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| author | Rich Felker <dalias@aerifal.cx> | 2011-09-25 21:10:50 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2011-09-25 21:10:50 -0400 |
| commit | cf940165d4caf132405a3fe3df58b57eb735ac04 (patch) | |
| tree | 5b82feae2971e4bae563ce75d0b24897a61c169c | |
| parent | 09ec0f3aab4df2993f4a2a992529655f6c4f7a70 (diff) | |
| download | musl-cf940165d4caf132405a3fe3df58b57eb735ac04.tar.gz musl-cf940165d4caf132405a3fe3df58b57eb735ac04.tar.bz2 musl-cf940165d4caf132405a3fe3df58b57eb735ac04.tar.xz musl-cf940165d4caf132405a3fe3df58b57eb735ac04.zip | |
optimize cond waiter move using atomic swap instead of cas loop
| -rw-r--r-- | src/thread/pthread_cond_broadcast.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/src/thread/pthread_cond_broadcast.c b/src/thread/pthread_cond_broadcast.c index 7e5ea91c..4fab9994 100644 --- a/src/thread/pthread_cond_broadcast.c +++ b/src/thread/pthread_cond_broadcast.c @@ -30,12 +30,8 @@ int pthread_cond_broadcast(pthread_cond_t *c) } /* Move waiter count to the mutex */ - for (;;) { - w = c->_c_waiters; - a_fetch_add(&m->_m_waiters, w); - if (a_cas(&c->_c_waiters, w, 0) == w) break; - a_fetch_add(&m->_m_waiters, -w); - } + w = a_swap(&c->_c_waiters, 0); + a_fetch_add(&m->_m_waiters, w); /* Perform the futex requeue, waking one waiter unless we know * that the calling thread holds the mutex. */ |