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| author | Bruce Momjian <bruce@momjian.us> | 2004-07-12 14:23:28 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2004-07-12 14:23:28 +0000 |
| commit | f4c5e06edf03774258886c802e63c5a3b9cf1e4c (patch) | |
| tree | e1f4598629ceee4835e49e60c43c297745e92632 /src | |
| parent | a29d26a3cdf8c61313ae459366eeb05f67772cc0 (diff) | |
| download | postgresql-f4c5e06edf03774258886c802e63c5a3b9cf1e4c.tar.gz postgresql-f4c5e06edf03774258886c802e63c5a3b9cf1e4c.zip | |
> win32 doesn't support a static initializer for mutexes, thus the first
> user must initialize the lock. The problem are concurrent "first" users
> - the pthread_mutex_t initialization must be synchronized.
> The current implementation is broken, the attached patches fixes that:
> mutex_initlock is a spinlock. If the pthread_mutex_t mutex is not
> initialized, then the spinlock is acquired, if the pthread_mutex_t is
> initialized if it's not yet initialized and then the spinlock is dropped.
Manfred Spraul
Diffstat (limited to 'src')
| -rw-r--r-- | src/interfaces/libpq/fe-connect.c | 16 | ||||
| -rw-r--r-- | src/interfaces/libpq/fe-secure.c | 16 |
2 files changed, 22 insertions, 10 deletions
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c index 89130a0f17b..ef503811228 100644 --- a/src/interfaces/libpq/fe-connect.c +++ b/src/interfaces/libpq/fe-connect.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.277 2004/07/12 14:16:28 momjian Exp $ + * $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.278 2004/07/12 14:23:28 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -3193,10 +3193,16 @@ default_threadlock(int acquire) #ifndef WIN32 static pthread_mutex_t singlethread_lock = PTHREAD_MUTEX_INITIALIZER; #else - static pthread_mutex_t singlethread_lock; - static long mutex_initialized = 0; - if (!InterlockedExchange(&mutex_initialized, 1L)) - pthread_mutex_init(&singlethread_lock, NULL); + static pthread_mutex_t singlethread_lock = NULL; + static long mutex_initlock = 0; + + if (singlethread_lock == NULL) { + while(InterlockedExchange(&mutex_initlock, 1) == 1) + /* loop, another thread own the lock */ ; + if (singlethread_lock == NULL) + pthread_mutex_init(&singlethread_lock, NULL); + InterlockedExchange(&mutex_initlock,0); + } #endif if (acquire) pthread_mutex_lock(&singlethread_lock); diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c index a60f34875d9..6e76e9674c4 100644 --- a/src/interfaces/libpq/fe-secure.c +++ b/src/interfaces/libpq/fe-secure.c @@ -11,7 +11,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.44 2004/07/12 14:16:28 momjian Exp $ + * $PostgreSQL: pgsql/src/interfaces/libpq/fe-secure.c,v 1.45 2004/07/12 14:23:28 momjian Exp $ * * NOTES * The client *requires* a valid server certificate. Since @@ -867,10 +867,16 @@ init_ssl_system(PGconn *conn) #ifndef WIN32 static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER; #else - static pthread_mutex_t init_mutex; - static long mutex_initialized = 0L; - if (!InterlockedExchange(&mutex_initialized, 1L)) - pthread_mutex_init(&init_mutex, NULL); + static pthread_mutex_t init_mutex = NULL; + static long mutex_initlock = 0; + + if (init_mutex == NULL) { + while(InterlockedExchange(&mutex_initlock, 1) == 1) + /* loop, another thread own the lock */ ; + if (init_mutex == NULL) + pthread_mutex_init(&init_mutex, NULL); + InterlockedExchange(&mutex_initlock,0); + } #endif pthread_mutex_lock(&init_mutex); |