// Copyright (c) 2014 Justin Walsh.

// All rights reserved.

//

// Permission is hereby granted, free of charge, to any person obtaining a copy

// of this software and associated documentation files (the "Software"), to deal

// in the Software without restriction, including without limitation the rights

// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

// copies of the Software, and to permit persons to whom the Software is

// furnished to do so, subject to the following conditions:

//

// The above copyright notice and this permission notice shall be included in all

// copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

// SOFTWARE.

#include "stackd/coroutine.h"

#include <boost/context/all.hpp>

namespace stackd

{

coroutine* internal::active_context = nullptr;

void yield(bool terminate)

{

if (internal::active_context == nullptr) return;

if (terminate) throw internal::unwind_coroutine();

internal::active_context->yield(terminate);

}

coroutine::coroutine(void* cptr, void (*handler)(intptr_t))

{

terminated = false;

start.coroutine_delegate = cptr;

start.context = this;

stack = new std::array<intptr_t, 64 * 1024>();

context = boost::context::make_fcontext(stack->data() + stack->size(), stack->size(), handler);

}

coroutine::coroutine(coroutine&& other)

{

delete stack;

stack = other.stack;

other.stack = nullptr;

delete context;

context = std::move(other.context);

other.context = nullptr;

context_main = std::move(context_main);

start.coroutine_delegate = other.start.coroutine_delegate;

start.context = this;

terminated = other.terminated;

}

coroutine& coroutine::operator=(coroutine&& other)

{

if (this != &other)

{

delete stack;

stack = other.stack;

other.stack = nullptr;

delete context;

context = std::move(other.context);

other.context = nullptr;

context_main = std::move(context_main);

start.coroutine_delegate = other.start.coroutine_delegate;

start.context = this;

terminated = other.terminated;

}

return *this;

}

bool coroutine::active()

{

return !terminated;

}

bool coroutine::resume()

{

if (terminated) return terminated;

internal::active_context = this;

terminated = (bool)boost::context::jump_fcontext(&context_main, context, (intptr_t)&start);

return terminated;

}

void coroutine::yield(bool terminate)

{

if (terminated) return;

internal::active_context = nullptr;

boost::context::jump_fcontext(context, &context_main, (intptr_t)terminate);

}

}