diff --git a/libs/ardour/ardour/audioengine.h b/libs/ardour/ardour/audioengine.h
index 0226e23282..7060e68331 100644
--- a/libs/ardour/ardour/audioengine.h
+++ b/libs/ardour/ardour/audioengine.h
@@ -240,7 +240,7 @@ _	   the regular process() call to session->process() is not made.
 	static AudioEngine* instance() { return _instance; }
 	void died ();
 
-        pthread_t create_process_thread (boost::function<void()>, size_t stacksize);
+        int create_process_thread (boost::function<void()>, pthread_t*, size_t stacksize);
 
   private:
 	static AudioEngine*       _instance;
diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
index 7a3c279705..5f619d8392 100644
--- a/libs/ardour/audioengine.cc
+++ b/libs/ardour/audioengine.cc
@@ -1477,19 +1477,18 @@ AudioEngine::is_realtime () const
 	return jack_is_realtime (_priv_jack);
 }
 
-pthread_t
-AudioEngine::create_process_thread (boost::function<void()> f, size_t stacksize)
+int
+AudioEngine::create_process_thread (boost::function<void()> f, pthread_t* thread, size_t stacksize)
 {
         GET_PRIVATE_JACK_POINTER_RET (_jack, 0);
-        pthread_t thread;
         ThreadData* td = new ThreadData (this, f, stacksize);
 
-        if (jack_client_create_thread (_priv_jack, &thread, jack_client_real_time_priority (_priv_jack), 
+        if (jack_client_create_thread (_priv_jack, thread, jack_client_real_time_priority (_priv_jack), 
                                        jack_is_realtime (_priv_jack), _start_process_thread, td)) {
                 return -1;
         } 
 
-        return thread;
+        return 0;
 }
 
 void*
diff --git a/libs/ardour/graph.cc b/libs/ardour/graph.cc
index 0987b979a2..6dc76673ff 100644
--- a/libs/ardour/graph.cc
+++ b/libs/ardour/graph.cc
@@ -82,10 +82,15 @@ Graph::Graph (Session & session)
 
         info << string_compose (_("Using %2 threads on %1 CPUs"), num_cpu, num_threads) << endmsg;
 
-        _thread_list.push_back (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::main_thread, this), 100000));
+	pthread_t a_thread;
+
+	if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::main_thread, this), &a_thread, 100000) == 0) {
+		_thread_list.push_back (a_thread);
+	}
 
         for (int i = 1; i < num_threads; ++i) {
-                _thread_list.push_back (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::helper_thread, this), 100000));
+		if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::helper_thread, this), &a_thread, 100000));
+                _thread_list.push_back (a_thread);
         }
 }
 
@@ -317,7 +322,10 @@ Graph::run_one()
                 to_run = 0;
         }
 
-        int wakeup = min ((int) _execution_tokens, (int) _trigger_queue.size());
+	int et = _execution_tokens;
+	int ts = _trigger_queue.size();
+
+        int wakeup = min (et, ts);
         _execution_tokens -= wakeup;
 
         for (int i=0; i<wakeup; i++ ) {