diff options
Diffstat (limited to 'src/thread/pthread_rwlock_unlock.c')
| -rw-r--r-- | src/thread/pthread_rwlock_unlock.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/src/thread/pthread_rwlock_unlock.c b/src/thread/pthread_rwlock_unlock.c index 060e3fe1..5edca634 100644 --- a/src/thread/pthread_rwlock_unlock.c +++ b/src/thread/pthread_rwlock_unlock.c @@ -2,16 +2,17 @@ int pthread_rwlock_unlock(pthread_rwlock_t *rw) { - struct pthread *self = pthread_self(); - if (rw->_rw_owner == self->tid) { - rw->_rw_owner = 0; - a_store(&rw->_rw_wrlock, 0); - if (rw->_rw_waiters) - __wake(&rw->_rw_wrlock, -1, 0); - return 0; - } - a_dec(&rw->_rw_readers); - if (rw->_rw_waiters && !rw->_rw_readers) - __wake(&rw->_rw_readers, 1, 0); + int val, cnt, waiters, new; + + do { + val = rw->_rw_lock; + cnt = val & 0x7fffffff; + waiters = rw->_rw_waiters; + new = (cnt == 0x7fffffff || cnt == 1) ? 0 : val-1; + } while (a_cas(&rw->_rw_lock, val, new) != val); + + if (!new && (waiters || val<0)) + __wake(&rw->_rw_lock, 1, 0); + return 0; } |