projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | |
| 2 | // Copyright Oliver Kowalke 2014. | |
| 3 | // Distributed under the Boost Software License, Version 1.0. | |
| 4 | // (See accompanying file LICENSE_1_0.txt or copy at | |
| 5 | // http://www.boost.org/LICENSE_1_0.txt) | |
| 6 | ||
| 7 | #ifndef BOOST_CONTEXT_PROTECTED_FIXEDSIZE_H | |
| 8 | #define BOOST_CONTEXT_PROTECTED_FIXEDSIZE_H | |
| 9 | ||
| 10 | extern "C" { | |
| 11 | #include <windows.h> | |
| 12 | } | |
| 13 | ||
| 14 | #include <cmath> | |
| 15 | #include <cstddef> | |
| 16 | #include <new> | |
| 17 | ||
| 18 | #include <boost/config.hpp> | |
| 19 | ||
| 20 | #include <boost/context/detail/config.hpp> | |
| 21 | #include <boost/context/stack_context.hpp> | |
| 22 | #include <boost/context/stack_traits.hpp> | |
| 23 | ||
| 24 | #ifdef BOOST_HAS_ABI_HEADERS | |
| 25 | # include BOOST_ABI_PREFIX | |
| 26 | #endif | |
| 27 | ||
| 28 | namespace boost { | |
| 29 | namespace context { | |
| 30 | ||
| 31 | template< typename traitsT > | |
| 32 | class basic_protected_fixedsize_stack { | |
| 33 | private: | |
| 34 | std::size_t size_; | |
| 35 | ||
| 36 | public: | |
| 37 | typedef traitsT traits_type; | |
| 38 | ||
| 39 | basic_protected_fixedsize_stack( std::size_t size = traits_type::default_size() ) BOOST_NOEXCEPT_OR_NOTHROW : | |
| 40 | size_( size) { | |
| 41 | BOOST_ASSERT( traits_type::minimum_size() <= size_); | |
| 42 | BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= size_) ); | |
| 43 | } | |
| 44 | ||
| 45 | stack_context allocate() { | |
| 46 | // page at bottom will be used as guard-page | |
| 47 | const std::size_t pages( | |
| 48 | static_cast< std::size_t >( | |
| 49 | std::floor( | |
| 50 | static_cast< float >( size_) / traits_type::page_size() ) ) ); | |
| 51 | BOOST_ASSERT_MSG( 2 <= pages, "at least two pages must fit into stack (one page is guard-page)"); | |
| 52 | const std::size_t size__( pages * traits_type::page_size() ); | |
| 53 | BOOST_ASSERT( 0 != size_ && 0 != size__); | |
| 54 | BOOST_ASSERT( size__ <= size_); | |
| 55 | ||
| 56 | void * vp = ::VirtualAlloc( 0, size__, MEM_COMMIT, PAGE_READWRITE); | |
| 57 | if ( ! vp) throw std::bad_alloc(); | |
| 58 | ||
| 59 | DWORD old_options; | |
| 60 | #if defined(BOOST_DISABLE_ASSERTS) | |
| 61 | ::VirtualProtect( | |
| 62 | vp, traits_type::page_size(), PAGE_READWRITE | PAGE_GUARD /*PAGE_NOACCESS*/, & old_options); | |
| 63 | #else | |
| 64 | const BOOL result = ::VirtualProtect( | |
| 65 | vp, traits_type::page_size(), PAGE_READWRITE | PAGE_GUARD /*PAGE_NOACCESS*/, & old_options); | |
| 66 | BOOST_ASSERT( FALSE != result); | |
| 67 | #endif | |
| 68 | ||
| 69 | stack_context sctx; | |
| 70 | sctx.size = size__; | |
| 71 | sctx.sp = static_cast< char * >( vp) + sctx.size; | |
| 72 | return sctx; | |
| 73 | } | |
| 74 | ||
| 75 | void deallocate( stack_context & sctx) BOOST_NOEXCEPT_OR_NOTHROW { | |
| 76 | BOOST_ASSERT( sctx.sp); | |
| 77 | BOOST_ASSERT( traits_type::minimum_size() <= sctx.size); | |
| 78 | BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= sctx.size) ); | |
| 79 | ||
| 80 | void * vp = static_cast< char * >( sctx.sp) - sctx.size; | |
| 81 | ::VirtualFree( vp, 0, MEM_RELEASE); | |
| 82 | } | |
| 83 | }; | |
| 84 | ||
| 85 | typedef basic_protected_fixedsize_stack< stack_traits > protected_fixedsize_stack; | |
| 86 | ||
| 87 | }} | |
| 88 | ||
| 89 | #ifdef BOOST_HAS_ABI_HEADERS | |
| 90 | # include BOOST_ABI_SUFFIX | |
| 91 | #endif | |
| 92 | ||
| 93 | #endif // BOOST_CONTEXT_PROTECTED_FIXEDSIZE_H |