */
3026   assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
3027   assert( locktype!=PENDING_LOCK );
3028   assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
3029 
3030   /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
3031   ** a SHARED lock.  If we are acquiring a SHARED lock, the acquisition of
3032   ** the PENDING_LOCK byte is temporary.
3033   */
3034   newLocktype = pFile->locktype;
3035   if(   (pFile->locktype==NO_LOCK)
3036      || (   (locktype==EXCLUSIVE_LOCK)
3037          && (pFile->locktype==RESERVED_LOCK))
3038   ){
3039     int cnt = 3;
3040     while( cnt-->0 && (res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS,
3041                                          PENDING_BYTE, 0, 1, 0))==0 ){
3042       /* Try 3 times to get the pending lock.  This is needed to work
3043       ** around problems caused by indexing and/or anti-virus software on
3044       ** Windows systems.
3045       ** If you are using this code as a model for alternative VFSes, do not
3046       ** copy this retry logic.  It is a hack intended for Windows only.
3047       */
3048       lastErrno = osGetLastError();
3049       OSTRACE(("LOCK-PENDING-FAIL file=%p, count=%d, result=%d\n",
3050                pFile->h, cnt, res));
3051       if( lastErrno==ERROR_INVALID_HANDLE ){
3052         pFile->lastErrno = lastErrno;
3053         rc = SQLITE_IOERR_LOCK;
3054         OSTRACE(("LOCK-FAIL file=%p, count=%d, rc=%s\n",
3055                  pFile->h, cnt, sqlite3ErrName(rc)));
3056         return rc;
3057       }
3058       if( cnt ) sqlite3_win32_sleep(1);
3059     }
3060     gotPendingLock = res;
3061     if( !res ){
3062       lastErrno = osGetLastError();
3063     }
3064   }
3065 
3066   /* Acquire a shared lock
3067   */
3068   if( locktype==SHARED_LOCK && res ){
3069     assert( pFile->locktype==NO_LOCK );
3070     res = winGetReadLock(pFile);
3071     if( res ){
3072       newLocktype = SHARED_LOCK;
3073     }else{
3074       lastErrno = osGetLastError();
3075     }
3076   }
3077 
3078   /* Acquire a RESERVED lock
3079   */
3080   if( locktype==RESERVED_LOCK && res ){
3081     assert( pFile->locktype==SHARED_LOCK );
3082     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, RESERVED_BYTE, 0, 1, 0);
3083     if( res ){
3084       newLocktype = RESERVED_LOCK;
3085     }else{
3086       lastErrno = osGetLastError();
3087     }
3088   }
3089 
3090   /* Acquire a PENDING lock
3091   */
3092   if( locktype==EXCLUSIVE_LOCK && res ){
3093     newLocktype = PENDING_LOCK;
3094     gotPendingLock = 0;
3095   }
3096 
3097   /* Acquire an EXCLUSIVE lock
3098   */
3099   if( locktype==EXCLUSIVE_LOCK && res ){
3100     assert( pFile->locktype>=SHARED_LOCK );
3101     res = winUnlockReadLock(pFile);
3102     res = winLockFile(&pFile->h, SQLITE_LOCKFILE_FLAGS, SHARED_FIRST, 0,
3103                       SHARED_SIZE, 0);
3104     if( res ){
3105       newLocktype = EXCLUSIVE_LOCK;
3106     }else{
3107       lastErrno = osGetLastError();
3108       winGetReadLock(pFile);
3109     }
3110   }
3111 
3112   /* If we are holding a PENDING lock that ought to be released, then
3113   ** release it now.
3114   */
3115   if( gotPendingLock && locktype==SHARED_LOCK ){
3116     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
3117   }
3118 
3119   /* Update the state of the lock has held in the file descriptor then
3120   ** return the appropriate result code.
3121   */
3122   if( res ){
3123     rc = SQLITE_OK;
3124   }else{
3125     pFile->lastErrno = lastErrno;
3126     rc = SQLITE_BUSY;
3127     OSTRACE(("LOCK-FAIL file=%p, wanted=%d, got=%d\n",
3128              pFile->h, locktype, newLocktype));
3129   }
3130   pFile->locktype = (u8)newLocktype;
3131   OSTRACE(("LOCK file=%p, lock=%d, rc=%s\n",
3132            pFile->h, pFile->locktype, sqlite3ErrName(rc)));
3133   return rc;
3134 }
3135 
3136 /*
3137 ** This routine checks if there is a RESERVED lock held on the specified
3138 ** file by this or any other process. If such a lock is held, return
3139 ** non-zero, otherwise zero.
3140 */
3141 static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
3142   int res;
3143   winFile *pFile = (winFile*)id;
3144 
3145   SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
3146   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));
3147 
3148   assert( id!=0 );
3149   if( pFile->locktype>=RESERVED_LOCK ){
3150     res = 1;
3151     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (local)\n", pFile->h, res));
3152   }else{
3153     res = winLockFile(&pFile->h, SQLITE_LOCKFILEEX_FLAGS,RESERVED_BYTE, 0, 1, 0);
3154     if( res ){
3155       winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
3156     }
3157     res = !res;
3158     OSTRACE(("TEST-WR-LOCK file=%p, result=%d (remote)\n", pFile->h, res));
3159   }
3160   *pResOut = res;
3161   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
3162            pFile->h, pResOut, *pResOut));
3163   return SQLITE_OK;
3164 }
3165 
3166 /*
3167 ** Lower the locking level on file descriptor id to locktype.  locktype
3168 ** must be either NO_LOCK or SHARED_LOCK.
3169 **
3170 ** If the locking level of the file descriptor is already at or below
3171 ** the requested locking level, this routine is a no-op.
3172 **
3173 ** It is not possible for this routine to fail if the second argument
3174 ** is NO_LOCK.  If the second argument is SHARED_LOCK then this routine
3175 ** might return SQLITE_IOERR;
3176 */
3177 static int winUnlock(sqlite3_file *id, int locktype){
3178   int type;
3179   winFile *pFile = (winFile*)id;
3180   int rc = SQLITE_OK;
3181   assert( pFile!=0 );
3182   assert( locktype<=SHARED_LOCK );
3183   OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
3184            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
3185   type = pFile->locktype;
3186   if( type>=EXCLUSIVE_LOCK ){
3187     winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
3188     if( locktype==SHARED_LOCK && !winGetReadLock(pFile) ){
3189       /* This should never happen.  We should always be able to
3190       ** reacquire the read lock */
3191       rc = winLogError(SQLITE_IOERR_UNLOCK, osGetLastError(),
3192                        "winUnlock", pFile->zPath);
3193     }
3194   }
3195   if( type>=RESERVED_LOCK ){
3196     winUnlockFile(&pFile->h, RESERVED_BYTE, 0, 1, 0);
3197   }
3198   if( locktype==NO_LOCK && type>=SHARED_LOCK ){
3199     winUnlockReadLock(pFile);
3200   }
3201   if( type>=PENDING_LOCK ){
3202     winUnlockFile(&pFile->h, PENDING_BYTE, 0, 1, 0);
3203   }
3204   pFile->locktype = (u8)locktype;
3205   OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",
3206            pFile->h, pFile->locktype, sqlite3ErrName(rc)));
3207   return rc;
3208 }
3209 
3210 /*
3211 ** If *pArg is initially negative then this is a query.  Set *pArg to
3212 ** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
3213 **
3214 ** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.
3215 */
3216 static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){
3217   if( *pArg<0 ){
3218     *pArg = (pFile->ctrlFlags & mask)!=0;
3219   }else if( (*pArg)==0 ){
3220     pFile->ctrlFlags &= ~mask;
3221   }else{
3222     pFile->ctrlFlags |= mask;
3223   }
3224 }
3225 
3226 /* Forward references to VFS helper methods used for temporary files */
3227 static int winGetTempname(sqlite3_vfs *, char **);
3228 static int winIsDir(const void *);
3229 static BOOL winIsDriveLetterAndColon(const char *);
3230 
3231 /*
3232 ** Control and query of the open file handle.
3233 */
3234 static int winFileControl(sqlite3_file *id, int op, void *pArg){
3235   winFile *pFile = (winFile*)id;
3236   OSTRACE(("FCNTL file=%p, op=%d, pArg=%p\n", pFile->h, op, pArg));
3237   switch( op ){
3238     case SQLITE_FCNTL_LOCKSTATE: {
3239       *(int*)pArg = pFile->locktype;
3240       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3241       return SQLITE_OK;
3242     }
3243     case SQLITE_LAST_ERRNO: {
3244       *(int*)pArg = (int)pFile->lastErrno;
3245       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3246       return SQLITE_OK;
3247     }
3248     case SQLITE_FCNTL_CHUNK_SIZE: {
3249       pFile->szChunk = *(int *)pArg;
3250       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3251       return SQLITE_OK;
3252     }
3253     case SQLITE_FCNTL_SIZE_HINT: {
3254       if( pFile->szChunk>0 ){
3255         sqlite3_int64 oldSz;
3256         int rc = winFileSize(id, &oldSz);
3257         if( rc==SQLITE_OK ){
3258           sqlite3_int64 newSz = *(sqlite3_int64*)pArg;
3259           if( newSz>oldSz ){
3260             SimulateIOErrorBenign(1);
3261             rc = winTruncate(id, newSz);
3262             SimulateIOErrorBenign(0);
3263           }
3264         }
3265         OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3266         return rc;
3267       }
3268       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3269       return SQLITE_OK;
3270     }
3271     case SQLITE_FCNTL_PERSIST_WAL: {
3272       winModeBit(pFile, WINFILE_PERSIST_WAL, (int*)pArg);
3273       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3274       return SQLITE_OK;
3275     }
3276     case SQLITE_FCNTL_POWERSAFE_OVERWRITE: {
3277       winModeBit(pFile, WINFILE_PSOW, (int*)pArg);
3278       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3279       return SQLITE_OK;
3280     }
3281     case SQLITE_FCNTL_VFSNAME: {
3282       *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
3283       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3284       return SQLITE_OK;
3285     }
3286     case SQLITE_FCNTL_WIN32_AV_RETRY: {
3287       int *a = (int*)pArg;
3288       if( a[0]>0 ){
3289         winIoerrRetry = a[0];
3290       }else{
3291         a[0] = winIoerrRetry;
3292       }
3293       if( a[1]>0 ){
3294         winIoerrRetryDelay = a[1];
3295       }else{
3296         a[1] = winIoerrRetryDelay;
3297       }
3298       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
3299       return SQLITE_OK;
3300     }
3301 #ifdef SQLITE_TEST
3302     case SQLITE_FCNTL_WIN32_SET_HANDLE: {
3303       LPHANDLE phFile = (LPHANDLE)pArg;
3304       HANDLE hOldFile = pFile->h;
3305       pFile->h = *phFile;
3306       *phFile = hOldFile;
3307       OSTRACE(("FCNTL oldFile=%p, newFile=%p, rc=SQLITE_OK\n",
3308                hOldFile, pFile->h));
3309       return SQLITE_OK;
3310     }
3311 #endif
3312     case SQLITE_FCNTL_TEMPFILENAME: {
3313       char *zTFile = 0;
3314       int rc = winGetTempname(pFile->pVfs, &zTFile);
3315       if( rc==SQLITE_OK ){
3316         *(char**)pArg = zTFile;
3317       }
3318       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3319       return rc;
3320     }
3321 #if SQLITE_MAX_MMAP_SIZE>0
3322     case SQLITE_FCNTL_MMAP_SIZE: {
3323       i64 newLimit = *(i64*)pArg;
3324       int rc = SQLITE_OK;
3325       if( newLimit>sqlite3GlobalConfig.mxMmap ){
3326         newLimit = sqlite3GlobalConfig.mxMmap;
3327       }
3328       *(i64*)pArg = pFile->mmapSizeMax;
3329       if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
3330         pFile->mmapSizeMax = newLimit;
3331         if( pFile->mmapSize>0 ){
3332           winUnmapfile(pFile);
3333           rc = winMapfile(pFile, -1);
3334         }
3335       }
3336       OSTRACE(("FCNTL file=%p, rc=%s\n", pFile->h, sqlite3ErrName(rc)));
3337       return rc;
3338     }
3339 #endif
3340   }
3341   OSTRACE(("FCNTL file=%p, rc=SQLITE_NOTFOUND\n", pFile->h));
3342   return SQLITE_NOTFOUND;
3343 }
3344 
3345 /*
3346 ** Return the sector size in bytes of the underlying block device for
3347 ** the specified file. This is almost always 512 bytes, but may be
3348 ** larger for some devices.
3349 **
3350 ** SQLite code assumes this function cannot fail. It also assumes that
3351 ** if two files are created in the same file-system directory (i.e.
3352 ** a database and its journal file) that the sector size will be the
3353 ** same for both.
3354 */
3355 static int winSectorSize(sqlite3_file *id){
3356   (void)id;
3357   return SQLITE_DEFAULT_SECTOR_SIZE;
3358 }
3359 
3360 /*
3361 ** Return a vector of device characteristics.
3362 */
3363 static int winDeviceCharacteristics(sqlite3_file *id){
3364   winFile *p = (winFile*)id;
3365   return SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN |
3366          ((p->ctrlFlags & WINFILE_PSOW)?SQLITE_IOCAP_POWERSAFE_OVERWRITE:0);
3367 }
3368 
3369 /*
3370 ** Windows will only let you create file view mappings
3371 ** on allocation size granularity boundaries.
3372 ** During sqlite3_os_init() we do a GetSystemInfo()
3373 ** to get the granularity size.
