boost/libs/context/example/exit.cpp

//          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 <iostream>

#include <boost/assert.hpp>
#include <boost/context/all.hpp>

#include "simple_stack_allocator.hpp"

namespace ctx = boost::context;

typedef ctx::simple_stack_allocator<
    8 * 1024 * 1024, // 8MB
    64 * 1024, // 64kB
    8 * 1024 // 8kB
>       stack_allocator;

ctx::fcontext_t fcm = 0;
ctx::fcontext_t fc1 = 0;
ctx::fcontext_t fc2 = 0;

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;

    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;
    BOOST_ASSERT( false && ! "main: never returns");

    return EXIT_SUCCESS;
}