[Boost-bugs] [Boost C++ Libraries] #5502: race condition between shared_mutex timed_lock and lock_shared

Subject: [Boost-bugs] [Boost C++ Libraries] #5502: race condition between shared_mutex timed_lock and lock_shared
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-04-25 18:05:13

#5502: race condition between shared_mutex timed_lock and lock_shared
-------------------------------------+--------------------------------------
 Reporter:  eliothorowitz@…          |       Owner:  anthonyw   
     Type:  Bugs                     |      Status:  new        
Milestone:  To Be Determined         |   Component:  thread     
  Version:  Boost Release Branch     |    Severity:  Showstopper
 Keywords:                           |  
-------------------------------------+--------------------------------------
 There is a potential race condition between 3 threads.
 Thread 1 - has a shared lock
 Thread 2 - goes into a timed_lock loop with a small sleep
 Thread 3 - tries shared_lock

 Expected behavior:  Thread 3 gets the lock when thread 2 fails to get
 exclusive lock.

 What happens: based on timing, there can be a race condition causing a
 hang unless Thread 1 releases the lock.

 Test and patch for boost-trunk that fixes the problem for me attached.

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Ticket URL: <https://svn.boost.org/trac/boost/ticket/5502>
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