How to avoid locking during changing state of element?

[박성호]

Hi Experts,

I made a demuxing element for test.
But it is very similar with ffmpeg's.
It works nice in pull mode.
However in push mode (i.e. streaming like dlna), it hangs at changing state
PAUSED to READY.
Hanging occurs only at middle of contents.
After end of content, normally changed.

This is the last log with --gst-debug=GST_STATES:5
==============================================================
LOG               GST_STATES
gstelement.c:2942:gst_element_change_state_func:<seonghotsdemuxer0> default
handler tries setting state from PAUSED to READY (001a)
==============================================================

Because of my poor googling ability, I didn't find solution to avoid this.
I just heard "Use new progress message api" "Use asynchronous state
changing" and "Improve your element".

I need more information with regard to changing state.
Anything, thanks.

Best regards.
Seongho.