--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/webengine/webkitutils/SqliteSymbian/os_win.c Mon Mar 30 12:54:55 2009 +0300
@@ -0,0 +1,1556 @@
+/*
+** 2004 May 22
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code that is specific to windows.
+*/
+#include "sqliteInt.h"
+#include "os.h"
+#if OS_WIN /* This file is used for windows only */
+
+#include <winbase.h>
+
+#ifdef __CYGWIN__
+# include <sys/cygwin.h>
+#endif
+
+/*
+** Macros used to determine whether or not to use threads.
+*/
+#if defined(THREADSAFE) && THREADSAFE
+# define SQLITE_W32_THREADS 1
+#endif
+
+/*
+** Include code that is common to all os_*.c files
+*/
+#include "os_common.h"
+
+/*
+** Determine if we are dealing with WindowsCE - which has a much
+** reduced API.
+*/
+#if defined(_WIN32_WCE)
+# define OS_WINCE 1
+#else
+# define OS_WINCE 0
+#endif
+
+/*
+** WinCE lacks native support for file locking so we have to fake it
+** with some code of our own.
+*/
+#if OS_WINCE
+typedef struct winceLock {
+ int nReaders; /* Number of reader locks obtained */
+ BOOL bPending; /* Indicates a pending lock has been obtained */
+ BOOL bReserved; /* Indicates a reserved lock has been obtained */
+ BOOL bExclusive; /* Indicates an exclusive lock has been obtained */
+} winceLock;
+#endif
+
+/*
+** The winFile structure is a subclass of OsFile specific to the win32
+** portability layer.
+*/
+typedef struct winFile winFile;
+struct winFile {
+ IoMethod const *pMethod;/* Must be first */
+ HANDLE h; /* Handle for accessing the file */
+ unsigned char locktype; /* Type of lock currently held on this file */
+ short sharedLockByte; /* Randomly chosen byte used as a shared lock */
+#if OS_WINCE
+ WCHAR *zDeleteOnClose; /* Name of file to delete when closing */
+ HANDLE hMutex; /* Mutex used to control access to shared lock */
+ HANDLE hShared; /* Shared memory segment used for locking */
+ winceLock local; /* Locks obtained by this instance of winFile */
+ winceLock *shared; /* Global shared lock memory for the file */
+#endif
+};
+
+
+/*
+** Do not include any of the File I/O interface procedures if the
+** SQLITE_OMIT_DISKIO macro is defined (indicating that there database
+** will be in-memory only)
+*/
+#ifndef SQLITE_OMIT_DISKIO
+
+/*
+** The following variable is (normally) set once and never changes
+** thereafter. It records whether the operating system is Win95
+** or WinNT.
+**
+** 0: Operating system unknown.
+** 1: Operating system is Win95.
+** 2: Operating system is WinNT.
+**
+** In order to facilitate testing on a WinNT system, the test fixture
+** can manually set this value to 1 to emulate Win98 behavior.
+*/
+int sqlite3_os_type = 0;
+
+/*
+** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
+** or WinCE. Return false (zero) for Win95, Win98, or WinME.
+**
+** Here is an interesting observation: Win95, Win98, and WinME lack
+** the LockFileEx() API. But we can still statically link against that
+** API as long as we don't call it win running Win95/98/ME. A call to
+** this routine is used to determine if the host is Win95/98/ME or
+** WinNT/2K/XP so that we will know whether or not we can safely call
+** the LockFileEx() API.
+*/
+#if OS_WINCE
+# define isNT() (1)
+#else
+ static int isNT(void){
+ if( sqlite3_os_type==0 ){
+ OSVERSIONINFO sInfo;
+ sInfo.dwOSVersionInfoSize = sizeof(sInfo);
+ GetVersionEx(&sInfo);
+ sqlite3_os_type = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
+ }
+ return sqlite3_os_type==2;
+ }
+#endif /* OS_WINCE */
+
+/*
+** Convert a UTF-8 string to UTF-32. Space to hold the returned string
+** is obtained from sqliteMalloc.
+*/
+static WCHAR *utf8ToUnicode(const char *zFilename){
+ int nChar;
+ WCHAR *zWideFilename;
+
+ if( !isNT() ){
+ return 0;
+ }
+ nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
+ zWideFilename = sqliteMalloc( nChar*sizeof(zWideFilename[0]) );
+ if( zWideFilename==0 ){
+ return 0;
+ }
+ nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename, nChar);
+ if( nChar==0 ){
+ sqliteFree(zWideFilename);
+ zWideFilename = 0;
+ }
+ return zWideFilename;
+}
+
+/*
+** Convert UTF-32 to UTF-8. Space to hold the returned string is
+** obtained from sqliteMalloc().
+*/
+static char *unicodeToUtf8(const WCHAR *zWideFilename){
+ int nByte;
+ char *zFilename;
+
+ nByte = WideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, 0, 0, 0, 0);
+ zFilename = sqliteMalloc( nByte );
+ if( zFilename==0 ){
+ return 0;
+ }
+ nByte = WideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, zFilename, nByte,
+ 0, 0);
+ if( nByte == 0 ){
+ sqliteFree(zFilename);
+ zFilename = 0;
+ }
+ return zFilename;
+}
+
+#if OS_WINCE
+/*************************************************************************
+** This section contains code for WinCE only.
+*/
+/*
+** WindowsCE does not have a localtime() function. So create a
+** substitute.