3374 */
3375 static SYSTEM_INFO winSysInfo;
3376 
3377 #ifndef SQLITE_OMIT_WAL
3378 
3379 /*
3380 ** Helper functions to obtain and relinquish the global mutex. The
3381 ** global mutex is used to protect the winLockInfo objects used by
3382 ** this file, all of which may be shared by multiple threads.
3383 **
3384 ** Function winShmMutexHeld() is used to assert() that the global mutex
3385 ** is held when required. This function is only used as part of assert()
3386 ** statements. e.g.
3387 **
3388 **   winShmEnterMutex()
3389 **     assert( winShmMutexHeld() );
3390 **   winShmLeaveMutex()
3391 */
3392 static void winShmEnterMutex(void){
3393   sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
3394 }
3395 static void winShmLeaveMutex(void){
3396   sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
3397 }
3398 #ifndef NDEBUG
3399 static int winShmMutexHeld(void) {
3400   return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
3401 }
3402 #endif
3403 
3404 /*
3405 ** Object used to represent a single file opened and mmapped to provide
3406 ** shared memory.  When multiple threads all reference the same
3407 ** log-summary, each thread has its own winFile object, but they all
3408 ** point to a single instance of this object.  In other words, each
3409 ** log-summary is opened only once per process.
3410 **
3411 ** winShmMutexHeld() must be true when creating or destroying
3412 ** this object or while reading or writing the following fields:
3413 **
3414 **      nRef
3415 **      pNext
3416 **
3417 ** The following fields are read-only after the object is created:
3418 **
3419 **      fid
3420 **      zFilename
3421 **
3422 ** Either winShmNode.mutex must be held or winShmNode.nRef==0 and
3423 ** winShmMutexHeld() is true when reading or writing any other field
3424 ** in this structure.
3425 **
3426 */
3427 struct winShmNode {
3428   sqlite3_mutex *mutex;      /* Mutex to access this object */
3429   char *zFilename;           /* Name of the file */
3430   winFile hFile;             /* File handle from winOpen */
3431 
3432   int szRegion;              /* Size of shared-memory regions */
3433   int nRegion;               /* Size of array apRegion */
3434   struct ShmRegion {
3435     HANDLE hMap;             /* File handle from CreateFileMapping */
3436     void *pMap;
3437   } *aRegion;
3438   DWORD lastErrno;           /* The Windows errno from the last I/O error */
3439 
3440   int nRef;                  /* Number of winShm objects pointing to this */
3441   winShm *pFirst;            /* All winShm objects pointing to this */
3442   winShmNode *pNext;         /* Next in list of all winShmNode objects */
3443 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3444   u8 nextShmId;              /* Next available winShm.id value */
3445 #endif
3446 };
3447 
3448 /*
3449 ** A global array of all winShmNode objects.
3450 **
3451 ** The winShmMutexHeld() must be true while reading or writing this list.
3452 */
3453 static winShmNode *winShmNodeList = 0;
3454 
3455 /*
3456 ** Structure used internally by this VFS to record the state of an
3457 ** open shared memory connection.
3458 **
3459 ** The following fields are initialized when this object is created and
3460 ** are read-only thereafter:
3461 **
3462 **    winShm.pShmNode
3463 **    winShm.id
3464 **
3465 ** All other fields are read/write.  The winShm.pShmNode->mutex must be held
3466 ** while accessing any read/write fields.
3467 */
3468 struct winShm {
3469   winShmNode *pShmNode;      /* The underlying winShmNode object */
3470   winShm *pNext;             /* Next winShm with the same winShmNode */
3471   u8 hasMutex;               /* True if holding the winShmNode mutex */
3472   u16 sharedMask;            /* Mask of shared locks held */
3473   u16 exclMask;              /* Mask of exclusive locks held */
3474 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3475   u8 id;                     /* Id of this connection with its winShmNode */
3476 #endif
3477 };
3478 
3479 /*
3480 ** Constants used for locking
3481 */
3482 #define WIN_SHM_BASE   ((22+SQLITE_SHM_NLOCK)*4)        /* first lock byte */
3483 #define WIN_SHM_DMS    (WIN_SHM_BASE+SQLITE_SHM_NLOCK)  /* deadman switch */
3484 
3485 /*
3486 ** Apply advisory locks for all n bytes beginning at ofst.
3487 */
3488 #define _SHM_UNLCK  1
3489 #define _SHM_RDLCK  2
3490 #define _SHM_WRLCK  3
3491 static int winShmSystemLock(
3492   winShmNode *pFile,    /* Apply locks to this open shared-memory segment */
3493   int lockType,         /* _SHM_UNLCK, _SHM_RDLCK, or _SHM_WRLCK */
3494   int ofst,             /* Offset to first byte to be locked/unlocked */
3495   int nByte             /* Number of bytes to lock or unlock */
3496 ){
3497   int rc = 0;           /* Result code form Lock/UnlockFileEx() */
3498 
3499   /* Access to the winShmNode object is serialized by the caller */
3500   assert( sqlite3_mutex_held(pFile->mutex) || pFile->nRef==0 );
3501 
3502   OSTRACE(("SHM-LOCK file=%p, lock=%d, offset=%d, size=%d\n",
3503            pFile->hFile.h, lockType, ofst, nByte));
3504 
3505   /* Release/Acquire the system-level lock */
3506   if( lockType==_SHM_UNLCK ){
3507     rc = winUnlockFile(&pFile->hFile.h, ofst, 0, nByte, 0);
3508   }else{
3509     /* Initialize the locking parameters */
3510     DWORD dwFlags = LOCKFILE_FAIL_IMMEDIATELY;
3511     if( lockType == _SHM_WRLCK ) dwFlags |= LOCKFILE_EXCLUSIVE_LOCK;
3512     rc = winLockFile(&pFile->hFile.h, dwFlags, ofst, 0, nByte, 0);
3513   }
3514 
3515   if( rc!= 0 ){
3516     rc = SQLITE_OK;
3517   }else{
3518     pFile->lastErrno =  osGetLastError();
3519     rc = SQLITE_BUSY;
3520   }
3521 
3522   OSTRACE(("SHM-LOCK file=%p, func=%s, errno=%lu, rc=%s\n",
3523            pFile->hFile.h, (lockType == _SHM_UNLCK) ? "winUnlockFile" :
3524            "winLockFile", pFile->lastErrno, sqlite3ErrName(rc)));
3525 
3526   return rc;
3527 }
3528 
3529 /* Forward references to VFS methods */
3530 static int winOpen(sqlite3_vfs*,const char*,sqlite3_file*,int,int*);
3531 static int winDelete(sqlite3_vfs *,const char*,int);
3532 
3533 /*
3534 ** Purge the winShmNodeList list of all entries with winShmNode.nRef==0.
3535 **
3536 ** This is not a VFS shared-memory method; it is a utility function called
3537 ** by VFS shared-memory methods.
3538 */
3539 static void winShmPurge(sqlite3_vfs *pVfs, int deleteFlag){
3540   winShmNode **pp;
3541   winShmNode *p;
3542   assert( winShmMutexHeld() );
3543   OSTRACE(("SHM-PURGE pid=%lu, deleteFlag=%d\n",
3544            osGetCurrentProcessId(), deleteFlag));
3545   pp = &winShmNodeList;
3546   while( (p = *pp)!=0 ){
3547     if( p->nRef==0 ){
3548       int i;
3549       if( p->mutex ){ sqlite3_mutex_free(p->mutex); }
3550       for(i=0; i<p->nRegion; i++){
3551         BOOL bRc = osUnmapViewOfFile(p->aRegion[i].pMap);
3552         OSTRACE(("SHM-PURGE-UNMAP pid=%lu, region=%d, rc=%s\n",
3553                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
3554         UNUSED_VARIABLE_VALUE(bRc);
3555         bRc = osCloseHandle(p->aRegion[i].hMap);
3556         OSTRACE(("SHM-PURGE-CLOSE pid=%lu, region=%d, rc=%s\n",
3557                  osGetCurrentProcessId(), i, bRc ? "ok" : "failed"));
3558         UNUSED_VARIABLE_VALUE(bRc);
3559       }
3560       if( p->hFile.h!=NULL && p->hFile.h!=INVALID_HANDLE_VALUE ){
3561         SimulateIOErrorBenign(1);
3562         winClose((sqlite3_file *)&p->hFile);
3563         SimulateIOErrorBenign(0);
3564       }
3565       if( deleteFlag ){
3566         SimulateIOErrorBenign(1);
3567         sqlite3BeginBenignMalloc();
3568         winDelete(pVfs, p->zFilename, 0);
3569         sqlite3EndBenignMalloc();
3570         SimulateIOErrorBenign(0);
3571       }
3572       *pp = p->pNext;
3573       sqlite3_free(p->aRegion);
3574       sqlite3_free(p);
3575     }else{
3576       pp = &p->pNext;
3577     }
3578   }
3579 }
3580 
3581 /*
3582 ** Open the shared-memory area associated with database file pDbFd.
3583 **
3584 ** When opening a new shared-memory file, if no other instances of that
3585 ** file are currently open, in this process or in other processes, then
3586 ** the file must be truncated to zero length or have its header cleared.
3587 */
3588 static int winOpenSharedMemory(winFile *pDbFd){
3589   struct winShm *p;                  /* The connection to be opened */
3590   struct winShmNode *pShmNode = 0;   /* The underlying mmapped file */
3591   int rc;                            /* Result code */
3592   struct winShmNode *pNew;           /* Newly allocated winShmNode */
3593   int nName;                         /* Size of zName in bytes */
3594 
3595   assert( pDbFd->pShm==0 );    /* Not previously opened */
3596 
3597   /* Allocate space for the new sqlite3_shm object.  Also speculatively
3598   ** allocate space for a new winShmNode and filename.
3599   */
3600   p = sqlite3MallocZero( sizeof(*p) );
3601   if( p==0 ) return SQLITE_IOERR_NOMEM;
3602   nName = sqlite3Strlen30(pDbFd->zPath);
3603   pNew = sqlite3MallocZero( sizeof(*pShmNode) + nName + 17 );
3604   if( pNew==0 ){
3605     sqlite3_free(p);
3606     return SQLITE_IOERR_NOMEM;
3607   }
3608   pNew->zFilename = (char*)&pNew[1];
3609   sqlite3_snprintf(nName+15, pNew->zFilename, "%s-shm", pDbFd->zPath);
3610   sqlite3FileSuffix3(pDbFd->zPath, pNew->zFilename);
3611 
3612   /* Look to see if there is an existing winShmNode that can be used.
3613   ** If no matching winShmNode currently exists, create a new one.
3614   */
3615   winShmEnterMutex();
3616   for(pShmNode = winShmNodeList; pShmNode; pShmNode=pShmNode->pNext){
3617     /* TBD need to come up with better match here.  Perhaps
3618     ** use FILE_ID_BOTH_DIR_INFO Structure.
3619     */
3620     if( sqlite3StrICmp(pShmNode->zFilename, pNew->zFilename)==0 ) break;
3621   }
3622   if( pShmNode ){
3623     sqlite3_free(pNew);
3624   }else{
3625     pShmNode = pNew;
3626     pNew = 0;
3627     ((winFile*)(&pShmNode->hFile))->h = INVALID_HANDLE_VALUE;
3628     pShmNode->pNext = winShmNodeList;
3629     winShmNodeList = pShmNode;
3630 
3631     pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
3632     if( pShmNode->mutex==0 ){
3633       rc = SQLITE_IOERR_NOMEM;
3634       goto shm_open_err;
3635     }
3636 
3637     rc = winOpen(pDbFd->pVfs,
3638                  pShmNode->zFilename,             /* Name of the file (UTF-8) */
3639                  (sqlite3_file*)&pShmNode->hFile,  /* File handle here */
3640                  SQLITE_OPEN_WAL | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
3641                  0);
3642     if( SQLITE_OK!=rc ){
3643       goto shm_open_err;
3644     }
3645 
3646     /* Check to see if another process is holding the dead-man switch.
3647     ** If not, truncate the file to zero length.
3648     */
3649     if( winShmSystemLock(pShmNode, _SHM_WRLCK, WIN_SHM_DMS, 1)==SQLITE_OK ){
3650       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, 0);
3651       if( rc!=SQLITE_OK ){
3652         rc = winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),
3653                          "winOpenShm", pDbFd->zPath);
3654       }
3655     }
3656     if( rc==SQLITE_OK ){
3657       winShmSystemLock(pShmNode, _SHM_UNLCK, WIN_SHM_DMS, 1);
3658       rc = winShmSystemLock(pShmNode, _SHM_RDLCK, WIN_SHM_DMS, 1);
3659     }
3660     if( rc ) goto shm_open_err;
3661   }
3662 
3663   /* Make the new connection a child of the winShmNode */
3664   p->pShmNode = pShmNode;
3665 #if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
3666   p->id = pShmNode->nextShmId++;
3667 #endif
3668   pShmNode->nRef++;
3669   pDbFd->pShm = p;
3670   winShmLeaveMutex();
3671 
3672   /* The reference count on pShmNode has already been incremented under
3673   ** the cover of the winShmEnterMutex() mutex and the pointer from the
3674   ** new (struct winShm) object to the pShmNode has been set. All that is
3675   ** left to do is to link the new object into the linked list starting
3676   ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex
3677   ** mutex.
3678   */
3679   sqlite3_mutex_enter(pShmNode->mutex);
3680   p->pNext = pShmNode->pFirst;
3681   pShmNode->pFirst = p;
3682   sqlite3_mutex_leave(pShmNode->mutex);
3683   return SQLITE_OK;
3684 
3685   /* Jump here on any error */
3686 shm_open_err:
3687   winShmSystemLock(pShmNode, _SHM_UNLCK, WIN_SHM_DMS, 1);
3688   winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */
3689   sqlite3_free(p);
3690   sqlite3_free(pNew);
3691   winShmLeaveMutex();
3692   return rc;
3693 }
3694 
3695 /*
3696 ** Close a connection to shared-memory.  Delete the underlying
3697 ** storage if deleteFlag is true.
