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authorJakub Jelinek <jakub@redhat.com>2021-01-18 07:18:46 +0100
committerJakub Jelinek <jakub@redhat.com>2021-01-18 07:18:46 +0100
commitd3b41bde961713ff4af7e18011126434c497edba (patch)
tree72a909a9aa158d38893c15a79b86ac0649849b27
parent994fb69ac1b7d52348e84a021c07b24e285294d0 (diff)
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libgomp: Don't access gomp_sem_t as int using atomics unconditionally
This patch introduces gomp_sem_getcount wrapper, which uses sem_getvalue for POSIX and atomic loads for linux futex and accel. rtems for now remains broken. 2021-01-18 Jakub Jelinek <jakub@redhat.com> * config/linux/sem.h (gomp_sem_getcount): New function. * config/posix/sem.h (gomp_sem_getcount): New function. * config/posix/sem.c (gomp_sem_getcount): New function. * config/accel/sem.h (gomp_sem_getcount): New function. * task.c (task_fulfilled_p): Use gomp_sem_getcount. (omp_fulfill_event): Likewise.
-rw-r--r--libgomp/config/accel/sem.h9
-rw-r--r--libgomp/config/linux/sem.h9
-rw-r--r--libgomp/config/posix/sem.c20
-rw-r--r--libgomp/config/posix/sem.h10
-rw-r--r--libgomp/task.c4
5 files changed, 50 insertions, 2 deletions
diff --git a/libgomp/config/accel/sem.h b/libgomp/config/accel/sem.h
index aacd010..1b3cf99 100644
--- a/libgomp/config/accel/sem.h
+++ b/libgomp/config/accel/sem.h
@@ -62,4 +62,13 @@ gomp_sem_post (gomp_sem_t *sem)
{
(void) __atomic_add_fetch (sem, 1, MEMMODEL_RELEASE);
}
+
+static inline int
+gomp_sem_getcount (gomp_sem_t *sem)
+{
+ int count = __atomic_load_n (sem, MEMMODEL_RELAXED);
+ if (count < 0)
+ return -1;
+ return count;
+}
#endif /* GOMP_SEM_H */
diff --git a/libgomp/config/linux/sem.h b/libgomp/config/linux/sem.h
index da06ae5..bc0627d 100644
--- a/libgomp/config/linux/sem.h
+++ b/libgomp/config/linux/sem.h
@@ -85,4 +85,13 @@ gomp_sem_post (gomp_sem_t *sem)
if (__builtin_expect (count & SEM_WAIT, 0))
gomp_sem_post_slow (sem);
}
+
+static inline int
+gomp_sem_getcount (gomp_sem_t *sem)
+{
+ int count = __atomic_load_n (sem, MEMMODEL_RELAXED);
+ if ((count & SEM_WAIT) != 0)
+ return -1;
+ return count / SEM_INC;
+}
#endif /* GOMP_SEM_H */
diff --git a/libgomp/config/posix/sem.c b/libgomp/config/posix/sem.c
index d9bf6fb..18db25b 100644
--- a/libgomp/config/posix/sem.c
+++ b/libgomp/config/posix/sem.c
@@ -112,6 +112,26 @@ void gomp_sem_destroy (gomp_sem_t *sem)
return;
}
+
+int gomp_sem_getcount (gomp_sem_t *sem)
+{
+ int ret, count;
+
+ ret = pthread_mutex_lock (&sem->mutex);
+ if (ret)
+ return -1;
+
+ count = sem->value;
+
+ ret = pthread_mutex_unlock (&sem->mutex);
+ if (ret)
+ return -1;
+
+ if (count < 0)
+ return -1;
+
+ return count;
+}
#else /* HAVE_BROKEN_POSIX_SEMAPHORES */
void
gomp_sem_wait (gomp_sem_t *sem)
diff --git a/libgomp/config/posix/sem.h b/libgomp/config/posix/sem.h
index 34b17e9..4d7921b 100644
--- a/libgomp/config/posix/sem.h
+++ b/libgomp/config/posix/sem.h
@@ -64,6 +64,8 @@ extern void gomp_sem_post (gomp_sem_t *sem);
extern void gomp_sem_destroy (gomp_sem_t *sem);
+extern int gomp_sem_getcount (gomp_sem_t *sem);
+
#else /* HAVE_BROKEN_POSIX_SEMAPHORES */
typedef sem_t gomp_sem_t;
@@ -84,5 +86,13 @@ static inline void gomp_sem_destroy (gomp_sem_t *sem)
{
sem_destroy (sem);
}
+
+static inline int gomp_sem_getcount (gomp_sem_t *sem)
+{
+ int val;
+ if (sem_getvalue (sem, &val) < 0)
+ return -1;
+ return val;
+}
#endif /* doesn't HAVE_BROKEN_POSIX_SEMAPHORES */
#endif /* GOMP_SEM_H */
diff --git a/libgomp/task.c b/libgomp/task.c
index 5ece878..8db031c 100644
--- a/libgomp/task.c
+++ b/libgomp/task.c
@@ -330,7 +330,7 @@ gomp_task_handle_depend (struct gomp_task *task, struct gomp_task *parent,
static bool
task_fulfilled_p (struct gomp_task *task)
{
- return __atomic_load_n (&task->completion_sem, __ATOMIC_RELAXED);
+ return gomp_sem_getcount (&task->completion_sem) > 0;
}
/* Called when encountering an explicit task directive. If IF_CLAUSE is
@@ -2406,7 +2406,7 @@ omp_fulfill_event (omp_event_handle_t event)
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr ? thr->ts.team : NULL;
- if (__atomic_load_n (sem, __ATOMIC_RELAXED))
+ if (gomp_sem_getcount (sem) > 0)
gomp_fatal ("omp_fulfill_event: %p event already fulfilled!\n", sem);
gomp_debug (0, "omp_fulfill_event: %p\n", sem);