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June 2, 2015 22:33
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// 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) | |
#include <cstdlib> | |
#include <cstring> | |
#include <iostream> | |
#include <boost/assert.hpp> | |
#include <boost/context/all.hpp> | |
#ifndef BOOST_CONTEXT_SIMPLE_STACK_ALLOCATOR_H | |
#define BOOST_CONTEXT_SIMPLE_STACK_ALLOCATOR_H | |
#include <cstddef> | |
#include <cstdlib> | |
#include <stdexcept> | |
#include <boost/assert.hpp> | |
#include <boost/config.hpp> | |
#include <boost/context/detail/config.hpp> | |
#ifdef BOOST_HAS_ABI_HEADERS | |
# include BOOST_ABI_PREFIX | |
#endif | |
namespace boost { | |
namespace context { | |
template< std::size_t Max, std::size_t Default, std::size_t Min > | |
class simple_stack_allocator | |
{ | |
public: | |
static std::size_t maximum_stacksize() | |
{ return Max; } | |
static std::size_t default_stacksize() | |
{ return Default; } | |
static std::size_t minimum_stacksize() | |
{ return Min; } | |
void * allocate( std::size_t size) const | |
{ | |
BOOST_ASSERT( minimum_stacksize() <= size); | |
BOOST_ASSERT( maximum_stacksize() >= size); | |
void * limit = std::malloc( size); | |
if ( ! limit) throw std::bad_alloc(); | |
return static_cast< char * >( limit) + size; | |
} | |
void deallocate( void * vp, std::size_t size) const | |
{ | |
BOOST_ASSERT( vp); | |
BOOST_ASSERT( minimum_stacksize() <= size); | |
BOOST_ASSERT( maximum_stacksize() >= size); | |
void * limit = static_cast< char * >( vp) - size; | |
std::free( limit); | |
} | |
}; | |
}} | |
#ifdef BOOST_HAS_ABI_HEADERS | |
# include BOOST_ABI_SUFFIX | |
#endif | |
#endif // BOOST_CONTEXT_SIMPLE_STACK_ALLOCATOR_H | |
// 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) | |
namespace ctx = boost::context; | |
typedef ctx::simple_stack_allocator< | |
8 * 1024 * 1024, // 8MB | |
64 * 1024, // 64kB | |
8 * 1024 // 8kB | |
> stack_allocator; | |
ctx::fcontext_t * fc1; | |
ctx::fcontext_t * fc2; | |
ctx::fcontext_t * fc3; | |
void f1( intptr_t) | |
{ | |
std::cout << "f1: entered" << std::endl; | |
std::cout << "f1: call jump_fcontext( fc1, fc2, 0)" << std::endl; | |
ctx::jump_fcontext( fc1, fc2, 0); | |
std::cout << "f1: return" << std::endl; | |
} | |
void f2( intptr_t) | |
{ | |
std::cout << "f2: entered" << std::endl; | |
std::cout << "f2: call jump_fcontext( fc2, fc1, 0)" << std::endl; | |
ctx::jump_fcontext( fc2, fc1, 0); | |
BOOST_ASSERT( false && ! "f2: never returns"); | |
} | |
int main( int argc, char * argv[]) | |
{ | |
std::cout << "size: 0x" << std::hex << sizeof( ctx::fcontext_t) << std::endl; | |
ctx::fcontext_t fcm; | |
fc3 = &fcm; | |
stack_allocator alloc; | |
void * sp1 = alloc.allocate( stack_allocator::default_stacksize()); | |
fc1 = ctx::make_fcontext( sp1, stack_allocator::default_stacksize(), f1); | |
void * sp2 = alloc.allocate( stack_allocator::default_stacksize()); | |
fc2 = ctx::make_fcontext( sp2, stack_allocator::default_stacksize(), f2); | |
std::cout << "main: call start_fcontext( & fcm, fc1, 0)" << std::endl; | |
ctx::jump_fcontext( & fcm, fc1, 0); | |
std::cout << "main: done" << std::endl; | |
alloc.deallocate(sp2, stack_allocator::default_stacksize()); | |
alloc.deallocate(sp1, stack_allocator::default_stacksize()); | |
return EXIT_SUCCESS; | |
} |
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