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
|
// Copyright Oliver Kowalke 2009.
// 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)
#ifndef BOOST_COROUTINES_PROTECTED_STACK_ALLOCATOR_H
#define BOOST_COROUTINES_PROTECTED_STACK_ALLOCATOR_H
extern "C" {
#include <windows.h>
}
#include <cmath>
#include <cstddef>
#include <new>
#include <boost/config.hpp>
#include <boost/coroutine/detail/config.hpp>
#include <boost/coroutine/stack_traits.hpp>
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_PREFIX
#endif
namespace boost {
namespace coroutines {
struct stack_context;
template< typename traitsT >
struct basic_protected_stack_allocator
{
typedef traitsT traits_type;
void allocate( stack_context & ctx, std::size_t size)
{
BOOST_ASSERT( traits_type::minimum_size() <= size);
BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= size) );
// page at bottom will be used as guard-page
const std::size_t pages(
static_cast< std::size_t >(
std::floor(
static_cast< float >( size) / traits_type::page_size() ) ) );
BOOST_ASSERT_MSG( 2 <= pages, "at least two pages must fit into stack (one page is guard-page)");
const std::size_t size_ = pages * traits_type::page_size();
BOOST_ASSERT( 0 < size && 0 < size_);
void * limit = ::VirtualAlloc( 0, size_, MEM_COMMIT, PAGE_READWRITE);
if ( ! limit) throw std::bad_alloc();
DWORD old_options;
#if defined(BOOST_DISABLE_ASSERTS)
::VirtualProtect(
limit, traits_type::page_size(), PAGE_READWRITE | PAGE_GUARD /*PAGE_NOACCESS*/, & old_options);
#else
const BOOL result = ::VirtualProtect(
limit, traits_type::page_size(), PAGE_READWRITE | PAGE_GUARD /*PAGE_NOACCESS*/, & old_options);
BOOST_ASSERT( FALSE != result);
#endif
ctx.size = size_;
ctx.sp = static_cast< char * >( limit) + ctx.size;
}
void deallocate( stack_context & ctx)
{
BOOST_ASSERT( ctx.sp);
BOOST_ASSERT( traits_type::minimum_size() <= ctx.size);
BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= ctx.size) );
void * limit = static_cast< char * >( ctx.sp) - ctx.size;
::VirtualFree( limit, 0, MEM_RELEASE);
}
};
typedef basic_protected_stack_allocator< stack_traits > protected_stack_allocator;
}}
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_SUFFIX
#endif
#endif // BOOST_COROUTINES_PROTECTED_STACK_ALLOCATOR_H
|
