Lock draw_queue id to prevent race conditions

On Windows, the main loop runs right after the idle source is added.
This causes the callback queue_draw function to assign a dead ID which
leads to the viewer never refreshing.

diff --git a/src/grits-viewer.c b/src/grits-viewer.c
index 67d25fb6027085129858af2f8bbb90739234add9..86d00c45256751f59d549c35bfa3a55641aff615 100644 (file)
--- a/src/grits-viewer.c
+++ b/src/grits-viewer.c
@@ -74,8 +74,10 @@ static void _grits_viewer_fix_rotation(GritsViewer *viewer)
 static gboolean _grits_viewer_queue_draw_cb(gpointer _viewer)
 {
        GritsViewer *viewer = _viewer;
+       g_mutex_lock(&viewer->draw_lock);
        gtk_widget_queue_draw(GTK_WIDGET(viewer));
        viewer->draw_source = 0;
+       g_mutex_unlock(&viewer->draw_lock);
        return FALSE;
 }
 
@@ -441,9 +443,11 @@ gboolean grits_viewer_get_offline(GritsViewer *viewer)
  */
 void grits_viewer_queue_draw(GritsViewer *viewer)
 {
+       g_mutex_lock(&viewer->draw_lock);
        if (!viewer->draw_source)
                viewer->draw_source = g_idle_add_full(G_PRIORITY_HIGH,
                                _grits_viewer_queue_draw_cb, viewer, NULL);
+       g_mutex_unlock(&viewer->draw_lock);
 }
 
 /***********************************
@@ -615,6 +619,8 @@ static void grits_viewer_init(GritsViewer *viewer)
        viewer->rotation[1] = 0;
        viewer->rotation[2] = 0;
 
+       g_mutex_init(&viewer->draw_lock);
+
        g_object_set(viewer, "can-focus", TRUE, NULL);
        gtk_widget_add_events(GTK_WIDGET(viewer),
                        GDK_BUTTON_PRESS_MASK |
@@ -636,13 +642,17 @@ static void grits_viewer_dispose(GObject *gobject)
 {
        g_debug("GritsViewer: dispose");
        GritsViewer *viewer = GRITS_VIEWER(gobject);
+       g_mutex_lock(&viewer->draw_lock);
        if (viewer->draw_source)
                g_source_remove(viewer->draw_source);
+       g_mutex_unlock(&viewer->draw_lock);
        G_OBJECT_CLASS(grits_viewer_parent_class)->dispose(gobject);
 }
 static void grits_viewer_finalize(GObject *gobject)
 {
        g_debug("GritsViewer: finalize");
+       GritsViewer *viewer = GRITS_VIEWER(gobject);
+       g_mutex_clear(&viewer->draw_lock);
        G_OBJECT_CLASS(grits_viewer_parent_class)->finalize(gobject);
        g_debug("GritsViewer: finalize - done");
 }

diff --git a/src/grits-viewer.h b/src/grits-viewer.h
index fa9fc079694b2789153840d7d54032e9e26de5d8..581751edfa10369763e18bda7637c9252ef8c8e1 100644 (file)
--- a/src/grits-viewer.h
+++ b/src/grits-viewer.h
@@ -122,6 +122,7 @@ struct _GritsViewer {
 
        /* For queue_draw */
        guint   draw_source;
+       GMutex  draw_lock;
 };
 
 struct _GritsViewerClass {