summaryrefslogtreecommitdiff
path: root/libpthread/nptl/pthread_cond_destroy.c
diff options
context:
space:
mode:
Diffstat (limited to 'libpthread/nptl/pthread_cond_destroy.c')
-rw-r--r--libpthread/nptl/pthread_cond_destroy.c43
1 files changed, 34 insertions, 9 deletions
diff --git a/libpthread/nptl/pthread_cond_destroy.c b/libpthread/nptl/pthread_cond_destroy.c
index ebc6d78fc..b67b53506 100644
--- a/libpthread/nptl/pthread_cond_destroy.c
+++ b/libpthread/nptl/pthread_cond_destroy.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
@@ -22,16 +22,20 @@
int
-__pthread_cond_destroy (pthread_cond_t *cond)
+__pthread_cond_destroy (
+ pthread_cond_t *cond)
{
+ int pshared = (cond->__data.__mutex == (void *) ~0l)
+ ? LLL_SHARED : LLL_PRIVATE;
+
/* Make sure we are alone. */
- lll_mutex_lock (cond->__data.__lock);
+ lll_lock (cond->__data.__lock, pshared);
if (cond->__data.__total_seq > cond->__data.__wakeup_seq)
{
/* If there are still some waiters which have not been
woken up, this is an application bug. */
- lll_mutex_unlock (cond->__data.__lock);
+ lll_unlock (cond->__data.__lock, pshared);
return EBUSY;
}
@@ -42,15 +46,36 @@ __pthread_cond_destroy (pthread_cond_t *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_NWAITERS_SHIFT))
{
- 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,
+ PTHREAD_MUTEX_PSHARED (mut));
+ }
+
+ do
+ {
+ lll_unlock (cond->__data.__lock, pshared);
- lll_futex_wait (&cond->__data.__nwaiters, nwaiters);
+ lll_futex_wait (&cond->__data.__nwaiters, nwaiters, pshared);
- lll_mutex_lock (cond->__data.__lock);
+ lll_lock (cond->__data.__lock, pshared);
- nwaiters = cond->__data.__nwaiters;
+ nwaiters = cond->__data.__nwaiters;
+ }
+ while (nwaiters >= (1 << COND_NWAITERS_SHIFT));
}
return 0;