From a83075398bddff015658d993a056417cf3e4bfbb Mon Sep 17 00:00:00 2001
From: paul <paul@0c269be4-1314-0410-8aa9-9f06e86f4224>
Date: Wed, 27 Jan 2010 18:45:36 +0000
Subject: [PATCH] fix race when ending freewheeling (from torben)

git-svn-id: svn+ssh://jackaudio.org/trunk/jack@3879 0c269be4-1314-0410-8aa9-9f06e86f4224
---
 jack/engine.h  |  5 +++--
 jackd/engine.c | 10 +++++++---
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/jack/engine.h b/jack/engine.h
index 438b13b..bab00ba 100644
--- a/jack/engine.h
+++ b/jack/engine.h
@@ -111,8 +111,10 @@ struct _jack_engine {
     unsigned long   fifo_size;
     unsigned long   external_client_cnt;
     int		    rtpriority;
-    char	    freewheeling;
+    volatile char   freewheeling;
+    volatile char   stop_freewheeling;
     jack_client_id_t fwclient;
+    pthread_t       freewheel_thread;
     char	    verbose;
     char	    do_munlock;
     const char	   *server_name;
@@ -122,7 +124,6 @@ struct _jack_engine {
     int		    feedbackcount;
     int             removing_clients;
     pid_t           wait_pid;
-    pthread_t       freewheel_thread;
     int             nozombies;
     volatile int    problems;
 
diff --git a/jackd/engine.c b/jackd/engine.c
index f1b659e..93b86b6 100644
--- a/jackd/engine.c
+++ b/jackd/engine.c
@@ -1749,6 +1749,7 @@ jack_engine_new (int realtime, int rtpriority, int do_mlock, int do_unlock,
 	engine->server_name = server_name;
 	engine->temporary = temporary;
 	engine->freewheeling = 0;
+	engine->stop_freewheeling = 0;
 	engine->fwclient = 0;
 	engine->feedbackcount = 0;
 	engine->wait_pid = wait_pid;
@@ -2019,7 +2020,7 @@ jack_engine_freewheel (void *arg)
 
 	client = jack_client_internal_by_id (engine, engine->fwclient);
 
-	while (engine->freewheeling) {
+	while (!engine->stop_freewheeling) {
 
 		jack_run_one_cycle (engine, engine->control->buffer_size, 0.0f);
 
@@ -2067,6 +2068,7 @@ jack_start_freewheeling (jack_engine_t* engine, jack_client_id_t client_id)
 	}
 
 	engine->freewheeling = 1;
+	engine->stop_freewheeling = 0;
 
 	event.type = StartFreewheel;
 	jack_deliver_event_to_all (engine, &event);
@@ -2104,13 +2106,15 @@ jack_stop_freewheeling (jack_engine_t* engine, int engine_exiting)
 	   to exit.
 	*/
 
-	engine->fwclient = 0;
-	engine->freewheeling = 0;
+	engine->stop_freewheeling = 1;
 
 	VERBOSE (engine, "freewheeling stopped, waiting for thread");
 	pthread_join (engine->freewheel_thread, &ftstatus);
 	VERBOSE (engine, "freewheel thread has returned");
 
+	engine->fwclient = 0;
+	engine->freewheeling = 0;
+
 	if (!engine_exiting) {
 		/* tell everyone we've stopped */