libs/interprocess/example/doc_private_node_allocator.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 #include <boost/interprocess/detail/workaround.hpp>
  12 //[doc_private_node_allocator
  13 #include <boost/interprocess/managed_shared_memory.hpp>
  14 #include <boost/interprocess/allocators/private_node_allocator.hpp>
  15 #include <cassert>
  16 //<-
  17 #include "../test/get_process_id_name.hpp"
  18 //->
  19
  20 using namespace boost::interprocess;
  21
  22 int main ()
  23 {
  24    //Remove shared memory on construction and destruction
  25    struct shm_remove
  26    {
  27    //<-
  28    #if 1
  29       shm_remove() { shared_memory_object::remove(test::get_process_id_name()); }
  30       ~shm_remove(){ shared_memory_object::remove(test::get_process_id_name()); }
  31    #else
  32    //->
  33       shm_remove() { shared_memory_object::remove("MySharedMemory"); }
  34       ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
  35    //<-
  36    #endif
  37    //->
  38    }  remover;
  39
  40    //Create shared memory
  41    //<-
  42    #if 1
  43    managed_shared_memory segment(create_only,
  44                                  test::get_process_id_name(),  //segment name
  45                                  65536);
  46    #else
  47    //->
  48    managed_shared_memory segment(create_only,
  49                                  "MySharedMemory",  //segment name
  50                                  65536);
  51    //<-
  52    #endif
  53    //->
  54
  55    //Create a private_node_allocator that allocates ints from the managed segment
  56    //The number of chunks per segment is the default value
  57    typedef private_node_allocator<int, managed_shared_memory::segment_manager>
  58       private_node_allocator_t;
  59    private_node_allocator_t allocator_instance(segment.get_segment_manager());
  60
  61    //Create another private_node_allocator.
  62    private_node_allocator_t allocator_instance2(segment.get_segment_manager());
  63
  64    //Although the segment manager address
  65    //is the same, this private_node_allocator will have its own pool so
  66    //"allocator_instance2" CAN'T deallocate nodes allocated by "allocator_instance".
  67    //"allocator_instance2" is NOT equal to "allocator_instance"
  68    assert(allocator_instance != allocator_instance2);
  69
  70    //Create another node_allocator using copy-constructor.
  71    private_node_allocator_t allocator_instance3(allocator_instance2);
  72
  73    //This allocator is also unequal to allocator_instance2
  74    assert(allocator_instance2 != allocator_instance3);
  75
  76    //Pools are destroyed with the allocators
  77    return 0;
  78 }
  79 //]
  80 #include <boost/interprocess/detail/config_end.hpp>