Implement error checking for pthreads calls in thread-safe mode. They really

should always succeed, but in the likely event of a failure we would
previously fall through *without locking* - the new code will exit(1).

Printing the error message on stderr will not work for all applications, but
it's better than nothing at all - and our API doesn't provide a way to return
the error to the caller.

src/interfaces/libpq/fe-connect.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.357 2008/03/31 02:43:14 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.358 2008/05/16 18:30:53 mha Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3835,14 +3835,23 @@ default_threadlock(int acquire)
 		while (InterlockedExchange(&mutex_initlock, 1) == 1)
 			 /* loop, another thread own the lock */ ;
 		if (singlethread_lock == NULL)
-			pthread_mutex_init(&singlethread_lock, NULL);
+		{
+			if (pthread_mutex_init(&singlethread_lock, NULL))
+				PGTHREAD_ERROR("failed to initialize mutex");
+		}
 		InterlockedExchange(&mutex_initlock, 0);
 	}
 #endif
 	if (acquire)
-		pthread_mutex_lock(&singlethread_lock);
+	{
+		if (pthread_mutex_lock(&singlethread_lock))
+			PGTHREAD_ERROR("failed to lock mutex");
+	}
 	else
-		pthread_mutex_unlock(&singlethread_lock);
+	{
+		if (pthread_mutex_unlock(&singlethread_lock))
+			PGTHREAD_ERROR("failed to unlock mutex");
+	}
 #endif
 }
 

src/interfaces/libpq/fe-secure.c

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.104 2008/03/31 02:43:14 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.105 2008/05/16 18:30:53 mha Exp $
  *
  * NOTES
  *	  [ Most of these notes are wrong/obsolete, but perhaps not all ]
@@ -796,12 +796,21 @@ static void
 pq_lockingcallback(int mode, int n, const char *file, int line)
 {
 	if (mode & CRYPTO_LOCK)
-		pthread_mutex_lock(&pq_lockarray[n]);
+	{
+		if (pthread_mutex_lock(&pq_lockarray[n]))
+			PGTHREAD_ERROR("failed to lock mutex");
+	}
 	else
-		pthread_mutex_unlock(&pq_lockarray[n]);
+	{
+		if (pthread_mutex_unlock(&pq_lockarray[n]))
+			PGTHREAD_ERROR("failed to unlock mutex");
+	}
 }
 #endif   /* ENABLE_THREAD_SAFETY */
 
+/*
+ * Also see similar code in fe-connect.c, default_threadlock()
+ */
 static int
 init_ssl_system(PGconn *conn)
 {
@@ -817,11 +826,15 @@ init_ssl_system(PGconn *conn)
 		while (InterlockedExchange(&mutex_initlock, 1) == 1)
 			 /* loop, another thread own the lock */ ;
 		if (init_mutex == NULL)
-			pthread_mutex_init(&init_mutex, NULL);
+		{
+			if (pthread_mutex_init(&init_mutex, NULL))
+				return -1;
+		}
 		InterlockedExchange(&mutex_initlock, 0);
 	}
 #endif
-	pthread_mutex_lock(&init_mutex);
+	if (pthread_mutex_lock(&init_mutex))
+		return -1;
 
 	if (pq_initssllib && pq_lockarray == NULL)
 	{
@@ -836,7 +849,10 @@ init_ssl_system(PGconn *conn)
 			return -1;
 		}
 		for (i = 0; i < CRYPTO_num_locks(); i++)
-			pthread_mutex_init(&pq_lockarray[i], NULL);
+		{
+			if (pthread_mutex_init(&pq_lockarray[i], NULL))
+				return -1;
+		}
 
 		CRYPTO_set_locking_callback(pq_lockingcallback);
 	}

src/interfaces/libpq/libpq-int.h

@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.129 2008/01/01 19:46:00 momjian Exp $
+ * $PostgreSQL: pgsql/src/interfaces/libpq/libpq-int.h,v 1.130 2008/05/16 18:30:53 mha Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -439,6 +439,13 @@ extern bool pqGetHomeDirectory(char *buf, int bufsize);
 #ifdef ENABLE_THREAD_SAFETY
 extern pgthreadlock_t pg_g_threadlock;
 
+#define PGTHREAD_ERROR(msg) \
+	do { \
+		fprintf(stderr, "%s\n", msg); \
+		exit(1); \
+	} while (0)
+
+
 #define pglock_thread()		pg_g_threadlock(true)
 #define pgunlock_thread()	pg_g_threadlock(false)
 #else

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 1.15 2008/01/01 19:46:00 momjian Exp $
+*	$PostgreSQL: pgsql/src/interfaces/libpq/pthread-win32.c,v 1.16 2008/05/16 18:30:53 mha Exp $
 *
 *-------------------------------------------------------------------------
 */
@@ -32,20 +32,27 @@ pthread_getspecific(pthread_key_t key)
 	return NULL;
 }
 
-void
+int
 pthread_mutex_init(pthread_mutex_t *mp, void *attr)
 {
 	*mp = CreateMutex(0, 0, 0);
+	if (*mp == NULL)
+		return 1;
+	return 0;
 }
 
-void
+int
 pthread_mutex_lock(pthread_mutex_t *mp)
 {
-	WaitForSingleObject(*mp, INFINITE);
+	if (WaitForSingleObject(*mp, INFINITE) != WAIT_OBJECT_0)
+		return 1;
+	return 0;
 }
 
-void
+int
 pthread_mutex_unlock(pthread_mutex_t *mp)
 {
-	ReleaseMutex(*mp);
+	if (!ReleaseMutex(*mp))
+		return 1;
+	return 0;
 }