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-rw-r--r--src/internal/pthread_impl.h9
-rw-r--r--src/thread/pthread_cond_broadcast.c41
-rw-r--r--src/thread/pthread_cond_init.c5
-rw-r--r--src/thread/pthread_cond_timedwait.c21
4 files changed, 69 insertions, 7 deletions
diff --git a/src/internal/pthread_impl.h b/src/internal/pthread_impl.h
index d123e5e3..4c743d2e 100644
--- a/src/internal/pthread_impl.h
+++ b/src/internal/pthread_impl.h
@@ -64,9 +64,12 @@ struct __timer {
#define _m_prev __u.__p[3]
#define _m_next __u.__p[4]
#define _m_count __u.__i[5]
-#define _c_block __u.__i[0]
-#define _c_clock __u.__i[1]
-#define _c_waiters __u.__i[2]
+#define _c_mutex __u.__p[0]
+#define _c_block __u.__i[2]
+#define _c_waiters __u.__i[3]
+#define _c_clock __u.__i[4]
+#define _c_bcast __u.__i[5]
+#define _c_leavers __u.__i[6]
#define _rw_lock __u.__i[0]
#define _rw_waiters __u.__i[1]
#define _b_inst __u.__p[0]
diff --git a/src/thread/pthread_cond_broadcast.c b/src/thread/pthread_cond_broadcast.c
index dec91164..3daa7817 100644
--- a/src/thread/pthread_cond_broadcast.c
+++ b/src/thread/pthread_cond_broadcast.c
@@ -1,8 +1,47 @@
#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);
- if (c->_c_waiters) __wake(&c->_c_block, -1, 0);
+
+ 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);
+ return 0;
+ }
+
+ /* 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);
+ }
+
+ /* Perform the futex requeue, waking one waiter if and only if
+ * the calling thread does not hold the mutex. */
+ __syscall(SYS_futex, &c->_c_block, FUTEX_REQUEUE,
+ m->_m_lock!=pthread_self()->tid, INT_MAX, &m->_m_lock);
+
+ unlock(c);
return 0;
}
diff --git a/src/thread/pthread_cond_init.c b/src/thread/pthread_cond_init.c
index dc4fb981..03aff768 100644
--- a/src/thread/pthread_cond_init.c
+++ b/src/thread/pthread_cond_init.c
@@ -3,6 +3,9 @@
int pthread_cond_init(pthread_cond_t *c, const pthread_condattr_t *a)
{
memset(c, 0, sizeof *c);
- if (a) c->_c_clock = *a & 0x7fffffff;
+ if (a) {
+ c->_c_clock = *a & 0x7fffffff;
+ if (*a>>31) c->_c_mutex = (void *)-1;
+ }
return 0;
}
diff --git a/src/thread/pthread_cond_timedwait.c b/src/thread/pthread_cond_timedwait.c
index c71edc95..9616dd85 100644
--- a/src/thread/pthread_cond_timedwait.c
+++ b/src/thread/pthread_cond_timedwait.c
@@ -5,10 +5,25 @@ struct cm {
pthread_mutex_t *m;
};
+static void unwait(pthread_cond_t *c, pthread_mutex_t *m)
+{
+ int w;
+
+ /* Cannot leave waiting status if there are any live broadcasters
+ * which might be inspecting/using the mutex. */
+ while ((w=c->_c_bcast)) __wait(&c->_c_bcast, &c->_c_leavers, w, 0);
+
+ /* If the waiter count is zero, it must be the case that the
+ * caller's count has been moved to the mutex due to bcast. */
+ do w = c->_c_waiters;
+ while (w && a_cas(&c->_c_waiters, w, w-1)!=w);
+ if (!w) a_dec(&m->_m_waiters);
+}
+
static void cleanup(void *p)
{
struct cm *cm = p;
- a_dec(&cm->c->_c_waiters);
+ unwait(cm->c, cm->m);
pthread_mutex_lock(cm->m);
}
@@ -22,6 +37,8 @@ int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct t
pthread_testcancel();
+ if (c->_c_mutex != (void *)-1) c->_c_mutex = m;
+
a_inc(&c->_c_waiters);
c->_c_block = tid = pthread_self()->tid;
@@ -31,7 +48,7 @@ int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct t
while (c->_c_block == tid && (!e || e==EINTR));
if (e == EINTR) e = 0;
- a_dec(&c->_c_waiters);
+ unwait(c, m);
if ((r=pthread_mutex_lock(m))) return r;