3698 */
3699 static int winShmUnmap(
3700   sqlite3_file *fd,          /* Database holding shared memory */
3701   int deleteFlag             /* Delete after closing if true */
3702 ){
3703   winFile *pDbFd;       /* Database holding shared-memory */
3704   winShm *p;            /* The connection to be closed */
3705   winShmNode *pShmNode; /* The underlying shared-memory file */
3706   winShm **pp;          /* For looping over sibling connections */
3707 
3708   pDbFd = (winFile*)fd;
3709   p = pDbFd->pShm;
3710   if( p==0 ) return SQLITE_OK;
3711   pShmNode = p->pShmNode;
3712 
3713   /* Remove connection p from the set of connections associated
3714   ** with pShmNode */
3715   sqlite3_mutex_enter(pShmNode->mutex);
3716   for(pp=&pShmNode->pFirst; (*pp)!=p; pp = &(*pp)->pNext){}
3717   *pp = p->pNext;
3718 
3719   /* Free the connection p */
3720   sqlite3_free(p);
3721   pDbFd->pShm = 0;
3722   sqlite3_mutex_leave(pShmNode->mutex);
3723 
3724   /* If pShmNode->nRef has reached 0, then close the underlying
3725   ** shared-memory file, too */
3726   winShmEnterMutex();
3727   assert( pShmNode->nRef>0 );
3728   pShmNode->nRef--;
3729   if( pShmNode->nRef==0 ){
3730     winShmPurge(pDbFd->pVfs, deleteFlag);
3731   }
3732   winShmLeaveMutex();
3733 
3734   return SQLITE_OK;
3735 }
3736 
3737 /*
3738 ** Change the lock state for a shared-memory segment.
3739 */
3740 static int winShmLock(
3741   sqlite3_file *fd,          /* Database file holding the shared memory */
3742   int ofst,                  /* First lock to acquire or release */
3743   int n,                     /* Number of locks to acquire or release */
3744   int flags                  /* What to do with the lock */
3745 ){
3746   winFile *pDbFd = (winFile*)fd;        /* Connection holding shared memory */
3747   winShm *p = pDbFd->pShm;              /* The shared memory being locked */
3748   winShm *pX;                           /* For looping over all siblings */
3749   winShmNode *pShmNode = p->pShmNode;
3750   int rc = SQLITE_OK;                   /* Result code */
3751   u16 mask;                             /* Mask of locks to take or release */
3752 
3753   assert( ofst>=0 && ofst+n<=SQLITE_SHM_NLOCK );
3754   assert( n>=1 );
3755   assert( flags==(SQLITE_SHM_LOCK | SQLITE_SHM_SHARED)
3756        || flags==(SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE)
3757        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED)
3758        || flags==(SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE) );
3759   assert( n==1 || (flags & SQLITE_SHM_EXCLUSIVE)!=0 );
3760 
3761   mask = (u16)((1U<<(ofst+n)) - (1U<<ofst));
3762   assert( n>1 || mask==(1<<ofst) );
3763   sqlite3_mutex_enter(pShmNode->mutex);
3764   if( flags & SQLITE_SHM_UNLOCK ){
3765     u16 allMask = 0; /* Mask of locks held by siblings */
3766 
3767     /* See if any siblings hold this same lock */
3768     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
3769       if( pX==p ) continue;
3770       assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );
3771       allMask |= pX->sharedMask;
3772     }
3773 
3774     /* Unlock the system-level locks */
3775     if( (mask & allMask)==0 ){
3776       rc = winShmSystemLock(pShmNode, _SHM_UNLCK, ofst+WIN_SHM_BASE, n);
3777     }else{
3778       rc = SQLITE_OK;
3779     }
3780 
3781     /* Undo the local locks */
3782     if( rc==SQLITE_OK ){
3783       p->exclMask &= ~mask;
3784       p->sharedMask &= ~mask;
3785     }
3786   }else if( flags & SQLITE_SHM_SHARED ){
3787     u16 allShared = 0;  /* Union of locks held by connections other than "p" */
3788 
3789     /* Find out which shared locks are already held by sibling connections.
3790     ** If any sibling already holds an exclusive lock, go ahead and return
3791     ** SQLITE_BUSY.
3792     */
3793     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
3794       if( (pX->exclMask & mask)!=0 ){
3795         rc = SQLITE_BUSY;
3796         break;
3797       }
3798       allShared |= pX->sharedMask;
3799     }
3800 
3801     /* Get shared locks at the system level, if necessary */
3802     if( rc==SQLITE_OK ){
3803       if( (allShared & mask)==0 ){
3804         rc = winShmSystemLock(pShmNode, _SHM_RDLCK, ofst+WIN_SHM_BASE, n);
3805       }else{
3806         rc = SQLITE_OK;
3807       }
3808     }
3809 
3810     /* Get the local shared locks */
3811     if( rc==SQLITE_OK ){
3812       p->sharedMask |= mask;
3813     }
3814   }else{
3815     /* Make sure no sibling connections hold locks that will block this
3816     ** lock.  If any do, return SQLITE_BUSY right away.
3817     */
3818     for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
3819       if( (pX->exclMask & mask)!=0 || (pX->sharedMask & mask)!=0 ){
3820         rc = SQLITE_BUSY;
3821         break;
3822       }
3823     }
3824 
3825     /* Get the exclusive locks at the system level.  Then if successful
3826     ** also mark the local connection as being locked.
3827     */
3828     if( rc==SQLITE_OK ){
3829       rc = winShmSystemLock(pShmNode, _SHM_WRLCK, ofst+WIN_SHM_BASE, n);
3830       if( rc==SQLITE_OK ){
3831         assert( (p->sharedMask & mask)==0 );
3832         p->exclMask |= mask;
3833       }
3834     }
3835   }
3836   sqlite3_mutex_leave(pShmNode->mutex);
3837   OSTRACE(("SHM-LOCK pid=%lu, id=%d, sharedMask=%03x, exclMask=%03x, rc=%s\n",
3838            osGetCurrentProcessId(), p->id, p->sharedMask, p->exclMask,
3839            sqlite3ErrName(rc)));
3840   return rc;
3841 }
3842 
3843 /*
3844 ** Implement a memory barrier or memory fence on shared memory.
3845 **
3846 ** All loads and stores begun before the barrier must complete before
3847 ** any load or store begun after the barrier.
3848 */
3849 static void winShmBarrier(
3850   sqlite3_file *fd          /* Database holding the shared memory */
3851 ){
3852   UNUSED_PARAMETER(fd);
3853   /* MemoryBarrier(); // does not work -- do not know why not */
3854   winShmEnterMutex();
3855   winShmLeaveMutex();
3856 }
3857 
3858 /*
3859 ** This function is called to obtain a pointer to region iRegion of the
3860 ** shared-memory associated with the database file fd. Shared-memory regions
3861 ** are numbered starting from zero. Each shared-memory region is szRegion
3862 ** bytes in size.
3863 **
3864 ** If an error occurs, an error code is returned and *pp is set to NULL.
3865 **
3866 ** Otherwise, if the isWrite parameter is 0 and the requested shared-memory
3867 ** region has not been allocated (by any client, including one running in a
3868 ** separate process), then *pp is set to NULL and SQLITE_OK returned. If
3869 ** isWrite is non-zero and the requested shared-memory region has not yet
3870 ** been allocated, it is allocated by this function.
3871 **
3872 ** If the shared-memory region has already been allocated or is allocated by
3873 ** this call as described above, then it is mapped into this processes
3874 ** address space (if it is not already), *pp is set to point to the mapped
3875 ** memory and SQLITE_OK returned.
3876 */
3877 static int winShmMap(
3878   sqlite3_file *fd,               /* Handle open on database file */
3879   int iRegion,                    /* Region to retrieve */
3880   int szRegion,                   /* Size of regions */
3881   int isWrite,                    /* True to extend file if necessary */
3882   void volatile **pp              /* OUT: Mapped memory */
3883 ){
3884   winFile *pDbFd = (winFile*)fd;
3885   winShm *pShm = pDbFd->pShm;
3886   winShmNode *pShmNode;
3887   int rc = SQLITE_OK;
3888 
3889   if( !pShm ){
3890     rc = winOpenSharedMemory(pDbFd);
3891     if( rc!=SQLITE_OK ) return rc;
3892     pShm = pDbFd->pShm;
3893   }
3894   pShmNode = pShm->pShmNode;
3895 
3896   sqlite3_mutex_enter(pShmNode->mutex);
3897   assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
3898 
3899   if( pShmNode->nRegion<=iRegion ){
3900     struct ShmRegion *apNew;           /* New aRegion[] array */
3901     int nByte = (iRegion+1)*szRegion;  /* Minimum required file size */
3902     sqlite3_int64 sz;                  /* Current size of wal-index file */
3903 
3904     pShmNode->szRegion = szRegion;
3905 
3906     /* The requested region is not mapped into this processes address space.
3907     ** Check to see if it has been allocated (i.e. if the wal-index file is
3908     ** large enough to contain the requested region).
3909     */
3910     rc = winFileSize((sqlite3_file *)&pShmNode->hFile, &sz);
3911     if( rc!=SQLITE_OK ){
3912       rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
3913                        "winShmMap1", pDbFd->zPath);
3914       goto shmpage_out;
3915     }
3916 
3917     if( sz<nByte ){
3918       /* The requested memory region does not exist. If isWrite is set to
3919       ** zero, exit early. *pp will be set to NULL and SQLITE_OK returned.
3920       **
3921       ** Alternatively, if isWrite is non-zero, use ftruncate() to allocate
3922       ** the requested memory region.
3923       */
3924       if( !isWrite ) goto shmpage_out;
3925       rc = winTruncate((sqlite3_file *)&pShmNode->hFile, nByte);
3926       if( rc!=SQLITE_OK ){
3927         rc = winLogError(SQLITE_IOERR_SHMSIZE, osGetLastError(),
3928                          "winShmMap2", pDbFd->zPath);
3929         goto shmpage_out;
3930       }
3931     }
3932 
3933     /* Map the requested memory region into this processes address space. */
3934     apNew = (struct ShmRegion *)sqlite3_realloc64(
3935         pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])
3936     );
3937     if( !apNew ){
3938       rc = SQLITE_IOERR_NOMEM;
3939       goto shmpage_out;
3940     }
3941     pShmNode->aRegion = apNew;
3942 
3943     while( pShmNode->nRegion<=iRegion ){
3944       HANDLE hMap = NULL;         /* file-mapping handle */
3945       void *pMap = 0;             /* Mapped memory region */
3946 
3947 #if SQLITE_OS_WINRT
3948       hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,
3949           NULL, PAGE_READWRITE, nByte, NULL
3950       );
3951 #elif defined(SQLITE_WIN32_HAS_WIDE)
3952       hMap = osCreateFileMappingW(pShmNode->hFile.h,
3953           NULL, PAGE_READWRITE, 0, nByte, NULL
3954       );
3955 #elif defined(SQLITE_WIN32_HAS_ANSI)
3956       hMap = osCreateFileMappingA(pShmNode->hFile.h,
3957           NULL, PAGE_READWRITE, 0, nByte, NULL
3958       );
3959 #endif
3960       OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
3961                osGetCurrentProcessId(), pShmNode->nRegion, nByte,
3962                hMap ? "ok" : "failed"));
3963       if( hMap ){
3964         int iOffset = pShmNode->nRegion*szRegion;
3965         int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
3966 #if SQLITE_OS_WINRT
3967         pMap = osMapViewOfFileFromApp(hMap, FILE_MAP_WRITE | FILE_MAP_READ,
3968             iOffset - iOffsetShift, szRegion + iOffsetShift
3969         );
3970 #else
3971         pMap = osMapViewOfFile(hMap, FILE_MAP_WRITE | FILE_MAP_READ,
3972             0, iOffset - iOffsetShift, szRegion + iOffsetShift
3973         );
3974 #endif
3975         OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",
3976                  osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
3977                  szRegion, pMap ? "ok" : "failed"));
3978       }
3979       if( !pMap ){
3980         pShmNode->lastErrno = osGetLastError();
3981         rc = winLogError(SQLITE_IOERR_SHMMAP, pShmNode->lastErrno,
3982                          "winShmMap3", pDbFd->zPath);
3983         if( hMap ) osCloseHandle(hMap);
3984         goto shmpage_out;
3985       }
3986 
3987       pShmNode->aRegion[pShmNode->nRegion].pMap = pMap;
3988       pShmNode->aRegion[pShmNode->nRegion].hMap = hMap;
3989       pShmNode->nRegion++;
3990     }
3991   }
3992 
3993 shmpage_out:
3994   if( pShmNode->nRegion>iRegion ){
3995     int iOffset = iRegion*szRegion;
3996     int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
3997     char *p = (char *)pShmNode->aRegion[iRegion].pMap;
3998     *pp = (void *)&p[iOffsetShift];
3999   }else{
4000     *pp = 0;
4001   }
4002   sqlite3_mutex_leave(pShmNode->mutex);
4003   return rc;
4004 }
4005 
4006 #else
4007 # define winShmMap     0
4008 # define winShmLock    0
4009 # define winShmBarrier 0
4010 # define winShmUnmap   0
4011 #endif /* #ifndef SQLITE_OMIT_WAL */
4012 
4013 /*
4014 ** Cleans up the mapped region of the specified file, if any.
