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authorUlrich Drepper <drepper@redhat.com>2005-09-25 23:58:51 +0000
committerUlrich Drepper <drepper@redhat.com>2005-09-25 23:58:51 +0000
commit560b47093fedfc210e2020d93c20fcfe3e620312 (patch)
tree67299737972434af7a2a89d8c64a520dc612dff8
parent9c5a79048766f0ac89aa84ad0c9a2f6e6dffec17 (diff)
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* pthread_cond_destroy.c (__pthread_cond_destroy): If there are
waiters, awake all waiters on the associated mutex.
-rw-r--r--nptl/ChangeLog5
-rw-r--r--nptl/pthread_cond_destroy.c30
2 files changed, 30 insertions, 5 deletions
diff --git a/nptl/ChangeLog b/nptl/ChangeLog
index 4884cc2..8e48cfd 100644
--- a/nptl/ChangeLog
+++ b/nptl/ChangeLog
@@ -1,3 +1,8 @@
+2004-09-02 Jakub Jelinek <jakub@redhat.com>
+
+ * pthread_cond_destroy.c (__pthread_cond_destroy): If there are
+ waiters, awake all waiters on the associated mutex.
+
2005-09-22 Roland McGrath <roland@redhat.com>
* perf.c [__x86_64__] (HP_TIMING_NOW): New macro (copied from
diff --git a/nptl/pthread_cond_destroy.c b/nptl/pthread_cond_destroy.c
index 0208d18..3e4ec8d 100644
--- a/nptl/pthread_cond_destroy.c
+++ b/nptl/pthread_cond_destroy.c
@@ -44,15 +44,35 @@ __pthread_cond_destroy (cond)
broadcasted, but still are using the pthread_cond_t structure,
pthread_cond_destroy needs to wait for them. */
unsigned int nwaiters = cond->__data.__nwaiters;
- while (nwaiters >= (1 << COND_CLOCK_BITS))
+
+ if (nwaiters >= (1 << COND_CLOCK_BITS))
{
- lll_mutex_unlock (cond->__data.__lock);
+ /* Wake everybody on the associated mutex in case there are
+ threads that have been requeued to it.
+ Without this, pthread_cond_destroy could block potentially
+ for a long time or forever, as it would depend on other
+ thread's using the mutex.
+ When all threads waiting on the mutex are woken up, pthread_cond_wait
+ only waits for threads to acquire and release the internal
+ condvar lock. */
+ if (cond->__data.__mutex != NULL
+ && cond->__data.__mutex != (void *) ~0l)
+ {
+ pthread_mutex_t *mut = (pthread_mutex_t *) cond->__data.__mutex;
+ lll_futex_wake (&mut->__data.__lock, INT_MAX);
+ }
+
+ do
+ {
+ lll_mutex_unlock (cond->__data.__lock);
- lll_futex_wait (&cond->__data.__nwaiters, nwaiters);
+ lll_futex_wait (&cond->__data.__nwaiters, nwaiters);
- lll_mutex_lock (cond->__data.__lock);
+ lll_mutex_lock (cond->__data.__lock);
- nwaiters = cond->__data.__nwaiters;
+ nwaiters = cond->__data.__nwaiters;
+ }
+ while (nwaiters >= (1 << COND_CLOCK_BITS));
}
return 0;