[Boost-bugs] [Boost C++ Libraries] #4978: Deadlock on interrupt() all threads if they are in wait()

Subject: [Boost-bugs] [Boost C++ Libraries] #4978: Deadlock on interrupt() all threads if they are in wait()
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-12-13 14:53:36

#4978: Deadlock on interrupt() all threads if they are in wait()
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 Reporter:  d.schneider@…           |       Owner:  anthonyw   
     Type:  Bugs                    |      Status:  new        
Milestone:  To Be Determined        |   Component:  thread     
  Version:  Boost 1.45.0            |    Severity:  Showstopper
 Keywords:                          |  
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 After the change in changeset 66228 a deadlock can happen, if many threads
 are in waiting state and then all threads will be interrupted.
 I just saw the problem on a 4-core 64-bit machine (gcc (Ubuntu
 4.4.3-4ubuntu5) 4.4.3). On an older 2-core machine (gcc (GCC) 3.4.6
 20060404 (Red Hat 3.4.6-11)) this newer occurred. It only happened with
 more than 5 threads, in average in every 2nd or 3th run.

 In condition_variable::wait() the following two mutex get locked:
 1. in interrupt_checker c-tor internal_mutex, there also
 thread_info::'''cond_mutex''' = internal_mutex get set
 2. in this_thread::interrupt_point thread_info->'''data_mutex''' to
 protect thread_info::interrupt_requested

 In thread::interrupt() the same two mutex get locked in reversed order:
 1. local_thread_info->'''data_mutex'''
 2. boost::pthread::pthread_mutex_scoped_lock
 internal_lock(local_thread_info->'''cond_mutex''');

 I attached my test code.

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Ticket URL: <https://svn.boost.org/trac/boost/ticket/4978>
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