/*
** 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 */
Submit an article or tip