[mythtv-users] Reproducible Backend Crash (0.18.fixes)

[E Norm]

My master backend is crashing when the slave backend is terminated.
This does not always occur but rougly every other restart
of the slave backend will cause this segfault.

I'm using:
* http://svn.mythtv.org/svn/branches/release-0-18-fixes/mythtv
* gentoo x11-libs/qt-3.3.4-r8
* gentoo dev-db/mysql-4.1.14
on both servers.

The problem occurs in 0.18.1 as well (that's why i switched to 0.18.fixes)

I've been trying to look into the code, but the
PlaybackSock.sockLock attribute seems 100% legit.
It's a private attribute only used by one class method.

Oh, maybe the entire PlaybackSock instance is deleted when
the slave backend terminates while some other thread is
using it..

Could someone take a look at this?

regards
/Dan


(gdb) run
Starting program: /usr/bin/mythbackend --verbose quiet --logfile 
/var/log/mythtv/mythbackend.log
[Thread debugging using libthread_db enabled]
[New Thread 16384 (LWP 26094)]
Qt: gdb: -nograb added to command-line options.
          Use the -dograb option to enforce grabbing.
[New Thread 32769 (LWP 26100)]
[New Thread 16386 (LWP 26101)]
[New Thread 32771 (LWP 26103)]
[New Thread 49156 (LWP 26104)]
[New Thread 65541 (LWP 26105)]
[New Thread 81926 (LWP 26106)]
[New Thread 98311 (LWP 26107)]
[New Thread 114696 (LWP 26110)]
[New Thread 131081 (LWP 26111)]
[New Thread 147466 (LWP 26112)]
[New Thread 163851 (LWP 26113)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 32771 (LWP 26103)]
0x45525f59 in ?? ()





(gdb) thread apply all bt full
Thread 12 (Thread 163851 (LWP 26113)):
#0  0xb66f2094 in __pthread_sigsuspend () from /lib/libpthread.so.0
No symbol table info available.
#1  0xb66f1ed9 in __pthread_wait_for_restart_signal () from 
/lib/libpthread.so.0
No symbol table info available.
#2  0xb66edfdb in pthread_cond_wait at GLIBC_2.0 () from /lib/libpthread.so.0
No symbol table info available.
#3  0xb2fd1e08 in ?? ()
No symbol table info available.
#4  0x00000000 in ?? ()
No symbol table info available.
#5  0x080fdea8 in ?? ()
No symbol table info available.
#6  0xb66ede80 in pthread_cond_destroy at GLIBC_2.0 () from 
/lib/libpthread.so.0
No symbol table info available.
Previous frame inner to this frame (corrupt stack?)
#0  0x45525f59 in ?? ()
(gdb) st
start     step      stepi     stepping  stop





(gdb) backtrace
#0  0x45525f59 in ?? ()
#1  0xb6e548c8 in QMutex::unlock () from /usr/qt/3/lib/libqt-mt.so.3
#2  0x08095023 in PlaybackSock::SendReceiveStringList (this=0x80e1218, 
strlist=@0xb57d1ba0) at playbacksock.cpp:60
#3  0x08095725 in PlaybackSock::IsBusy (this=0x80e1218, 
capturecardnum=1) at playbacksock.cpp:145
#4  0x0805d9ee in EncoderLink::IsBusy (this=0x80f3460) at encoderlink.cpp:65
#5  0x0809d5ed in Scheduler::RunScheduler (this=0x80f3db0) at 
scheduler.cpp:1127
#6  0x0809e553 in Scheduler::SchedulerThread (param=0x80f3db0) at 
scheduler.cpp:1293
#7  0xb66ef18e in pthread_start_thread () from /lib/libpthread.so.0
#8  0xb66ef334 in pthread_start_thread_event () from /lib/libpthread.so.0
#9  0xb659eaaa in clone () from /lib/libc.so.6
(gdb)