From 5ed38596a529c1a63d6a3fab72861d14fbf1401c Mon Sep 17 00:00:00 2001
From: José Bollo <jose.bollo@iot.bzh>
Date: Fri, 1 Dec 2017 12:32:07 +0100
Subject: jobs: Fix locks in event loops
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Change-Id: Ie07a9bc4f930a0ecd2102a94e7f5f7b0daa705ef
Signed-off-by: José Bollo <jose.bollo@iot.bzh>
---
src/jobs.c | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)
diff --git a/src/jobs.c b/src/jobs.c
index e3df8f57..4b753fa1 100644
--- 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(¤t_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(¤t_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(¤t_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);
--
cgit