+*/
+#include <time.h>
+struct tm *__cdecl localtime(const time_t *t)
+{
+ static struct tm y;
+ FILETIME uTm, lTm;
+ SYSTEMTIME pTm;
+ i64 t64;
+ t64 = *t;
+ t64 = (t64 + 11644473600)*10000000;
+ uTm.dwLowDateTime = t64 & 0xFFFFFFFF;
+ uTm.dwHighDateTime= t64 >> 32;
+ FileTimeToLocalFileTime(&uTm,&lTm);
+ FileTimeToSystemTime(&lTm,&pTm);
+ y.tm_year = pTm.wYear - 1900;
+ y.tm_mon = pTm.wMonth - 1;
+ y.tm_wday = pTm.wDayOfWeek;
+ y.tm_mday = pTm.wDay;
+ y.tm_hour = pTm.wHour;
+ y.tm_min = pTm.wMinute;
+ y.tm_sec = pTm.wSecond;
+ return &y;
+}
+
+/* This will never be called, but defined to make the code compile */
+#define GetTempPathA(a,b)
+
+#define LockFile(a,b,c,d,e) winceLockFile(&a, b, c, d, e)
+#define UnlockFile(a,b,c,d,e) winceUnlockFile(&a, b, c, d, e)
+#define LockFileEx(a,b,c,d,e,f) winceLockFileEx(&a, b, c, d, e, f)
+
+#define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-offsetof(winFile,h)]
+
+/*
+** Acquire a lock on the handle h
+*/
+static void winceMutexAcquire(HANDLE h){
+ DWORD dwErr;
+ do {
+ dwErr = WaitForSingleObject(h, INFINITE);
+ } while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);
+}
+/*
+** Release a lock acquired by winceMutexAcquire()
+*/
+#define winceMutexRelease(h) ReleaseMutex(h)
+
+/*
+** Create the mutex and shared memory used for locking in the file
+** descriptor pFile
+*/
+static BOOL winceCreateLock(const char *zFilename, winFile *pFile){
+ WCHAR *zTok;
+ WCHAR *zName = utf8ToUnicode(zFilename);
+ BOOL bInit = TRUE;
+
+ /* Initialize the local lockdata */
+ ZeroMemory(&pFile->local, sizeof(pFile->local));
+
+ /* Replace the backslashes from the filename and lowercase it
+ ** to derive a mutex name. */
+ zTok = CharLowerW(zName);
+ for (;*zTok;zTok++){
+ if (*zTok == '\\') *zTok = '_';
+ }
+
+ /* Create/open the named mutex */
+ pFile->hMutex = CreateMutexW(NULL, FALSE, zName);
+ if (!pFile->hMutex){
+ sqliteFree(zName);
+ return FALSE;
+ }
+
+ /* Acquire the mutex before continuing */
+ winceMutexAcquire(pFile->hMutex);
+
+ /* Since the names of named mutexes, semaphores, file mappings etc are
+ ** case-sensitive, take advantage of that by uppercasing the mutex name
+ ** and using that as the shared filemapping name.
+ */
+ CharUpperW(zName);
+ pFile->hShared = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
+ PAGE_READWRITE, 0, sizeof(winceLock),
+ zName);
+
+ /* Set a flag that indicates we're the first to create the memory so it
+ ** must be zero-initialized */
+ if (GetLastError() == ERROR_ALREADY_EXISTS){
+ bInit = FALSE;
+ }
+
+ sqliteFree(zName);
+
+ /* If we succeeded in making the shared memory handle, map it. */
+ if (pFile->hShared){
+ pFile->shared = (winceLock*)MapViewOfFile(pFile->hShared,
+ FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
+ /* If mapping failed, close the shared memory handle and erase it */
+ if (!pFile->shared){
+ CloseHandle(pFile->hShared);
+ pFile->hShared = NULL;
+ }
+ }
+
+ /* If shared memory could not be created, then close the mutex and fail */
+ if (pFile->hShared == NULL){
+ winceMutexRelease(pFile->hMutex);
+ CloseHandle(pFile->hMutex);
+ pFile->hMutex = NULL;
+ return FALSE;
+ }
+
+ /* Initialize the shared memory if we're supposed to */
+ if (bInit) {
+ ZeroMemory(pFile->shared, sizeof(winceLock));
+ }
+
+ winceMutexRelease(pFile->hMutex);
+ return TRUE;
+}
+
+/*
+** Destroy the part of winFile that deals with wince locks
+*/
+static void winceDestroyLock(winFile *pFile){
+ if (pFile->hMutex){
+ /* Acquire the mutex */
+ winceMutexAcquire(pFile->hMutex);
+
+ /* The following blocks should probably assert in debug mode, but they
+ are to cleanup in case any locks remained open */
+ if (pFile->local.nReaders){
+ pFile->shared->nReaders --;
+ }
+ if (pFile->local.bReserved){
+ pFile->shared->bReserved = FALSE;
+ }
+ if (pFile->local.bPending){
+ pFile->shared->bPending = FALSE;
+ }
+ if (pFile->local.bExclusive){
+ pFile->shared->bExclusive = FALSE;
+ }
+
+ /* De-reference and close our copy of the shared memory handle */
+ UnmapViewOfFile(pFile->shared);
+ CloseHandle(pFile->hShared);
+
+ /* Done with the mutex */
+ winceMutexRelease(pFile->hMutex);
+ CloseHandle(pFile->hMutex);
+ pFile->hMutex = NULL;
+ }
+}
+
+/*
+** An implementation of the LockFile() API of windows for wince
+*/
+static BOOL winceLockFile(
+ HANDLE *phFile,
+ DWORD dwFileOffsetLow,
+ DWORD dwFileOffsetHigh,
+ DWORD nNumberOfBytesToLockLow,
+ DWORD nNumberOfBytesToLockHigh
+){
+ winFile *pFile = HANDLE_TO_WINFILE(phFile);
+ BOOL bReturn = FALSE;
+
+ if (!pFile->hMutex) return TRUE;
+ winceMutexAcquire(pFile->hMutex);
+
+ /* Wanting an exclusive lock? */
+ if (dwFileOffsetLow == SHARED_FIRST
+ && nNumberOfBytesToLockLow == SHARED_SIZE){
+ if (pFile->shared->nReaders == 0 && pFile->shared->bExclusive == 0){
+ pFile->shared->bExclusive = TRUE;
+ pFile->local.bExclusive = TRUE;
+ bReturn = TRUE;
+ }
+ }
+
+ /* Want a read-only lock? */
+ else if ((dwFileOffsetLow >= SHARED_FIRST &&
+ dwFileOffsetLow < SHARED_FIRST + SHARED_SIZE) &&
+ nNumberOfBytesToLockLow == 1){
+ if (pFile->shared->bExclusive == 0){
+ pFile->local.nReaders ++;
+ if (pFile->local.nReaders == 1){
+ pFile->shared->nReaders ++;
+ }
+ bReturn = TRUE;
+ }
+ }
+
+ /* Want a pending lock? */
+ else if (dwFileOffsetLow == PENDING_BYTE && nNumberOfBytesToLockLow == 1){
+ /* If no pending lock has been acquired, then acquire it */
+ if (pFile->shared->bPending == 0) {
+ pFile->shared->bPending = TRUE;
+ pFile->local.bPending = TRUE;
+ bReturn = TRUE;
+ }
+ }
+ /* Want a reserved lock? */
+ else if (dwFileOffsetLow == RESERVED_BYTE && nNumberOfBytesToLockLow == 1){
+ if (pFile->shared->bReserved == 0) {
+ pFile->shared->bReserved = TRUE;
+ pFile->local.bReserved = TRUE;
+ bReturn = TRUE;
+ }
+ }
+
+ winceMutexRelease(pFile->hMutex);
+ return bReturn;
+}
+
+/*
+** An implementation of the UnlockFile API of windows for wince
