/*
 * Copyright (C) 2008-2009 Tobias Brunner
 * Copyright (C) 2008 Martin Willi
 * HSR Hochschule fuer Technik Rapperswil
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

/**
 * @defgroup condvar condvar
 * @{ @ingroup threading
 */

#ifndef THREADING_CONDVAR_H_
#define THREADING_CONDVAR_H_

typedef struct condvar_t condvar_t;
typedef enum condvar_type_t condvar_type_t;

#include "mutex.h"

/**
 * Type of condvar.
 */
enum condvar_type_t {
	/** default condvar */
	CONDVAR_TYPE_DEFAULT = 0,
};

/**
 * Condvar wrapper to use in conjunction with mutex_t.
 */
struct condvar_t {

	/**
	 * Wait on a condvar until it gets signalized.
	 *
	 * @param mutex			mutex to release while waiting
	 */
	void (*wait)(condvar_t *this, mutex_t *mutex);

	/**
	 * Wait on a condvar until it gets signalized, or times out.
	 *
	 * @param mutex			mutex to release while waiting
	 * @param timeout		timeout im ms
	 * @return				TRUE if timed out, FALSE otherwise
	 */
	bool (*timed_wait)(condvar_t *this, mutex_t *mutex, u_int timeout);

	/**
	 * Wait on a condvar until it gets signalized, or times out.
	 *
	 * The passed timeval should be calculated based on the time_monotonic()
	 * function.
	 *
	 * @param mutex			mutex to release while waiting
	 * @param tv			absolute time until timeout
	 * @return				TRUE if timed out, FALSE otherwise
	 */
	bool (*timed_wait_abs)(condvar_t *this, mutex_t *mutex, timeval_t tv);

	/**
	 * Wake up a single thread in a condvar.
	 */
	void (*signal)(condvar_t *this);

	/**
	 * Wake up all threads in a condvar.
	 */
	void (*broadcast)(condvar_t *this);

	/**
	 * Destroy a condvar and free its resources.
	 */
	void (*destroy)(condvar_t *this);
};

/**
 * Create a condvar instance.
 *
 * @param type		type of condvar to create
 * @return			condvar instance
 */
condvar_t *condvar_create(condvar_type_t type);

#endif /** THREADING_CONDVAR_H_ @} */

