** 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.
*/
/*
** 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
#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 || SQLITE_OS_WINRT */
+#define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0 }
#endif
#ifdef SQLITE_DEBUG
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.
*/
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.
+
+/* 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;
+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;
}
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 ){
winMutex_isInit = 0;
}
}
- return SQLITE_OK;
+ return SQLITE_OK;
}
/*
**
** 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.
*/
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);
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;
}
*/
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);
** 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
** For that reason, we will omit this optimization for now. See
** ticket #2685.
*/
-#if 0
+#if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0400
assert( winMutex_isInit==1 );
- if( mutexIsNT() && TryEnterCriticalSection(&p->mutex) ){
+ if( sqlite3_win32_is_nt() && 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;
** 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--;
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
}
0
#endif
};
-
return &sMutex;
}
+
#endif /* SQLITE_MUTEX_W32 */
projects / thirdparty / sqlite.git / commitdiff
