[Boost-users] Boost::Interprocess mutex with condition variable

Subject: [Boost-users] Boost::Interprocess mutex with condition variable
From: Riskybiz (riskybizLive_at_[hidden])
Date: 2013-07-10 12:27:49

I'm trying to get a working implementation of a boost::interprocess
named_mutex with a  named_condition_variable.  I have created the following
toy console applications to try and understand what's necessary.  The
console application 'Sleeper' is run first; it simply creates some resources
and then goes to sleep.  Then 'Waker' is run with the intention that it
would cause the 'Sleeper' instance to resume execution and print out a
further message.  Ultimately the intention is to have one Waker process and
several Sleeper processes. 

 

When each application is run in a separate terminal window then the Sleeper
process sleeps and the Waker process tries to wake; but it is ineffective.
Can anyone advise what is wrong here and how to get the notify_all() to take
effect?

 

Thanks

 

Riskybiz.

 

// Sleeper.cpp : Defines the entry point for the console application.

//

 

#include "stdafx.h"

 

#include <boost/interprocess/managed_shared_memory.hpp>

#include <boost/interprocess/sync/named_mutex.hpp>

#include <boost/interprocess/sync/named_condition.hpp>

#include <iostream>

 

 

int _tmain(int argc, _TCHAR* argv[])

{

using namespace boost::interprocess;

 

//Clean up resources from any prior instances

named_condition::remove("msm_named_condition");

named_mutex::remove("msm_named_mutex");

//shared_memory_object::remove("msm");

 

//Setup shared memory resources

managed_shared_memory *msm = new managed_shared_memory(create_only, "msm",
10000);

named_mutex *nm = new named_mutex(create_only, "msm_named_mutex");

named_condition *nc = new named_condition(create_only,
"msm_named_condition");

 

try

{

scoped_lock<named_mutex> lock(*nm);//acquire scoped lock for mutex

std::cout << "Going to sleep now...." << std::endl;

nc->wait(lock);//induce wait

 std::cout << "Wide awake and back in the room" << std::endl;//print this
out on waking up

}

catch(interprocess_exception &ipe)

  {

  std::cout << "Error in Sleeper process: interprocess_exception: "<<
ipe.what() << std::endl;

  }

 

 

//Clean up

delete msm;

delete nm;

delete nc;

 

return 0;

}

 

 

 

// Waker.cpp : Defines the entry point for the console application.

//

 

#include "stdafx.h"

 

#include <boost/interprocess/managed_shared_memory.hpp>

#include <boost/interprocess/sync/named_mutex.hpp>

#include <boost/interprocess/sync/named_condition.hpp>

#include <iostream>

 

int _tmain(int argc, _TCHAR* argv[])

{

using namespace boost::interprocess;

 

//Setup shared memory resources

managed_shared_memory *msm = new managed_shared_memory(open_only, "msm");

named_mutex *nm = new named_mutex(open_only, "msm_named_mutex");

named_condition *nc = new named_condition(open_only, "msm_named_condition");

 

try

{

scoped_lock<named_mutex> lock(*nm);//acquire scoped lock for mutex

std::cout << "Going to Notify...." << std::endl;

nc->notify_all();//notify to release the wait condition

std::cout << "Wakey Wakey....Notified...." << std::endl;

}

catch(interprocess_exception &ipe)

  {

  std::cout << "Error in Waker process: interprocess_exception: "<<
ipe.what() << std::endl;

  }

 

//Clean up

delete msm;

delete nm;

delete nc;

 

return 0;

}