ext-boost/boost/context/fixedsize_stack.hpp
2020-02-10 12:31:57 -04:00

98 lines
2.3 KiB
C++

// Copyright Oliver Kowalke 2014.
// 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_CONTEXT_FIXEDSIZE_H
#define BOOST_CONTEXT_FIXEDSIZE_H
#include <cstddef>
#include <cstdlib>
#include <new>
#include <boost/assert.hpp>
#include <boost/config.hpp>
#include <boost/context/detail/config.hpp>
#include <boost/context/stack_context.hpp>
#include <boost/context/stack_traits.hpp>
#if defined(BOOST_CONTEXT_USE_MAP_STACK)
extern "C" {
#include <sys/mman.h>
}
#endif
#if defined(BOOST_USE_VALGRIND)
#include <valgrind/valgrind.h>
#endif
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_PREFIX
#endif
namespace boost {
namespace context {
template< typename traitsT >
class basic_fixedsize_stack {
private:
std::size_t size_;
public:
typedef traitsT traits_type;
basic_fixedsize_stack( std::size_t size = traits_type::default_size() ) BOOST_NOEXCEPT_OR_NOTHROW :
size_( size) {
}
stack_context allocate() {
#if defined(BOOST_CONTEXT_USE_MAP_STACK)
void * vp = ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON | MAP_STACK, -1, 0);
if ( vp == MAP_FAILED) {
throw std::bad_alloc();
}
#else
void * vp = std::malloc( size_);
if ( ! vp) {
throw std::bad_alloc();
}
#endif
stack_context sctx;
sctx.size = size_;
sctx.sp = static_cast< char * >( vp) + sctx.size;
#if defined(BOOST_USE_VALGRIND)
sctx.valgrind_stack_id = VALGRIND_STACK_REGISTER( sctx.sp, vp);
#endif
return sctx;
}
void deallocate( stack_context & sctx) BOOST_NOEXCEPT_OR_NOTHROW {
BOOST_ASSERT( sctx.sp);
#if defined(BOOST_USE_VALGRIND)
VALGRIND_STACK_DEREGISTER( sctx.valgrind_stack_id);
#endif
void * vp = static_cast< char * >( sctx.sp) - sctx.size;
#if defined(BOOST_CONTEXT_USE_MAP_STACK)
::munmap( vp, sctx.size);
#else
std::free( vp);
#endif
}
};
typedef basic_fixedsize_stack< stack_traits > fixedsize_stack;
# if ! defined(BOOST_USE_SEGMENTED_STACKS)
typedef fixedsize_stack default_stack;
# endif
}}
#ifdef BOOST_HAS_ABI_HEADERS
# include BOOST_ABI_SUFFIX
#endif
#endif // BOOST_CONTEXT_FIXEDSIZE_H