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- // 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
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