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-rw-r--r--src/thread/sem_post.c9
-rw-r--r--src/thread/sem_timedwait.c36
-rw-r--r--src/thread/sem_trywait.c5
3 files changed, 23 insertions, 27 deletions
diff --git a/src/thread/sem_post.c b/src/thread/sem_post.c
index 8f4700c3..148ab780 100644
--- a/src/thread/sem_post.c
+++ b/src/thread/sem_post.c
@@ -3,8 +3,11 @@
int sem_post(sem_t *sem)
{
- a_inc(sem->__val);
- if (sem->__val[1])
- __wake(sem->__val, 1, 0);
+ int val, waiters;
+ do {
+ val = sem->__val[0];
+ waiters = sem->__val[1];
+ } while (a_cas(sem->__val, val, val+1+(val<0)) != val);
+ if (val<0 || waiters) __wake(sem->__val, 1, 0);
return 0;
}
diff --git a/src/thread/sem_timedwait.c b/src/thread/sem_timedwait.c
index db05b417..1d4b3e2c 100644
--- a/src/thread/sem_timedwait.c
+++ b/src/thread/sem_timedwait.c
@@ -8,31 +8,21 @@ static void cleanup(void *p)
int sem_timedwait(sem_t *sem, const struct timespec *at)
{
- int r;
-
- if (a_fetch_add(sem->__val, -1) > 0) return 0;
- a_inc(sem->__val);
-
- if (at && at->tv_nsec >= 1000000000UL) {
- errno = EINVAL;
- return -1;
- }
-
- a_inc(sem->__val+1);
- pthread_cleanup_push(cleanup, sem->__val+1)
-
- for (;;) {
- r = 0;
- if (!sem_trywait(sem)) break;
- r = __timedwait_cp(sem->__val, 0, CLOCK_REALTIME, at, 0);
+ while (sem_trywait(sem)) {
+ int r;
+ if (at && at->tv_nsec >= 1000000000UL) {
+ errno = EINVAL;
+ return -1;
+ }
+ a_inc(sem->__val+1);
+ a_cas(sem->__val, 0, -1);
+ pthread_cleanup_push(cleanup, sem->__val+1);
+ r = __timedwait_cp(sem->__val, -1, CLOCK_REALTIME, at, 0);
+ pthread_cleanup_pop(1);
if (r) {
errno = r;
- r = -1;
- break;
+ return -1;
}
}
-
- pthread_cleanup_pop(1);
-
- return r;
+ return 0;
}
diff --git a/src/thread/sem_trywait.c b/src/thread/sem_trywait.c
index dd8f57e3..55d90075 100644
--- a/src/thread/sem_trywait.c
+++ b/src/thread/sem_trywait.c
@@ -4,7 +4,10 @@
int sem_trywait(sem_t *sem)
{
int val = sem->__val[0];
- if (val>0 && a_cas(sem->__val, val, val-1)==val) return 0;
+ if (val>0) {
+ int new = val-1-(val==1 && sem->__val[1]);
+ if (a_cas(sem->__val, val, new)==val) return 0;
+ }
errno = EAGAIN;
return -1;
}