database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-07 02:42:48 +03:00
Code Activity

Restore the sqlite3_mutex_try() optimization on winNT systems. (CVS 4402)

Browse Source 
FossilOrigin-Name: 3aace2fa91e96038f7a32366828ac7520470fa67
This commit is contained in:
drh
2007-09-05 14:30:42 +00:00
parent ed10afb4c0
commit df6a81c838
3 changed files with 37 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
src/mutex_w32.c
View File

@@ -11,7 +11,7 @@
*************************************************************************
** This file contains the C functions that implement mutexes for win32
**
** $Id: mutex_w32.c,v 1.3 2007/09/04 22:31:37 drh Exp $
** $Id: mutex_w32.c,v 1.4 2007/09/05 14:30:42 drh Exp $
*/
#include "sqliteInt.h"
@@ -31,6 +31,33 @@ struct sqlite3_mutex {
DWORD owner; /* Thread holding this mutex */
};
/*
** 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 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 /* OS_WINCE */
/*
** The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. If it returns NULL
@@ -141,16 +168,10 @@ void sqlite3_mutex_enter(sqlite3_mutex *p){
p->nRef++;
}
int sqlite3_mutex_try(sqlite3_mutex *p){
/* The TryEnterCriticalSection() interface is not available on all
** windows systems. Since sqlite3_mutex_try() is only used as an
** optimization, we can skip it on windows. */
return SQLITE_BUSY;
#if 0 /* Not Available */
int rc;
assert( p );
assert( p->id==SQLITE_MUTEX_RECURSIVE || sqlite3_mutex_notheld(p) );
if( TryEnterCriticalSection(&p->mutex) ){
if( mutexIsNT() && TryEnterCriticalSection(&p->mutex) ){
p->owner = GetCurrentThreadId();
p->nRef++;
rc = SQLITE_OK;
@@ -158,7 +179,6 @@ int sqlite3_mutex_try(sqlite3_mutex *p){
rc = SQLITE_BUSY;
}
return rc;
#endif
}
/*