diff options
Diffstat (limited to 'src/mutex_w32.c')
| -rw-r--r-- | src/mutex_w32.c | 167 |
1 files changed, 98 insertions, 69 deletions
diff --git a/src/mutex_w32.c b/src/mutex_w32.c index 27d10af..218342d 100644 --- a/src/mutex_w32.c +++ b/src/mutex_w32.c @@ -9,13 +9,25 @@ ** May you share freely, never taking more than you give. ** ************************************************************************* -** This file contains the C functions that implement mutexes for win32 +** This file contains the C functions that implement mutexes for Win32. */ #include "sqliteInt.h" +#if SQLITE_OS_WIN +/* +** Include code that is common to all os_*.c files +*/ +#include "os_common.h" + +/* +** Include the header file for the Windows VFS. +*/ +#include "os_win.h" +#endif + /* ** The code in this file is only used if we are compiling multithreaded -** on a win32 system. +** on a Win32 system. */ #ifdef SQLITE_MUTEX_W32 @@ -28,48 +40,22 @@ struct sqlite3_mutex { #ifdef SQLITE_DEBUG volatile int nRef; /* Number of enterances */ volatile DWORD owner; /* Thread holding this mutex */ - int trace; /* True to trace changes */ + volatile int trace; /* True to trace changes */ #endif }; -#define SQLITE_W32_MUTEX_INITIALIZER { 0 } -#ifdef SQLITE_DEBUG -#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0, 0L, (DWORD)0, 0 } -#else -#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0 } -#endif /* -** 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. -** -** mutexIsNT() is only used for the TryEnterCriticalSection() API call, -** 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. +** These are the initializer values used when declaring a "static" mutex +** on Win32. It should be noted that all mutexes require initialization +** on the Win32 platform. */ -#if 0 -#if SQLITE_OS_WINCE || SQLITE_OS_WINRT -# define mutexIsNT() (1) +#define SQLITE_W32_MUTEX_INITIALIZER { 0 } + +#ifdef SQLITE_DEBUG +#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0, \ + 0L, (DWORD)0, 0 } #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 */ +#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0 } #endif #ifdef SQLITE_DEBUG @@ -80,20 +66,24 @@ struct sqlite3_mutex { static int winMutexHeld(sqlite3_mutex *p){ return p->nRef!=0 && p->owner==GetCurrentThreadId(); } + static int winMutexNotheld2(sqlite3_mutex *p, DWORD tid){ return p->nRef==0 || p->owner!=tid; } + static int winMutexNotheld(sqlite3_mutex *p){ - DWORD tid = GetCurrentThreadId(); + DWORD tid = GetCurrentThreadId(); return winMutexNotheld2(p, tid); } #endif - /* ** Initialize and deinitialize the mutex subsystem. */ -static sqlite3_mutex winMutex_staticMutexes[6] = { +static sqlite3_mutex winMutex_staticMutexes[] = { + SQLITE3_MUTEX_INITIALIZER, + SQLITE3_MUTEX_INITIALIZER, + SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, @@ -101,17 +91,20 @@ static sqlite3_mutex winMutex_staticMutexes[6] = { SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER }; + static int winMutex_isInit = 0; -/* As winMutexInit() and winMutexEnd() are called as part -** of the sqlite3_initialize and sqlite3_shutdown() -** processing, the "interlocked" magic is probably not -** strictly necessary. +static int winMutex_isNt = -1; /* <0 means "need to query" */ + +/* As the winMutexInit() and winMutexEnd() functions are called as part +** of the sqlite3_initialize() and sqlite3_shutdown() processing, the +** "interlocked" magic used here is probably not strictly necessary. */ -static long winMutex_lock = 0; +static LONG volatile winMutex_lock = 0; +int sqlite3_win32_is_nt(void); /* os_win.c */ void sqlite3_win32_sleep(DWORD milliseconds); /* os_win.c */ -static int winMutexInit(void){ +static int winMutexInit(void){ /* The first to increment to 1 does actual initialization */ if( InterlockedCompareExchange(&winMutex_lock, 1, 0)==0 ){ int i; @@ -124,16 +117,17 @@ static int winMutexInit(void){ } winMutex_isInit = 1; }else{ - /* Someone else is in the process of initing the static mutexes */ + /* Another thread is (in the process of) initializing the static + ** mutexes */ while( !winMutex_isInit ){ sqlite3_win32_sleep(1); } } - return SQLITE_OK; + return SQLITE_OK; } -static int winMutexEnd(void){ - /* The first to decrement to 0 does actual shutdown +static int winMutexEnd(void){ + /* The first to decrement to 0 does actual shutdown ** (which should be the last to shutdown.) */ if( InterlockedCompareExchange(&winMutex_lock, 0, 1)==1 ){ if( winMutex_isInit==1 ){ @@ -144,7 +138,7 @@ static int winMutexEnd(void){ winMutex_isInit = 0; } } - return SQLITE_OK; + return SQLITE_OK; } /* @@ -159,10 +153,13 @@ static int winMutexEnd(void){ ** <li> SQLITE_MUTEX_RECURSIVE ** <li> SQLITE_MUTEX_STATIC_MASTER ** <li> SQLITE_MUTEX_STATIC_MEM -** <li> SQLITE_MUTEX_STATIC_MEM2 +** <li> SQLITE_MUTEX_STATIC_OPEN ** <li> SQLITE_MUTEX_STATIC_PRNG ** <li> SQLITE_MUTEX_STATIC_LRU ** <li> SQLITE_MUTEX_STATIC_PMEM +** <li> SQLITE_MUTEX_STATIC_APP1 +** <li> SQLITE_MUTEX_STATIC_APP2 +** <li> SQLITE_MUTEX_STATIC_APP3 ** </ul> ** ** The first two constants cause sqlite3_mutex_alloc() to create @@ -185,7 +182,7 @@ static int winMutexEnd(void){ ** ** 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 +** 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. */ @@ -196,9 +193,12 @@ static sqlite3_mutex *winMutexAlloc(int iType){ case SQLITE_MUTEX_FAST: case SQLITE_MUTEX_RECURSIVE: { p = sqlite3MallocZero( sizeof(*p) ); - if( p ){ + if( p ){ #ifdef SQLITE_DEBUG p->id = iType; +#ifdef SQLITE_WIN32_MUTEX_TRACE_DYNAMIC + p->trace = 1; +#endif #endif #if SQLITE_OS_WINRT InitializeCriticalSectionEx(&p->mutex, 0, 0); @@ -209,12 +209,15 @@ static sqlite3_mutex *winMutexAlloc(int iType){ break; } default: { - assert( winMutex_isInit==1 ); assert( iType-2 >= 0 ); assert( iType-2 < ArraySize(winMutex_staticMutexes) ); + assert( winMutex_isInit==1 ); p = &winMutex_staticMutexes[iType-2]; #ifdef SQLITE_DEBUG p->id = iType; +#ifdef SQLITE_WIN32_MUTEX_TRACE_STATIC + p->trace = 1; +#endif #endif break; } @@ -230,8 +233,11 @@ static sqlite3_mutex *winMutexAlloc(int iType){ */ static void winMutexFree(sqlite3_mutex *p){ assert( p ); +#ifdef SQLITE_DEBUG assert( p->nRef==0 && p->owner==0 ); assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE ); +#endif + assert( winMutex_isInit==1 ); DeleteCriticalSection(&p->mutex); sqlite3_free(p); } @@ -248,30 +254,39 @@ static void winMutexFree(sqlite3_mutex *p){ ** more than once, the behavior is undefined. */ static void winMutexEnter(sqlite3_mutex *p){ +#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) + DWORD tid = GetCurrentThreadId(); +#endif #ifdef SQLITE_DEBUG - DWORD tid = GetCurrentThreadId(); + assert( p ); assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld2(p, tid) ); +#else + assert( p ); #endif + assert( winMutex_isInit==1 ); EnterCriticalSection(&p->mutex); #ifdef SQLITE_DEBUG assert( p->nRef>0 || p->owner==0 ); - p->owner = tid; + p->owner = tid; p->nRef++; if( p->trace ){ - printf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef); + OSTRACE(("ENTER-MUTEX tid=%lu, mutex=%p (%d), nRef=%d\n", + tid, p, p->trace, p->nRef)); } #endif } + static int winMutexTry(sqlite3_mutex *p){ -#ifndef NDEBUG - DWORD tid = GetCurrentThreadId(); +#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) + DWORD tid = GetCurrentThreadId(); #endif int rc = SQLITE_BUSY; + assert( p ); assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld2(p, tid) ); /* ** 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. + ** fail. ** ** The TryEnterCriticalSection() interface is only available on WinNT. ** And some windows compilers complain if you try to use it without @@ -279,18 +294,27 @@ static int winMutexTry(sqlite3_mutex *p){ ** For that reason, we will omit this optimization for now. See ** ticket #2685. */ -#if 0 - if( mutexIsNT() && TryEnterCriticalSection(&p->mutex) ){ +#if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0400 + assert( winMutex_isInit==1 ); + assert( winMutex_isNt>=-1 && winMutex_isNt<=1 ); + if( winMutex_isNt<0 ){ + winMutex_isNt = sqlite3_win32_is_nt(); + } + assert( winMutex_isNt==0 || winMutex_isNt==1 ); + if( winMutex_isNt && TryEnterCriticalSection(&p->mutex) ){ +#ifdef SQLITE_DEBUG p->owner = tid; p->nRef++; +#endif rc = SQLITE_OK; } #else UNUSED_PARAMETER(p); #endif #ifdef SQLITE_DEBUG - if( rc==SQLITE_OK && p->trace ){ - printf("try mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef); + if( p->trace ){ + OSTRACE(("TRY-MUTEX tid=%lu, mutex=%p (%d), owner=%lu, nRef=%d, rc=%s\n", + tid, p, p->trace, p->owner, p->nRef, sqlite3ErrName(rc))); } #endif return rc; @@ -303,18 +327,23 @@ static int winMutexTry(sqlite3_mutex *p){ ** is not currently allocated. SQLite will never do either. */ static void winMutexLeave(sqlite3_mutex *p){ -#ifndef NDEBUG +#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) DWORD tid = GetCurrentThreadId(); +#endif + assert( p ); +#ifdef SQLITE_DEBUG assert( p->nRef>0 ); assert( p->owner==tid ); p->nRef--; if( p->nRef==0 ) p->owner = 0; assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE ); #endif + assert( winMutex_isInit==1 ); LeaveCriticalSection(&p->mutex); #ifdef SQLITE_DEBUG if( p->trace ){ - printf("leave mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef); + OSTRACE(("LEAVE-MUTEX tid=%lu, mutex=%p (%d), nRef=%d\n", + tid, p, p->trace, p->nRef)); } #endif } @@ -336,7 +365,7 @@ sqlite3_mutex_methods const *sqlite3DefaultMutex(void){ 0 #endif }; - return &sMutex; } + #endif /* SQLITE_MUTEX_W32 */ |