jobs: Fix locks in event loops

Change-Id: Ie07a9bc4f930a0ecd2102a94e7f5f7b0daa705ef
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

diff --git a/src/jobs.c b/src/jobs.c
index e3df8f5..4b753fa 100644 (file)
--- a/src/jobs.c
+++ b/src/jobs.c
@@ -282,7 +282,7 @@ static void evloop_run(int signum, void *arg)
                                        ERROR("sd_event_wait returned an error (state: %d): %m", sd_event_get_state(se));
                                }
                        }
-                       el->state &= ~(EVLOOP_STATE_WAIT);
+                       __atomic_and_fetch(&el->state, ~(EVLOOP_STATE_WAIT), __ATOMIC_RELAXED);
 
                        if (rc > 0) {
                                rc = sd_event_dispatch(se);
@@ -293,7 +293,7 @@ static void evloop_run(int signum, void *arg)
                        }
                }
        }
-       el->state &= ~(EVLOOP_STATE_WAIT|EVLOOP_STATE_RUN);
+       __atomic_and_fetch(&el->state, ~(EVLOOP_STATE_WAIT|EVLOOP_STATE_RUN), __ATOMIC_RELAXED);
 }
 
 
@@ -326,8 +326,8 @@ static void thread_run(volatile struct thread *me)
        /* loop until stopped */
        while (!me->stop) {
                /* release the event loop */
-               if (current_evloop && !(current_evloop->state & EVLOOP_STATE_RUN)) {
-                       current_evloop->state -= EVLOOP_STATE_LOCK;
+               if (current_evloop) {
+                       __atomic_sub_fetch(&current_evloop->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED);
                        current_evloop = NULL;
                }
 
@@ -349,9 +349,9 @@ static void thread_run(volatile struct thread *me)
                } else {
                        /* no job, check events */
                        el = &evloop[0];
-                       if (el->sdev && !el->state) {
+                       if (el->sdev && !__atomic_load_n(&el->state, __ATOMIC_RELAXED)) {
                                /* run the events */
-                               el->state = EVLOOP_STATE_LOCK|EVLOOP_STATE_RUN|EVLOOP_STATE_WAIT;
+                               __atomic_store_n(&el->state, EVLOOP_STATE_LOCK|EVLOOP_STATE_RUN|EVLOOP_STATE_WAIT, __ATOMIC_RELAXED);
                                current_evloop = el;
                                pthread_mutex_unlock(&mutex);
                                sig_monitor(0, evloop_run, el);
@@ -369,6 +369,12 @@ static void thread_run(volatile struct thread *me)
                }
        }
 
+       /* release the event loop */
+       if (current_evloop) {
+               __atomic_sub_fetch(&current_evloop->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED);
+               current_evloop = NULL;
+       }
+
        /* unlink the current thread and cleanup */
        prv = &threads;
        while (*prv != me)
@@ -657,6 +663,8 @@ struct sd_event *jobs_get_sd_event()
        /* creates the evloop on need */
        el = &evloop[0];
        if (!el->sdev) {
+               /* start the creation */
+               el->state = 0;
                /* creates the eventfd for waking up polls */
                el->efd = eventfd(0, EFD_CLOEXEC);
                if (el->efd < 0) {
@@ -681,20 +689,18 @@ error1:
                        pthread_mutex_unlock(&mutex);
                        return NULL;
                }
-               /* terminate creation */
-               el->state = 0;
        }
 
        /* attach the event loop to the current thread */
        if (current_evloop != el) {
                if (current_evloop)
-                       current_evloop->state -= EVLOOP_STATE_LOCK;
+                       __atomic_sub_fetch(&current_evloop->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED);
                current_evloop = el;
-               el->state += EVLOOP_STATE_LOCK;
+               __atomic_add_fetch(&el->state, EVLOOP_STATE_LOCK, __ATOMIC_RELAXED);
        }
 
        /* wait for a modifiable event loop */
-       while (el->state & EVLOOP_STATE_WAIT) {
+       while (__atomic_load_n(&el->state, __ATOMIC_RELAXED) & EVLOOP_STATE_WAIT) {
                x = 1;
                write(el->efd, &x, sizeof x);
                pthread_cond_wait(&el->cond, &mutex);