4015 */
4016 #if SQLITE_MAX_MMAP_SIZE>0
4017 static int winUnmapfile(winFile *pFile){
4018   assert( pFile!=0 );
4019   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, pMapRegion=%p, "
4020            "mmapSize=%lld, mmapSizeActual=%lld, mmapSizeMax=%lld\n",
4021            osGetCurrentProcessId(), pFile, pFile->hMap, pFile->pMapRegion,
4022            pFile->mmapSize, pFile->mmapSizeActual, pFile->mmapSizeMax));
4023   if( pFile->pMapRegion ){
4024     if( !osUnmapViewOfFile(pFile->pMapRegion) ){
4025       pFile->lastErrno = osGetLastError();
4026       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, pMapRegion=%p, "
4027                "rc=SQLITE_IOERR_MMAP\n", osGetCurrentProcessId(), pFile,
4028                pFile->pMapRegion));
4029       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
4030                          "winUnmapfile1", pFile->zPath);
4031     }
4032     pFile->pMapRegion = 0;
4033     pFile->mmapSize = 0;
4034     pFile->mmapSizeActual = 0;
4035   }
4036   if( pFile->hMap!=NULL ){
4037     if( !osCloseHandle(pFile->hMap) ){
4038       pFile->lastErrno = osGetLastError();
4039       OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, hMap=%p, rc=SQLITE_IOERR_MMAP\n",
4040                osGetCurrentProcessId(), pFile, pFile->hMap));
4041       return winLogError(SQLITE_IOERR_MMAP, pFile->lastErrno,
4042                          "winUnmapfile2", pFile->zPath);
4043     }
4044     pFile->hMap = NULL;
4045   }
4046   OSTRACE(("UNMAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4047            osGetCurrentProcessId(), pFile));
4048   return SQLITE_OK;
4049 }
4050 
4051 /*
4052 ** Memory map or remap the file opened by file-descriptor pFd (if the file
4053 ** is already mapped, the existing mapping is replaced by the new). Or, if
4054 ** there already exists a mapping for this file, and there are still
4055 ** outstanding xFetch() references to it, this function is a no-op.
4056 **
4057 ** If parameter nByte is non-negative, then it is the requested size of
4058 ** the mapping to create. Otherwise, if nByte is less than zero, then the
4059 ** requested size is the size of the file on disk. The actual size of the
4060 ** created mapping is either the requested size or the value configured
4061 ** using SQLITE_FCNTL_MMAP_SIZE, whichever is smaller.
4062 **
4063 ** SQLITE_OK is returned if no error occurs (even if the mapping is not
4064 ** recreated as a result of outstanding references) or an SQLite error
4065 ** code otherwise.
4066 */
4067 static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
4068   sqlite3_int64 nMap = nByte;
4069   int rc;
4070 
4071   assert( nMap>=0 || pFd->nFetchOut==0 );
4072   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, size=%lld\n",
4073            osGetCurrentProcessId(), pFd, nByte));
4074 
4075   if( pFd->nFetchOut>0 ) return SQLITE_OK;
4076 
4077   if( nMap<0 ){
4078     rc = winFileSize((sqlite3_file*)pFd, &nMap);
4079     if( rc ){
4080       OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_IOERR_FSTAT\n",
4081                osGetCurrentProcessId(), pFd));
4082       return SQLITE_IOERR_FSTAT;
4083     }
4084   }
4085   if( nMap>pFd->mmapSizeMax ){
4086     nMap = pFd->mmapSizeMax;
4087   }
4088   nMap &= ~(sqlite3_int64)(winSysInfo.dwPageSize - 1);
4089 
4090   if( nMap==0 && pFd->mmapSize>0 ){
4091     winUnmapfile(pFd);
4092   }
4093   if( nMap!=pFd->mmapSize ){
4094     void *pNew = 0;
4095     DWORD protect = PAGE_READONLY;
4096     DWORD flags = FILE_MAP_READ;
4097 
4098     winUnmapfile(pFd);
4099     if( (pFd->ctrlFlags & WINFILE_RDONLY)==0 ){
4100       protect = PAGE_READWRITE;
4101       flags |= FILE_MAP_WRITE;
4102     }
4103 #if SQLITE_OS_WINRT
4104     pFd->hMap = osCreateFileMappingFromApp(pFd->h, NULL, protect, nMap, NULL);
4105 #elif defined(SQLITE_WIN32_HAS_WIDE)
4106     pFd->hMap = osCreateFileMappingW(pFd->h, NULL, protect,
4107                                 (DWORD)((nMap>>32) & 0xffffffff),
4108                                 (DWORD)(nMap & 0xffffffff), NULL);
4109 #elif defined(SQLITE_WIN32_HAS_ANSI)
4110     pFd->hMap = osCreateFileMappingA(pFd->h, NULL, protect,
4111                                 (DWORD)((nMap>>32) & 0xffffffff),
4112                                 (DWORD)(nMap & 0xffffffff), NULL);
4113 #endif
4114     if( pFd->hMap==NULL ){
4115       pFd->lastErrno = osGetLastError();
4116       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
4117                        "winMapfile1", pFd->zPath);
4118       /* Log the error, but continue normal operation using xRead/xWrite */
4119       OSTRACE(("MAP-FILE-CREATE pid=%lu, pFile=%p, rc=%s\n",
4120                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4121       return SQLITE_OK;
4122     }
4123     assert( (nMap % winSysInfo.dwPageSize)==0 );
4124     assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );
4125 #if SQLITE_OS_WINRT
4126     pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, (SIZE_T)nMap);
4127 #else
4128     pNew = osMapViewOfFile(pFd->hMap, flags, 0, 0, (SIZE_T)nMap);
4129 #endif
4130     if( pNew==NULL ){
4131       osCloseHandle(pFd->hMap);
4132       pFd->hMap = NULL;
4133       pFd->lastErrno = osGetLastError();
4134       rc = winLogError(SQLITE_IOERR_MMAP, pFd->lastErrno,
4135                        "winMapfile2", pFd->zPath);
4136       /* Log the error, but continue normal operation using xRead/xWrite */
4137       OSTRACE(("MAP-FILE-MAP pid=%lu, pFile=%p, rc=%s\n",
4138                osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4139       return SQLITE_OK;
4140     }
4141     pFd->pMapRegion = pNew;
4142     pFd->mmapSize = nMap;
4143     pFd->mmapSizeActual = nMap;
4144   }
4145 
4146   OSTRACE(("MAP-FILE pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4147            osGetCurrentProcessId(), pFd));
4148   return SQLITE_OK;
4149 }
4150 #endif /* SQLITE_MAX_MMAP_SIZE>0 */
4151 
4152 /*
4153 ** If possible, return a pointer to a mapping of file fd starting at offset
4154 ** iOff. The mapping must be valid for at least nAmt bytes.
4155 **
4156 ** If such a pointer can be obtained, store it in *pp and return SQLITE_OK.
4157 ** Or, if one cannot but no error occurs, set *pp to 0 and return SQLITE_OK.
4158 ** Finally, if an error does occur, return an SQLite error code. The final
4159 ** value of *pp is undefined in this case.
4160 **
4161 ** If this function does return a pointer, the caller must eventually
4162 ** release the reference by calling winUnfetch().
4163 */
4164 static int winFetch(sqlite3_file *fd, i64 iOff, int nAmt, void **pp){
4165 #if SQLITE_MAX_MMAP_SIZE>0
4166   winFile *pFd = (winFile*)fd;   /* The underlying database file */
4167 #endif
4168   *pp = 0;
4169 
4170   OSTRACE(("FETCH pid=%lu, pFile=%p, offset=%lld, amount=%d, pp=%p\n",
4171            osGetCurrentProcessId(), fd, iOff, nAmt, pp));
4172 
4173 #if SQLITE_MAX_MMAP_SIZE>0
4174   if( pFd->mmapSizeMax>0 ){
4175     if( pFd->pMapRegion==0 ){
4176       int rc = winMapfile(pFd, -1);
4177       if( rc!=SQLITE_OK ){
4178         OSTRACE(("FETCH pid=%lu, pFile=%p, rc=%s\n",
4179                  osGetCurrentProcessId(), pFd, sqlite3ErrName(rc)));
4180         return rc;
4181       }
4182     }
4183     if( pFd->mmapSize >= iOff+nAmt ){
4184       *pp = &((u8 *)pFd->pMapRegion)[iOff];
4185       pFd->nFetchOut++;
4186     }
4187   }
4188 #endif
4189 
4190   OSTRACE(("FETCH pid=%lu, pFile=%p, pp=%p, *pp=%p, rc=SQLITE_OK\n",
4191            osGetCurrentProcessId(), fd, pp, *pp));
4192   return SQLITE_OK;
4193 }
4194 
4195 /*
4196 ** If the third argument is non-NULL, then this function releases a
4197 ** reference obtained by an earlier call to winFetch(). The second
4198 ** argument passed to this function must be the same as the corresponding
4199 ** argument that was passed to the winFetch() invocation.
4200 **
4201 ** Or, if the third argument is NULL, then this function is being called
4202 ** to inform the VFS layer that, according to POSIX, any existing mapping
4203 ** may now be invalid and should be unmapped.
4204 */
4205 static int winUnfetch(sqlite3_file *fd, i64 iOff, void *p){
4206 #if SQLITE_MAX_MMAP_SIZE>0
4207   winFile *pFd = (winFile*)fd;   /* The underlying database file */
4208 
4209   /* If p==0 (unmap the entire file) then there must be no outstanding
4210   ** xFetch references. Or, if p!=0 (meaning it is an xFetch reference),
4211   ** then there must be at least one outstanding.  */
4212   assert( (p==0)==(pFd->nFetchOut==0) );
4213 
4214   /* If p!=0, it must match the iOff value. */
4215   assert( p==0 || p==&((u8 *)pFd->pMapRegion)[iOff] );
4216 
4217   OSTRACE(("UNFETCH pid=%lu, pFile=%p, offset=%lld, p=%p\n",
4218            osGetCurrentProcessId(), pFd, iOff, p));
4219 
4220   if( p ){
4221     pFd->nFetchOut--;
4222   }else{
4223     /* FIXME:  If Windows truly always prevents truncating or deleting a
4224     ** file while a mapping is held, then the following winUnmapfile() call
4225     ** is unnecessary can be omitted - potentially improving
4226     ** performance.  */
4227     winUnmapfile(pFd);
4228   }
4229 
4230   assert( pFd->nFetchOut>=0 );
4231 #endif
4232 
4233   OSTRACE(("UNFETCH pid=%lu, pFile=%p, rc=SQLITE_OK\n",
4234            osGetCurrentProcessId(), fd));
4235   return SQLITE_OK;
4236 }
4237 
4238 /*
4239 ** Here ends the implementation of all sqlite3_file methods.
4240 **
4241 ********************** End sqlite3_file Methods *******************************
4242 ******************************************************************************/
4243 
4244 /*
4245 ** This vector defines all the methods that can operate on an
4246 ** sqlite3_file for win32.
4247 */
4248 static const sqlite3_io_methods winIoMethod = {
4249   3,                              /* iVersion */
4250   winClose,                       /* xClose */
4251   winRead,                        /* xRead */
4252   winWrite,                       /* xWrite */
4253   winTruncate,                    /* xTruncate */
4254   winSync,                        /* xSync */
4255   winFileSize,                    /* xFileSize */
4256   winLock,                        /* xLock */
4257   winUnlock,                      /* xUnlock */
4258   winCheckReservedLock,           /* xCheckReservedLock */
4259   winFileControl,                 /* xFileControl */
4260   winSectorSize,                  /* xSectorSize */
4261   winDeviceCharacteristics,       /* xDeviceCharacteristics */
4262   winShmMap,                      /* xShmMap */
4263   winShmLock,                     /* xShmLock */
4264   winShmBarrier,                  /* xShmBarrier */
4265   winShmUnmap,                    /* xShmUnmap */
4266   winFetch,                       /* xFetch */
4267   winUnfetch                      /* xUnfetch */
4268 };
4269 
4270 /****************************************************************************
4271 **************************** sqlite3_vfs methods ****************************
4272 **
4273 ** This division contains the implementation of methods on the
4274 ** sqlite3_vfs object.
4275 */
4276 
4277 #if defined(__CYGWIN__)
4278 /*
4279 ** Convert a filename from whatever the underlying operating system
4280 ** supports for filenames into UTF-8.  Space to hold the result is
4281 ** obtained from malloc and must be freed by the calling function.
4282 */
4283 static char *winConvertToUtf8Filename(const void *zFilename){
4284   char *zConverted = 0;
4285   if( osIsNT() ){
4286     zConverted = winUnicodeToUtf8(zFilename);
4287   }
4288 #ifdef SQLITE_WIN32_HAS_ANSI
4289   else{
4290     zConverted = sqlite3_win32_mbcs_to_utf8(zFilename);
4291   }
4292 #endif
4293   /* caller will handle out of memory */
4294   return zConverted;
4295 }
4296 #endif
4297 
4298 /*
4299 ** Convert a UTF-8 filename into whatever form the underlying
4300 ** operating system wants filenames in.  Space to hold the result
4301 ** is obtained from malloc and must be freed by the calling
4302 ** function.
4303 */
4304 static void *winConvertFromUtf8Filename(const char *zFilename){
4305   void *zConverted = 0;
4306   if( osIsNT() ){
4307     zConverted = winUtf8ToUnicode(zFilename);
4308   }
4309 #ifdef SQLITE_WIN32_HAS_ANSI
4310   else{
4311     zConverted = sqlite3_win32_utf8_to_mbcs(zFilename);
4312   }
4313 #endif
4314   /* caller will handle out of memory */
4315   return zConverted;
4316 }
4317 
4318 /*
4319 ** This function returns non-zero if the specified UTF-8 string buffer
4320 ** ends with a directory separator character or one was successfully
4321 ** added to it.
