[Boost-bugs] [Boost C++ Libraries] #5836: tss.cpp: tss_data_dec_use suffers a race condition

Subject: [Boost-bugs] [Boost C++ Libraries] #5836: tss.cpp: tss_data_dec_use suffers a race condition
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-08-30 05:48:25

#5836: tss.cpp: tss_data_dec_use suffers a race condition
--------------------------------+-------------------------------------------
 Reporter:  noloader@…          |       Owner:         
     Type:  Bugs                |      Status:  new    
Milestone:  To Be Determined    |   Component:  None   
  Version:  Boost 1.47.0        |    Severity:  Problem
 Keywords:                      |  
--------------------------------+-------------------------------------------
 It appears the reference counting of tss_data_use suffers a race
 condition. Perhaps it would be best to use an interlocked decrement on
 tss_data_use:

 {{{
 void tss_data_dec_use(boost::mutex::scoped_lock& lk)
 {
     if (0 == --tss_data_use)
     {
         tss_data_cleanup_handlers_type::size_type i;
         for (i = 0; i < tss_data_cleanup_handlers->size(); ++i)
         {
             delete (*tss_data_cleanup_handlers)[i];
         }
         delete tss_data_cleanup_handlers;
         tss_data_cleanup_handlers = 0;
         lk.unlock();
         delete tss_data_mutex;
         tss_data_mutex = 0;
 #if defined(BOOST_HAS_WINTHREADS)
         TlsFree(tss_data_native_key);
 #elif defined(BOOST_HAS_PTHREADS)
         pthread_key_delete(tss_data_native_key);
 #elif defined(BOOST_HAS_MPTASKS)
         // Don't know what to put here.
         // But MPTASKS isn't currently maintained anyways...
 #endif
     }
 }
 }}}

 In addition, it appears code built with BOOST_HAS_MPTASKS will fail in
 unexpected ways. Perhaps it would be a good idea to create a compile time
 failure to save users:

 Index: tss.cpp
 ===================================================================
 RCS file: /cvsroot/boost/boost/libs/thread/src/tss.cpp,v
 retrieving revision 1.20
 diff -r1.20 tss.cpp
 67a68
 >         #error "MPTASKS isn't currently maintained"

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5836>
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