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Diffstat (limited to 'src/thread/pthread_cond_broadcast.c')
-rw-r--r--src/thread/pthread_cond_broadcast.c45
1 files changed, 18 insertions, 27 deletions
diff --git a/src/thread/pthread_cond_broadcast.c b/src/thread/pthread_cond_broadcast.c
index 7e5ea91c..bf6de048 100644
--- a/src/thread/pthread_cond_broadcast.c
+++ b/src/thread/pthread_cond_broadcast.c
@@ -1,48 +1,39 @@
#include "pthread_impl.h"
-static void unlock(pthread_cond_t *c)
-{
- a_dec(&c->_c_bcast);
- if (c->_c_leavers) __wake(&c->_c_bcast, -1, 0);
-}
-
int pthread_cond_broadcast(pthread_cond_t *c)
{
pthread_mutex_t *m;
- int w;
if (!c->_c_waiters) return 0;
- a_inc(&c->_c_bcast);
- if (!c->_c_waiters) {
- unlock(c);
- return 0;
- }
- a_store(&c->_c_block, 0);
+ a_inc(&c->_c_seq);
- m = c->_c_mutex;
-
- /* If mutex ptr is not available, simply wake all waiters. */
- if (m == (void *)-1) {
- unlock(c);
- __wake(&c->_c_block, -1, 0);
+ /* If cond var is process-shared, simply wake all waiters. */
+ if (c->_c_mutex == (void *)-1) {
+ __wake(&c->_c_seq, -1, 0);
return 0;
}
+ /* Block waiters from returning so we can use the mutex. */
+ while (a_swap(&c->_c_lock, 1))
+ __wait(&c->_c_lock, &c->_c_lockwait, 1, 1);
+ if (!c->_c_waiters)
+ goto out;
+ m = c->_c_mutex;
+
/* 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);
- }
+ a_fetch_add(&m->_m_waiters, c->_c_waiters);
+ a_store(&c->_c_waiters, 0);
/* Perform the futex requeue, waking one waiter unless we know
* that the calling thread holds the mutex. */
- __syscall(SYS_futex, &c->_c_block, FUTEX_REQUEUE,
+ __syscall(SYS_futex, &c->_c_seq, FUTEX_REQUEUE,
!m->_m_type || (m->_m_lock&INT_MAX)!=pthread_self()->tid,
INT_MAX, &m->_m_lock);
- unlock(c);
+out:
+ a_store(&c->_c_lock, 0);
+ if (c->_c_lockwait) __wake(&c->_c_lock, 1, 0);
+
return 0;
}