timerm.nc.svn-base

802.15.4协议的实现

// $Id: TimerM.nc,v 1.21 2004/04/14 23:52:18 idgay Exp $

/*									tab:4
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 * two paragraphs and the author appear in all copies of this software.
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 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
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 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
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 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
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 * Copyright (c) 2002-2003 Intel Corporation
 * All rights reserved.
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 * This file is distributed under the terms in the attached INTEL-LICENSE     
 * file. If you do not find these files, copies can be found by writing to
 * Intel Research Berkeley, 2150 Shattuck Avenue, Suite 1300, Berkeley, CA, 
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/*
 *
 * Authors:             Su Ping <[e-mail]>
 * Revision:            $Id: TimerM.nc,v 1.21 2004/04/14 23:52:18 idgay Exp $
 * This implementation assumes that DEFAULT_SCALE is 3.
 */

/**
 * @author Su Ping <[e-mail]>
 */


module TimerM {
    provides interface Timer[uint8_t id];
    provides interface StdControl;
    uses {
	interface Leds;
	interface Clock;
	interface PowerManagement;
    }
}

implementation {
    uint32_t mState;		// each bit represent a timer state 
    uint8_t  setIntervalFlag; 
    uint8_t mScale, mInterval;
    int8_t queue_head;
    int8_t queue_tail;
    uint8_t queue_size;
    uint8_t queue[NUM_TIMERS];

    struct timer_s {
        uint8_t type;		// one-short or repeat timer
        int32_t ticks;		// clock ticks for a repeat timer 
        int32_t ticksLeft;	// ticks left before the timer expires
    } mTimerList[NUM_TIMERS];
  
    enum {
	maxTimerInterval = 230
    };
    command result_t StdControl.init() {
        mState=0;
        setIntervalFlag = 0;
        queue_head = queue_tail = -1;
        queue_size = 0;
        mScale = 3;
        mInterval = maxTimerInterval;
        return call Clock.setRate(mInterval, mScale) ;
    }

    command result_t StdControl.start() {
        return SUCCESS;
    }

    command result_t StdControl.stop() {
        mState=0;
        mInterval = maxTimerInterval;
        setIntervalFlag = 0;
        return SUCCESS;
    }

    command result_t Timer.start[uint8_t id](char type, 
				   uint32_t interval) {
	uint8_t diff;
        if (id >= NUM_TIMERS) return FAIL;
        if (type>1) return FAIL;
        mTimerList[id].ticks = interval ;
        mTimerList[id].type = type;
	
        atomic {
            diff = call Clock.readCounter();
            interval += diff;
            mTimerList[id].ticksLeft = interval;
            mState|=(0x1L<<id);
            if (interval < mInterval) {
                mInterval=interval;
                call Clock.setInterval(mInterval);
                setIntervalFlag = 0;
                call PowerManagement.adjustPower();
            }
	} 
        return SUCCESS;
    }

    static void adjustInterval() {
        uint8_t i, val = maxTimerInterval;
        if ( mState) {
            for (i=0;i<NUM_TIMERS;i++) {
                if ((mState&(0x1L<<i)) && (mTimerList[i].ticksLeft <val )) {
                    val = mTimerList[i].ticksLeft;
		}
            }
            atomic {
                mInterval =  val;
                call Clock.setInterval(mInterval);
                setIntervalFlag = 0;
            }

        } else {
            atomic {
              mInterval=maxTimerInterval;
              call Clock.setInterval(mInterval);
              setIntervalFlag = 0;
            }
        }
	call PowerManagement.adjustPower();
    }

    command result_t Timer.stop[uint8_t id]() {

        if (id>=NUM_TIMERS) return FAIL;
        if (mState&(0x1L<<id)) { // if the timer is running 
	    atomic mState &= ~(0x1L<<id);
	    if (!mState) {
	        setIntervalFlag = 1;
	    } 	
            return SUCCESS;
        }
        return FAIL; //timer not running
    }


    default event result_t Timer.fired[uint8_t id]() {
        return SUCCESS;
    }

    void enqueue(uint8_t value) {
      if (queue_tail == NUM_TIMERS - 1)
	queue_tail = -1;
      queue_tail++;
      queue_size++;
      queue[(uint8_t)queue_tail] = value;
    }

    uint8_t dequeue() {
      if (queue_size == 0)
        return NUM_TIMERS;
      if (queue_head == NUM_TIMERS - 1)
        queue_head = -1;
      queue_head++;
      queue_size--;
      return queue[(uint8_t)queue_head];
    }

    task void signalOneTimer() {
      uint8_t itimer = dequeue();
      if (itimer < NUM_TIMERS)
        signal Timer.fired[itimer]();
    }

    task void HandleFire() {
        uint8_t i; 
	setIntervalFlag = 1;
        if (mState) {
            for (i=0;i<NUM_TIMERS;i++)  {
                if (mState&(0x1L<<i)) {
                    mTimerList[i].ticksLeft -= (mInterval+1) ; 
                    if (mTimerList[i].ticksLeft<=2) {
                        if (mTimerList[i].type==TIMER_REPEAT) {
                            mTimerList[i].ticksLeft += mTimerList[i].ticks;
                        } else {// one shot timer 
                            mState &=~(0x1L<<i); 
                        }
                        enqueue(i);
			post signalOneTimer();
                    }
                }
            }
        }
	adjustInterval();
    }

    async event result_t Clock.fire() {
	post HandleFire();
        return SUCCESS;
    }
}