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#if defined(BOOST_INTERPROCESS_MAPPED_FILES)
11
12
13//[doc_managed_multiple_allocation
14#include <boost/interprocess/managed_shared_memory.hpp>
15#include <boost/move/utility_core.hpp> //boost::move
16#include <cassert>//assert
17#include <cstring>//std::memset
18#include <new> //std::nothrow
19#include <vector> //std::vector
20//<-
21#include "../test/get_process_id_name.hpp"
22//->
23
24int main()
25{
26 using namespace boost::interprocess;
27 typedef managed_shared_memory::multiallocation_chain multiallocation_chain;
28
29 //Remove shared memory on construction and destruction
30 struct shm_remove
31 {
32 //<-
33 #if 1
34 shm_remove() { shared_memory_object::remove(test::get_process_id_name()); }
35 ~shm_remove(){ shared_memory_object::remove(test::get_process_id_name()); }
36 #else
37 //->
38 shm_remove() { shared_memory_object::remove("MySharedMemory"); }
39 ~shm_remove(){ shared_memory_object::remove("MySharedMemory"); }
40 //<-
41 #endif
42 //->
43 } remover;
44 //<-
45 (void)remover;
46 //->
47
48 //<-
49 #if 1
50 managed_shared_memory managed_shm(create_only,test::get_process_id_name(), 65536);
51 #else
52 //->
53 managed_shared_memory managed_shm(create_only,"MySharedMemory", 65536);
54 //<-
55 #endif
56 //->
57
58 //Allocate 16 elements of 100 bytes in a single call. Non-throwing version.
59 multiallocation_chain chain;
60 managed_shm.allocate_many(std::nothrow, 100, 16, chain);
61
62 //Check if the memory allocation was successful
63 if(chain.empty()) return 1;
64
65 //Allocated buffers
66 std::vector<void*> allocated_buffers;
67
68 //Initialize our data
69 while(!chain.empty()){
70 void *buf = chain.pop_front();
71 allocated_buffers.push_back(buf);
72 //The iterator must be incremented before overwriting memory
73 //because otherwise, the iterator is invalidated.
74 std::memset(buf, 0, 100);
75 }
76
77 //Now deallocate
78 while(!allocated_buffers.empty()){
79 managed_shm.deallocate(allocated_buffers.back());
80 allocated_buffers.pop_back();
81 }
82
83 //Allocate 10 buffers of different sizes in a single call. Throwing version
84 managed_shared_memory::size_type sizes[10];
85 for(std::size_t i = 0; i < 10; ++i)
86 sizes[i] = i*3;
87
88 managed_shm.allocate_many(sizes, 10, 1, chain);
89 managed_shm.deallocate_many(chain);
90 return 0;
91}
92//]
93
94
95#else //#if defined(BOOST_INTERPROCESS_MAPPED_FILES)
96int main()
97{
98 return 0;
99}
100#endif//#if defined(BOOST_INTERPROCESS_MAPPED_FILES)
101

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