4322 */
4323 static int winMakeEndInDirSep(int nBuf, char *zBuf){
4324   if( zBuf ){
4325     int nLen = sqlite3Strlen30(zBuf);
4326     if( nLen>0 ){
4327       if( winIsDirSep(zBuf[nLen-1]) ){
4328         return 1;
4329       }else if( nLen+1<nBuf ){
4330         zBuf[nLen] = winGetDirSep();
4331         zBuf[nLen+1] = '\0';
4332         return 1;
4333       }
4334     }
4335   }
4336   return 0;
4337 }
4338 
4339 /*
4340 ** Create a temporary file name and store the resulting pointer into pzBuf.
4341 ** The pointer returned in pzBuf must be freed via sqlite3_free().
4342 */
4343 static int winGetTempname(sqlite3_vfs *pVfs, char **pzBuf){
4344   static char zChars[] =
4345     "abcdefghijklmnopqrstuvwxyz"
4346     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
4347     "0123456789";
4348   size_t i, j;
4349   int nPre = sqlite3Strlen30(SQLITE_TEMP_FILE_PREFIX);
4350   int nMax, nBuf, nDir, nLen;
4351   char *zBuf;
4352 
4353   /* It's odd to simulate an io-error here, but really this is just
4354   ** using the io-error infrastructure to test that SQLite handles this
4355   ** function failing.
4356   */
4357   SimulateIOError( return SQLITE_IOERR );
4358 
4359   /* Allocate a temporary buffer to store the fully qualified file
4360   ** name for the temporary file.  If this fails, we cannot continue.
4361   */
4362   nMax = pVfs->mxPathname; nBuf = nMax + 2;
4363   zBuf = sqlite3MallocZero( nBuf );
4364   if( !zBuf ){
4365     OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4366     return SQLITE_IOERR_NOMEM;
4367   }
4368 
4369   /* Figure out the effective temporary directory.  First, check if one
4370   ** has been explicitly set by the application; otherwise, use the one
4371   ** configured by the operating system.
4372   */
4373   nDir = nMax - (nPre + 15);
4374   assert( nDir>0 );
4375   if( sqlite3_temp_directory ){
4376     int nDirLen = sqlite3Strlen30(sqlite3_temp_directory);
4377     if( nDirLen>0 ){
4378       if( !winIsDirSep(sqlite3_temp_directory[nDirLen-1]) ){
4379         nDirLen++;
4380       }
4381       if( nDirLen>nDir ){
4382         sqlite3_free(zBuf);
4383         OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4384         return winLogError(SQLITE_ERROR, 0, "winGetTempname1", 0);
4385       }
4386       sqlite3_snprintf(nMax, zBuf, "%s", sqlite3_temp_directory);
4387     }
4388   }
4389 #if defined(__CYGWIN__)
4390   else{
4391     static const char *azDirs[] = {
4392        0, /* getenv("SQLITE_TMPDIR") */
4393        0, /* getenv("TMPDIR") */
4394        0, /* getenv("TMP") */
4395        0, /* getenv("TEMP") */
4396        0, /* getenv("USERPROFILE") */
4397        "/var/tmp",
4398        "/usr/tmp",
4399        "/tmp",
4400        ".",
4401        0        /* List terminator */
4402     };
4403     unsigned int i;
4404     const char *zDir = 0;
4405 
4406     if( !azDirs[0] ) azDirs[0] = getenv("SQLITE_TMPDIR");
4407     if( !azDirs[1] ) azDirs[1] = getenv("TMPDIR");
4408     if( !azDirs[2] ) azDirs[2] = getenv("TMP");
4409     if( !azDirs[3] ) azDirs[3] = getenv("TEMP");
4410     if( !azDirs[4] ) azDirs[4] = getenv("USERPROFILE");
4411     for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); zDir=azDirs[i++]){
4412       void *zConverted;
4413       if( zDir==0 ) continue;
4414       /* If the path starts with a drive letter followed by the colon
4415       ** character, assume it is already a native Win32 path; otherwise,
4416       ** it must be converted to a native Win32 path via the Cygwin API
4417       ** prior to using it.
4418       */
4419       if( winIsDriveLetterAndColon(zDir) ){
4420         zConverted = winConvertFromUtf8Filename(zDir);
4421         if( !zConverted ){
4422           sqlite3_free(zBuf);
4423           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4424           return SQLITE_IOERR_NOMEM;
4425         }
4426         if( winIsDir(zConverted) ){
4427           sqlite3_snprintf(nMax, zBuf, "%s", zDir);
4428           sqlite3_free(zConverted);
4429           break;
4430         }
4431         sqlite3_free(zConverted);
4432       }else{
4433         zConverted = sqlite3MallocZero( nMax+1 );
4434         if( !zConverted ){
4435           sqlite3_free(zBuf);
4436           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4437           return SQLITE_IOERR_NOMEM;
4438         }
4439         if( cygwin_conv_path(
4440                 osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A, zDir,
4441                 zConverted, nMax+1)<0 ){
4442           sqlite3_free(zConverted);
4443           sqlite3_free(zBuf);
4444           OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_CONVPATH\n"));
4445           return winLogError(SQLITE_IOERR_CONVPATH, (DWORD)errno,
4446                              "winGetTempname2", zDir);
4447         }
4448         if( winIsDir(zConverted) ){
4449           /* At this point, we know the candidate directory exists and should
4450           ** be used.  However, we may need to convert the string containing
4451           ** its name into UTF-8 (i.e. if it is UTF-16 right now).
4452           */
4453           char *zUtf8 = winConvertToUtf8Filename(zConverted);
4454           if( !zUtf8 ){
4455             sqlite3_free(zConverted);
4456             sqlite3_free(zBuf);
4457             OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4458             return SQLITE_IOERR_NOMEM;
4459           }
4460           sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
4461           sqlite3_free(zUtf8);
4462           sqlite3_free(zConverted);
4463           break;
4464         }
4465         sqlite3_free(zConverted);
4466       }
4467     }
4468   }
4469 #elif !SQLITE_OS_WINRT && !defined(__CYGWIN__)
4470   else if( osIsNT() ){
4471     char *zMulti;
4472     LPWSTR zWidePath = sqlite3MallocZero( nMax*sizeof(WCHAR) );
4473     if( !zWidePath ){
4474       sqlite3_free(zBuf);
4475       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4476       return SQLITE_IOERR_NOMEM;
4477     }
4478     if( osGetTempPathW(nMax, zWidePath)==0 ){
4479       sqlite3_free(zWidePath);
4480       sqlite3_free(zBuf);
4481       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
4482       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
4483                          "winGetTempname2", 0);
4484     }
4485     zMulti = winUnicodeToUtf8(zWidePath);
4486     if( zMulti ){
4487       sqlite3_snprintf(nMax, zBuf, "%s", zMulti);
4488       sqlite3_free(zMulti);
4489       sqlite3_free(zWidePath);
4490     }else{
4491       sqlite3_free(zWidePath);
4492       sqlite3_free(zBuf);
4493       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4494       return SQLITE_IOERR_NOMEM;
4495     }
4496   }
4497 #ifdef SQLITE_WIN32_HAS_ANSI
4498   else{
4499     char *zUtf8;
4500     char *zMbcsPath = sqlite3MallocZero( nMax );
4501     if( !zMbcsPath ){
4502       sqlite3_free(zBuf);
4503       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4504       return SQLITE_IOERR_NOMEM;
4505     }
4506     if( osGetTempPathA(nMax, zMbcsPath)==0 ){
4507       sqlite3_free(zBuf);
4508       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
4509       return winLogError(SQLITE_IOERR_GETTEMPPATH, osGetLastError(),
4510                          "winGetTempname3", 0);
4511     }
4512     zUtf8 = sqlite3_win32_mbcs_to_utf8(zMbcsPath);
4513     if( zUtf8 ){
4514       sqlite3_snprintf(nMax, zBuf, "%s", zUtf8);
4515       sqlite3_free(zUtf8);
4516     }else{
4517       sqlite3_free(zBuf);
4518       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
4519       return SQLITE_IOERR_NOMEM;
4520     }
4521   }
4522 #endif /* SQLITE_WIN32_HAS_ANSI */
4523 #endif /* !SQLITE_OS_WINRT */
4524 
4525   /*
4526   ** Check to make sure the temporary directory ends with an appropriate
4527   ** separator.  If it does not and there is not enough space left to add
4528   ** one, fail.
4529   */
4530   if( !winMakeEndInDirSep(nDir+1, zBuf) ){
4531     sqlite3_free(zBuf);
4532     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4533     return winLogError(SQLITE_ERROR, 0, "winGetTempname4", 0);
4534   }
4535 
4536   /*
4537   ** Check that the output buffer is large enough for the temporary file
4538   ** name in the following format:
4539   **
4540   **   "<temporary_directory>/etilqs_XXXXXXXXXXXXXXX\0\0"
4541   **
4542   ** If not, return SQLITE_ERROR.  The number 17 is used here in order to
4543   ** account for the space used by the 15 character random suffix and the
4544   ** two trailing NUL characters.  The final directory separator character
4545   ** has already added if it was not already present.
4546   */
4547   nLen = sqlite3Strlen30(zBuf);
4548   if( (nLen + nPre + 17) > nBuf ){
4549     sqlite3_free(zBuf);
4550     OSTRACE(("TEMP-FILENAME rc=SQLITE_ERROR\n"));
4551     return winLogError(SQLITE_ERROR, 0, "winGetTempname5", 0);
4552   }
4553 
4554   sqlite3_snprintf(nBuf-16-nLen, zBuf+nLen, SQLITE_TEMP_FILE_PREFIX);
4555 
4556   j = sqlite3Strlen30(zBuf);
4557   sqlite3_randomness(15, &zBuf[j]);
4558   for(i=0; i<15; i++, j++){
4559     zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
4560   }
4561   zBuf[j] = 0;
4562   zBuf[j+1] = 0;
4563   *pzBuf = zBuf;
4564 
4565   OSTRACE(("TEMP-FILENAME name=%s, rc=SQLITE_OK\n", zBuf));
4566   return SQLITE_OK;
4567 }
4568 
4569 /*
4570 ** Return TRUE if the named file is really a directory.  Return false if
4571 ** it is something other than a directory, or if there is any kind of memory
4572 ** allocation failure.
4573 */
4574 static int winIsDir(const void *zConverted){
4575   DWORD attr;
4576   int rc = 0;
4577   DWORD lastErrno;
4578 
4579   if( osIsNT() ){
4580     int cnt = 0;
4581     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
4582     memset(&sAttrData, 0, sizeof(sAttrData));
4583     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
4584                              GetFileExInfoStandard,
4585                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
4586     if( !rc ){
4587       return 0; /* Invalid name? */
4588     }
4589     attr = sAttrData.dwFileAttributes;
4590 #if SQLITE_OS_WINCE==0
4591   }else{
4592     attr = osGetFileAttributesA((char*)zConverted);
4593 #endif
4594   }
4595   return (attr!=INVALID_FILE_ATTRIBUTES) && (attr&FILE_ATTRIBUTE_DIRECTORY);
4596 }
4597 
4598 /*
4599 ** Open a file.
4600 */
4601 static int winOpen(
4602   sqlite3_vfs *pVfs,        /* Used to get maximum path name length */
4603   const char *zName,        /* Name of the file (UTF-8) */
4604   sqlite3_file *id,         /* Write the SQLite file handle here */
4605   int flags,                /* Open mode flags */
4606   int *pOutFlags            /* Status return flags */
4607 ){
4608   HANDLE h;
4609   DWORD lastErrno = 0;
4610   DWORD dwDesiredAccess;
4611   DWORD dwShareMode;
4612   DWORD dwCreationDisposition;
4613   DWORD dwFlagsAndAttributes = 0;
4614 #if SQLITE_OS_WINCE
4615   int isTemp = 0;
4616 #endif
4617   winFile *pFile = (winFile*)id;
4618   void *zConverted;              /* Filename in OS encoding */
4619   const char *zUtf8Name = zName; /* Filename in UTF-8 encoding */
4620   int cnt = 0;
4621 
4622   /* If argument zPath is a NULL pointer, this function is required to open
4623   ** a temporary file. Use this buffer to store the file name in.
4624   */
4625   char *zTmpname = 0; /* For temporary filename, if necessary. */
4626 
4627   int rc = SQLITE_OK;            /* Function Return Code */
4628 #if !defined(NDEBUG) || SQLITE_OS_WINCE
4629   int eType = flags&0xFFFFFF00;  /* Type of file to open */
4630 #endif
4631 
4632   int isExclusive  = (flags & SQLITE_OPEN_EXCLUSIVE);
4633   int isDelete     = (flags & SQLITE_OPEN_DELETEONCLOSE);
4634   int isCreate     = (flags & SQLITE_OPEN_CREATE);
4635   int isReadonly   = (flags & SQLITE_OPEN_READONLY);
4636   int isReadWrite  = (flags & SQLITE_OPEN_READWRITE);
4637 
4638 #ifndef NDEBUG
4639   int isOpenJournal = (isCreate && (
4640         eType==SQLITE_OPEN_MASTER_JOURNAL
4641      || eType==SQLITE_OPEN_MAIN_JOURNAL
4642      || eType==SQLITE_OPEN_WAL
4643   ));
4644 #endif
4645 
4646   OSTRACE(("OPEN name=%s, pFile=%p, flags=%x, pOutFlags=%p\n",
4647            zUtf8Name, id, flags, pOutFlags));
4648 
4649   /* Check the following statements are true:
4650   **
4651   **   (a) Exactly one of the READWRITE and READONLY flags must be set, and
4652   **   (b) if CREATE is set, then READWRITE must also be set, and
4653   **   (c) if EXCLUSIVE is set, then CREATE must also be set.
