Bug 773131 – playbin3: Fix deadlock when adding multiple parsebin

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Bug 773131 - playbin3: Fix deadlock when adding multiple parsebin


Summary:	playbin3: Fix deadlock when adding multiple parsebin


Status:	RESOLVED FIXED

Product:	GStreamer
Classification:	Platform
Component:	gst-plugins-base
Version:	git master
Hardware:	Other Linux

Importance:	Normal normal
Target Milestone:	1.10.1
Assigned To:	GStreamer Maintainers
QA Contact:	GStreamer Maintainers

URL:
Whiteboard:

Depends on:
Blocks:

Reported:	2016-10-18 05:38 UTC by Wonchul Lee
Modified:	2016-11-15 10:08 UTC

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

Attachments
playbin3: Fix deadlock when adding multiple parsebin (1.26 KB, patch) 2016-10-18 05:39 UTC, Wonchul Lee	none	Details \| Review

Description Wonchul Lee 2016-10-18 05:38:38 UTC

It can be rarely reproduced with validate.dash.playback.change_state_intensive.dash_exMPD_BIP_TC1 validate case.

It happens when decodebin consist more than two parsebin in the pipeline such as the dash case and intensive playback. One holds SourceGroup lock in urisrc_pad_added() and try to acquire shutdown lock in pad_added_cb(). The other hold shutdown lock in no_more_pads_cb() and try to get SourceGroup lock. So I try to release SourceGroup lock before request a pad what will trigger pad_added_cb() in urisrc_pad_added().

In addition, I saw another type of deadlock with this validate test case which occurs regardless of this case. (not yet investigated deeply)

* Attached related stack trace

+ Trace 236747

Thread 6 (Thread 0x7fffd758b700 (LWP 1032))

#0 syscall
at ../sysdeps/unix/sysv/linux/x86_64/syscall.S line 38
#1 g_mutex_lock_slowpath
at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/gthread-posix.c line 1314
#2 no_more_pads_cb
at gstplaybin3.c line 3129
#3 pad_added_cb
at gstplaybin3.c line 2940
#4 g_cclosure_marshal_VOID__OBJECTv
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gmarshal.c line 1312
#5 _g_closure_invoke_va
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gclosure.c line 831
#6 g_signal_emit_valist
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gsignal.c line 3218
#7 g_signal_emit
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gsignal.c line 3365
#8 gst_element_add_pad
at gstelement.c line 713
#9 reconfigure_output_stream
at gstdecodebin3.c line 1891
#10 multiqueue_src_probe
at gstdecodebin3.c line 1480
#11 probe_hook_marshal
at gstpad.c line 3469
#12 g_hook_list_marshal
at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/ghook.c line 672
#13 do_probe_callbacks
at gstpad.c line 3621
#14 gst_pad_push_event_unchecked
at gstpad.c line 5238
#15 push_sticky
at gstpad.c line 3807
#16 events_foreach
at gstpad.c line 603
#17 check_sticky
at gstpad.c line 3864
#18 gst_pad_push_event
at gstpad.c line 5395
#19 gst_single_queue_push_one
at gstmultiqueue.c line 1652
#20 gst_multi_queue_loop
at gstmultiqueue.c line 1915
#21 gst_task_func
at gsttask.c line 334
#22 default_func
at gsttaskpool.c line 68
#23 g_thread_pool_thread_proxy
#24 g_thread_proxy
at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/gthread.c line 764
#25 start_thread
at pthread_create.c line 309
#26 clone
at ../sysdeps/unix/sysv/linux/x86_64/clone.S line 111

Thread 7 (Thread 0x7fffd6d8a700 (LWP 2103))

#0 syscall
at ../sysdeps/unix/sysv/linux/x86_64/syscall.S line 38
#1 g_mutex_lock_slowpath
at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/gthread-posix.c line 1314
#2 pad_added_cb
at gstplaybin3.c line 2807
#3 g_cclosure_marshal_VOID__OBJECTv
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gmarshal.c line 1312
#4 _g_closure_invoke_va
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gclosure.c line 831
#5 g_signal_emit_valist
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gsignal.c line 3218
#6 g_signal_emit
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gsignal.c line 3365
#7 gst_element_add_pad
at gstelement.c line 713
#8 create_new_input
at gstdecodebin3.c line 861
#9 gst_decodebin3_request_new_pad
at gstdecodebin3.c line 878
#10 _gst_element_request_pad
at gstelement.c line 982
#11 gst_element_get_request_pad
at gstelement.c line 1088
#12 urisrc_pad_added
at gstplaybin3.c line 4529
#13 g_cclosure_marshal_VOID__OBJECTv
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gmarshal.c line 1312
#14 _g_closure_invoke_va
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gclosure.c line 831
#15 g_signal_emit_valist
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gsignal.c line 3218
#16 g_signal_emit
at /build/glib2.0-y6934K/glib2.0-2.42.1/./gobject/gsignal.c line 3365
#17 gst_element_add_pad
at gstelement.c line 713
#18 expose_output_pad
at gsturisourcebin.c line 1318
#19 pending_pad_blocked
at gsturisourcebin.c line 990
#20 probe_hook_marshal
at gstpad.c line 3469
#21 g_hook_list_marshal
at /build/glib2.0-y6934K/glib2.0-2.42.1/./glib/ghook.c line 672
#22 do_probe_callbacks
at gstpad.c line 3621
#23 gst_pad_push_event_unchecked
at gstpad.c line 5231
#24 push_sticky
at gstpad.c line 3807
#25 events_foreach
at gstpad.c line 603
#26 check_sticky
at gstpad.c line 3864
#27 gst_pad_push_event
at gstpad.c line 5395
#28 gst_adaptive_demux_stream_push_buffer
at gstadaptivedemux.c line 2058
#29 gst_dash_demux_data_received

Comment 1 Wonchul Lee 2016-10-18 05:39:27 UTC

Created attachment 337915 [details] [review]
playbin3: Fix deadlock when adding multiple parsebin

Comment 2 Jan Schmidt 2016-11-15 10:08:01 UTC

Thanks, pushed to master and 1.10:

commit 8b95d17f75f2959175c387307be7449d752bef09
Author: Wonchul Lee <wonchul.lee@collabora.com>
Date:   Mon Oct 17 15:38:37 2016 +0900

    playbin3: Fix deadlock when adding multiple parsebin
    
    https://bugzilla.gnome.org/show_bug.cgi?id=773131