| |
| // 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 <fcntl.h> |
| #include <sys/mman.h> |
| #include <sys/stat.h> |
| #include <unistd.h> |
| } |
| |
| #if defined(BOOST_USE_VALGRIND) |
| #include <valgrind/valgrind.h> |
| #endif |
| |
| #include <cmath> |
| #include <cstddef> |
| #include <new> |
| |
| #include <boost/assert.hpp> |
| #include <boost/config.hpp> |
| |
| #include <boost/coroutine/detail/config.hpp> |
| #include <boost/coroutine/stack_context.hpp> |
| #include <boost/coroutine/stack_traits.hpp> |
| |
| #ifdef BOOST_HAS_ABI_HEADERS |
| # include BOOST_ABI_PREFIX |
| #endif |
| |
| namespace boost { |
| namespace coroutines { |
| |
| template< typename traitsT > |
| struct basic_protected_stack_allocator |
| { |
| typedef traitsT traits_type; |
| |
| void allocate( stack_context & ctx, std::size_t size = traits_type::minimum_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_); |
| BOOST_ASSERT( size_ <= size); |
| |
| // conform to POSIX.4 (POSIX.1b-1993, _POSIX_C_SOURCE=199309L) |
| #if defined(MAP_ANON) |
| void * limit = ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); |
| #else |
| void * limit = ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| #endif |
| if ( MAP_FAILED == limit) throw std::bad_alloc(); |
| |
| // conforming to POSIX.1-2001 |
| #if defined(BOOST_DISABLE_ASSERTS) |
| ::mprotect( limit, traits_type::page_size(), PROT_NONE); |
| #else |
| const int result( ::mprotect( limit, traits_type::page_size(), PROT_NONE) ); |
| BOOST_ASSERT( 0 == result); |
| #endif |
| |
| ctx.size = size_; |
| ctx.sp = static_cast< char * >( limit) + ctx.size; |
| #if defined(BOOST_USE_VALGRIND) |
| ctx.valgrind_stack_id = VALGRIND_STACK_REGISTER( ctx.sp, limit); |
| #endif |
| } |
| |
| 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) ); |
| |
| #if defined(BOOST_USE_VALGRIND) |
| VALGRIND_STACK_DEREGISTER( ctx.valgrind_stack_id); |
| #endif |
| void * limit = static_cast< char * >( ctx.sp) - ctx.size; |
| // conform to POSIX.4 (POSIX.1b-1993, _POSIX_C_SOURCE=199309L) |
| ::munmap( limit, ctx.size); |
| } |
| }; |
| |
| 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 |