4654   **   (d) if DELETEONCLOSE is set, then CREATE must also be set.
4655   */
4656   assert((isReadonly==0 || isReadWrite==0) && (isReadWrite || isReadonly));
4657   assert(isCreate==0 || isReadWrite);
4658   assert(isExclusive==0 || isCreate);
4659   assert(isDelete==0 || isCreate);
4660 
4661   /* The main DB, main journal, WAL file and master journal are never
4662   ** automatically deleted. Nor are they ever temporary files.  */
4663   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_DB );
4664   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MAIN_JOURNAL );
4665   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_MASTER_JOURNAL );
4666   assert( (!isDelete && zName) || eType!=SQLITE_OPEN_WAL );
4667 
4668   /* Assert that the upper layer has set one of the "file-type" flags. */
4669   assert( eType==SQLITE_OPEN_MAIN_DB      || eType==SQLITE_OPEN_TEMP_DB
4670        || eType==SQLITE_OPEN_MAIN_JOURNAL || eType==SQLITE_OPEN_TEMP_JOURNAL
4671        || eType==SQLITE_OPEN_SUBJOURNAL   || eType==SQLITE_OPEN_MASTER_JOURNAL
4672        || eType==SQLITE_OPEN_TRANSIENT_DB || eType==SQLITE_OPEN_WAL
4673   );
4674 
4675   assert( pFile!=0 );
4676   memset(pFile, 0, sizeof(winFile));
4677   pFile->h = INVALID_HANDLE_VALUE;
4678 
4679 #if SQLITE_OS_WINRT
4680   if( !zUtf8Name && !sqlite3_temp_directory ){
4681     sqlite3_log(SQLITE_ERROR,
4682         "sqlite3_temp_directory variable should be set for WinRT");
4683   }
4684 #endif
4685 
4686   /* If the second argument to this function is NULL, generate a
4687   ** temporary file name to use
4688   */
4689   if( !zUtf8Name ){
4690     assert( isDelete && !isOpenJournal );
4691     rc = winGetTempname(pVfs, &zTmpname);
4692     if( rc!=SQLITE_OK ){
4693       OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));
4694       return rc;
4695     }
4696     zUtf8Name = zTmpname;
4697   }
4698 
4699   /* Database filenames are double-zero terminated if they are not
4700   ** URIs with parameters.  Hence, they can always be passed into
4701   ** sqlite3_uri_parameter().
4702   */
4703   assert( (eType!=SQLITE_OPEN_MAIN_DB) || (flags & SQLITE_OPEN_URI) ||
4704        zUtf8Name[sqlite3Strlen30(zUtf8Name)+1]==0 );
4705 
4706   /* Convert the filename to the system encoding. */
4707   zConverted = winConvertFromUtf8Filename(zUtf8Name);
4708   if( zConverted==0 ){
4709     sqlite3_free(zTmpname);
4710     OSTRACE(("OPEN name=%s, rc=SQLITE_IOERR_NOMEM", zUtf8Name));
4711     return SQLITE_IOERR_NOMEM;
4712   }
4713 
4714   if( winIsDir(zConverted) ){
4715     sqlite3_free(zConverted);
4716     sqlite3_free(zTmpname);
4717     OSTRACE(("OPEN name=%s, rc=SQLITE_CANTOPEN_ISDIR", zUtf8Name));
4718     return SQLITE_CANTOPEN_ISDIR;
4719   }
4720 
4721   if( isReadWrite ){
4722     dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
4723   }else{
4724     dwDesiredAccess = GENERIC_READ;
4725   }
4726 
4727   /* SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is
4728   ** created. SQLite doesn't use it to indicate "exclusive access"
4729   ** as it is usually understood.
4730   */
4731   if( isExclusive ){
4732     /* Creates a new file, only if it does not already exist. */
4733     /* If the file exists, it fails. */
4734     dwCreationDisposition = CREATE_NEW;
4735   }else if( isCreate ){
4736     /* Open existing file, or create if it doesn't exist */
4737     dwCreationDisposition = OPEN_ALWAYS;
4738   }else{
4739     /* Opens a file, only if it exists. */
4740     dwCreationDisposition = OPEN_EXISTING;
4741   }
4742 
4743   dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
4744 
4745   if( isDelete ){
4746 #if SQLITE_OS_WINCE
4747     dwFlagsAndAttributes = FILE_ATTRIBUTE_HIDDEN;
4748     isTemp = 1;
4749 #else
4750     dwFlagsAndAttributes = FILE_ATTRIBUTE_TEMPORARY
4751                                | FILE_ATTRIBUTE_HIDDEN
4752                                | FILE_FLAG_DELETE_ON_CLOSE;
4753 #endif
4754   }else{
4755     dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
4756   }
4757   /* Reports from the internet are that performance is always
4758   ** better if FILE_FLAG_RANDOM_ACCESS is used.  Ticket #2699. */
4759 #if SQLITE_OS_WINCE
4760   dwFlagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;
4761 #endif
4762 
4763   if( osIsNT() ){
4764 #if SQLITE_OS_WINRT
4765     CREATEFILE2_EXTENDED_PARAMETERS extendedParameters;
4766     extendedParameters.dwSize = sizeof(CREATEFILE2_EXTENDED_PARAMETERS);
4767     extendedParameters.dwFileAttributes =
4768             dwFlagsAndAttributes & FILE_ATTRIBUTE_MASK;
4769     extendedParameters.dwFileFlags = dwFlagsAndAttributes & FILE_FLAG_MASK;
4770     extendedParameters.dwSecurityQosFlags = SECURITY_ANONYMOUS;
4771     extendedParameters.lpSecurityAttributes = NULL;
4772     extendedParameters.hTemplateFile = NULL;
4773     while( (h = osCreateFile2((LPCWSTR)zConverted,
4774                               dwDesiredAccess,
4775                               dwShareMode,
4776                               dwCreationDisposition,
4777                               &extendedParameters))==INVALID_HANDLE_VALUE &&
4778                               winRetryIoerr(&cnt, &lastErrno) ){
4779                /* Noop */
4780     }
4781 #else
4782     while( (h = osCreateFileW((LPCWSTR)zConverted,
4783                               dwDesiredAccess,
4784                               dwShareMode, NULL,
4785                               dwCreationDisposition,
4786                               dwFlagsAndAttributes,
4787                               NULL))==INVALID_HANDLE_VALUE &&
4788                               winRetryIoerr(&cnt, &lastErrno) ){
4789                /* Noop */
4790     }
4791 #endif
4792   }
4793 #ifdef SQLITE_WIN32_HAS_ANSI
4794   else{
4795     while( (h = osCreateFileA((LPCSTR)zConverted,
4796                               dwDesiredAccess,
4797                               dwShareMode, NULL,
4798                               dwCreationDisposition,
4799                               dwFlagsAndAttributes,
4800                               NULL))==INVALID_HANDLE_VALUE &&
4801                               winRetryIoerr(&cnt, &lastErrno) ){
4802                /* Noop */
4803     }
4804   }
4805 #endif
4806   winLogIoerr(cnt, __LINE__);
4807 
4808   OSTRACE(("OPEN file=%p, name=%s, access=%lx, rc=%s\n", h, zUtf8Name,
4809            dwDesiredAccess, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
4810 
4811   if( h==INVALID_HANDLE_VALUE ){
4812     pFile->lastErrno = lastErrno;
4813     winLogError(SQLITE_CANTOPEN, pFile->lastErrno, "winOpen", zUtf8Name);
4814     sqlite3_free(zConverted);
4815     sqlite3_free(zTmpname);
4816     if( isReadWrite && !isExclusive ){
4817       return winOpen(pVfs, zName, id,
4818          ((flags|SQLITE_OPEN_READONLY) &
4819                      ~(SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE)),
4820          pOutFlags);
4821     }else{
4822       return SQLITE_CANTOPEN_BKPT;
4823     }
4824   }
4825 
4826   if( pOutFlags ){
4827     if( isReadWrite ){
4828       *pOutFlags = SQLITE_OPEN_READWRITE;
4829     }else{
4830       *pOutFlags = SQLITE_OPEN_READONLY;
4831     }
4832   }
4833 
4834   OSTRACE(("OPEN file=%p, name=%s, access=%lx, pOutFlags=%p, *pOutFlags=%d, "
4835            "rc=%s\n", h, zUtf8Name, dwDesiredAccess, pOutFlags, pOutFlags ?
4836            *pOutFlags : 0, (h==INVALID_HANDLE_VALUE) ? "failed" : "ok"));
4837 
4838 #if SQLITE_OS_WINCE
4839   if( isReadWrite && eType==SQLITE_OPEN_MAIN_DB
4840        && (rc = winceCreateLock(zName, pFile))!=SQLITE_OK
4841   ){
4842     osCloseHandle(h);
4843     sqlite3_free(zConverted);
4844     sqlite3_free(zTmpname);
4845     OSTRACE(("OPEN-CE-LOCK name=%s, rc=%s\n", zName, sqlite3ErrName(rc)));
4846     return rc;
4847   }
4848   if( isTemp ){
4849     pFile->zDeleteOnClose = zConverted;
4850   }else
4851 #endif
4852   {
4853     sqlite3_free(zConverted);
4854   }
4855 
4856   sqlite3_free(zTmpname);
4857   pFile->pMethod = &winIoMethod;
4858   pFile->pVfs = pVfs;
4859   pFile->h = h;
4860   if( isReadonly ){
4861     pFile->ctrlFlags |= WINFILE_RDONLY;
4862   }
4863   if( sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE) ){
4864     pFile->ctrlFlags |= WINFILE_PSOW;
4865   }
4866   pFile->lastErrno = NO_ERROR;
4867   pFile->zPath = zName;
4868 #if SQLITE_MAX_MMAP_SIZE>0
4869   pFile->hMap = NULL;
4870   pFile->pMapRegion = 0;
4871   pFile->mmapSize = 0;
4872   pFile->mmapSizeActual = 0;
4873   pFile->mmapSizeMax = sqlite3GlobalConfig.szMmap;
4874 #endif
4875 
4876   OpenCounter(+1);
4877   return rc;
4878 }
4879 
4880 /*
4881 ** Delete the named file.
4882 **
4883 ** Note that Windows does not allow a file to be deleted if some other
4884 ** process has it open.  Sometimes a virus scanner or indexing program
4885 ** will open a journal file shortly after it is created in order to do
4886 ** whatever it does.  While this other process is holding the
4887 ** file open, we will be unable to delete it.  To work around this
4888 ** problem, we delay 100 milliseconds and try to delete again.  Up
4889 ** to MX_DELETION_ATTEMPTs deletion attempts are run before giving
4890 ** up and returning an error.
4891 */
4892 static int winDelete(
4893   sqlite3_vfs *pVfs,          /* Not used on win32 */
4894   const char *zFilename,      /* Name of file to delete */
4895   int syncDir                 /* Not used on win32 */
4896 ){
4897   int cnt = 0;
4898   int rc;
4899   DWORD attr;
4900   DWORD lastErrno = 0;
4901   void *zConverted;
4902   UNUSED_PARAMETER(pVfs);
4903   UNUSED_PARAMETER(syncDir);
4904 
4905   SimulateIOError(return SQLITE_IOERR_DELETE);
4906   OSTRACE(("DELETE name=%s, syncDir=%d\n", zFilename, syncDir));
4907 
4908   zConverted = winConvertFromUtf8Filename(zFilename);
4909   if( zConverted==0 ){
4910     OSTRACE(("DELETE name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
4911     return SQLITE_IOERR_NOMEM;
4912   }
4913   if( osIsNT() ){
4914     do {
4915 #if SQLITE_OS_WINRT
4916       WIN32_FILE_ATTRIBUTE_DATA sAttrData;
4917       memset(&sAttrData, 0, sizeof(sAttrData));
4918       if ( osGetFileAttributesExW(zConverted, GetFileExInfoStandard,
4919                                   &sAttrData) ){
4920         attr = sAttrData.dwFileAttributes;
4921       }else{
4922         lastErrno = osGetLastError();
4923         if( lastErrno==ERROR_FILE_NOT_FOUND
4924          || lastErrno==ERROR_PATH_NOT_FOUND ){
4925           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
4926         }else{
4927           rc = SQLITE_ERROR;
4928         }
4929         break;
4930       }
4931 #else
4932       attr = osGetFileAttributesW(zConverted);
4933 #endif
4934       if ( attr==INVALID_FILE_ATTRIBUTES ){
4935         lastErrno = osGetLastError();
4936         if( lastErrno==ERROR_FILE_NOT_FOUND
4937          || lastErrno==ERROR_PATH_NOT_FOUND ){
4938           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
4939         }else{
4940           rc = SQLITE_ERROR;
4941         }
4942         break;
4943       }
4944       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
4945         rc = SQLITE_ERROR; /* Files only. */
4946         break;
4947       }
4948       if ( osDeleteFileW(zConverted) ){
4949         rc = SQLITE_OK; /* Deleted OK. */
4950         break;
4951       }
4952       if ( !winRetryIoerr(&cnt, &lastErrno) ){
4953         rc = SQLITE_ERROR; /* No more retries. */
4954         break;
4955       }
4956     } while(1);
4957   }
4958 #ifdef SQLITE_WIN32_HAS_ANSI
4959   else{
4960     do {
4961       attr = osGetFileAttributesA(zConverted);
4962       if ( attr==INVALID_FILE_ATTRIBUTES ){
4963         lastErrno = osGetLastError();
4964         if( lastErrno==ERROR_FILE_NOT_FOUND
4965          || lastErrno==ERROR_PATH_NOT_FOUND ){
4966           rc = SQLITE_IOERR_DELETE_NOENT; /* Already gone? */
4967         }else{
4968           rc = SQLITE_ERROR;
4969         }
4970         break;
4971       }
4972       if ( attr&FILE_ATTRIBUTE_DIRECTORY ){
4973         rc = SQLITE_ERROR; /* Files only. */
4974         break;
4975       }
4976       if ( osDeleteFileA(zConverted) ){
4977         rc = SQLITE_OK; /* Deleted OK. */
4978         break;
4979       }
4980       if ( !winRetryIoerr(&cnt, &lastErrno) ){
4981         rc = SQLITE_ERROR; /* No more retries. */
4982         break;
4983       }
4984     } while(1);
4985   }
4986 #endif
4987   if( rc && rc!=SQLITE_IOERR_DELETE_NOENT ){
4988     rc = winLogError(SQLITE_IOERR_DELETE, lastErrno, "winDelete", zFilename);
4989   }else{
4990     winLogIoerr(cnt, __LINE__);
4991   }
4992   sqlite3_free(zConverted);
4993   OSTRACE(("DELETE name=%s, rc=%s\n", zFilename, sqlite3ErrName(rc)));
4994   return rc;
4995 }
4996 
4997 /*
4998 ** Check the existence and status of a file.
