[mythtv-commits] Ticket #13150: Backend spawns threads until it crashes when user jobs active

[MythTV]

#13150: Backend spawns threads until it crashes when user jobs active
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     Reporter:  mythwiki@…          |      Owner:
         Type:  Bug Report - Crash  |     Status:  new
     Priority:  minor               |  Milestone:  needs_triage
    Component:  MythTV - General    |    Version:  Unspecified
     Severity:  medium              |   Keywords:
Ticket locked:  0                   |
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 I'm using LinHES, and the past two upgrades have had mythbackends that
 crash.  There seems to be a system that spawns a new thread roughly every
 two seconds.  Screen output when running in gdb is:

 {{{
 [New Thread 0x7ffd6bd37700 (LWP 30169)]
 2017-10-12 11:54:23.158482 I  MainServer: MainServer::ANN Monitor
 2017-10-12 11:54:23.158490 I  MainServer: adding:
 mythtv.i.cneufeld.ca(ca1920) as a client (events: 0)
 2017-10-12 11:54:23.728318 I  Monitor sock(ca1920) 'mythtv.i.cneufeld.ca'
 disconnected
 [New Thread 0x7ffd6b536700 (LWP 30225)]
 2017-10-12 11:54:24.941168 I  MainServer: MainServer::ANN Monitor
 2017-10-12 11:54:24.941177 I  MainServer: adding:
 mythtv.i.cneufeld.ca(ca19f0) as a client (events: 0)
 2017-10-12 11:54:25.517690 I  Monitor sock(ca19f0) 'mythtv.i.cneufeld.ca'
 disconnected
 }}}

 Eventually the system runs out of file descriptors for pipes and the
 backend crashes.
 In normal operation, there seems to be some housekeeping routine that is
 reaping the threads.  However, when there is a long-running user job (mine
 can run for hours), the threads pile up and the backend crashes.  It then
 is restarted by the system, and so resubmits the long job with the same
 jobqueue ID.

 My current version is  v0.28.1-44-gebd69ec
 There is a backtrace with some details at https://pastebin.com/mpN9eNcA

 I've built a backend with debugging symbols, and can test patches.

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Ticket URL: <https://code.mythtv.org/trac/ticket/13150>
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