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boost interprocess named mutex remains acquired after a crash

I am using a boost::interpocess::scoped_lock using a named_mutex and a timeout; I am running in Linux OS.

During one of my tests I had a crash: since then, everytime I try to run again the application, it gets stuck on the point where I created the lock; it looks like the mutex remained acquired some way ( no possible process using it is running ).

On top of that if you look at the code below I am expecting that after 150 microseconds, the timed scoped_lock returns to give me an error..but this is not the case..it just hangs there.

      #include <boost/interprocess/sync/named_mutex.hpp>
      namespace bi = boost::interprocess;
      bi::named_mutex m_mutex;

 try{
      boost::posix_time::ptime pt( 
          boost::posix_time::microsec_clock::local_time() ) ;

      pt+= boost::posix_time::microseconds( 150 );
      bi::scoped_lock< bi::named_mutex > lock( m_mutex, pt );

      if( !lock.owns() ){
        FATAL( "I didn't acquire the lock." );
           return EXIT_FAILURE;
      }
     ....

My questions are the following:

  1. How to make sure that boost::interprocess named mutex is destroyed? ( so how to see the shared mutex across the processes and how to destroy them )
  2. Why acquiring the mutex doesn't return after 150 microseconds? Is here any something wrong in the code below?

Thanks a lot

AFG

like image 340
Abruzzo Forte e Gentile Avatar asked Oct 18 '11 14:10

Abruzzo Forte e Gentile


2 Answers

I found the solution: I missed to call the following to destroy the mutex

 boost::interprocess::named_mutex::remove( "MutexName" );

This code makes all the necessary clean up.

like image 115
Abruzzo Forte e Gentile Avatar answered Oct 13 '22 03:10

Abruzzo Forte e Gentile


boost::interprocess::named_mutex::remove( "MutexName" ); 

This should not be correct. This will unlock the mutex for all other processes, too.

like image 40
Borislav Ervacanin Avatar answered Oct 13 '22 04:10

Borislav Ervacanin