4999 */
5000 static int winAccess(
5001   sqlite3_vfs *pVfs,         /* Not used on win32 */
5002   const char *zFilename,     /* Name of file to check */
5003   int flags,                 /* Type of test to make on this file */
5004   int *pResOut               /* OUT: Result */
5005 ){
5006   DWORD attr;
5007   int rc = 0;
5008   DWORD lastErrno = 0;
5009   void *zConverted;
5010   UNUSED_PARAMETER(pVfs);
5011 
5012   SimulateIOError( return SQLITE_IOERR_ACCESS; );
5013   OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",
5014            zFilename, flags, pResOut));
5015 
5016   zConverted = winConvertFromUtf8Filename(zFilename);
5017   if( zConverted==0 ){
5018     OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
5019     return SQLITE_IOERR_NOMEM;
5020   }
5021   if( osIsNT() ){
5022     int cnt = 0;
5023     WIN32_FILE_ATTRIBUTE_DATA sAttrData;
5024     memset(&sAttrData, 0, sizeof(sAttrData));
5025     while( !(rc = osGetFileAttributesExW((LPCWSTR)zConverted,
5026                              GetFileExInfoStandard,
5027                              &sAttrData)) && winRetryIoerr(&cnt, &lastErrno) ){}
5028     if( rc ){
5029       /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
5030       ** as if it does not exist.
5031       */
5032       if(    flags==SQLITE_ACCESS_EXISTS
5033           && sAttrData.nFileSizeHigh==0
5034           && sAttrData.nFileSizeLow==0 ){
5035         attr = INVALID_FILE_ATTRIBUTES;
5036       }else{
5037         attr = sAttrData.dwFileAttributes;
5038       }
5039     }else{
5040       winLogIoerr(cnt, __LINE__);
5041       if( lastErrno!=ERROR_FILE_NOT_FOUND && lastErrno!=ERROR_PATH_NOT_FOUND ){
5042         sqlite3_free(zConverted);
5043         return winLogError(SQLITE_IOERR_ACCESS, lastErrno, "winAccess",
5044                            zFilename);
5045       }else{
5046         attr = INVALID_FILE_ATTRIBUTES;
5047       }
5048     }
5049   }
5050 #ifdef SQLITE_WIN32_HAS_ANSI
5051   else{
5052     attr = osGetFileAttributesA((char*)zConverted);
5053   }
5054 #endif
5055   sqlite3_free(zConverted);
5056   switch( flags ){
5057     case SQLITE_ACCESS_READ:
5058     case SQLITE_ACCESS_EXISTS:
5059       rc = attr!=INVALID_FILE_ATTRIBUTES;
5060       break;
5061     case SQLITE_ACCESS_READWRITE:
5062       rc = attr!=INVALID_FILE_ATTRIBUTES &&
5063              (attr & FILE_ATTRIBUTE_READONLY)==0;
5064       break;
5065     default:
5066       assert(!"Invalid flags argument");
5067   }
5068   *pResOut = rc;
5069   OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
5070            zFilename, pResOut, *pResOut));
5071   return SQLITE_OK;
5072 }
5073 
5074 /*
5075 ** Returns non-zero if the specified path name starts with a drive letter
5076 ** followed by a colon character.
5077 */
5078 static BOOL winIsDriveLetterAndColon(
5079   const char *zPathname
5080 ){
5081   return ( sqlite3Isalpha(zPathname[0]) && zPathname[1]==':' );
5082 }
5083 
5084 /*
5085 ** Returns non-zero if the specified path name should be used verbatim.  If
5086 ** non-zero is returned from this function, the calling function must simply
5087 ** use the provided path name verbatim -OR- resolve it into a full path name
5088 ** using the GetFullPathName Win32 API function (if available).
5089 */
5090 static BOOL winIsVerbatimPathname(
5091   const char *zPathname
5092 ){
5093   /*
5094   ** If the path name starts with a forward slash or a backslash, it is either
5095   ** a legal UNC name, a volume relative path, or an absolute path name in the
5096   ** "Unix" format on Windows.  There is no easy way to differentiate between
5097   ** the final two cases; therefore, we return the safer return value of TRUE
5098   ** so that callers of this function will simply use it verbatim.
5099   */
5100   if ( winIsDirSep(zPathname[0]) ){
5101     return TRUE;
5102   }
5103 
5104   /*
5105   ** If the path name starts with a letter and a colon it is either a volume
5106   ** relative path or an absolute path.  Callers of this function must not
5107   ** attempt to treat it as a relative path name (i.e. they should simply use
5108   ** it verbatim).
5109   */
5110   if ( winIsDriveLetterAndColon(zPathname) ){
5111     return TRUE;
5112   }
5113 
5114   /*
5115   ** If we get to this point, the path name should almost certainly be a purely
5116   ** relative one (i.e. not a UNC name, not absolute, and not volume relative).
5117   */
5118   return FALSE;
5119 }
5120 
5121 /*
5122 ** Turn a relative pathname into a full pathname.  Write the full
5123 ** pathname into zOut[].  zOut[] will be at least pVfs->mxPathname
5124 ** bytes in size.
5125 */
5126 static int winFullPathname(
5127   sqlite3_vfs *pVfs,            /* Pointer to vfs object */
5128   const char *zRelative,        /* Possibly relative input path */
5129   int nFull,                    /* Size of output buffer in bytes */
5130   char *zFull                   /* Output buffer */
5131 ){
5132 
5133 #if defined(__CYGWIN__)
5134   SimulateIOError( return SQLITE_ERROR );
5135   UNUSED_PARAMETER(nFull);
5136   assert( nFull>=pVfs->mxPathname );
5137   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5138     /*
5139     ** NOTE: We are dealing with a relative path name and the data
5140     **       directory has been set.  Therefore, use it as the basis
5141     **       for converting the relative path name to an absolute
5142     **       one by prepending the data directory and a slash.
5143     */
5144     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
5145     if( !zOut ){
5146       return SQLITE_IOERR_NOMEM;
5147     }
5148     if( cygwin_conv_path(
5149             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A) |
5150             CCP_RELATIVE, zRelative, zOut, pVfs->mxPathname+1)<0 ){
5151       sqlite3_free(zOut);
5152       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
5153                          "winFullPathname1", zRelative);
5154     }else{
5155       char *zUtf8 = winConvertToUtf8Filename(zOut);
5156       if( !zUtf8 ){
5157         sqlite3_free(zOut);
5158         return SQLITE_IOERR_NOMEM;
5159       }
5160       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5161                        sqlite3_data_directory, winGetDirSep(), zUtf8);
5162       sqlite3_free(zUtf8);
5163       sqlite3_free(zOut);
5164     }
5165   }else{
5166     char *zOut = sqlite3MallocZero( pVfs->mxPathname+1 );
5167     if( !zOut ){
5168       return SQLITE_IOERR_NOMEM;
5169     }
5170     if( cygwin_conv_path(
5171             (osIsNT() ? CCP_POSIX_TO_WIN_W : CCP_POSIX_TO_WIN_A),
5172             zRelative, zOut, pVfs->mxPathname+1)<0 ){
5173       sqlite3_free(zOut);
5174       return winLogError(SQLITE_CANTOPEN_CONVPATH, (DWORD)errno,
5175                          "winFullPathname2", zRelative);
5176     }else{
5177       char *zUtf8 = winConvertToUtf8Filename(zOut);
5178       if( !zUtf8 ){
5179         sqlite3_free(zOut);
5180         return SQLITE_IOERR_NOMEM;
5181       }
5182       sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zUtf8);
5183       sqlite3_free(zUtf8);
5184       sqlite3_free(zOut);
5185     }
5186   }
5187   return SQLITE_OK;
5188 #endif
5189 
5190 #if (SQLITE_OS_WINCE || SQLITE_OS_WINRT) && !defined(__CYGWIN__)
5191   SimulateIOError( return SQLITE_ERROR );
5192   /* WinCE has no concept of a relative pathname, or so I am told. */
5193   /* WinRT has no way to convert a relative path to an absolute one. */
5194   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5195     /*
5196     ** NOTE: We are dealing with a relative path name and the data
5197     **       directory has been set.  Therefore, use it as the basis
5198     **       for converting the relative path name to an absolute
5199     **       one by prepending the data directory and a backslash.
5200     */
5201     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5202                      sqlite3_data_directory, winGetDirSep(), zRelative);
5203   }else{
5204     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zRelative);
5205   }
5206   return SQLITE_OK;
5207 #endif
5208 
5209 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && !defined(__CYGWIN__)
5210   DWORD nByte;
5211   void *zConverted;
5212   char *zOut;
5213 
5214   /* If this path name begins with "/X:", where "X" is any alphabetic
5215   ** character, discard the initial "/" from the pathname.
5216   */
5217   if( zRelative[0]=='/' && winIsDriveLetterAndColon(zRelative+1) ){
5218     zRelative++;
5219   }
5220 
5221   /* It's odd to simulate an io-error here, but really this is just
5222   ** using the io-error infrastructure to test that SQLite handles this
5223   ** function failing. This function could fail if, for example, the
5224   ** current working directory has been unlinked.
5225   */
5226   SimulateIOError( return SQLITE_ERROR );
5227   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
5228     /*
5229     ** NOTE: We are dealing with a relative path name and the data
5230     **       directory has been set.  Therefore, use it as the basis
5231     **       for converting the relative path name to an absolute
5232     **       one by prepending the data directory and a backslash.
5233     */
5234     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s%c%s",
5235                      sqlite3_data_directory, winGetDirSep(), zRelative);
5236     return SQLITE_OK;
5237   }
5238   zConverted = winConvertFromUtf8Filename(zRelative);
5239   if( zConverted==0 ){
5240     return SQLITE_IOERR_NOMEM;
5241   }
5242   if( osIsNT() ){
5243     LPWSTR zTemp;
5244     nByte = osGetFullPathNameW((LPCWSTR)zConverted, 0, 0, 0);
5245     if( nByte==0 ){
5246       sqlite3_free(zConverted);
5247       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5248                          "winFullPathname1", zRelative);
5249     }
5250     nByte += 3;
5251     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
5252     if( zTemp==0 ){
5253       sqlite3_free(zConverted);
5254       return SQLITE_IOERR_NOMEM;
5255     }
5256     nByte = osGetFullPathNameW((LPCWSTR)zConverted, nByte, zTemp, 0);
5257     if( nByte==0 ){
5258       sqlite3_free(zConverted);
5259       sqlite3_free(zTemp);
5260       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5261                          "winFullPathname2", zRelative);
5262     }
5263     sqlite3_free(zConverted);
5264     zOut = winUnicodeToUtf8(zTemp);
5265     sqlite3_free(zTemp);
5266   }
5267 #ifdef SQLITE_WIN32_HAS_ANSI
5268   else{
5269     char *zTemp;
5270     nByte = osGetFullPathNameA((char*)zConverted, 0, 0, 0);
5271     if( nByte==0 ){
5272       sqlite3_free(zConverted);
5273       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5274                          "winFullPathname3", zRelative);
5275     }
5276     nByte += 3;
5277     zTemp = sqlite3MallocZero( nByte*sizeof(zTemp[0]) );
5278     if( zTemp==0 ){
5279       sqlite3_free(zConverted);
5280       return SQLITE_IOERR_NOMEM;
5281     }
5282     nByte = osGetFullPathNameA((char*)zConverted, nByte, zTemp, 0);
5283     if( nByte==0 ){
5284       sqlite3_free(zConverted);
5285       sqlite3_free(zTemp);
5286       return winLogError(SQLITE_CANTOPEN_FULLPATH, osGetLastError(),
5287                          "winFullPathname4", zRelative);
5288     }
5289     sqlite3_free(zConverted);
5290     zOut = sqlite3_win32_mbcs_to_utf8(zTemp);
5291     sqlite3_free(zTemp);
5292   }
5293 #endif
5294   if( zOut ){
5295     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s", zOut);
5296     sqlite3_free(zOut);
5297     return SQLITE_OK;
5298   }else{
5299     return SQLITE_IOERR_NOMEM;
5300   }
5301 #endif
5302 }
5303 
5304 #ifndef SQLITE_OMIT_LOAD_EXTENSION
5305 /*
5306 ** Interfaces for opening a shared library, finding entry points
5307 ** within the shared library, and closing the shared library.