+*/
+static BOOL winceUnlockFile(
+ HANDLE *phFile,
+ DWORD dwFileOffsetLow,
+ DWORD dwFileOffsetHigh,
+ DWORD nNumberOfBytesToUnlockLow,
+ DWORD nNumberOfBytesToUnlockHigh
+){
+ winFile *pFile = HANDLE_TO_WINFILE(phFile);
+ BOOL bReturn = FALSE;
+
+ if (!pFile->hMutex) return TRUE;
+ winceMutexAcquire(pFile->hMutex);
+
+ /* Releasing a reader lock or an exclusive lock */
+ if (dwFileOffsetLow >= SHARED_FIRST &&
+ dwFileOffsetLow < SHARED_FIRST + SHARED_SIZE){
+ /* Did we have an exclusive lock? */
+ if (pFile->local.bExclusive){
+ pFile->local.bExclusive = FALSE;
+ pFile->shared->bExclusive = FALSE;
+ bReturn = TRUE;
+ }
+
+ /* Did we just have a reader lock? */
+ else if (pFile->local.nReaders){
+ pFile->local.nReaders --;
+ if (pFile->local.nReaders == 0)
+ {
+ pFile->shared->nReaders --;
+ }
+ bReturn = TRUE;
+ }
+ }
+
+ /* Releasing a pending lock */
+ else if (dwFileOffsetLow == PENDING_BYTE && nNumberOfBytesToUnlockLow == 1){
+ if (pFile->local.bPending){
+ pFile->local.bPending = FALSE;
+ pFile->shared->bPending = FALSE;
+ bReturn = TRUE;
+ }
+ }
+ /* Releasing a reserved lock */
+ else if (dwFileOffsetLow == RESERVED_BYTE && nNumberOfBytesToUnlockLow == 1){
+ if (pFile->local.bReserved) {
+ pFile->local.bReserved = FALSE;
+ pFile->shared->bReserved = FALSE;
+ bReturn = TRUE;
+ }
+ }
+
+ winceMutexRelease(pFile->hMutex);
+ return bReturn;
+}
+
+/*
+** An implementation of the LockFileEx() API of windows for wince
+*/
+static BOOL winceLockFileEx(
+ HANDLE *phFile,
+ DWORD dwFlags,
+ DWORD dwReserved,
+ DWORD nNumberOfBytesToLockLow,
+ DWORD nNumberOfBytesToLockHigh,
+ LPOVERLAPPED lpOverlapped
+){
+ /* If the caller wants a shared read lock, forward this call
+ ** to winceLockFile */
+ if (lpOverlapped->Offset == SHARED_FIRST &&
+ dwFlags == 1 &&
+ nNumberOfBytesToLockLow == SHARED_SIZE){
+ return winceLockFile(phFile, SHARED_FIRST, 0, 1, 0);
+ }
+ return FALSE;
+}
+/*
+** End of the special code for wince
+*****************************************************************************/
+#endif /* OS_WINCE */
+
+/*
+** Delete the named file.
+**
+** Note that windows does not allow a file to be deleted if some other
+** process has it open. Sometimes a virus scanner or indexing program
+** will open a journal file shortly after it is created in order to do
+** whatever it is it does. While this other process is holding the
+** file open, we will be unable to delete it. To work around this
+** problem, we delay 100 milliseconds and try to delete again. Up
+** to MX_DELETION_ATTEMPTs deletion attempts are run before giving
+** up and returning an error.
+*/
+#define MX_DELETION_ATTEMPTS 3
+int sqlite3WinDelete(const char *zFilename){
+ WCHAR *zWide = utf8ToUnicode(zFilename);
+ int cnt = 0;
+ int rc;
+ if( zWide ){
+ do{
+ rc = DeleteFileW(zWide);
+ }while( rc==0 && cnt++ < MX_DELETION_ATTEMPTS && (Sleep(100), 1) );
+ sqliteFree(zWide);
+ }else{
+#if OS_WINCE
+ return SQLITE_NOMEM;
+#else
+ do{
+ rc = DeleteFileA(zFilename);
+ }while( rc==0 && cnt++ < MX_DELETION_ATTEMPTS && (Sleep(100), 1) );
+#endif
+ }
+ TRACE2("DELETE \"%s\"\n", zFilename);
+ return rc==0 ? SQLITE_OK : SQLITE_IOERR;
+}
+
+/*
+** Return TRUE if the named file exists.
+*/
+int sqlite3WinFileExists(const char *zFilename){
+ int exists = 0;
+ WCHAR *zWide = utf8ToUnicode(zFilename);
+ if( zWide ){
+ exists = GetFileAttributesW(zWide) != 0xffffffff;
+ sqliteFree(zWide);
+ }else{
+#if OS_WINCE
+ return SQLITE_NOMEM;
+#else
+ exists = GetFileAttributesA(zFilename) != 0xffffffff;
+#endif
+ }
+ return exists;
+}
+
+/* Forward declaration */
+static int allocateWinFile(winFile *pInit, OsFile **pId);
+
+/*
+** Attempt to open a file for both reading and writing. If that
+** fails, try opening it read-only. If the file does not exist,
+** try to create it.
+**
+** On success, a handle for the open file is written to *id
+** and *pReadonly is set to 0 if the file was opened for reading and
+** writing or 1 if the file was opened read-only. The function returns
+** SQLITE_OK.
+**
+** On failure, the function returns SQLITE_CANTOPEN and leaves
+** *id and *pReadonly unchanged.
+*/
+int sqlite3WinOpenReadWrite(
+ const char *zFilename,
+ OsFile **pId,
+ int *pReadonly
+){
+ winFile f;
+ HANDLE h;
+ WCHAR *zWide = utf8ToUnicode(zFilename);
+ assert( *pId==0 );
+ if( zWide ){
+ h = CreateFileW(zWide,
+ GENERIC_READ | GENERIC_WRITE,
+ FILE_SHARE_READ | FILE_SHARE_WRITE,
+ NULL,
+ OPEN_ALWAYS,
+ FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS,
+ NULL
+ );
+ if( h==INVALID_HANDLE_VALUE ){
+ h = CreateFileW(zWide,
+ GENERIC_READ,
+ FILE_SHARE_READ | FILE_SHARE_WRITE,
+ NULL,
+ OPEN_ALWAYS,
+ FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS,
+ NULL
+ );
+ if( h==INVALID_HANDLE_VALUE ){
+ sqliteFree(zWide);
+ return SQLITE_CANTOPEN;
+ }
+ *pReadonly = 1;
+ }else{
+ *pReadonly = 0;
+ }
+#if OS_WINCE
+ if (!winceCreateLock(zFilename, &f)){
+ CloseHandle(h);
+ sqliteFree(zWide);
+ return SQLITE_CANTOPEN;
+ }
+#endif
+ sqliteFree(zWide);
+ }else{
+#if OS_WINCE
+ return SQLITE_NOMEM;
+#else
+ h = CreateFileA(zFilename,
+ GENERIC_READ | GENERIC_WRITE,
+ FILE_SHARE_READ | FILE_SHARE_WRITE,
+ NULL,
+ OPEN_ALWAYS,
+ FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS,
+ NULL
+ );
+ if( h==INVALID_HANDLE_VALUE ){
+ h = CreateFileA(zFilename,
+ GENERIC_READ,
+ FILE_SHARE_READ | FILE_SHARE_WRITE,
+ NULL,
+ OPEN_ALWAYS,
+ FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS,
+ NULL
+ );
+ if( h==INVALID_HANDLE_VALUE ){
+ return SQLITE_CANTOPEN;
+ }
+ *pReadonly = 1;
+ }else{
+ *pReadonly = 0;
+ }
+#endif /* OS_WINCE */
+ }
+ f.h = h;
+#if OS_WINCE
+ f.zDeleteOnClose = 0;
+#endif
+ TRACE3("OPEN R/W %d \"%s\"\n", h, zFilename);
+ return allocateWinFile(&f, pId);
+}
+
+
+/*
+** Attempt to open a new file for exclusive access by this process.
