[Boost-bugs] [Boost C++ Libraries] #12690: Boost Asio race condition

Subject: [Boost-bugs] [Boost C++ Libraries] #12690: Boost Asio race condition
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2016-12-14 14:39:48

#12690: Boost Asio race condition
-------------------------------------+----------------------------
 Reporter:  Ivan Kostov <ikostov@…>  |      Owner:  chris_kohlhoff
     Type:  Bugs                     |     Status:  new
Milestone:  To Be Determined         |  Component:  asio
  Version:  Boost 1.62.0             |   Severity:  Problem
 Keywords:  race condition           |
-------------------------------------+----------------------------
 The following test case issues an warning when executed with the thread
 sanitizer. The problem occurs when there is a pending job and the
 associated work is canceled.

 {{{
 BOOST_AUTO_TEST_CASE(ioServiceShallWaitForPendingJobs)
 {
   auto test = []()
   {
     boost::asio::io_service service;
     std::unique_ptr<boost::asio::io_service::work> work
       (new boost::asio::io_service::work(service));
     std::thread t(
       [&service]()
       {
         service.run();
       }
     );
     std::atomic_bool called{false};
     service.post(
         [&called]()
         {
           std::this_thread::sleep_for (std::chrono::milliseconds(50));
           called = true;
         }
     );
     std::this_thread::sleep_for (std::chrono::milliseconds(1));

     work.reset(); // -> race
     t.join();
     BOOST_REQUIRE(called);
   };

   for( size_t i = 0 ; i < 100000; ++i)
   {
     BOOST_TEST_MESSAGE(i);
     test();
   }
 }

 }}}

 The fix is in asio/detail/posix_event.hpp:55
 {{{
   // Signal the event and unlock the mutex.
   template <typename Lock>
   void signal_and_unlock(Lock& lock)
   {
     BOOST_ASIO_ASSERT(lock.locked());
     signalled_ = true;
 //    lock.unlock();
     ::pthread_cond_signal(&cond_); // Ignore EINVAL.
     lock.unlock(); // first signal and then unlock as the name implies
   }
 }}}
 Please find the output of the Clang as an attachment

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/12690>
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