Reset process-graph semaphores on engine-restart

[ardour.git] / libs / ardour / graph.cc

diff --git a/libs/ardour/graph.cc b/libs/ardour/graph.cc
index 8f021a56953923ba69a9ed6a81aeaa6deb15484d..7b3719605f0307568552c6e9b872527d0e073a40 100644 (file)
--- a/libs/ardour/graph.cc
+++ b/libs/ardour/graph.cc
@@ -88,6 +88,9 @@ Graph::Graph (Session & session)
 void
 Graph::engine_stopped ()
 {
+#ifndef NDEBUG
+       cerr << "Graph::engine_stopped. n_thread: " << AudioEngine::instance()->process_thread_count() << endl;
+#endif
        if (AudioEngine::instance()->process_thread_count() != 0) {
                drop_threads ();
        }
@@ -162,7 +165,24 @@ Graph::drop_threads ()
 
        AudioEngine::instance()->join_process_threads ();
 
+       /* signal main process thread if it's waiting for an already terminated thread */
+       _callback_done_sem.signal ();
        _execution_tokens = 0;
+
+       /* reset semaphores.
+        * This is somewhat ugly, yet if a thread is killed (e.g jackd terminates
+        * abnormally), some semaphores are still unlocked.
+        */
+#ifndef NDEBUG
+       int d1 = _execution_sem.reset ();
+       int d2 = _callback_start_sem.reset ();
+       int d3 = _callback_done_sem.reset ();
+       cerr << "Graph::drop_threads() sema-counts: " << d1 << ", " << d2<< ", " << d3 << endl;
+#else
+       _execution_sem.reset ();
+       _callback_start_sem.reset ();
+       _callback_done_sem.reset ();
+#endif
 }
 
 void
@@ -438,6 +458,8 @@ again:
        DEBUG_TRACE(DEBUG::ProcessThreads, "main thread is awake\n");
 
        if (!_threads_active) {
+               pt->drop_buffers();
+               delete (pt);
                return;
        }