1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2006-2012. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////
//[doc_managed_grow
#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/interprocess/managed_mapped_file.hpp>
#include <cassert>
//<-
#include "../test/get_process_id_name.hpp"
//->
class MyClass
{
//...
};
int main()
{
using namespace boost::interprocess;
//Remove shared memory on construction and destruction
struct shm_remove
{
shm_remove() { shared_memory_object::remove(test::get_process_id_name()); }
~shm_remove(){ shared_memory_object::remove(test::get_process_id_name()); }
} remover;
//<-
(void)remover;
//->
{
//Create a managed shared memory
managed_shared_memory shm(create_only, test::get_process_id_name(), 1000);
//Check size
assert(shm.get_size() == 1000);
//Construct a named object
MyClass *myclass = shm.construct<MyClass>("MyClass")();
//The managed segment is unmapped here
//<-
(void)myclass;
//->
}
{
//Now that the segment is not mapped grow it adding extra 500 bytes
managed_shared_memory::grow(test::get_process_id_name(), 500);
//Map it again
managed_shared_memory shm(open_only, test::get_process_id_name());
//Check size
assert(shm.get_size() == 1500);
//Check "MyClass" is still there
MyClass *myclass = shm.find<MyClass>("MyClass").first;
assert(myclass != 0);
//<-
(void)myclass;
//->
//The managed segment is unmapped here
}
{
//Now minimize the size of the segment
managed_shared_memory::shrink_to_fit(test::get_process_id_name());
//Map it again
managed_shared_memory shm(open_only, test::get_process_id_name());
//Check size
assert(shm.get_size() < 1000);
//Check "MyClass" is still there
MyClass *myclass = shm.find<MyClass>("MyClass").first;
assert(myclass != 0);
//The managed segment is unmapped here
//<-
(void)myclass;
//->
}
return 0;
}
//]
|
