Dear Team, I am involved in development of UI program that reads & writes metadata to a video MP4 files. Reading & writing is done by lower level library, apart from UI program, which also implemented by me. <pre style="font-family: arial,helvetica,sans-serif;" class="bz_comment_text" id="comment_text_11">This is the design implementation from lower-library is to read metadata from a video: 1. using a g_main_loop_new (NULL, FALSE); --> with default context 2. getting a bus from a pipeline & adding a bus watch for the gst_messages and upon EOS / in-case any error /Paused state , iam quitting the mainloop. bus = gst_pipeline_get_bus (GST_PIPELINE (self->pipeline)); gst_bus_add_watch (bus, bus_call, (gpointer)self); 3. The UI program is inturn having a g_main_loop and invoking this lower-library api for reading & writing the metadata . There are asyncrounous things happening .Reasons: i) since in case of large video files the lower-library is taking long time while reading or witing metadata . ii) mean while if we do any UI operations ..let us say suppose the same file is deleted . In this case .. before the control commes out of that lower-level api , the file is subjected to delete . this resulting in improper behavior . Is there any possibility of the 2 gmainloops mixing with each other ..? Is there any alternative ..so that we can remove the g_main_loop from lower-libray and use some other approach ? How to avoid g_main_loop in lower level Library ?can i replace with any..? How can i make this syncronous ? i tried with few : 1. creating new context in lowwer-library : I tried with context = g_main_context_new() and creating the loop = g_main_loop_new(context,FALSE) with that context . resulting in freezing upon g_main_loop_run(loop). 2. Instead of gst_bus_add_watch() , i used gst_bus_add_signal_watch () as shown below : here i removed g_main_loop & used g_main_iteration() Api until EOS/Error Stability of the reading/writing tags is undefined, some times this works & some it wont . 3)link: <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/chapter-bus.html">http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/chapter-bus.html</a> last 2 lines states that : If you aren't using GLib mainloop, the asynchronous message signals won't be available by default. You can however install a custom sync handler that wakes up the custom mainloop and that uses <code class="function">gst_bus_async_signal_func ()</code> to emit the signals. (see also <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/stable/gstreamer/html/GstBus.html" target="_top">documentation</a> for details) didnt get the idea ,how to implement this async handler .. Please suggest ... </pre>4) Please suggest if any more ideas ... Thanks & Regards, suman.