Chris@102: 
Chris@102: //          Copyright Oliver Kowalke 2014.
Chris@102: // Distributed under the Boost Software License, Version 1.0.
Chris@102: //    (See accompanying file LICENSE_1_0.txt or copy at
Chris@102: //          http://www.boost.org/LICENSE_1_0.txt)
Chris@102: 
Chris@102: #ifndef BOOST_CONTEXT_SEGMENTED_H
Chris@102: #define BOOST_CONTEXT_SEGMENTED_H
Chris@102: 
Chris@102: #include <cstddef>
Chris@102: #include <new>
Chris@102: 
Chris@102: #include <boost/config.hpp>
Chris@102: 
Chris@102: #include <boost/context/detail/config.hpp>
Chris@102: #include <boost/context/stack_context.hpp>
Chris@102: #include <boost/context/stack_traits.hpp>
Chris@102: 
Chris@102: #ifdef BOOST_HAS_ABI_HEADERS
Chris@102: #  include BOOST_ABI_PREFIX
Chris@102: #endif
Chris@102: 
Chris@102: // forward declaration for splitstack-functions defined in libgcc
Chris@102: extern "C" {
Chris@102: void *__splitstack_makecontext( std::size_t,
Chris@102:                                 void * [BOOST_CONTEXT_SEGMENTS],
Chris@102:                                 std::size_t *);
Chris@102: 
Chris@102: void __splitstack_releasecontext( void * [BOOST_CONTEXT_SEGMENTS]);
Chris@102: 
Chris@102: void __splitstack_resetcontext( void * [BOOST_CONTEXT_SEGMENTS]);
Chris@102: 
Chris@102: void __splitstack_block_signals_context( void * [BOOST_CONTEXT_SEGMENTS],
Chris@102:                                          int * new_value, int * old_value);
Chris@102: }
Chris@102: 
Chris@102: namespace boost {
Chris@102: namespace context {
Chris@102: 
Chris@102: template< typename traitsT >
Chris@102: class basic_segmented_stack {
Chris@102: private:
Chris@102:     std::size_t     size_;
Chris@102: 
Chris@102: public:
Chris@102:     typedef traitsT traits_type;
Chris@102: 
Chris@102:     basic_segmented_stack( std::size_t size = traits_type::default_size() ) :
Chris@102:         size_( size) {
Chris@102:         BOOST_ASSERT( traits_type::minimum_size() <= size_);
Chris@102:         BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= size_) );
Chris@102:     }
Chris@102: 
Chris@102:     stack_context allocate() {
Chris@102:         stack_context sctx;
Chris@102:         void * vp = __splitstack_makecontext( size_, sctx.segments_ctx, & sctx.size);
Chris@102:         if ( ! vp) throw std::bad_alloc();
Chris@102: 
Chris@102:         // sctx.size is already filled by __splitstack_makecontext
Chris@102:         sctx.sp = static_cast< char * >( vp) + sctx.size;
Chris@102: 
Chris@102:         int off = 0;
Chris@102:         __splitstack_block_signals_context( sctx.segments_ctx, & off, 0);
Chris@102: 
Chris@102:         return sctx;
Chris@102:     }
Chris@102: 
Chris@102:     void deallocate( stack_context & sctx) {
Chris@102:         __splitstack_releasecontext( sctx.segments_ctx);
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: typedef basic_segmented_stack< stack_traits > segmented_stack;
Chris@102: 
Chris@102: }}
Chris@102: 
Chris@102: #ifdef BOOST_HAS_ABI_HEADERS
Chris@102: #  include BOOST_ABI_SUFFIX
Chris@102: #endif
Chris@102: 
Chris@102: #endif // BOOST_CONTEXT_SEGMENTED_H