+** The file will be opened for both reading and writing. To avoid
+** a potential security problem, we do not allow the file to have
+** previously existed. Nor do we allow the file to be a symbolic
+** link.
+**
+** If delFlag is true, then make arrangements to automatically delete
+** the file when it is closed.
+**
+** On success, write the file handle into *id and return SQLITE_OK.
+**
+** On failure, return SQLITE_CANTOPEN.
+**
+** Sometimes if we have just deleted a prior journal file, windows
+** will fail to open a new one because there is a "pending delete".
+** To work around this bug, we pause for 100 milliseconds and attempt
+** a second open after the first one fails. The whole operation only
+** fails if both open attempts are unsuccessful.
+*/
+int sqlite3WinOpenExclusive(const char *zFilename, OsFile **pId, int delFlag){
+ winFile f;
+ HANDLE h;
+ int fileflags;
+ WCHAR *zWide = utf8ToUnicode(zFilename);
+ assert( *pId == 0 );
+ fileflags = FILE_FLAG_RANDOM_ACCESS;
+#if !OS_WINCE
+ if( delFlag ){
+ fileflags |= FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE;
+ }
+#endif
+ if( zWide ){
+ int cnt = 0;
+ do{
+ h = CreateFileW(zWide,
+ GENERIC_READ | GENERIC_WRITE,
+ 0,
+ NULL,
+ CREATE_ALWAYS,
+ fileflags,
+ NULL
+ );
+ }while( h==INVALID_HANDLE_VALUE && cnt++ < 2 && (Sleep(100), 1) );
+ sqliteFree(zWide);
+ }else{
+#if OS_WINCE
+ return SQLITE_NOMEM;
+#else
+ int cnt = 0;
+ do{
+ h = CreateFileA(zFilename,
+ GENERIC_READ | GENERIC_WRITE,
+ 0,
+ NULL,
+ CREATE_ALWAYS,
+ fileflags,
+ NULL
+ );
+ }while( h==INVALID_HANDLE_VALUE && cnt++ < 2 && (Sleep(100), 1) );
+#endif /* OS_WINCE */
+ }
+ if( h==INVALID_HANDLE_VALUE ){
+ return SQLITE_CANTOPEN;
+ }
+ f.h = h;
+#if OS_WINCE
+ f.zDeleteOnClose = delFlag ? utf8ToUnicode(zFilename) : 0;
+ f.hMutex = NULL;
+#endif
+ TRACE3("OPEN EX %d \"%s\"\n", h, zFilename);
+ return allocateWinFile(&f, pId);
+}
+
+/*
+** Attempt to open a new file for read-only access.
+**
+** On success, write the file handle into *id and return SQLITE_OK.
+**
+** On failure, return SQLITE_CANTOPEN.
+*/
+int sqlite3WinOpenReadOnly(const char *zFilename, OsFile **pId){
+ winFile f;
+ HANDLE h;
+ WCHAR *zWide = utf8ToUnicode(zFilename);
+ assert( *pId==0 );
+ if( zWide ){
+ h = CreateFileW(zWide,
+ GENERIC_READ,
+ 0,
+ NULL,
+ OPEN_EXISTING,
+ FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS,
+ NULL
+ );
+ sqliteFree(zWide);
+ }else{
+#if OS_WINCE
+ return SQLITE_NOMEM;
+#else
+ h = CreateFileA(zFilename,
+ GENERIC_READ,
+ 0,
+ NULL,
+ OPEN_EXISTING,
+ FILE_ATTRIBUTE_NORMAL | FILE_FLAG_RANDOM_ACCESS,
+ NULL
+ );
+#endif
+ }
+ if( h==INVALID_HANDLE_VALUE ){
+ return SQLITE_CANTOPEN;
+ }
+ f.h = h;
+#if OS_WINCE
+ f.zDeleteOnClose = 0;
+ f.hMutex = NULL;
+#endif
+ TRACE3("OPEN RO %d \"%s\"\n", h, zFilename);
+ return allocateWinFile(&f, pId);
+}
+
+/*
+** Attempt to open a file descriptor for the directory that contains a
+** file. This file descriptor can be used to fsync() the directory
+** in order to make sure the creation of a new file is actually written
+** to disk.
+**
+** This routine is only meaningful for Unix. It is a no-op under
+** windows since windows does not support hard links.
+**
+** On success, a handle for a previously open file is at *id is
+** updated with the new directory file descriptor and SQLITE_OK is
+** returned.
+**
+** On failure, the function returns SQLITE_CANTOPEN and leaves
+** *id unchanged.
+*/
+static int winOpenDirectory(
+ OsFile *id,
+ const char *zDirname
+){
+ return SQLITE_OK;
+}
+
+/*
+** If the following global variable points to a string which is the
+** name of a directory, then that directory will be used to store
+** temporary files.
+*/
+char *sqlite3_temp_directory = 0;
+
+/*
+** Create a temporary file name in zBuf. zBuf must be big enough to
+** hold at least SQLITE_TEMPNAME_SIZE characters.
