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Use ucond to implement barrier.

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This commit is contained in:
David Xu 2006-12-05 06:54:25 +00:00
parent 670b44d65a
commit 4d617f2d10
2 changed files with 10 additions and 8 deletions
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9
lib/libthr/thread/thr_barrier.c
View File

@ -70,6 +70,7 @@ _pthread_barrier_init(pthread_barrier_t *barrier,
return (ENOMEM);
_thr_umutex_init(&bar->b_lock);
_thr_ucond_init(&bar->b_cv);
bar->b_cycle = 0;
bar->b_waiters = 0;
bar->b_count = count;
@ -83,7 +84,7 @@ _pthread_barrier_wait(pthread_barrier_t *barrier)
{
struct pthread *curthread = _get_curthread();
pthread_barrier_t bar;
long cycle;
int64_t cycle;
int ret;
if (barrier == NULL || *barrier == NULL)
@ -95,16 +96,16 @@ _pthread_barrier_wait(pthread_barrier_t *barrier)
/* Current thread is lastest thread */
bar->b_waiters = 0;
bar->b_cycle++;
_thr_umtx_wake(&bar->b_cycle, bar->b_count - 1);
_thr_ucond_broadcast(&bar->b_cv);
THR_UMUTEX_UNLOCK(curthread, &bar->b_lock);
ret = PTHREAD_BARRIER_SERIAL_THREAD;
} else {
cycle = bar->b_cycle;
THR_UMUTEX_UNLOCK(curthread, &bar->b_lock);
do {
_thr_umtx_wait(&bar->b_cycle, cycle, NULL);
_thr_ucond_wait(&bar->b_cv, &bar->b_lock, NULL, 0);
/* test cycle to avoid bogus wakeup */
} while (cycle == bar->b_cycle);
THR_UMUTEX_UNLOCK(curthread, &bar->b_lock);
ret = 0;
}
return (ret);

9
lib/libthr/thread/thr_private.h
View File

@ -155,10 +155,11 @@ struct pthread_cond_attr {
};
struct pthread_barrier {
struct umutex b_lock;
volatile umtx_t b_cycle;
volatile int b_count;
volatile int b_waiters;
struct umutex b_lock;
struct ucond b_cv;
volatile int64_t b_cycle;
volatile int b_count;
volatile int b_waiters;
};
struct pthread_barrierattr {