camerabin2: protect image location list with mutex

Rename the image taglists' mutex into image capture mutex and
use it also for the image capture list to prevent concurrent
access from different threads (application and capture threads).

2 files changed, 13 insertions, 10 deletions

diff --git a/gst/camerabin2/gstcamerabin2.c b/gst/camerabin2/gstcamerabin2.c
index d53b0da88..afae1014a 100644
--- a/gst/camerabin2/gstcamerabin2.c
+++ b/gst/camerabin2/gstcamerabin2.c
@@ -401,8 +401,10 @@ gst_camera_bin_start_capture (GstCameraBin2 * camerabin)
     }
   } else {
     /* store the next capture buffer filename */
+    g_mutex_lock (camerabin->image_capture_mutex);
     camerabin->image_location_list =
         g_slist_append (camerabin->image_location_list, g_strdup (location));
+    g_mutex_unlock (camerabin->image_capture_mutex);
   }
 
   if (camerabin->post_previews) {
@@ -433,11 +435,11 @@ gst_camera_bin_start_capture (GstCameraBin2 * camerabin)
   if (camerabin->mode == MODE_IMAGE) {
     /* Store image tags in a list and push them later, this prevents
        start_capture() from blocking in pad_push_event call */
-    g_mutex_lock (camerabin->image_tags_mutex);
+    g_mutex_lock (camerabin->image_capture_mutex);
     camerabin->image_tags_list =
         g_slist_append (camerabin->image_tags_list,
         taglist ? gst_tag_list_copy (taglist) : NULL);
-    g_mutex_unlock (camerabin->image_tags_mutex);
+    g_mutex_unlock (camerabin->image_capture_mutex);
   } else if (taglist) {
     GstPad *active_pad;
 
@@ -532,7 +534,7 @@ gst_camera_bin_dispose (GObject * object)
 
   g_free (camerabin->location);
   g_mutex_free (camerabin->preview_list_mutex);
-  g_mutex_free (camerabin->image_tags_mutex);
+  g_mutex_free (camerabin->image_capture_mutex);
 
   if (camerabin->src_capture_notify_id)
     g_signal_handler_disconnect (camerabin->src,
@@ -889,7 +891,7 @@ gst_camera_bin_init (GstCameraBin2 * camera)
   camera->max_zoom = MAX_ZOOM;
   camera->flags = DEFAULT_FLAGS;
   camera->preview_list_mutex = g_mutex_new ();
-  camera->image_tags_mutex = g_mutex_new ();
+  camera->image_capture_mutex = g_mutex_new ();
 
   /* capsfilters are created here as we proxy their caps properties and
    * this way we avoid having to store the caps while on NULL state to 
@@ -1273,14 +1275,14 @@ gst_camera_bin_image_src_buffer_probe (GstPad * pad, GstBuffer * buf,
   GstPad *peer;
   GstTagList *tags;
 
+  g_mutex_lock (camerabin->image_capture_mutex);
+
   /* Push pending image tags */
-  g_mutex_lock (camerabin->image_tags_mutex);
   if (camerabin->image_tags_list) {
     tags = camerabin->image_tags_list->data;
     camerabin->image_tags_list =
         g_slist_delete_link (camerabin->image_tags_list,
         camerabin->image_tags_list);
-    g_mutex_unlock (camerabin->image_tags_mutex);
     GST_DEBUG_OBJECT (camerabin, "Pushing tags from application: %"
         GST_PTR_FORMAT, tags);
     if (tags) {
@@ -1289,7 +1291,6 @@ gst_camera_bin_image_src_buffer_probe (GstPad * pad, GstBuffer * buf,
       gst_object_unref (peer);
     }
   } else {
-    g_mutex_unlock (camerabin->image_tags_mutex);
     GST_DEBUG_OBJECT (camerabin, "No tags from application to send");
   }
 
@@ -1303,8 +1304,10 @@ gst_camera_bin_image_src_buffer_probe (GstPad * pad, GstBuffer * buf,
         location);
   } else {
     GST_DEBUG_OBJECT (camerabin, "No filename location change to send");
+    g_mutex_unlock (camerabin->image_capture_mutex);
     return ret;
   }
+  g_mutex_unlock (camerabin->image_capture_mutex);
 
   if (location) {
     evt = gst_camera_bin_new_event_file_location (location);
@@ -1808,16 +1811,16 @@ gst_camera_bin_change_state (GstElement * element, GstStateChange trans)
       gst_tag_setter_reset_tags (GST_TAG_SETTER (camera));
       GST_CAMERA_BIN2_RESET_PROCESSING_COUNTER (camera);
 
+      g_mutex_lock (camera->image_capture_mutex);
       g_slist_foreach (camera->image_location_list, (GFunc) g_free, NULL);
       g_slist_free (camera->image_location_list);
       camera->image_location_list = NULL;
 
-      g_mutex_lock (camera->image_tags_mutex);
       g_slist_foreach (camera->image_tags_list,
           (GFunc) _gst_tag_list_free_maybe, NULL);
       g_slist_free (camera->image_tags_list);
       camera->image_tags_list = NULL;
-      g_mutex_unlock (camera->image_tags_mutex);
+      g_mutex_unlock (camera->image_capture_mutex);
 
       g_mutex_lock (camera->preview_list_mutex);
       g_slist_foreach (camera->preview_location_list, (GFunc) g_free, NULL);
diff --git a/gst/camerabin2/gstcamerabin2.h b/gst/camerabin2/gstcamerabin2.h
index 27115bdf4..ec740a57f 100644
--- a/gst/camerabin2/gstcamerabin2.h
+++ b/gst/camerabin2/gstcamerabin2.h
@@ -89,12 +89,12 @@ struct _GstCameraBin2
   /* Index of the auto incrementing file index for captures */
   gint capture_index;
 
+  GMutex *image_capture_mutex;
   /* stores list of image locations to be pushed to the image sink
    * as file location change notifications, they are pushed before
    * each buffer capture */
   GSList *image_location_list;
   /* Store also tags and push them before each captured image */
-  GMutex *image_tags_mutex;
   GSList *image_tags_list;
 
   /*