+*/
+int sqlite3WinTempFileName(char *zBuf){
+ static char zChars[] =
+ "abcdefghijklmnopqrstuvwxyz"
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "0123456789";
+ int i, j;
+ char zTempPath[SQLITE_TEMPNAME_SIZE];
+ if( sqlite3_temp_directory ){
+ strncpy(zTempPath, sqlite3_temp_directory, SQLITE_TEMPNAME_SIZE-30);
+ zTempPath[SQLITE_TEMPNAME_SIZE-30] = 0;
+ }else if( isNT() ){
+ char *zMulti;
+ WCHAR zWidePath[SQLITE_TEMPNAME_SIZE];
+ GetTempPathW(SQLITE_TEMPNAME_SIZE-30, zWidePath);
+ zMulti = unicodeToUtf8(zWidePath);
+ if( zMulti ){
+ strncpy(zTempPath, zMulti, SQLITE_TEMPNAME_SIZE-30);
+ zTempPath[SQLITE_TEMPNAME_SIZE-30] = 0;
+ sqliteFree(zMulti);
+ }
+ }else{
+ GetTempPathA(SQLITE_TEMPNAME_SIZE-30, zTempPath);
+ }
+ for(i=strlen(zTempPath); i>0 && zTempPath[i-1]=='\\'; i--){}
+ zTempPath[i] = 0;
+ for(;;){
+ sprintf(zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath);
+ j = strlen(zBuf);
+ sqlite3Randomness(15, &zBuf[j]);
+ for(i=0; i<15; i++, j++){
+ zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];
+ }
+ zBuf[j] = 0;
+ if( !sqlite3OsFileExists(zBuf) ) break;
+ }
+ TRACE2("TEMP FILENAME: %s\n", zBuf);
+ return SQLITE_OK;
+}
+
+/*
+** Close a file.
+**
+** It is reported that an attempt to close a handle might sometimes
+** fail. This is a very unreasonable result, but windows is notorious
+** for being unreasonable so I do not doubt that it might happen. If
+** the close fails, we pause for 100 milliseconds and try again. As
+** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before
+** giving up and returning an error.
+*/
+#define MX_CLOSE_ATTEMPT 3
+static int winClose(OsFile **pId){
+ winFile *pFile;
+ int rc = 1;
+ if( pId && (pFile = (winFile*)*pId)!=0 ){
+ int rc, cnt = 0;
+ TRACE2("CLOSE %d\n", pFile->h);
+ do{
+ rc = CloseHandle(pFile->h);
+ }while( rc==0 && cnt++ < MX_CLOSE_ATTEMPT && (Sleep(100), 1) );
+#if OS_WINCE
+ winceDestroyLock(pFile);
+ if( pFile->zDeleteOnClose ){
+ DeleteFileW(pFile->zDeleteOnClose);
+ sqliteFree(pFile->zDeleteOnClose);
+ }
+#endif
+ OpenCounter(-1);
+ sqliteFree(pFile);
+ *pId = 0;
+ }
+ return rc ? SQLITE_OK : SQLITE_IOERR;
+}
+
+/*
+** Read data from a file into a buffer. Return SQLITE_OK if all
+** bytes were read successfully and SQLITE_IOERR if anything goes
+** wrong.
+*/
+static int winRead(OsFile *id, void *pBuf, int amt){
+ DWORD got;
+ assert( id!=0 );
+ SimulateIOError(SQLITE_IOERR);
+ TRACE3("READ %d lock=%d\n", ((winFile*)id)->h, ((winFile*)id)->locktype);
+ if( !ReadFile(((winFile*)id)->h, pBuf, amt, &got, 0) ){
+ got = 0;
+ }
+ if( got==(DWORD)amt ){
+ return SQLITE_OK;
+ }else{
+ return SQLITE_IOERR;
+ }
+}
+
+/*
+** Write data from a buffer into a file. Return SQLITE_OK on success
+** or some other error code on failure.
+*/
+static int winWrite(OsFile *id, const void *pBuf, int amt){
+ int rc = 0;
+ DWORD wrote;
+ assert( id!=0 );
+ SimulateIOError(SQLITE_IOERR);
+ SimulateDiskfullError;
+ TRACE3("WRITE %d lock=%d\n", ((winFile*)id)->h, ((winFile*)id)->locktype);
+ assert( amt>0 );
+ while( amt>0 && (rc = WriteFile(((winFile*)id)->h, pBuf, amt, &wrote, 0))!=0
+ && wrote>0 ){
+ amt -= wrote;
+ pBuf = &((char*)pBuf)[wrote];
+ }
+ if( !rc || amt>(int)wrote ){
+ return SQLITE_FULL;
+ }
+ return SQLITE_OK;
+}
+
+/*
+** Some microsoft compilers lack this definition.
+*/
+#ifndef INVALID_SET_FILE_POINTER
+# define INVALID_SET_FILE_POINTER ((DWORD)-1)
+#endif
+
+/*
+** Move the read/write pointer in a file.
+*/
+static int winSeek(OsFile *id, i64 offset){
+ LONG upperBits = offset>>32;
+ LONG lowerBits = offset & 0xffffffff;
+ DWORD rc;
+ assert( id!=0 );
+#ifdef SQLITE_TEST
+ if( offset ) SimulateDiskfullError
+#endif
+ SEEK(offset/1024 + 1);
+ rc = SetFilePointer(((winFile*)id)->h, lowerBits, &upperBits, FILE_BEGIN);
+ TRACE3("SEEK %d %lld\n", ((winFile*)id)->h, offset);
+ if( rc==INVALID_SET_FILE_POINTER && GetLastError()!=NO_ERROR ){
+ return SQLITE_FULL;
+ }
+ return SQLITE_OK;
+}
+
+/*
+** Make sure all writes to a particular file are committed to disk.
+*/
+static int winSync(OsFile *id, int dataOnly){
+ assert( id!=0 );
+ TRACE3("SYNC %d lock=%d\n", ((winFile*)id)->h, ((winFile*)id)->locktype);
+ if( FlushFileBuffers(((winFile*)id)->h) ){
+ return SQLITE_OK;
+ }else{
+ return SQLITE_IOERR;
+ }
+}
+
+/*
+** Sync the directory zDirname. This is a no-op on operating systems other
+** than UNIX.
+*/
+int sqlite3WinSyncDirectory(const char *zDirname){
+ SimulateIOError(SQLITE_IOERR);
+ return SQLITE_OK;
+}
+
+/*
+** Truncate an open file to a specified size
+*/
+static int winTruncate(OsFile *id, i64 nByte){
+ LONG upperBits = nByte>>32;
+ assert( id!=0 );
+ TRACE3("TRUNCATE %d %lld\n", ((winFile*)id)->h, nByte);
+ SimulateIOError(SQLITE_IOERR);
+ SetFilePointer(((winFile*)id)->h, nByte, &upperBits, FILE_BEGIN);
+ SetEndOfFile(((winFile*)id)->h);
+ return SQLITE_OK;
+}
+
+/*
+** Determine the current size of a file in bytes
+*/
+static int winFileSize(OsFile *id, i64 *pSize){
+ DWORD upperBits, lowerBits;
+ assert( id!=0 );
+ SimulateIOError(SQLITE_IOERR);
+ lowerBits = GetFileSize(((winFile*)id)->h, &upperBits);
+ *pSize = (((i64)upperBits)<<32) + lowerBits;
+ return SQLITE_OK;
+}
+
+/*
+** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.
+*/
+#ifndef LOCKFILE_FAIL_IMMEDIATELY
+# define LOCKFILE_FAIL_IMMEDIATELY 1
+#endif
+
+/*
+** Acquire a reader lock.
