libs/interprocess/example/doc_adaptive_pool.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_adaptive_pool
  13 #include <boost/interprocess/managed_shared_memory.hpp>
  14 #include <boost/interprocess/allocators/adaptive_pool.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,test::get_process_id_name(), 65536);
  44    #else
  45    //->
  46    managed_shared_memory segment(create_only,
  47                                  "MySharedMemory",  //segment name
  48                                  65536);
  49    //<-
  50    #endif
  51    //->
  52
  53    //Create a adaptive_pool that allocates ints from the managed segment
  54    //The number of chunks per segment is the default value
  55    typedef adaptive_pool<int, managed_shared_memory::segment_manager>
  56       adaptive_pool_t;
  57    adaptive_pool_t allocator_instance(segment.get_segment_manager());
  58
  59    //Create another adaptive_pool. Since the segment manager address
  60    //is the same, this adaptive_pool will be
  61    //attached to the same pool so "allocator_instance2" can deallocate
  62    //nodes allocated by "allocator_instance"
  63    adaptive_pool_t allocator_instance2(segment.get_segment_manager());
  64
  65    //Create another adaptive_pool using copy-constructor. This
  66    //adaptive_pool will also be attached to the same pool
  67    adaptive_pool_t allocator_instance3(allocator_instance2);
  68
  69    //All allocators are equal
  70    assert(allocator_instance == allocator_instance2);
  71    assert(allocator_instance2 == allocator_instance3);
  72
  73    //So memory allocated with one can be deallocated with another
  74    allocator_instance2.deallocate(allocator_instance.allocate(1), 1);
  75    allocator_instance3.deallocate(allocator_instance2.allocate(1), 1);
  76
  77    //The common pool will be destroyed here, since no allocator is
  78    //attached to the pool
  79    return 0;
  80 }
  81 //]
  82 #include <boost/interprocess/detail/config_end.hpp>