| Index: third_party/sqlite/src/mutex_w32.c
|
| ===================================================================
|
| --- third_party/sqlite/src/mutex_w32.c (revision 56608)
|
| +++ third_party/sqlite/src/mutex_w32.c (working copy)
|
| @@ -1,284 +0,0 @@
|
| -/*
|
| -** 2007 August 14
|
| -**
|
| -** 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 the C functions that implement mutexes for win32
|
| -**
|
| -** $Id: mutex_w32.c,v 1.18 2009/08/10 03:23:21 shane Exp $
|
| -*/
|
| -#include "sqliteInt.h"
|
| -
|
| -/*
|
| -** The code in this file is only used if we are compiling multithreaded
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| -** on a win32 system.
|
| -*/
|
| -#ifdef SQLITE_MUTEX_W32
|
| -
|
| -/*
|
| -** Each recursive mutex is an instance of the following structure.
|
| -*/
|
| -struct sqlite3_mutex {
|
| - CRITICAL_SECTION mutex; /* Mutex controlling the lock */
|
| - int id; /* Mutex type */
|
| - int nRef; /* Number of enterances */
|
| - DWORD owner; /* Thread holding this mutex */
|
| -};
|
| -
|
| -/*
|
| -** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
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| -** 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
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| -** WinNT/2K/XP so that we will know whether or not we can safely call
|
| -** the LockFileEx() API.
|
| -**
|
| -** mutexIsNT() is only used for the TryEnterCriticalSection() API call,
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| -** which is only available if your application was compiled with
|
| -** _WIN32_WINNT defined to a value >= 0x0400. Currently, the only
|
| -** call to TryEnterCriticalSection() is #ifdef'ed out, so #ifdef
|
| -** this out as well.
|
| -*/
|
| -#if 0
|
| -#if SQLITE_OS_WINCE
|
| -# define mutexIsNT() (1)
|
| -#else
|
| - static int mutexIsNT(void){
|
| - static int osType = 0;
|
| - if( osType==0 ){
|
| - OSVERSIONINFO sInfo;
|
| - sInfo.dwOSVersionInfoSize = sizeof(sInfo);
|
| - GetVersionEx(&sInfo);
|
| - osType = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
|
| - }
|
| - return osType==2;
|
| - }
|
| -#endif /* SQLITE_OS_WINCE */
|
| -#endif
|
| -
|
| -#ifdef SQLITE_DEBUG
|
| -/*
|
| -** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
|
| -** intended for use only inside assert() statements.
|
| -*/
|
| -static int winMutexHeld(sqlite3_mutex *p){
|
| - return p->nRef!=0 && p->owner==GetCurrentThreadId();
|
| -}
|
| -static int winMutexNotheld(sqlite3_mutex *p){
|
| - return p->nRef==0 || p->owner!=GetCurrentThreadId();
|
| -}
|
| -#endif
|
| -
|
| -
|
| -/*
|
| -** Initialize and deinitialize the mutex subsystem.
|
| -*/
|
| -static sqlite3_mutex winMutex_staticMutexes[6];
|
| -static int winMutex_isInit = 0;
|
| -/* As winMutexInit() and winMutexEnd() are called as part
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| -** of the sqlite3_initialize and sqlite3_shutdown()
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| -** processing, the "interlocked" magic is probably not
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| -** strictly necessary.
|
| -*/
|
| -static long winMutex_lock = 0;
|
| -
|
| -static int winMutexInit(void){
|
| - /* The first to increment to 1 does actual initialization */
|
| - if( InterlockedCompareExchange(&winMutex_lock, 1, 0)==0 ){
|
| - int i;
|
| - for(i=0; i<ArraySize(winMutex_staticMutexes); i++){
|
| - InitializeCriticalSection(&winMutex_staticMutexes[i].mutex);
|
| - }
|
| - winMutex_isInit = 1;
|
| - }else{
|
| - /* Someone else is in the process of initing the static mutexes */
|
| - while( !winMutex_isInit ){
|
| - Sleep(1);
|
| - }
|
| - }
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static int winMutexEnd(void){
|
| - /* The first to decrement to 0 does actual shutdown
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| - ** (which should be the last to shutdown.) */
|
| - if( InterlockedCompareExchange(&winMutex_lock, 0, 1)==1 ){
|
| - if( winMutex_isInit==1 ){
|
| - int i;
|
| - for(i=0; i<ArraySize(winMutex_staticMutexes); i++){
|
| - DeleteCriticalSection(&winMutex_staticMutexes[i].mutex);
|
| - }
|
| - winMutex_isInit = 0;
|
| - }
|
| - }
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/*
|
| -** The sqlite3_mutex_alloc() routine allocates a new
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| -** mutex and returns a pointer to it. If it returns NULL
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| -** that means that a mutex could not be allocated. SQLite
|
| -** will unwind its stack and return an error. The argument
|
| -** to sqlite3_mutex_alloc() is one of these integer constants:
|
| -**
|
| -** <ul>
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| -** <li> SQLITE_MUTEX_FAST
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| -** <li> SQLITE_MUTEX_RECURSIVE
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| -** <li> SQLITE_MUTEX_STATIC_MASTER
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| -** <li> SQLITE_MUTEX_STATIC_MEM
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| -** <li> SQLITE_MUTEX_STATIC_MEM2
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| -** <li> SQLITE_MUTEX_STATIC_PRNG
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| -** <li> SQLITE_MUTEX_STATIC_LRU
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| -** <li> SQLITE_MUTEX_STATIC_LRU2
|
| -** </ul>
|
| -**
|
| -** The first two constants cause sqlite3_mutex_alloc() to create
|
| -** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
|
| -** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
|
| -** The mutex implementation does not need to make a distinction
|
| -** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
|
| -** not want to. But SQLite will only request a recursive mutex in
|
| -** cases where it really needs one. If a faster non-recursive mutex
|
| -** implementation is available on the host platform, the mutex subsystem
|
| -** might return such a mutex in response to SQLITE_MUTEX_FAST.
