//
// mp::fdnotify
//
// Copyright (C) 2008 FURUHASHI Sadayuki
//
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
//
//        http://www.apache.org/licenses/LICENSE-2.0
//
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.
//

#ifndef MP_FDNOTIFY_H__
#define MP_FDNOTIFY_H__

#include "mp/exception.h"

#ifndef MP_FDNOTIFY_VECTOR_SIZE
#define MP_FDNOTIFY_VECTOR_SIZE 32
#endif

namespace mp {


struct fdnotify_error : system_error {
	fdnotify_error(int errno_, const std::string& msg) :
		system_error(errno_, msg) {}
};


// Note that NotifyObject must be a POD

template <typename NotifyObject>
class fdnotify {
public:
	fdnotify();
	~fdnotify();

public:
	int getfd() const { return m_pipe[0]; }
	bool try_receive(NotifyObject* result);

	void send(const NotifyObject& obj);

private:
	int m_pipe[2];
	char m_buffer[sizeof(NotifyObject)*MP_FDNOTIFY_VECTOR_SIZE];
	char* m_head;
	char* m_tail;

private:
	bool receive_next(NotifyObject* result);

private:
	fdnotify(const fdnotify<NotifyObject>&);
};


}  // namespace mp

#include "mp/fdnotify_impl.h"

#endif /* mp/fdnotify.h */