Re: [Boost-bugs] [Boost C++ Libraries] #5752: boost::call_once() is unreliable on some platforms

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #5752: boost::call_once() is unreliable on some platforms
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-09-03 14:03:01

#5752: boost::call_once() is unreliable on some platforms
----------------------------------------------------+-----------------------
  Reporter:  Matthew Dempsky <matthew@…>            |       Owner:  viboes  
      Type:  Bugs                                   |      Status:  assigned
 Milestone:  Boost 1.52.0                           |   Component:  thread  
   Version:  Boost 1.47.0                           |    Severity:  Problem 
Resolution:                                         |    Keywords:  once    
----------------------------------------------------+-----------------------

Comment (by fhess):

 When SIG_ATOMIC_MAX is defined (that is, when I compile on Linux with g++
 4.4.5 and -std=c++0x) call_once does not work.  It never calls my function
 at all.  I debugged it, it happens because in thread/pthread/once.hpp in
 the call_once method it compares epoch and this_thread_epoch.  epoch is
 set to 0 and this_thread_epoch is set to -1 so the comparison is false and
 call once does nothing.  It seems the problem is due to uintmax_atomic_t
 being defined as a sig_atomic_t which turns out to be a signed rather than
 unsigned type.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5752#comment:9>
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