sna: Reorder writes during thread task decoupling

So that the lockless reads do not see the task complete signal prior to
marking the task as successful. Otherwise, we falsely detect that the
thread trapped a signal and kill them all.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/src/sna/sna_threads.c b/src/sna/sna_threads.c
index 089d8ab..52fa405 100644 (file)
--- a/src/sna/sna_threads.c
+++ b/src/sna/sna_threads.c
@@ -67,8 +67,8 @@ static void *__run__(void *arg)
                t->func(t->arg);
 
                pthread_mutex_lock(&t->mutex);
-               t->func = NULL;
                t->arg = NULL;
+               t->func = NULL;
                pthread_cond_signal(&t->cond);
        }
        pthread_mutex_unlock(&t->mutex);
@@ -190,8 +190,8 @@ void sna_threads_trap(int sig)
        ERR(("%s: thread[%d] caught signal %d\n", __func__, n, sig));
 
        pthread_mutex_lock(&threads[n].mutex);
-       threads[n].func = NULL;
        threads[n].arg = (void *)(intptr_t)sig;
+       threads[n].func = NULL;
        pthread_cond_signal(&threads[n].cond);
        pthread_mutex_unlock(&threads[n].mutex);