[633/906] display: fail properly in context creation in order to minimize a race...

previously, on context creation, when we failed to get a valid context
we would still atempt to run the window mainloop as well as setting an error
on the display. This would cause the calling element to finalize the display
and therefore attempt to quit the window mainloop.  However the mainloop
may not have started running.  Thus when the window mainloop ran it would
never a get a quit message and never end.

diff --git a/gst-libs/gst/gl/gstgldisplay.c b/gst-libs/gst/gl/gstgldisplay.c
index fb01dfd..8a1c4b7 100644 (file)
--- a/gst-libs/gst/gl/gstgldisplay.c
+++ b/gst-libs/gst/gl/gstgldisplay.c
@@ -402,7 +402,7 @@ _create_context_opengl (GstGLDisplay * display, gint * gl_major, gint * gl_minor
     GST_INFO ("GL_SHADING_LANGUAGE_VERSION: %s",
         glGetString (GL_SHADING_LANGUAGE_VERSION));
   else
-    GST_INFO ("Your driver does not support GLSL (OpenGL Shading Language)");
+    GST_WARNING ("Your driver does not support GLSL (OpenGL Shading Language)");
 
   if (glGetString (GL_VENDOR))
     GST_INFO ("GL_VENDOR: %s", glGetString (GL_VENDOR));
@@ -478,9 +478,7 @@ gst_gl_display_thread_create_context (GstGLDisplay * display)
 
   if (!display->gl_window || error) {
     gst_gl_display_set_error (display, error ? error->message : "Failed to create gl window");
-    g_cond_signal (display->cond_create_context);
-    gst_gl_display_unlock (display);
-    return NULL;
+    goto failure;
   }
 
   GST_INFO ("gl window created");
@@ -494,10 +492,12 @@ gst_gl_display_thread_create_context (GstGLDisplay * display)
   compiled_api_s = gst_gl_api_string (compiled_api);
   GST_INFO ("compiled api support: %s", compiled_api_s);
 
-  if ((compiled_api & display->gl_api) == GST_GL_API_NONE)
+  if ((compiled_api & display->gl_api) == GST_GL_API_NONE) {
     gst_gl_display_set_error (display, "failed to create_context, window "
         "could not provide correct api. compiled api supports:%s, window "
         "supports:%s", compiled_api_s, api_string);
+    goto failure;
+  }
 
   g_free (api_string);
   g_free (compiled_api_s);
@@ -512,8 +512,10 @@ gst_gl_display_thread_create_context (GstGLDisplay * display)
     ret = _create_context_gles2 (display, &gl_major, &gl_minor);
 #endif
 
-  if (!ret || !gl_major)
+  if (!ret || !gl_major) {
     gst_gl_display_set_error (display, "failed to create context, unknown reason");
+    goto failure;
+  }
 
   /* setup callbacks */
   gst_gl_window_set_resize_callback (display->gl_window,
@@ -544,6 +546,18 @@ gst_gl_display_thread_create_context (GstGLDisplay * display)
   gst_gl_display_unlock (display);
 
   return NULL;
+
+failure:
+  {
+    if (display->gl_window) {
+      g_object_unref (display->gl_window);
+      display->gl_window = NULL;
+    }
+
+    g_cond_signal (display->cond_create_context);
+    gst_gl_display_unlock (display);
+    return NULL;
+  }
 }