Fix T47342: hang with freestyle viewport render and animation playback.

Not sure why I made the logic so complicated before, this change should solve
the deadlock when the render thread tries to acquire the main thread lock while
the main thread is waiting for threads to finish.

1 files changed, 11 insertions, 19 deletions

diff --git a/source/blender/windowmanager/intern/wm_jobs.c b/source/blender/windowmanager/intern/wm_jobs.c
index e445de27108..5580d3217a5 100644
--- a/source/blender/windowmanager/intern/wm_jobs.c
+++ b/source/blender/windowmanager/intern/wm_jobs.c
@@ -124,7 +124,6 @@ struct wmJob {
 	/* ticket mutex for main thread locking while some job accesses
 	 * data that the main thread might modify at the same time */
 	TicketMutex *main_thread_mutex;
-	bool main_thread_mutex_ending;
 };
 
 /* Main thread locking */
@@ -132,25 +131,15 @@ struct wmJob {
 void WM_job_main_thread_lock_acquire(wmJob *wm_job)
 {
 	BLI_ticket_mutex_lock(wm_job->main_thread_mutex);
-
-	/* if BLI_end_threads is being called to stop the job before it's finished,
-	 * we no longer need to lock to get access to the main thread as it's
-	 * waiting and can't respond */
-	if (wm_job->main_thread_mutex_ending)
-		BLI_ticket_mutex_unlock(wm_job->main_thread_mutex);
 }
 
 void WM_job_main_thread_lock_release(wmJob *wm_job)
 {
-	if (!wm_job->main_thread_mutex_ending)
-		BLI_ticket_mutex_unlock(wm_job->main_thread_mutex);
+	BLI_ticket_mutex_unlock(wm_job->main_thread_mutex);
 }
 
-static void wm_job_main_thread_yield(wmJob *wm_job, bool ending)
+static void wm_job_main_thread_yield(wmJob *wm_job)
 {
-	if (ending)
-		wm_job->main_thread_mutex_ending = true;
-
 	/* unlock and lock the ticket mutex. because it's a fair mutex any job that
 	 * is waiting to acquire the lock will get it first, before we can lock */
 	BLI_ticket_mutex_unlock(wm_job->main_thread_mutex);
@@ -206,7 +195,7 @@ wmJob *WM_jobs_get(wmWindowManager *wm, wmWindow *win, void *owner, const char *
 		BLI_strncpy(wm_job->name, name, sizeof(wm_job->name));
 
 		wm_job->main_thread_mutex = BLI_ticket_mutex_alloc();
-		BLI_ticket_mutex_lock(wm_job->main_thread_mutex);
+		WM_job_main_thread_lock_acquire(wm_job);
 	}
 	/* else: a running job, be careful */
 	
@@ -448,7 +437,7 @@ void WM_jobs_start(wmWindowManager *wm, wmJob *wm_job)
 static void wm_job_free(wmWindowManager *wm, wmJob *wm_job)
 {
 	BLI_remlink(&wm->jobs, wm_job);
-	BLI_ticket_mutex_unlock(wm_job->main_thread_mutex);
+	WM_job_main_thread_lock_release(wm_job);
 	BLI_ticket_mutex_free(wm_job->main_thread_mutex);
 	MEM_freeN(wm_job);
 }
@@ -459,8 +448,10 @@ static void wm_jobs_kill_job(wmWindowManager *wm, wmJob *wm_job)
 	if (wm_job->running) {
 		/* signal job to end */
 		wm_job->stop = true;
-		wm_job_main_thread_yield(wm_job, true);
+
+		WM_job_main_thread_lock_release(wm_job);
 		BLI_end_threads(&wm_job->threads);
+		WM_job_main_thread_lock_acquire(wm_job);
 
 		if (wm_job->endjob)
 			wm_job->endjob(wm_job->run_customdata);
@@ -576,7 +567,7 @@ void wm_jobs_timer(const bContext *C, wmWindowManager *wm, wmTimer *wt)
 			if (wm_job->threads.first) {
 
 				/* let threads get temporary lock over main thread if needed */
-				wm_job_main_thread_yield(wm_job, false);
+				wm_job_main_thread_yield(wm_job);
 				
 				/* always call note and update when ready */
 				if (wm_job->do_update || wm_job->ready) {
@@ -608,9 +599,10 @@ void wm_jobs_timer(const bContext *C, wmWindowManager *wm, wmTimer *wt)
 					}
 
 					wm_job->running = false;
-					wm_job_main_thread_yield(wm_job, true);
+
+					WM_job_main_thread_lock_release(wm_job);
 					BLI_end_threads(&wm_job->threads);
-					wm_job->main_thread_mutex_ending = false;
+					WM_job_main_thread_lock_acquire(wm_job);
 					
 					if (wm_job->endnote)
 						WM_event_add_notifier(C, wm_job->endnote, NULL);