cond.h

MANTIS是由科罗拉多大学开发的传感器网络嵌入式操作系统。 这是mantis的0.9.5版本的源码。

//  This file is part of MANTIS OS, Operating System
//  See http://mantis.cs.colorado.edu/
//
//  Copyright (C) 2003,2004,2005 University of Colorado, Boulder
//
//  This program is free software; you can redistribute it and/or
//  modify it under the terms of the mos license (see file LICENSE)

/** @file micro/include/cond.h
 * @brief Basic condition variable support.
 *
 * THIS CODE HAS NOT BEEN TESTED
 * 
 * @author Lane Phillips
 * @date Created: 02/18/2005
 */

#ifndef COND_H_
#define COND_H_

#include "msched.h"
#include "tlist.h"
#include "mutex.h"

/** @brief Condition variable data structure */
typedef struct {
   /** @brief Thead list queue waiting on this condition variable */
   tlist_t q;
} mos_cond_t;

/** @brief Init a condition variable data structure.
 *
 * Must init before use.
 * @param cond Condition variable to init
 */
void mos_cond_init(mos_cond_t *cond);

/** @brief Signal exactly one thread waiting on a condition variable.
 *
 * The calling thread should lock the mutex that the waiting thread used to
 * call mos_cond_wait().  Unlike semaphores, signals are lost when no threads
 * waiting.
 * 
 * @param cond Condition variable to signal
 */
void mos_cond_signal(mos_cond_t *cond);

/** @brief Signal all threads waiting on a condition variable.
 *
 * The calling thread should lock the mutex that the waiting threads used to
 * call mos_cond_wait().  Unlike semaphores, signals are lost when no threads
 * waiting.
 * 
 * @param cond Condition variable to signal
 */
void mos_cond_broadcast(mos_cond_t *cond);

/** @brief Wait on a condition variable.
 * 
 * Atomically releases the mutex and waits on the condition variable.  On return
 * the mutex is locked again.  The caller should use the same mutex that the
 * threads that call mos_cond_broadcast() or mos_cond_signal() use for this
 * condition variable.
 * 
 * @param cond Condition variable to wait on
 * @param mt Mutex to unlock.  Locked on return.
 */
void mos_cond_wait(mos_cond_t *cond, mos_mutex_t *mt);

// Not implemented yet
//int8_t mos_cond_timedwait(mos_cond_t *cond, mutex *mt,
//	const struct timespec *abstime);

#endif