|
| -**
|
| -** The other allowed parameters to sqlite3_mutex_alloc() each return
|
| -** a pointer to a static preexisting mutex. Six static mutexes are
|
| -** used by the current version of SQLite. Future versions of SQLite
|
| -** may add additional static mutexes. Static mutexes are for internal
|
| -** use by SQLite only. Applications that use SQLite mutexes should
|
| -** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
|
| -** SQLITE_MUTEX_RECURSIVE.
|
| -**
|
| -** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
|
| -** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
|
| -** returns a different mutex on every call. But for the static
|
| -** mutex types, the same mutex is returned on every call that has
|
| -** the same type number.
|
| -*/
|
| -static sqlite3_mutex *winMutexAlloc(int iType){
|
| - sqlite3_mutex *p;
|
| -
|
| - switch( iType ){
|
| - case SQLITE_MUTEX_FAST:
|
| - case SQLITE_MUTEX_RECURSIVE: {
|
| - p = sqlite3MallocZero( sizeof(*p) );
|
| - if( p ){
|
| - p->id = iType;
|
| - InitializeCriticalSection(&p->mutex);
|
| - }
|
| - break;
|
| - }
|
| - default: {
|
| - assert( winMutex_isInit==1 );
|
| - assert( iType-2 >= 0 );
|
| - assert( iType-2 < ArraySize(winMutex_staticMutexes) );
|
| - p = &winMutex_staticMutexes[iType-2];
|
| - p->id = iType;
|
| - break;
|
| - }
|
| - }
|
| - return p;
|
| -}
|
| -
|
| -
|
| -/*
|
| -** This routine deallocates a previously
|
| -** allocated mutex. SQLite is careful to deallocate every
|
| -** mutex that it allocates.
|
| -*/
|
| -static void winMutexFree(sqlite3_mutex *p){
|
| - assert( p );
|
| - assert( p->nRef==0 );
|
| - assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
|
| - DeleteCriticalSection(&p->mutex);
|
| - sqlite3_free(p);
|
| -}
|
| -
|
| -/*
|
| -** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
|
| -** to enter a mutex. If another thread is already within the mutex,
|
| -** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
|
| -** SQLITE_BUSY. The sqlite3_mutex_try() interface returns SQLITE_OK
|
| -** upon successful entry. Mutexes created using SQLITE_MUTEX_RECURSIVE can
|
| -** be entered multiple times by the same thread. In such cases the,
|
| -** mutex must be exited an equal number of times before another thread
|
| -** can enter. If the same thread tries to enter any other kind of mutex
|
| -** more than once, the behavior is undefined.
|
| -*/
|
| -static void winMutexEnter(sqlite3_mutex *p){
|
| - assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld(p) );
|
| - EnterCriticalSection(&p->mutex);
|
| - p->owner = GetCurrentThreadId();
|
| - p->nRef++;
|
| -}
|
| -static int winMutexTry(sqlite3_mutex *p){
|
| - int rc = SQLITE_BUSY;
|
| - assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld(p) );
|
| - /*
|
| - ** The sqlite3_mutex_try() routine is very rarely used, and when it
|
| - ** is used it is merely an optimization. So it is OK for it to always
|
| - ** fail.
|
| - **
|
| - ** The TryEnterCriticalSection() interface is only available on WinNT.
|
| - ** And some windows compilers complain if you try to use it without
|
| - ** first doing some #defines that prevent SQLite from building on Win98.
|
| - ** For that reason, we will omit this optimization for now. See
|
| - ** ticket #2685.
|
| - */
|
| -#if 0
|
| - if( mutexIsNT() && TryEnterCriticalSection(&p->mutex) ){
|
| - p->owner = GetCurrentThreadId();
|
| - p->nRef++;
|
| - rc = SQLITE_OK;
|
| - }
|
| -#else
|
| - UNUSED_PARAMETER(p);
|
| -#endif
|
| - return rc;
|
| -}
|
| -
|
| -/*
|
| -** The sqlite3_mutex_leave() routine exits a mutex that was
|
| -** previously entered by the same thread. The behavior
|
| -** is undefined if the mutex is not currently entered or
|
| -** is not currently allocated. SQLite will never do either.
|
| -*/
|
| -static void winMutexLeave(sqlite3_mutex *p){
|
| - assert( p->nRef>0 );
|
| - assert( p->owner==GetCurrentThreadId() );
|
| - p->nRef--;
|
| - assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
|
| - LeaveCriticalSection(&p->mutex);
|
| -}
|
| -
|
| -sqlite3_mutex_methods *sqlite3DefaultMutex(void){
|
| - static sqlite3_mutex_methods sMutex = {
|
| - winMutexInit,
|
| - winMutexEnd,
|
| - winMutexAlloc,
|
| - winMutexFree,
|
| - winMutexEnter,
|
| - winMutexTry,
|
| - winMutexLeave,
|
| -#ifdef SQLITE_DEBUG
|
| - winMutexHeld,
|
| - winMutexNotheld
|
| -#else
|
| - 0,
|
| - 0
|
| -#endif
|
| - };
|
| -
|
| - return &sMutex;
|
| -}
|
| -#endif /* SQLITE_MUTEX_W32 */
|
|
|