interprocess/example/comp_doc_anonymous_semaphoreB.cpp

//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2006-2012. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////

//[doc_anonymous_semaphoreB
#include <boost/interprocess/shared_memory_object.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <iostream>
#include "doc_anonymous_semaphore_shared_data.hpp"
//<-
#include "../test/get_process_id_name.hpp"
//->


using namespace boost::interprocess;

int main ()
{
   //Remove shared memory on destruction
   struct shm_remove
   {
      ~shm_remove(){ shared_memory_object::remove(test::get_process_id_name()); }
   } remover;
   //<-
   (void)remover;
   //->

   //Create a shared memory object.
   shared_memory_object shm
      ( open_only                      //only open
      , test::get_process_id_name()    //name
      , read_write                     //read-write mode
      );

   //Map the whole shared memory in this process
   mapped_region region
      (shm                       //What to map
      ,read_write //Map it as read-write
      );

   //Get the address of the mapped region
   void * addr       = region.get_address();

   //Obtain the shared structure
   shared_memory_buffer * data = static_cast<shared_memory_buffer*>(addr);

   const int NumMsg = 100;

   int extracted_data [NumMsg];
   //<-
   (void)extracted_data;
   //->

   //Extract the data
   for(int i = 0; i < NumMsg; ++i){
      data->nstored.wait();
      data->mutex.wait();
      extracted_data[i] = data->items[i % shared_memory_buffer::NumItems];
      data->mutex.post();
      data->nempty.post();
   }
   return 0;
}
//]