Use CRITICAL_SECTION instead of Mutexes for thread-locking in libpq on

mhagander · mhagander · commit 206378e4ab02 · 2008-05-21T14:20:48.000Z
Windows, for better performance.

Per suggestion from Andrew Chernow, but not his patch since the underlying
code was changed to deal with return values.
diff --git a/src/interfaces/libpq/pthread-win32.c b/src/interfaces/libpq/pthread-win32.c
@@ -5,7 +5,7 @@
 *
 * Copyright (c) 2004-2008, PostgreSQL Global Development Group
 * IDENTIFICATION
-*	$PostgreSQL: pgsql/src/interfaces/libpq/pthread-win32.c,v 1.16 2008/05/16 18:30:53 mha Exp $
+*	$PostgreSQL: pgsql/src/interfaces/libpq/pthread-win32.c,v 1.17 2008/05/21 14:20:48 mha Exp $
 *
 *-------------------------------------------------------------------------
 */
@@ -35,24 +35,27 @@ pthread_getspecific(pthread_key_t key)
 int
 pthread_mutex_init(pthread_mutex_t *mp, void *attr)
 {
-	*mp = CreateMutex(0, 0, 0);
-	if (*mp == NULL)
+	*mp = (CRITICAL_SECTION *)malloc(sizeof(CRITICAL_SECTION));
+	if (!*mp)
 		return 1;
+	InitializeCriticalSection(*mp);
 	return 0;
 }
 
 int
 pthread_mutex_lock(pthread_mutex_t *mp)
 {
-	if (WaitForSingleObject(*mp, INFINITE) != WAIT_OBJECT_0)
+	if (!*mp)
 		return 1;
+	EnterCriticalSection(*mp);
 	return 0;
 }
 
 int
 pthread_mutex_unlock(pthread_mutex_t *mp)
 {
-	if (!ReleaseMutex(*mp))
+	if (!*mp)
 		return 1;
+	LeaveCriticalSection(*mp);
 	return 0;
 }
diff --git a/src/port/pthread-win32.h b/src/port/pthread-win32.h
@@ -1,11 +1,11 @@
 /*
- * $PostgreSQL: pgsql/src/port/pthread-win32.h,v 1.4 2008/05/17 01:28:25 adunstan Exp $ 
+ * $PostgreSQL: pgsql/src/port/pthread-win32.h,v 1.5 2008/05/21 14:20:48 mha Exp $ 
  */
 #ifndef __PTHREAD_H
 #define __PTHREAD_H
 
 typedef ULONG pthread_key_t;
-typedef HANDLE pthread_mutex_t;
+typedef CRITICAL_SECTION *pthread_mutex_t;
 typedef int pthread_once_t;
 
 DWORD		pthread_self(void);

Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,7 @@`
`5`	`5`	`*`
`6`	`6`	`* Copyright (c) 2004-2008, PostgreSQL Global Development Group`
`7`	`7`	`* IDENTIFICATION`
`8`		`-* $PostgreSQL: pgsql/src/interfaces/libpq/pthread-win32.c,v 1.16 2008/05/16 18:30:53 mha Exp $`
	`8`	`+* $PostgreSQL: pgsql/src/interfaces/libpq/pthread-win32.c,v 1.17 2008/05/21 14:20:48 mha Exp $`
`9`	`9`	`*`
`10`	`10`	`*-------------------------------------------------------------------------`
`11`	`11`	`*/`
`@@ -35,24 +35,27 @@ pthread_getspecific(pthread_key_t key)`
`35`	`35`	`int`
`36`	`36`	`pthread_mutex_init(pthread_mutex_t mp, void attr)`
`37`	`37`	`{`
`38`		`- *mp = CreateMutex(0, 0, 0);`
`39`		`- if (*mp == NULL)`
	`38`	`+ mp = (CRITICAL_SECTION )malloc(sizeof(CRITICAL_SECTION));`
	`39`	`+ if (!*mp)`
`40`	`40`	`return 1;`
	`41`	`+ InitializeCriticalSection(*mp);`
`41`	`42`	`return 0;`
`42`	`43`	`}`
`43`	`44`
`44`	`45`	`int`
`45`	`46`	`pthread_mutex_lock(pthread_mutex_t *mp)`
`46`	`47`	`{`
`47`		`- if (WaitForSingleObject(*mp, INFINITE) != WAIT_OBJECT_0)`
	`48`	`+ if (!*mp)`
`48`	`49`	`return 1;`
	`50`	`+ EnterCriticalSection(*mp);`
`49`	`51`	`return 0;`
`50`	`52`	`}`
`51`	`53`
`52`	`54`	`int`
`53`	`55`	`pthread_mutex_unlock(pthread_mutex_t *mp)`
`54`	`56`	`{`
`55`		`- if (!ReleaseMutex(*mp))`
	`57`	`+ if (!*mp)`
`56`	`58`	`return 1;`
	`59`	`+ LeaveCriticalSection(*mp);`
`57`	`60`	`return 0;`
`58`	`61`	`}`