From 7de0057a37e3025a51a9aea935eb08d0a45e378c Mon Sep 17 00:00:00 2001
From: Magnus Hagander <magnus@hagander.net>
Date: Wed, 21 May 2008 14:20:48 +0000
Subject: [PATCH] Use CRITICAL_SECTION instead of Mutexes for thread-locking in
 libpq on Windows, for better performance.

Per suggestion from Andrew Chernow, but not his patch since the underlying
code was changed to deal with return values.
---
 src/interfaces/libpq/pthread-win32.c | 11 +++++++----
 src/port/pthread-win32.h             |  4 ++--
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/interfaces/libpq/pthread-win32.c b/src/interfaces/libpq/pthread-win32.c
index 08629ca957..0133b8c92d 100644
--- a/src/interfaces/libpq/pthread-win32.c
+++ b/src/interfaces/libpq/pthread-win32.c
@@ -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
index 71574e2a51..dbbbebf5c2 100644
--- a/src/port/pthread-win32.h
+++ b/src/port/pthread-win32.h
@@ -1,11 +1,11 @@
 /*
- * $PostgreSQL:$ 
+ * $PostgreSQL$ 
  */
 #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);
-- 
2.39.5