+** Different API routines are called depending on whether or not this
+** is Win95 or WinNT.
+*/
+static int getReadLock(winFile *id){
+ int res;
+ if( isNT() ){
+ OVERLAPPED ovlp;
+ ovlp.Offset = SHARED_FIRST;
+ ovlp.OffsetHigh = 0;
+ ovlp.hEvent = 0;
+ res = LockFileEx(id->h, LOCKFILE_FAIL_IMMEDIATELY, 0, SHARED_SIZE,0,&ovlp);
+ }else{
+ int lk;
+ sqlite3Randomness(sizeof(lk), &lk);
+ id->sharedLockByte = (lk & 0x7fffffff)%(SHARED_SIZE - 1);
+ res = LockFile(id->h, SHARED_FIRST+id->sharedLockByte, 0, 1, 0);
+ }
+ return res;
+}
+
+/*
+** Undo a readlock
+*/
+static int unlockReadLock(winFile *pFile){
+ int res;
+ if( isNT() ){
+ res = UnlockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
+ }else{
+ res = UnlockFile(pFile->h, SHARED_FIRST + pFile->sharedLockByte, 0, 1, 0);
+ }
+ return res;
+}
+
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+/*
+** Check that a given pathname is a directory and is writable
+**
+*/
+int sqlite3WinIsDirWritable(char *zDirname){
+ int fileAttr;
+ WCHAR *zWide;
+ if( zDirname==0 ) return 0;
+ if( !isNT() && strlen(zDirname)>MAX_PATH ) return 0;
+ zWide = utf8ToUnicode(zDirname);
+ if( zWide ){
+ fileAttr = GetFileAttributesW(zWide);
+ sqliteFree(zWide);
+ }else{
+#if OS_WINCE
+ return 0;
+#else
+ fileAttr = GetFileAttributesA(zDirname);
+#endif
+ }
+ if( fileAttr == 0xffffffff ) return 0;
+ if( (fileAttr & FILE_ATTRIBUTE_DIRECTORY) != FILE_ATTRIBUTE_DIRECTORY ){
+ return 0;
+ }
+ return 1;
+}
+#endif /* SQLITE_OMIT_PAGER_PRAGMAS */
+
+/*
+** Lock the file with the lock specified by parameter locktype - one
+** of the following:
+**
+** (1) SHARED_LOCK
+** (2) RESERVED_LOCK
+** (3) PENDING_LOCK
+** (4) EXCLUSIVE_LOCK
+**
+** Sometimes when requesting one lock state, additional lock states
+** are inserted in between. The locking might fail on one of the later
+** transitions leaving the lock state different from what it started but
+** still short of its goal. The following chart shows the allowed
+** transitions and the inserted intermediate states:
+**
+** UNLOCKED -> SHARED
+** SHARED -> RESERVED
+** SHARED -> (PENDING) -> EXCLUSIVE
+** RESERVED -> (PENDING) -> EXCLUSIVE
+** PENDING -> EXCLUSIVE
+**
+** This routine will only increase a lock. The winUnlock() routine
+** erases all locks at once and returns us immediately to locking level 0.
+** It is not possible to lower the locking level one step at a time. You
+** must go straight to locking level 0.
+*/
+static int winLock(OsFile *id, int locktype){
+ int rc = SQLITE_OK; /* Return code from subroutines */
+ int res = 1; /* Result of a windows lock call */
+ int newLocktype; /* Set id->locktype to this value before exiting */
+ int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
+ winFile *pFile = (winFile*)id;
+
+ assert( pFile!=0 );
+ TRACE5("LOCK %d %d was %d(%d)\n",
+ pFile->h, locktype, pFile->locktype, pFile->sharedLockByte);
+
+ /* If there is already a lock of this type or more restrictive on the
+ ** OsFile, do nothing. Don't use the end_lock: exit path, as
+ ** sqlite3OsEnterMutex() hasn't been called yet.
+ */
+ if( pFile->locktype>=locktype ){
+ return SQLITE_OK;
+ }
+
+ /* Make sure the locking sequence is correct
+ */
+ assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
+ assert( locktype!=PENDING_LOCK );
+ assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );
+
+ /* Lock the PENDING_LOCK byte if we need to acquire a PENDING lock or
+ ** a SHARED lock. If we are acquiring a SHARED lock, the acquisition of
+ ** the PENDING_LOCK byte is temporary.
+ */
+ newLocktype = pFile->locktype;
+ if( pFile->locktype==NO_LOCK
+ || (locktype==EXCLUSIVE_LOCK && pFile->locktype==RESERVED_LOCK)
+ ){
+ int cnt = 3;
+ while( cnt-->0 && (res = LockFile(pFile->h, PENDING_BYTE, 0, 1, 0))==0 ){
+ /* Try 3 times to get the pending lock. The pending lock might be
+ ** held by another reader process who will release it momentarily.
+ */
+ TRACE2("could not get a PENDING lock. cnt=%d\n", cnt);
+ Sleep(1);
+ }
+ gotPendingLock = res;
+ }
+
+ /* Acquire a shared lock
+ */
+ if( locktype==SHARED_LOCK && res ){
+ assert( pFile->locktype==NO_LOCK );
+ res = getReadLock(pFile);
+ if( res ){
+ newLocktype = SHARED_LOCK;
+ }
+ }
+
+ /* Acquire a RESERVED lock
+ */
+ if( locktype==RESERVED_LOCK && res ){
+ assert( pFile->locktype==SHARED_LOCK );
+ res = LockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+ if( res ){
+ newLocktype = RESERVED_LOCK;
+ }
+ }
+
+ /* Acquire a PENDING lock
+ */
+ if( locktype==EXCLUSIVE_LOCK && res ){
+ newLocktype = PENDING_LOCK;
+ gotPendingLock = 0;
+ }
+
+ /* Acquire an EXCLUSIVE lock
+ */
+ if( locktype==EXCLUSIVE_LOCK && res ){
+ assert( pFile->locktype>=SHARED_LOCK );
+ res = unlockReadLock(pFile);
+ TRACE2("unreadlock = %d\n", res);
+ res = LockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
+ if( res ){
+ newLocktype = EXCLUSIVE_LOCK;
+ }else{
+ TRACE2("error-code = %d\n", GetLastError());
+ }
+ }
+
+ /* If we are holding a PENDING lock that ought to be released, then
+ ** release it now.
+ */
+ if( gotPendingLock && locktype==SHARED_LOCK ){
+ UnlockFile(pFile->h, PENDING_BYTE, 0, 1, 0);
+ }
+
+ /* Update the state of the lock has held in the file descriptor then
+ ** return the appropriate result code.
