Re: [Boost-bugs] [Boost C++ Libraries] #7461: detail::win32::ReleaseSemaphore may be called with count_to_release equal to 0

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #7461: detail::win32::ReleaseSemaphore may be called with count_to_release equal to 0
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-10-11 17:25:49

#7461: detail::win32::ReleaseSemaphore may be called with count_to_release equal
to 0
-----------------------------------------------------+----------------------
  Reporter:  Jesper Storm Bache <jsbache@…>          |       Owner:  viboes  
      Type:  Bugs                                    |      Status:  assigned
 Milestone:  To Be Determined                        |   Component:  thread  
   Version:  Boost 1.51.0                            |    Severity:  Problem 
Resolution:                                          |    Keywords:          
-----------------------------------------------------+----------------------

Comment (by jsbache@…):

 I apologize for the terseness. Here are a few detais.
 When I notice a zero count, the stack is:
         c4test.exe!boost::detail::basic_cv_list_entry::release(unsigned
 int count_to_release=0)  Line 68
         c4test.exe!boost::detail::basic_cv_list_entry::release_waiters()
 Line 73
         c4test.exe!boost::detail::basic_condition_variable::notify_all()
 Line 285 + 0x1a bytes

 My conditional breakpoint (condition: "count_to_release == 0) is on the
 following line (before we modify notified)
 {{{
    void release(unsigned count_to_release)
    {
    --break--       notified=true;
 }}}

 When I hit this, code I have the following state of the local variables.
 Note that notified = true at this point in time,
 {{{
 it      {px=0x0000000001dde7b0 }
         [ptr]   0x0000000001dd75b8 {px=0x0000000001dde7b0 }
         px      0x0000000001dde7b0
         semaphore       {handle_to_manage=0x0000000000000100 }
         wake_sem        {handle_to_manage=0x0000000000000184 }
         waiters         0
         notified        true
         references      1

 this    0x00000000003dee28
         internal_mutex  {...}   boost::mutex
         total_count     0       long
         active_generation_count 0       unsigned int
         generations     [2]({px=0x0000000001dde630
 },{px=0x0000000001dde7b0 })
         wake_sem        {handle_to_manage=0x0000000000000198 }
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7461#comment:4>
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