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
11#include <boost/interprocess/detail/workaround.hpp>
12//[doc_node_allocator
13#include <boost/interprocess/managed_shared_memory.hpp>
14#include <boost/interprocess/allocators/node_allocator.hpp>
15#include <cassert>
16//<-
17#include "../test/get_process_id_name.hpp"
18//->
19
20using namespace boost::interprocess;
21
22int 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(filename: test::get_process_id_name()); }
30 ~shm_remove(){ shared_memory_object::remove(filename: 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 (void)remover;
41 //->
42
43 //Create shared memory
44 //<-
45 #if 1
46 managed_shared_memory segment(create_only,
47 test::get_process_id_name(), //segment name
48 65536);
49 #else
50 //->
51 managed_shared_memory segment(create_only,
52 "MySharedMemory", //segment name
53 65536);
54 //<-
55 #endif
56 //->
57
58 //Create a node_allocator that allocates ints from the managed segment
59 //The number of chunks per segment is the default value
60 typedef node_allocator<int, managed_shared_memory::segment_manager>
61 node_allocator_t;
62 node_allocator_t allocator_instance(segment.get_segment_manager());
63
64 //Create another node_allocator. Since the segment manager address
65 //is the same, this node_allocator will be
66 //attached to the same pool so "allocator_instance2" can deallocate
67 //nodes allocated by "allocator_instance"
68 node_allocator_t allocator_instance2(segment.get_segment_manager());
69
70 //Create another node_allocator using copy-constructor. This
71 //node_allocator will also be attached to the same pool
72 node_allocator_t allocator_instance3(allocator_instance2);
73
74 //All allocators are equal
75 assert(allocator_instance == allocator_instance2);
76 assert(allocator_instance2 == allocator_instance3);
77
78 //So memory allocated with one can be deallocated with another
79 allocator_instance2.deallocate(ptr: allocator_instance.allocate(count: 1), count: 1);
80 allocator_instance3.deallocate(ptr: allocator_instance2.allocate(count: 1), count: 1);
81
82 //The common pool will be destroyed here, since no allocator is
83 //attached to the pool
84 return 0;
85}
86//]
87
88

source code of boost/libs/interprocess/example/doc_node_allocator.cpp