+ */
+ if( res ){
+ rc = SQLITE_OK;
+ }else{
+ TRACE4("LOCK FAILED %d trying for %d but got %d\n", pFile->h,
+ locktype, newLocktype);
+ rc = SQLITE_BUSY;
+ }
+ pFile->locktype = newLocktype;
+ return rc;
+}
+
+/*
+** This routine checks if there is a RESERVED lock held on the specified
+** file by this or any other process. If such a lock is held, return
+** non-zero, otherwise zero.
+*/
+static int winCheckReservedLock(OsFile *id){
+ int rc;
+ winFile *pFile = (winFile*)id;
+ assert( pFile!=0 );
+ if( pFile->locktype>=RESERVED_LOCK ){
+ rc = 1;
+ TRACE3("TEST WR-LOCK %d %d (local)\n", pFile->h, rc);
+ }else{
+ rc = LockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+ if( rc ){
+ UnlockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+ }
+ rc = !rc;
+ TRACE3("TEST WR-LOCK %d %d (remote)\n", pFile->h, rc);
+ }
+ return rc;
+}
+
+/*
+** Lower the locking level on file descriptor id to locktype. locktype
+** must be either NO_LOCK or SHARED_LOCK.
+**
+** If the locking level of the file descriptor is already at or below
+** the requested locking level, this routine is a no-op.
+**
+** It is not possible for this routine to fail if the second argument
+** is NO_LOCK. If the second argument is SHARED_LOCK then this routine
+** might return SQLITE_IOERR;
+*/
+static int winUnlock(OsFile *id, int locktype){
+ int type;
+ int rc = SQLITE_OK;
+ winFile *pFile = (winFile*)id;
+ assert( pFile!=0 );
+ assert( locktype<=SHARED_LOCK );
+ TRACE5("UNLOCK %d to %d was %d(%d)\n", pFile->h, locktype,
+ pFile->locktype, pFile->sharedLockByte);
+ type = pFile->locktype;
+ if( type>=EXCLUSIVE_LOCK ){
+ UnlockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
+ if( locktype==SHARED_LOCK && !getReadLock(pFile) ){
+ /* This should never happen. We should always be able to
+ ** reacquire the read lock */
+ rc = SQLITE_IOERR;
+ }
+ }
+ if( type>=RESERVED_LOCK ){
+ UnlockFile(pFile->h, RESERVED_BYTE, 0, 1, 0);
+ }
+ if( locktype==NO_LOCK && type>=SHARED_LOCK ){
+ unlockReadLock(pFile);
+ }
+ if( type>=PENDING_LOCK ){
+ UnlockFile(pFile->h, PENDING_BYTE, 0, 1, 0);
+ }
+ pFile->locktype = locktype;
+ return rc;
+}
+
+/*
+** Turn a relative pathname into a full pathname. Return a pointer
+** to the full pathname stored in space obtained from sqliteMalloc().
+** The calling function is responsible for freeing this space once it
+** is no longer needed.
+*/
+char *sqlite3WinFullPathname(const char *zRelative){
+ char *zFull;
+#if defined(__CYGWIN__)
+ int nByte;
+ nByte = strlen(zRelative) + MAX_PATH + 1001;
+ zFull = sqliteMalloc( nByte );
+ if( zFull==0 ) return 0;
+ if( cygwin_conv_to_full_win32_path(zRelative, zFull) ) return 0;
+#elif OS_WINCE
+ /* WinCE has no concept of a relative pathname, or so I am told. */
+ zFull = sqliteStrDup(zRelative);
+#else
+ char *zNotUsed;
+ WCHAR *zWide;
+ int nByte;
+ zWide = utf8ToUnicode(zRelative);
+ if( zWide ){
+ WCHAR *zTemp, *zNotUsedW;
+ nByte = GetFullPathNameW(zWide, 0, 0, &zNotUsedW) + 1;
+ zTemp = sqliteMalloc( nByte*sizeof(zTemp[0]) );
+ if( zTemp==0 ) return 0;
+ GetFullPathNameW(zWide, nByte, zTemp, &zNotUsedW);
+ sqliteFree(zWide);
+ zFull = unicodeToUtf8(zTemp);
+ sqliteFree(zTemp);
+ }else{
+ nByte = GetFullPathNameA(zRelative, 0, 0, &zNotUsed) + 1;
+ zFull = sqliteMalloc( nByte*sizeof(zFull[0]) );
+ if( zFull==0 ) return 0;
+ GetFullPathNameA(zRelative, nByte, zFull, &zNotUsed);
+ }
+#endif
+ return zFull;
+}
+
+/*
+** The fullSync option is meaningless on windows. This is a no-op.
+*/
+static void winSetFullSync(OsFile *id, int v){
+ return;
+}
+
+/*
+** Return the underlying file handle for an OsFile
+*/
+static int winFileHandle(OsFile *id){
+ return (int)((winFile*)id)->h;
+}
+
+/*
+** Return an integer that indices the type of lock currently held
+** by this handle. (Used for testing and analysis only.)
+*/
+static int winLockState(OsFile *id){
+ return ((winFile*)id)->locktype;
+}
+
+/*
+** This vector defines all the methods that can operate on an OsFile
+** for win32.
+*/
+static const IoMethod sqlite3WinIoMethod = {
+ winClose,
+ winOpenDirectory,
+ winRead,
+ winWrite,
+ winSeek,
+ winTruncate,
+ winSync,
+ winSetFullSync,
+ winFileHandle,
+ winFileSize,
+ winLock,
+ winUnlock,
+ winLockState,
+ winCheckReservedLock,
+};
+
+/*
+** Allocate memory for an OsFile. Initialize the new OsFile
+** to the value given in pInit and return a pointer to the new
+** OsFile. If we run out of memory, close the file and return NULL.
+*/
+static int allocateWinFile(winFile *pInit, OsFile **pId){
+ winFile *pNew;
+ pNew = sqliteMalloc( sizeof(*pNew) );
+ if( pNew==0 ){
+ CloseHandle(pInit->h);
+#if OS_WINCE
+ sqliteFree(pInit->zDeleteOnClose);
+#endif
+ *pId = 0;
+ return SQLITE_NOMEM;
+ }else{
+ *pNew = *pInit;
+ pNew->pMethod = &sqlite3WinIoMethod;
+ pNew->locktype = NO_LOCK;
+ pNew->sharedLockByte = 0;
+ *pId = (OsFile*)pNew;
+ OpenCounter(+1);
+ return SQLITE_OK;
+ }
+}
+
+
+#endif /* SQLITE_OMIT_DISKIO */
+/***************************************************************************
+** Everything above deals with file I/O. Everything that follows deals
+** with other miscellanous aspects of the operating system interface
+****************************************************************************/
+
+/*
+** Get information to seed the random number generator. The seed
+** is written into the buffer zBuf[256]. The calling function must
+** supply a sufficiently large buffer.
