ceph/src/boost/libs/interprocess/example/comp_doc_anonymous_conditionB.cpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2006-2012. 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_conditionB
  12 #include <boost/interprocess/shared_memory_object.hpp>
  13 #include <boost/interprocess/mapped_region.hpp>
  14 #include <boost/interprocess/sync/scoped_lock.hpp>
  15 #include <iostream>
  16 #include <cstring>
  17 #include "doc_anonymous_condition_shared_data.hpp"
  18
  19 using namespace boost::interprocess;
  20
  21 int main ()
  22 {
  23    //Create a shared memory object.
  24    shared_memory_object shm
  25       (open_only                    //only create
  26       ,"MySharedMemory"              //name
  27       ,read_write                   //read-write mode
  28       );
  29
  30    try{
  31       //Map the whole shared memory in this process
  32       mapped_region region
  33          (shm                       //What to map
  34          ,read_write //Map it as read-write
  35          );
  36
  37       //Get the address of the mapped region
  38       void * addr       = region.get_address();
  39
  40       //Obtain a pointer to the shared structure
  41       trace_queue * data = static_cast<trace_queue*>(addr);
  42
  43       //Print messages until the other process marks the end
  44       bool end_loop = false;
  45       do{
  46          scoped_lock<interprocess_mutex> lock(data->mutex);
  47          if(!data->message_in){
  48             data->cond_empty.wait(lock);
  49          }
  50          if(std::strcmp(data->items, "last message") == 0){
  51             end_loop = true;
  52          }
  53          else{
  54             //Print the message
  55             std::cout << data->items << std::endl;
  56             //Notify the other process that the buffer is empty
  57             data->message_in = false;
  58             data->cond_full.notify_one();
  59          }
  60       }
  61       while(!end_loop);
  62    }
  63    catch(interprocess_exception &ex){
  64       std::cout << ex.what() << std::endl;
  65       return 1;
  66    }
  67
  68    return 0;
  69 }
  70 //]
  71 #include <boost/interprocess/detail/config_end.hpp>