Bug 765132 – rtsp-server crash after last client is disconnected when media is shared

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Bug 765132 - rtsp-server crash after last client is disconnected when media is shared


Summary:	rtsp-server crash after last client is disconnected when media is shared


Status:	RESOLVED DUPLICATE of bug 764744

Product:	GStreamer
Classification:	Platform
Component:	gst-rtsp-server
Version:	1.8.0
Hardware:	Other Linux

Importance:	Normal normal
Target Milestone:	git master
Assigned To:	GStreamer Maintainers
QA Contact:	GStreamer Maintainers

URL:
Whiteboard:

Depends on:
Blocks:

Reported:	2016-04-16 05:11 UTC by Aleix Conchillo Flaqué
Modified:	2016-04-16 09:04 UTC

See Also:
GNOME target:	---
GNOME version:	---

Attachments
enabled media share (761 bytes, patch) 2016-04-16 05:11 UTC, Aleix Conchillo Flaqué	rejected	Details \| Review

Description Aleix Conchillo Flaqué 2016-04-16 05:11:14 UTC

Created attachment 326147 [details] [review]
enabled media share

When the last client is disconnected when media is shared, a crash occurs. The attached patch modifies examples/test-launch.c to enable media share.

These is the gdb session:

(lt-test-launch:12678): GStreamer-CRITICAL **: 
Trying to dispose element udpsrc1, but it is in PLAYING (locked) instead of the NULL state.
You need to explicitly set elements to the NULL state before
dropping the final reference, to allow them to clean up.
This problem may also be caused by a refcounting bug in the
application or some element.


Program received signal SIGTRAP, Trace/breakpoint trap.

+ Trace 236183

Thread 140737196738304 (LWP 12686)

#0 _g_log_abort
at gmessages.c line 324
#1 g_logv
at gmessages.c line 1081
#2 g_log
at gmessages.c line 1119
#3 g_object_unref
at gobject.c line 3142
#4 gst_object_unref
at gstobject.c line 282
#5 gst_bin_remove_func
at gstbin.c line 1638
#6 gst_bin_remove
at gstbin.c line 1700
#7 gst_bin_dispose
at gstbin.c line 527
#8 g_object_unref
at gobject.c line 3142
#9 gst_object_unref
at gstobject.c line 282
#10 gst_rtsp_media_finalize
at rtsp-media.c line 438
#11 g_object_unref
at gobject.c line 3179
#12 g_source_callback_unref
at gmain.c line 1561
#13 g_main_dispatch
at gmain.c line 3161
#14 g_main_context_dispatch
at gmain.c line 3769
#15 g_main_context_iterate
at gmain.c line 3840
#16 g_main_loop_run
at gmain.c line 4034
#17 do_loop
at rtsp-thread-pool.c line 329
#18 g_thread_pool_thread_proxy
at gthreadpool.c line 307
#19 g_thread_proxy
at gthread.c line 778
#20 start_thread
at pthread_create.c line 333
#21 clone
at ../sysdeps/unix/sysv/linux/x86_64/clone.S line 109

Comment 1 Aleix Conchillo Flaqué 2016-04-16 05:44:33 UTC

This is the offending commit:

https://cgit.freedesktop.org/gstreamer/gst-rtsp-server/commit/?id=f62a9a7eb9fda096fb88c013d6787c28090037a2

Comment 2 Aleix Conchillo Flaqué 2016-04-16 06:48:26 UTC

I believe the problem is that because the media is shared, new udpsrc ports are allocated in the same stream:

https://cgit.freedesktop.org/gstreamer/gst-rtsp-server/tree/gst/rtsp-server/rtsp-stream.c#n1514

Then, when we leave the bin we are only setting the NULL state to udpsrc_v4[0] and udpsrc_v4[1].

https://cgit.freedesktop.org/gstreamer/gst-rtsp-server/tree/gst/rtsp-server/rtsp-stream.c#n2938

But unfortunately we have lost the reference to the previous ones when the media is shared and there already was a first client

Before this patch I believe we were keeping a list of all the transports.

Comment 3 Sebastian Dröge (slomo) 2016-04-16 09:04:32 UTC

Thanks for taking the time to report this.
This particular bug has already been reported into our bug tracking system, but please feel free to report any further bugs you find.

*** This bug has been marked as a duplicate of bug 764744 ***