5308 */
5309 static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
5310   HANDLE h;
5311 #if defined(__CYGWIN__)
5312   int nFull = pVfs->mxPathname+1;
5313   char *zFull = sqlite3MallocZero( nFull );
5314   void *zConverted = 0;
5315   if( zFull==0 ){
5316     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5317     return 0;
5318   }
5319   if( winFullPathname(pVfs, zFilename, nFull, zFull)!=SQLITE_OK ){
5320     sqlite3_free(zFull);
5321     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5322     return 0;
5323   }
5324   zConverted = winConvertFromUtf8Filename(zFull);
5325   sqlite3_free(zFull);
5326 #else
5327   void *zConverted = winConvertFromUtf8Filename(zFilename);
5328   UNUSED_PARAMETER(pVfs);
5329 #endif
5330   if( zConverted==0 ){
5331     OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
5332     return 0;
5333   }
5334   if( osIsNT() ){
5335 #if SQLITE_OS_WINRT
5336     h = osLoadPackagedLibrary((LPCWSTR)zConverted, 0);
5337 #else
5338     h = osLoadLibraryW((LPCWSTR)zConverted);
5339 #endif
5340   }
5341 #ifdef SQLITE_WIN32_HAS_ANSI
5342   else{
5343     h = osLoadLibraryA((char*)zConverted);
5344   }
5345 #endif
5346   OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)h));
5347   sqlite3_free(zConverted);
5348   return (void*)h;
5349 }
5350 static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
5351   UNUSED_PARAMETER(pVfs);
5352   winGetLastErrorMsg(osGetLastError(), nBuf, zBufOut);
5353 }
5354 static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){
5355   FARPROC proc;
5356   UNUSED_PARAMETER(pVfs);
5357   proc = osGetProcAddressA((HANDLE)pH, zSym);
5358   OSTRACE(("DLSYM handle=%p, symbol=%s, address=%p\n",
5359            (void*)pH, zSym, (void*)proc));
5360   return (void(*)(void))proc;
5361 }
5362 static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
5363   UNUSED_PARAMETER(pVfs);
5364   osFreeLibrary((HANDLE)pHandle);
5365   OSTRACE(("DLCLOSE handle=%p\n", (void*)pHandle));
5366 }
5367 #else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
5368   #define winDlOpen  0
5369   #define winDlError 0
5370   #define winDlSym   0
5371   #define winDlClose 0
5372 #endif
5373 
5374 
5375 /*
5376 ** Write up to nBuf bytes of randomness into zBuf.
5377 */
5378 static int winRandomness(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5379   int n = 0;
5380   UNUSED_PARAMETER(pVfs);
5381 #if defined(SQLITE_TEST) || defined(SQLITE_OMIT_RANDOMNESS)
5382   n = nBuf;
5383   memset(zBuf, 0, nBuf);
5384 #else
5385   if( sizeof(SYSTEMTIME)<=nBuf-n ){
5386     SYSTEMTIME x;
5387     osGetSystemTime(&x);
5388     memcpy(&zBuf[n], &x, sizeof(x));
5389     n += sizeof(x);
5390   }
5391   if( sizeof(DWORD)<=nBuf-n ){
5392     DWORD pid = osGetCurrentProcessId();
5393     memcpy(&zBuf[n], &pid, sizeof(pid));
5394     n += sizeof(pid);
5395   }
5396 #if SQLITE_OS_WINRT
5397   if( sizeof(ULONGLONG)<=nBuf-n ){
5398     ULONGLONG cnt = osGetTickCount64();
5399     memcpy(&zBuf[n], &cnt, sizeof(cnt));
5400     n += sizeof(cnt);
5401   }
5402 #else
5403   if( sizeof(DWORD)<=nBuf-n ){
5404     DWORD cnt = osGetTickCount();
5405     memcpy(&zBuf[n], &cnt, sizeof(cnt));
5406     n += sizeof(cnt);
5407   }
5408 #endif
5409   if( sizeof(LARGE_INTEGER)<=nBuf-n ){
5410     LARGE_INTEGER i;
5411     osQueryPerformanceCounter(&i);
5412     memcpy(&zBuf[n], &i, sizeof(i));
5413     n += sizeof(i);
5414   }
5415 #if !SQLITE_OS_WINCE && !SQLITE_OS_WINRT && SQLITE_WIN32_USE_UUID
5416   if( sizeof(UUID)<=nBuf-n ){
5417     UUID id;
5418     memset(&id, 0, sizeof(UUID));
5419     osUuidCreate(&id);
5420     memcpy(&zBuf[n], &id, sizeof(UUID));
5421     n += sizeof(UUID);
5422   }
5423   if( sizeof(UUID)<=nBuf-n ){
5424     UUID id;
5425     memset(&id, 0, sizeof(UUID));
5426     osUuidCreateSequential(&id);
5427     memcpy(&zBuf[n], &id, sizeof(UUID));
5428     n += sizeof(UUID);
5429   }
5430 #endif
5431 #endif /* defined(SQLITE_TEST) || defined(SQLITE_ZERO_PRNG_SEED) */
5432   return n;
5433 }
5434 
5435 
5436 /*
5437 ** Sleep for a little while.  Return the amount of time slept.
5438 */
5439 static int winSleep(sqlite3_vfs *pVfs, int microsec){
5440   sqlite3_win32_sleep((microsec+999)/1000);
5441   UNUSED_PARAMETER(pVfs);
5442   return ((microsec+999)/1000)*1000;
5443 }
5444 
5445 /*
5446 ** The following variable, if set to a non-zero value, is interpreted as
5447 ** the number of seconds since 1970 and is used to set the result of
5448 ** sqlite3OsCurrentTime() during testing.
5449 */
5450 #ifdef SQLITE_TEST
5451 int sqlite3_current_time = 0;  /* Fake system time in seconds since 1970. */
5452 #endif
5453 
5454 /*
5455 ** Find the current time (in Universal Coordinated Time).  Write into *piNow
5456 ** the current time and date as a Julian Day number times 86_400_000.  In
5457 ** other words, write into *piNow the number of milliseconds since the Julian
5458 ** epoch of noon in Greenwich on November 24, 4714 B.C according to the
5459 ** proleptic Gregorian calendar.
5460 **
5461 ** On success, return SQLITE_OK.  Return SQLITE_ERROR if the time and date
5462 ** cannot be found.
5463 */
5464 static int winCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *piNow){
5465   /* FILETIME structure is a 64-bit value representing the number of
5466      100-nanosecond intervals since January 1, 1601 (= JD 2305813.5).
5467   */
5468   FILETIME ft;
5469   static const sqlite3_int64 winFiletimeEpoch = 23058135*(sqlite3_int64)8640000;
5470 #ifdef SQLITE_TEST
5471   static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000;
5472 #endif
5473   /* 2^32 - to avoid use of LL and warnings in gcc */
5474   static const sqlite3_int64 max32BitValue =
5475       (sqlite3_int64)2000000000 + (sqlite3_int64)2000000000 +
5476       (sqlite3_int64)294967296;
5477 
5478 #if SQLITE_OS_WINCE
5479   SYSTEMTIME time;
5480   osGetSystemTime(&time);
5481   /* if SystemTimeToFileTime() fails, it returns zero. */
5482   if (!osSystemTimeToFileTime(&time,&ft)){
5483     return SQLITE_ERROR;
5484   }
5485 #else
5486   osGetSystemTimeAsFileTime( &ft );
5487 #endif
5488 
5489   *piNow = winFiletimeEpoch +
5490             ((((sqlite3_int64)ft.dwHighDateTime)*max32BitValue) +
5491                (sqlite3_int64)ft.dwLowDateTime)/(sqlite3_int64)10000;
5492 
5493 #ifdef SQLITE_TEST
5494   if( sqlite3_current_time ){
5495     *piNow = 1000*(sqlite3_int64)sqlite3_current_time + unixEpoch;
5496   }
5497 #endif
5498   UNUSED_PARAMETER(pVfs);
5499   return SQLITE_OK;
5500 }
5501 
5502 /*
5503 ** Find the current time (in Universal Coordinated Time).  Write the
5504 ** current time and date as a Julian Day number into *prNow and
5505 ** return 0.  Return 1 if the time and date cannot be found.
5506 */
5507 static int winCurrentTime(sqlite3_vfs *pVfs, double *prNow){
5508   int rc;
5509   sqlite3_int64 i;
5510   rc = winCurrentTimeInt64(pVfs, &i);
5511   if( !rc ){
5512     *prNow = i/86400000.0;
5513   }
5514   return rc;
5515 }
5516 
5517 /*
5518 ** The idea is that this function works like a combination of
5519 ** GetLastError() and FormatMessage() on Windows (or errno and
5520 ** strerror_r() on Unix). After an error is returned by an OS
5521 ** function, SQLite calls this function with zBuf pointing to
5522 ** a buffer of nBuf bytes. The OS layer should populate the
5523 ** buffer with a nul-terminated UTF-8 encoded error message
5524 ** describing the last IO error to have occurred within the calling
5525 ** thread.
5526 **
5527 ** If the error message is too large for the supplied buffer,
5528 ** it should be truncated. The return value of xGetLastError
5529 ** is zero if the error message fits in the buffer, or non-zero
5530 ** otherwise (if the message was truncated). If non-zero is returned,
5531 ** then it is not necessary to include the nul-terminator character
5532 ** in the output buffer.
5533 **
5534 ** Not supplying an error message will have no adverse effect
5535 ** on SQLite. It is fine to have an implementation that never
5536 ** returns an error message:
5537 **
5538 **   int xGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5539 **     assert(zBuf[0]=='\0');
5540 **     return 0;
5541 **   }
5542 **
5543 ** However if an error message is supplied, it will be incorporated
5544 ** by sqlite into the error message available to the user using
5545 ** sqlite3_errmsg(), possibly making IO errors easier to debug.
5546 */
5547 static int winGetLastError(sqlite3_vfs *pVfs, int nBuf, char *zBuf){
5548   UNUSED_PARAMETER(pVfs);
5549   return winGetLastErrorMsg(osGetLastError(), nBuf, zBuf);
5550 }
5551 
5552 /*
5553 ** Initialize and deinitialize the operating system interface.
5554 */
5555 int sqlite3_os_init(void){
5556   static sqlite3_vfs winVfs = {
5557     3,                   /* iVersion */
5558     sizeof(winFile),     /* szOsFile */
5559     SQLITE_WIN32_MAX_PATH_BYTES, /* mxPathname */
5560     0,                   /* pNext */
5561     "win32",             /* zName */
5562     0,                   /* pAppData */
5563     winOpen,             /* xOpen */
5564     winDelete,           /* xDelete */
5565     winAccess,           /* xAccess */
5566     winFullPathname,     /* xFullPathname */
5567     winDlOpen,           /* xDlOpen */
5568     winDlError,          /* xDlError */
5569     winDlSym,            /* xDlSym */
5570     winDlClose,          /* xDlClose */
5571     winRandomness,       /* xRandomness */
5572     winSleep,            /* xSleep */
5573     winCurrentTime,      /* xCurrentTime */
5574     winGetLastError,     /* xGetLastError */
5575     winCurrentTimeInt64, /* xCurrentTimeInt64 */
5576     winSetSystemCall,    /* xSetSystemCall */
5577     winGetSystemCall,    /* xGetSystemCall */
5578     winNextSystemCall,   /* xNextSystemCall */
5579   };
5580 #if defined(SQLITE_WIN32_HAS_WIDE)
5581   static sqlite3_vfs winLongPathVfs = {
5582     3,                   /* iVersion */
5583     sizeof(winFile),     /* szOsFile */
5584     SQLITE_WINNT_MAX_PATH_BYTES, /* mxPathname */
5585     0,                   /* pNext */
5586     "win32-longpath",    /* zName */
5587     0,                   /* pAppData */
5588     winOpen,             /* xOpen */
5589     winDelete,           /* xDelete */
5590     winAccess,           /* xAccess */
5591     winFullPathname,     /* xFullPathname */
5592     winDlOpen,           /* xDlOpen */
5593     winDlError,          /* xDlError */
5594     winDlSym,            /* xDlSym */
5595     winDlClose,          /* xDlClose */
5596     winRandomness,       /* xRandomness */
5597     winSleep,            /* xSleep */
5598     winCurrentTime,      /* xCurrentTime */
5599     winGetLastError,     /* xGetLastError */
5600     winCurrentTimeInt64, /* xCurrentTimeInt64 */
5601     winSetSystemCall,    /* xSetSystemCall */
5602     winGetSystemCall,    /* xGetSystemCall */
5603     winNextSystemCall,   /* xNextSystemCall */
5604   };
5605 #endif
5606 
5607   /* Double-check that the aSyscall[] array has been constructed
5608   ** correctly.  See ticket [bb3a86e890c8e96ab] */
5609   assert( ArraySize(aSyscall)==80 );
5610 
5611   /* get memory map allocation granularity */
5612   memset(&winSysInfo, 0, sizeof(SYSTEM_INFO));
5613 #if SQLITE_OS_WINRT
5614   osGetNativeSystemInfo(&winSysInfo);
5615 #else
5616   osGetSystemInfo(&winSysInfo);
5617 #endif
5618   assert( winSysInfo.dwAllocationGranularity>0 );
5619   assert( winSysInfo.dwPageSize>0 );
5620 
5621   sqlite3_vfs_register(&winVfs, 1);
5622 
5623 #if defined(SQLITE_WIN32_HAS_WIDE)
5624   sqlite3_vfs_register(&winLongPathVfs, 0);
5625 #endif
5626 
5627   return SQLITE_OK;
5628 }
5629 
5630 int sqlite3_os_end(void){
5631 #if SQLITE_OS_WINRT
5632   if( sleepObj!=NULL ){
5633     osCloseHandle(sleepObj);
5634     sleepObj = NULL;
5635   }
5636 #endif
5637   return SQLITE_OK;
5638 }
5639 
5640 #endif /* SQLITE_OS_WIN */
5641