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
|
//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2006-2007. 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.
//
//////////////////////////////////////////////////////////////////////////////
#include <boost/interprocess/detail/config_begin.hpp>
//[doc_managed_aligned_allocation
#include <boost/interprocess/managed_shared_memory.hpp>
#include <cassert>
int main()
{
using namespace boost::interprocess;
//Managed memory segment that allocates portions of a shared memory
//segment with the default management algorithm
shared_memory_object::remove("MyManagedShm");
try{
managed_shared_memory managed_shm(create_only, "MyManagedShm", 65536);
const std::size_t Alignment = 128;
//Allocate 100 bytes aligned to Alignment from segment, throwing version
void *ptr = managed_shm.allocate_aligned(100, Alignment);
//Check alignment
assert(((char*)ptr-(char*)0) % Alignment == 0);
//Deallocate it
managed_shm.deallocate(ptr);
//Non throwing version
ptr = managed_shm.allocate_aligned(100, Alignment, std::nothrow);
//Check alignment
assert(((char*)ptr-(char*)0) % Alignment == 0);
//Deallocate it
managed_shm.deallocate(ptr);
//If we want to efficiently allocate aligned blocks of memory
//use managed_shared_memory::PayloadPerAllocation value
assert(Alignment > managed_shared_memory::PayloadPerAllocation);
//This allocation will maximize the size of the aligned memory
//and will increase the possibility of finding more aligned memory
ptr = managed_shm.allocate_aligned
(3*Alignment - managed_shared_memory::PayloadPerAllocation, Alignment);
//Check alignment
assert(((char*)ptr-(char*)0) % Alignment == 0);
//Deallocate it
managed_shm.deallocate(ptr);
}
catch(...){
shared_memory_object::remove("MyManagedShm");
throw;
}
shared_memory_object::remove("MyManagedShm");
return 0;
}
//]
#include <boost/interprocess/detail/config_end.hpp>
|
