[vlc-devel] [PATCH] src: os2: fix locking at quit
KO Myung-Hun
komh78 at gmail.com
Sat Oct 3 14:15:18 CEST 2015
Sometimes, especially at quit, vlc_cond_(timed)wait() may be called
very frequently. And this may exceed the limit the post count of
OS/2 event semaphore. As a result, waiting thread numbers cannot be
calculated properly.
To avoid this, increase/decrease waiting thread numbers in
vlc_cond_wait_common() instead of separating it into vlc_cond_signal()
and vlc_cond_wait_common().
---
src/os2/thread.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)
diff --git a/src/os2/thread.c b/src/os2/thread.c
index fa677ad..e805d08 100644
--- a/src/os2/thread.c
+++ b/src/os2/thread.c
@@ -350,18 +350,6 @@ void vlc_cond_signal (vlc_cond_t *p_condvar)
DosWaitEventSem (p_condvar->hevAck, SEM_INDEFINITE_WAIT);
DosResetEventSem (p_condvar->hevAck, &ulPost);
-
- while (ulPost-- > 0)
- __atomic_decrement (&p_condvar->waiters);
-
- /* Already timed out ? */
- if (__atomic_cmpxchg32 (&p_condvar->waiters, 0, 0) &&
- __atomic_cmpxchg32 (&p_condvar->signaled, 1, 1))
- {
- /* Clear signaled status */
- __atomic_xchg (&p_condvar->signaled, 0);
- DosResetEventSem (p_condvar->hev, &ulPost);
- }
}
}
@@ -380,12 +368,12 @@ static int vlc_cond_wait_common (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
ULONG ulPost;
ULONG rc;
- __atomic_increment (&p_condvar->waiters);
-
do
{
vlc_testcancel();
+ __atomic_increment (&p_condvar->waiters);
+
vlc_mutex_unlock (p_mutex);
do
@@ -396,6 +384,8 @@ static int vlc_cond_wait_common (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
} while (rc == NO_ERROR &&
__atomic_cmpxchg32 (&p_condvar->signaled, 0, 1) == 0);
+ __atomic_decrement (&p_condvar->waiters);
+
DosPostEventSem (p_condvar->hevAck);
vlc_mutex_lock (p_mutex);
--
2.5.2
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