libs/interprocess/example/comp_doc_anonymous_semaphoreB.cpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2006-2009. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/interprocess for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10 #include <boost/interprocess/detail/config_begin.hpp>
  11 //[doc_anonymous_semaphoreB
  12 #include <boost/interprocess/shared_memory_object.hpp>
  13 #include <boost/interprocess/mapped_region.hpp>
  14 #include <iostream>
  15 #include "doc_anonymous_semaphore_shared_data.hpp"
  16
  17 using namespace boost::interprocess;
  18
  19 int main ()
  20 {
  21    //Remove shared memory on destruction
  22    struct shm_remove
  23    {
  24       ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
  25    } remover;
  26
  27    //Create a shared memory object.
  28    shared_memory_object shm
  29       (open_only                    //only create
  30       ,"MySharedMemory"              //name
  31       ,read_write  //read-write mode
  32       );
  33
  34    //Map the whole shared memory in this process
  35    mapped_region region
  36       (shm                       //What to map
  37       ,read_write //Map it as read-write
  38       );
  39
  40    //Get the address of the mapped region
  41    void * addr       = region.get_address();
  42
  43    //Obtain the shared structure
  44    shared_memory_buffer * data = static_cast<shared_memory_buffer*>(addr);
  45
  46    const int NumMsg = 100;
  47
  48    int extracted_data [NumMsg];
  49
  50    //Extract the data
  51    for(int i = 0; i < NumMsg; ++i){
  52       data->nstored.wait();
  53       data->mutex.wait();
  54       extracted_data[i] = data->items[i % shared_memory_buffer::NumItems];
  55       data->mutex.post();
  56       data->nempty.post();
  57    }
  58    return 0;
  59 }
  60 //]
  61 #include <boost/interprocess/detail/config_end.hpp>