//          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)

#define BOOST_CONTEXT_SOURCE

#include <boost/context/stack_utils.hpp>

extern "C" {
#include <windows.h>
}

#include <cmath>
#include <csignal>

#include <boost/assert.hpp>

namespace {

static SYSTEM_INFO system_info_()
{
    SYSTEM_INFO si;
    ::GetSystemInfo( & si);
    return si;
}

static SYSTEM_INFO system_info()
{
    static SYSTEM_INFO si = system_info_();
    return si;
}

}

namespace boost {
namespace ctx {

BOOST_CONTEXT_DECL
std::size_t default_stacksize()
{
    static std::size_t size = 256 * 1024;
    return size;
}

BOOST_CONTEXT_DECL
std::size_t minimum_stacksize()
{
    static std::size_t stacksize(
        static_cast< std::size_t >( system_info().dwAllocationGranularity) );
    return stacksize;
}

BOOST_CONTEXT_DECL
std::size_t maximum_stacksize()
{
    BOOST_ASSERT( ! is_stack_unbound() );
    static std::size_t stacksize = 8 * 1024 * 1024;
    return stacksize;
}

// Windows seams not to provide a limit for the stacksize
BOOST_CONTEXT_DECL
bool is_stack_unbound()
{ return true; }

BOOST_CONTEXT_DECL
std::size_t pagesize()
{
    static std::size_t pagesize(
        static_cast< std::size_t >( system_info().dwPageSize) );
    return pagesize;
}

BOOST_CONTEXT_DECL
std::size_t page_count( std::size_t stacksize)
{
    return static_cast< std::size_t >(
        std::ceil(
            static_cast< float >( stacksize) / pagesize() ) );
}

}}