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| author | Rich Felker <dalias@aerifal.cx> | 2011-03-10 21:52:18 -0500 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2011-03-10 21:52:18 -0500 |
| commit | cfe581b6bc795e3f00ac30791314ec0f9be4b4ad (patch) | |
| tree | a9167b25647df5508a64e3b0b79b7582714c8e2e /src/thread/sem_trywait.c | |
| parent | 81af503610761a69476a3adbe8341fa8b6d078aa (diff) | |
| download | musl-cfe581b6bc795e3f00ac30791314ec0f9be4b4ad.tar.gz | |
fix some semaphore wait semantics (race condition deadlock and error checking)
Diffstat (limited to 'src/thread/sem_trywait.c')
| -rw-r--r-- | src/thread/sem_trywait.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/thread/sem_trywait.c b/src/thread/sem_trywait.c index d0e928ef..c5370c70 100644 --- a/src/thread/sem_trywait.c +++ b/src/thread/sem_trywait.c @@ -5,7 +5,8 @@ int sem_trywait(sem_t *sem) { int val = a_fetch_add(sem->__val, -1); if (val > 0) return 0; - a_inc(sem->__val); + if (!a_fetch_add(sem->__val, 1)) + __wake(sem->__val, 1, 0); errno = EAGAIN; return -1; } |