libs/interprocess/example/doc_shared_ptr_explicit.cpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2006-2009.
   4 // Distributed under the Boost Software License, Version 1.0.
   5 // (See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7 //
   8 // See http://www.boost.org/libs/interprocess for documentation.
   9 //
  10 //////////////////////////////////////////////////////////////////////////////
  11 #include <boost/interprocess/detail/config_begin.hpp>
  12 #include <boost/interprocess/detail/workaround.hpp>
  13
  14 //[doc_shared_ptr_explicit
  15 #include <boost/interprocess/managed_shared_memory.hpp>
  16 #include <boost/interprocess/smart_ptr/shared_ptr.hpp>
  17 #include <boost/interprocess/allocators/allocator.hpp>
  18 #include <boost/interprocess/smart_ptr/deleter.hpp>
  19 #include <cassert>
  20 //<-
  21 #include "../test/get_process_id_name.hpp"
  22 //->
  23
  24 using namespace boost::interprocess;
  25
  26 //This is type of the object we want to share
  27 class MyType
  28 {};
  29
  30 typedef managed_shared_memory::segment_manager segment_manager_type;
  31 typedef allocator<void, segment_manager_type>  void_allocator_type;
  32 typedef deleter<MyType, segment_manager_type>  deleter_type;
  33 typedef shared_ptr<MyType, void_allocator_type, deleter_type> my_shared_ptr;
  34
  35 int main ()
  36 {
  37    //Remove shared memory on construction and destruction
  38    struct shm_remove
  39    {
  40    //<-
  41    #if 1
  42       shm_remove() { shared_memory_object::remove(test::get_process_id_name()); }
  43       ~shm_remove(){ shared_memory_object::remove(test::get_process_id_name()); }
  44    #else
  45    //->
  46       shm_remove() { shared_memory_object::remove("MySharedMemory"); }
  47       ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
  48    //<-
  49    #endif
  50    //->
  51    } remover;
  52
  53    //<-
  54    #if 1
  55    managed_shared_memory segment(create_only, test::get_process_id_name(), 4096);
  56    #else
  57    //->
  58    managed_shared_memory segment(create_only, "MySharedMemory", 4096);
  59    //<-
  60    #endif
  61    //->
  62
  63    //Create a shared pointer in shared memory
  64    //pointing to a newly created object in the segment
  65    my_shared_ptr &shared_ptr_instance =
  66       *segment.construct<my_shared_ptr>("shared ptr")
  67          //Arguments to construct the shared pointer
  68          ( segment.construct<MyType>("object to share")()      //object to own
  69          , void_allocator_type(segment.get_segment_manager())  //allocator
  70          , deleter_type(segment.get_segment_manager())         //deleter
  71          );
  72    assert(shared_ptr_instance.use_count() == 1);
  73
  74    //Destroy "shared ptr". "object to share" will be automatically destroyed
  75    segment.destroy_ptr(&shared_ptr_instance);
  76
  77    return 0;
  78 }
  79 //]
  80 #include <boost/interprocess/detail/config_end.hpp>