+*/
+int sqlite3WinRandomSeed(char *zBuf){
+ /* We have to initialize zBuf to prevent valgrind from reporting
+ ** errors. The reports issued by valgrind are incorrect - we would
+ ** prefer that the randomness be increased by making use of the
+ ** uninitialized space in zBuf - but valgrind errors tend to worry
+ ** some users. Rather than argue, it seems easier just to initialize
+ ** the whole array and silence valgrind, even if that means less randomness
+ ** in the random seed.
+ **
+ ** When testing, initializing zBuf[] to zero is all we do. That means
+ ** that we always use the same random number sequence.* This makes the
+ ** tests repeatable.
+ */
+ memset(zBuf, 0, 256);
+ GetSystemTime((LPSYSTEMTIME)zBuf);
+ return SQLITE_OK;
+}
+
+/*
+** Sleep for a little while. Return the amount of time slept.
+*/
+int sqlite3WinSleep(int ms){
+ Sleep(ms);
+ return ms;
+}
+
+/*
+** Static variables used for thread synchronization
+*/
+static int inMutex = 0;
+#ifdef SQLITE_W32_THREADS
+ static DWORD mutexOwner;
+ static CRITICAL_SECTION cs;
+#endif
+
+/*
+** The following pair of routines implement mutual exclusion for
+** multi-threaded processes. Only a single thread is allowed to
+** executed code that is surrounded by EnterMutex() and LeaveMutex().
+**
+** SQLite uses only a single Mutex. There is not much critical
+** code and what little there is executes quickly and without blocking.
+**
+** Version 3.3.1 and earlier used a simple mutex. Beginning with
+** version 3.3.2, a recursive mutex is required.
+*/
+void sqlite3WinEnterMutex(){
+#ifdef SQLITE_W32_THREADS
+ static int isInit = 0;
+ while( !isInit ){
+ static long lock = 0;
+ if( InterlockedIncrement(&lock)==1 ){
+ InitializeCriticalSection(&cs);
+ isInit = 1;
+ }else{
+ Sleep(1);
+ }
+ }
+ EnterCriticalSection(&cs);
+ mutexOwner = GetCurrentThreadId();
+#endif
+ inMutex++;
+}
+void sqlite3WinLeaveMutex(){
+ assert( inMutex );
+ inMutex--;
+#ifdef SQLITE_W32_THREADS
+ assert( mutexOwner==GetCurrentThreadId() );
+ LeaveCriticalSection(&cs);
+#endif
+}
+
+/*
+** Return TRUE if the mutex is currently held.
+**
+** If the thisThreadOnly parameter is true, return true if and only if the
+** calling thread holds the mutex. If the parameter is false, return
+** true if any thread holds the mutex.
+*/
+int sqlite3WinInMutex(int thisThreadOnly){
+#ifdef SQLITE_W32_THREADS
+ return inMutex>0 && (thisThreadOnly==0 || mutexOwner==GetCurrentThreadId());
+#else
+ return inMutex>0;
+#endif
+}
+
+
+/*
+** The following variable, if set to a non-zero value, becomes the result
+** returned from sqlite3OsCurrentTime(). This is used for testing.
+*/
+#ifdef SQLITE_TEST
+int sqlite3_current_time = 0;
+#endif
+
+/*
+** Find the current time (in Universal Coordinated Time). Write the
+** current time and date as a Julian Day number into *prNow and
+** return 0. Return 1 if the time and date cannot be found.
+*/
+int sqlite3WinCurrentTime(double *prNow){
+ FILETIME ft;
+ /* FILETIME structure is a 64-bit value representing the number of
+ 100-nanosecond intervals since January 1, 1601 (= JD 2305813.5).
+ */
+ double now;
+#if OS_WINCE
+ SYSTEMTIME time;
+ GetSystemTime(&time);
+ SystemTimeToFileTime(&time,&ft);
+#else
+ GetSystemTimeAsFileTime( &ft );
+#endif
+ now = ((double)ft.dwHighDateTime) * 4294967296.0;
+ *prNow = (now + ft.dwLowDateTime)/864000000000.0 + 2305813.5;
+#ifdef SQLITE_TEST
+ if( sqlite3_current_time ){
+ *prNow = sqlite3_current_time/86400.0 + 2440587.5;
+ }
+#endif
+ return 0;
+}
+
+/*
+** Remember the number of thread-specific-data blocks allocated.
+** Use this to verify that we are not leaking thread-specific-data.
+** Ticket #1601
+*/
+#ifdef SQLITE_TEST
+int sqlite3_tsd_count = 0;
+# define TSD_COUNTER_INCR InterlockedIncrement(&sqlite3_tsd_count)
+# define TSD_COUNTER_DECR InterlockedDecrement(&sqlite3_tsd_count)
+#else
+# define TSD_COUNTER_INCR /* no-op */
+# define TSD_COUNTER_DECR /* no-op */
+#endif
+
+
+
+/*
+** If called with allocateFlag>1, then return a pointer to thread
+** specific data for the current thread. Allocate and zero the
+** thread-specific data if it does not already exist necessary.
+**
+** If called with allocateFlag==0, then check the current thread
+** specific data. Return it if it exists. If it does not exist,
+** then return NULL.
+**
+** If called with allocateFlag<0, check to see if the thread specific
+** data is allocated and is all zero. If it is then deallocate it.
+** Return a pointer to the thread specific data or NULL if it is
+** unallocated or gets deallocated.
+*/
+ThreadData *sqlite3WinThreadSpecificData(int allocateFlag){
+ static int key;
+ static int keyInit = 0;
+ static const ThreadData zeroData = {0};
+ ThreadData *pTsd;
+
+ if( !keyInit ){
+ sqlite3OsEnterMutex();
+ if( !keyInit ){
+ key = TlsAlloc();
+ if( key==0xffffffff ){
+ sqlite3OsLeaveMutex();
+ return 0;
+ }
+ keyInit = 1;
+ }
+ sqlite3OsLeaveMutex();
+ }
+ pTsd = TlsGetValue(key);
+ if( allocateFlag>0 ){
+ if( !pTsd ){
+ pTsd = sqlite3OsMalloc( sizeof(zeroData) );
+ if( pTsd ){
+ *pTsd = zeroData;
+ TlsSetValue(key, pTsd);
+ TSD_COUNTER_INCR;
+ }
+ }
+ }else if( pTsd!=0 && allocateFlag<0
+ && memcmp(pTsd, &zeroData, sizeof(ThreadData))==0 ){
+ sqlite3OsFree(pTsd);
+ TlsSetValue(key, 0);
+ TSD_COUNTER_DECR;
+ pTsd = 0;
+ }
+ return pTsd;
+}
+#endif /* OS_WIN */