gst/gstbus.c: Only allow one bus watch to be set at a time. This is necessary because...

Original commit message from CVS:
Base on Patch by: Olivier Crete <tester at tester dot ca>
* gst/gstbus.c: (gst_bus_source_finalize),
(gst_bus_add_watch_full), (gst_bus_add_signal_watch_full):
Only allow one bus watch to be set at a time. This is necessary
because the dispatcher pops the message from the bus and the second
watcher will then get NULL or the next message (and the first won't
get this next message then, etc). If more than one "watcher" is
required signal watches should be used. Fixes bug #526044.

diff --git a/ChangeLog b/ChangeLog
index 888983c..2356506 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2008-10-13  Sebastian Dröge  <sebastian.droege@collabora.co.uk>
+
+       Base on Patch by: Olivier Crete <tester at tester dot ca>
+
+       * gst/gstbus.c: (gst_bus_source_finalize),
+       (gst_bus_add_watch_full), (gst_bus_add_signal_watch_full):
+       Only allow one bus watch to be set at a time. This is necessary
+       because the dispatcher pops the message from the bus and the second
+       watcher will then get NULL or the next message (and the first won't
+       get this next message then, etc). If more than one "watcher" is
+       required signal watches should be used. Fixes bug #526044.
+
 2008-10-12  Jan Schmidt  <jan.schmidt@sun.com>
 
        * tools/gst-launch.c:

diff --git a/gst/gstbus.c b/gst/gstbus.c
index 73b4259..1e7a0c8 100644 (file)
--- a/gst/gstbus.c
+++ b/gst/gstbus.c
@@ -107,6 +107,8 @@ struct _GstBusPrivate
   guint num_sync_message_emitters;
 
   GCond *queue_cond;
+
+  guint watch_id;
 };
 
 GType
@@ -155,8 +157,8 @@ marshal_VOID__MINIOBJECT (GClosure * closure, GValue * return_value,
     data2 = closure->data;
   }
   callback =
-      (marshalfunc_VOID__MINIOBJECT) (marshal_data ? marshal_data : cc->
-      callback);
+      (marshalfunc_VOID__MINIOBJECT) (marshal_data ? marshal_data :
+      cc->callback);
 
   callback (data1, gst_value_get_mini_object (param_values + 1), data2);
 }
@@ -801,6 +803,9 @@ gst_bus_source_finalize (GSource * source)
 {
   GstBusSource *bsource = (GstBusSource *) source;
 
+  if (bsource->bus->priv->watch_id == g_source_get_id (source))
+    bsource->bus->priv->watch_id = 0;
+
   gst_object_unref (bsource->bus);
   bsource->bus = NULL;
 }
@@ -847,6 +852,8 @@ gst_bus_create_watch (GstBus * bus)
  *
  * Adds a bus watch to the default main context with the given @priority.
  * This function is used to receive asynchronous messages in the main loop.
+ * There can only be a single bus watch per bus, you must remove it before you
+ * can set a new one.
  *
  * When @func is called, the message belongs to the caller; if you want to
  * keep a copy of it, call gst_message_ref() before leaving @func.
@@ -867,6 +874,12 @@ gst_bus_add_watch_full (GstBus * bus, gint priority,
 
   g_return_val_if_fail (GST_IS_BUS (bus), 0);
 
+  if (bus->priv->watch_id) {
+    GST_ERROR_OBJECT (bus,
+        "Tried to add new watch while one was already there");
+    return 0;
+  }
+
   source = gst_bus_create_watch (bus);
 
   if (priority != G_PRIORITY_DEFAULT)
@@ -877,6 +890,8 @@ gst_bus_add_watch_full (GstBus * bus, gint priority,
   id = g_source_attach (source, NULL);
   g_source_unref (source);
 
+  bus->priv->watch_id = id;
+
   GST_DEBUG_OBJECT (bus, "New source %p", source);
   return id;
 }
@@ -889,6 +904,8 @@ gst_bus_add_watch_full (GstBus * bus, gint priority,
  *
  * Adds a bus watch to the default main context with the default priority.
  * This function is used to receive asynchronous messages in the main loop.
+ * There can only be a single bus watch per bus, you must remove it before you
+ * can set a new one.
  *
  * The watch can be removed using g_source_remove() or by returning FALSE
  * from @func.
@@ -1188,6 +1205,9 @@ gst_bus_disable_sync_message_emission (GstBus * bus)
  * responsible for calling gst_bus_remove_signal_watch() as many times as this
  * function is called.
  *
+ * There can only be a single bus watch per bus, you most remove all signal watch
+ * before you can set another type of watch.
+ *
  * MT safe.
  */
 void
@@ -1207,6 +1227,12 @@ gst_bus_add_signal_watch_full (GstBus * bus, gint priority)
       gst_bus_add_watch_full (bus, priority, gst_bus_async_signal_func, NULL,
       NULL);
 
+  if (bus->signal_watch_id == 0) {
+    GST_ERROR_OBJECT (bus, "Could not add signal watch to bus");
+    GST_OBJECT_UNLOCK (bus);
+    return;
+  }
+
 done:
 
   bus->num_signal_watchers++;