Opened 8 years ago

Closed 6 years ago

#10564 closed Bug Report - Crash (Fixed)

mythbackend SIGSEGV in __pthread_mutex_lock()

Reported by: Marc Randolph <mrand@…> Owned by:
Priority: minor Milestone: 0.27
Component: MythTV - General Version: Master Head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

StacktraceTop:
 __pthread_mutex_lock (mutex=0x0) at pthread_mutex_lock.c:50
 QWaitCondition::wakeAll (this=0xa9c3d1b0) at thread/qwaitcondition_unix.cpp:139
 PreviewGenerator::TeardownAll (this=0xa9c3d198) at previewgenerator.cpp:91
 PreviewGenerator::deleteLater (this=0xa9c3d198) at previewgenerator.cpp:97
 PreviewGeneratorQueue::~PreviewGeneratorQueue (this=0x82fe8d8, __in_chrg=<optimized out>) at previewgeneratorqueue.cpp:57

Version: mythtv-backend 2:0.25.0~master.20120223.532cee8-0ubuntu1 Forwarding upstream from: https://bugs.launchpad.net/ubuntu/+source/mythtv/+bug/946257 See attachments for more complete traces.

Attachments (3)

ThreadStacktrace.txt (46.6 KB) - added by Marc Randolph <mrand@…> 8 years ago.
Stacktrace.txt (3.3 KB) - added by Marc Randolph <mrand@…> 8 years ago.
var.log.mythtv.mythbackend.log.txt.gz (347.3 KB) - added by Marc Randolph <mrand@…> 8 years ago.

Download all attachments as: .zip

Change History (5)

Changed 8 years ago by Marc Randolph <mrand@…>

Attachment: ThreadStacktrace.txt added

Changed 8 years ago by Marc Randolph <mrand@…>

Attachment: Stacktrace.txt added

Changed 8 years ago by Marc Randolph <mrand@…>

comment:1 Changed 6 years ago by Stuart Morgan <smorgan@…>

In 71988bd893c12fb9445120fa380257ad56d85e6e/mythtv:

Set previewgenerator point to NULL after deletion. If by chance the same generator has ended up in the queue twice this may possibly cause a segfault when tearing down the preview generator. Refs #10564

comment:2 Changed 6 years ago by stuartm

Milestone: unknown0.27
Resolution: Fixed
Status: newclosed

I can't really tell from the backtrace what might have triggered this segfault. I've pushed a possible fix, although I doubt that it really explains this issue. I'm closing as fixed for now, but please re-open the ticket if you see the same trace.

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