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[[!meta title="libpthread: __pthread_enqueue: Assertion `thread->prevp == 0'
failed"]]

[[!tag open_issue_libpthread]]

IRC, OFTC, #debian-hurd, 2011-10-21:

    [Python testsuite]
    <pinotree> [169/340/1] test_logging
    <pinotree> python:
      /home/pino/sources/hurd/hurd-20110519/./libpthread/pthread/pt-internal.h:109:
      __pthread_enqueue: Assertion `thread->prevp == 0' failed.
    <pinotree> sigh

IRC, freenode, #hurd, 2011-10-21:

    <pinotree> am i missing anything, or in libpthread the __pthread_threads
      list does not ever has elements removed from it?
    <pinotree> ... thus potentially causing
      "./libpthread/pthread/pt-internal.h:109: __pthread_enqueue: Assertion
      `thread->prevp == 0' failed." because threads can be appended on
      __pthread_dealloc() to the __pthread_free_threads list as well?
    <pinotree> maybe reusing the same next+prevp pointers in the __pthread
      struct for more than one list at the same time isn't a good idea...

2011-10-23:

    <youpi> pinotree: I don't understand the relation between thread->prevp !=
      0 and the __pthread_threads list
    <youpi> the list never has elements removed indeed, since libpthread never
      frees __pthread structures apparently
    <pinotree> youpi: ye sorry, that relation is indeed nonsense
    <youpi> in which condition did you get prevp != 0
    <pinotree> i wa trying to find some explaination for the "thread->prevp ==
      0" assertion in the _queue function
    <youpi> ?
    <pinotree> *was
    <youpi> it's not obvious to me how libpthread makes sure the various
      cond/mutex/rwlock make sure that it's not queued several times
    <pinotree> yeah
    <pinotree> apparently prevp/next are used for lists of held
      waitcond/mutex/rwlock and free threads