boost/coroutine/posix/segmented_stack_allocator.hpp
// 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_SEGMENTED_STACK_ALLOCATOR_H
#define BOOST_COROUTINES_SEGMENTED_STACK_ALLOCATOR_H
#include <cstddef>
#include <new>
#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
// forward declaration for splitstack-functions defined in libgcc
extern "C" {
void *__splitstack_makecontext( std::size_t,
void * [BOOST_CONTEXT_SEGMENTS],
std::size_t *);
void __splitstack_releasecontext( void * [BOOST_CONTEXT_SEGMENTS]);
void __splitstack_resetcontext( void * [BOOST_CONTEXT_SEGMENTS]);
void __splitstack_block_signals_context( void * [BOOST_CONTEXT_SEGMENTS],
int * new_value, int * old_value);
}
namespace boost {
namespace coroutines {
template< typename traitsT >
struct basic_segmented_stack_allocator
{
typedef traitsT traits_type;
void allocate( stack_context & ctx, std::size_t size = traits_type::minimum_size() )
{
void * limit = __splitstack_makecontext( size, ctx.segments_ctx, & ctx.size);
if ( ! limit) throw std::bad_alloc();
// ctx.size is already filled by __splitstack_makecontext
ctx.sp = static_cast< char * >( limit) + ctx.size;
int off = 0;
__splitstack_block_signals_context( ctx.segments_ctx, & off, 0);
}
void deallocate( stack_context & ctx)
{ __splitstack_releasecontext( ctx.segments_ctx); }
};
typedef basic_segmented_stack_allocator< stack_traits > segmented_stack_allocator;
}}
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_SUFFIX
#endif
#endif // BOOST_COROUTINES_SEGMENTED_STACK_ALLOCATOR_H