diff options
Diffstat (limited to 'src/thread/sem_trywait.c')
| -rw-r--r-- | src/thread/sem_trywait.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/src/thread/sem_trywait.c b/src/thread/sem_trywait.c index beb7aa5d..dd8f57e3 100644 --- a/src/thread/sem_trywait.c +++ b/src/thread/sem_trywait.c @@ -3,9 +3,8 @@ int sem_trywait(sem_t *sem) { - if (a_fetch_add(sem->__val, -1) > 0) return 0; - if (!a_fetch_add(sem->__val, 1) && sem->__val[1]) - __wake(sem->__val, 1, 0); + int val = sem->__val[0]; + if (val>0 && a_cas(sem->__val, val, val-1)==val) return 0; errno = EAGAIN; return -1; } |