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| author | davidxu <davidxu@FreeBSD.org> | 2012-03-16 04:35:52 +0000 |
|---|---|---|
| committer | davidxu <davidxu@FreeBSD.org> | 2012-03-16 04:35:52 +0000 |
| commit | 02e067d118d4246773de1b129e5154ab8d455aff (patch) | |
| tree | e238c1fe839072498e9acbcafb15e2e66020ae0e /lib/libthr | |
| parent | dd9eff8d3914d10be3494051291f65b525a21fda (diff) | |
| download | FreeBSD-src-02e067d118d4246773de1b129e5154ab8d455aff.zip FreeBSD-src-02e067d118d4246773de1b129e5154ab8d455aff.tar.gz | |
When destroying a barrier, waiting all threads exit the barrier,
this makes it possible a thread received PTHREAD_BARRIER_SERIAL_THREAD
immediately free memory area of the barrier.
Diffstat (limited to 'lib/libthr')
| -rw-r--r-- | lib/libthr/thread/thr_barrier.c | 27 | ||||
| -rw-r--r-- | lib/libthr/thread/thr_private.h | 8 |
2 files changed, 31 insertions, 4 deletions
diff --git a/lib/libthr/thread/thr_barrier.c b/lib/libthr/thread/thr_barrier.c index bbd4447..86f880e 100644 --- a/lib/libthr/thread/thr_barrier.c +++ b/lib/libthr/thread/thr_barrier.c @@ -42,13 +42,34 @@ int _pthread_barrier_destroy(pthread_barrier_t *barrier) { pthread_barrier_t bar; + struct pthread *curthread; if (barrier == NULL || *barrier == NULL) return (EINVAL); + curthread = _get_curthread(); bar = *barrier; - if (bar->b_waiters > 0) + THR_UMUTEX_LOCK(curthread, &bar->b_lock); + if (bar->b_destroying) { + THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); return (EBUSY); + } + bar->b_destroying = 1; + do { + if (bar->b_waiters > 0) { + bar->b_destroying = 0; + THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); + return (EBUSY); + } + if (bar->b_refcount != 0) { + _thr_ucond_wait(&bar->b_cv, &bar->b_lock, NULL, 0); + THR_UMUTEX_LOCK(curthread, &bar->b_lock); + } else + break; + } while (1); + bar->b_destroying = 0; + THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); + *barrier = NULL; free(bar); return (0); @@ -74,6 +95,7 @@ _pthread_barrier_init(pthread_barrier_t *barrier, bar->b_cycle = 0; bar->b_waiters = 0; bar->b_count = count; + bar->b_refcount = 0; *barrier = bar; return (0); @@ -101,11 +123,14 @@ _pthread_barrier_wait(pthread_barrier_t *barrier) ret = PTHREAD_BARRIER_SERIAL_THREAD; } else { cycle = bar->b_cycle; + bar->b_refcount++; do { _thr_ucond_wait(&bar->b_cv, &bar->b_lock, NULL, 0); THR_UMUTEX_LOCK(curthread, &bar->b_lock); /* test cycle to avoid bogus wakeup */ } while (cycle == bar->b_cycle); + if (--bar->b_refcount == 0 && bar->b_destroying) + _thr_ucond_broadcast(&bar->b_cv); THR_UMUTEX_UNLOCK(curthread, &bar->b_lock); ret = 0; } diff --git a/lib/libthr/thread/thr_private.h b/lib/libthr/thread/thr_private.h index 7a9727f..4b9219d 100644 --- a/lib/libthr/thread/thr_private.h +++ b/lib/libthr/thread/thr_private.h @@ -182,9 +182,11 @@ struct pthread_cond_attr { struct pthread_barrier { struct umutex b_lock; struct ucond b_cv; - volatile int64_t b_cycle; - volatile int b_count; - volatile int b_waiters; + int64_t b_cycle; + int b_count; + int b_waiters; + int b_refcount; + int b_destroying; }; struct pthread_barrierattr { |
