mac-timers.cc~

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/* -*-	Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 1997 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the Computer Systems
 *	Engineering Group at Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/* Ported from CMU/Monarch's code, nov'98 -Padma.*/


#include <delay.h>
#include <connector.h>
#include <packet.h>
#include <random.h>

// #define DEBUG
//#include <debug.h>
#include <arp.h>
#include <ll.h>
#include <mac.h>
#include <mac-timers.h>
#include <mac-802_11.h>

/*
 * Force timers to expire on slottime boundries.
 */
// #define USE_SLOT_TIME

#define ROUND_TIME()	\
	{								\
		assert(slottime);					\
		double rmd = remainder(s.clock() + rtime, slottime);	\
		if(rmd > 0.0)						\
			rtime += (slottime - rmd);			\
		else							\
			rtime += (-rmd);				\
	}


/* ======================================================================
   Timers
   ====================================================================== */

void
MacTimer::start(double time)
{
	Scheduler &s = Scheduler::instance();
	assert(busy_ == 0);

	busy_ = 1;
	paused_ = 0;
	stime = s.clock();
	rtime = time;
	assert(rtime >= 0.0);


	s.schedule(this, &intr, rtime);
}

void
MacTimer::stop(void)
{
	Scheduler &s = Scheduler::instance();

	assert(busy_);

	if(paused_ == 0)
		s.cancel(&intr);

	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;
}

/* ======================================================================
   Defer Timer
   ====================================================================== */
void
DeferTimer::start(double time)
{
	Scheduler &s = Scheduler::instance();

	assert(busy_ == 0);

	busy_ = 1;
	paused_ = 0;
	stime = s.clock();
	rtime = time;
#ifdef USE_SLOT_TIME
	ROUND_TIME();
#endif
	assert(rtime >= 0.0);

	//if (mac->index_==0) printf("\tDEFERTimer[%d]::start(%f) \ttime %2.9f\n",d_tc_,time,stime); //DEBUG
	s.schedule(this, &intr, rtime);
}


void
DeferTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;


	//if (mac->index_==0) printf("\tDEFERTimer[%d]::handle \t\ttime %2.9f\n",d_tc_,Scheduler::instance().clock()); //DEBUG

	mac->deferHandler(d_tc_); // Mac802_11 *mac (vd. MacTimer)
}
/*====================================================================== */
void
NavTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;

	mac->navHandler(n_tc_);
}


/* ======================================================================
   Receive Timer
   ====================================================================== */
void
RxTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;

	mac->recvHandler();
}


/* ======================================================================
   Send Timer
   ====================================================================== */
void
TxTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;



	mac->sendHandler();
}


/* ======================================================================
   Interface Timer
   ====================================================================== */
void
IFTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;

	mac->txHandler();
}


/* ======================================================================
   Backoff Timer
   ====================================================================== */
void
BackoffTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;
	difs_wait = 0.0;

	//if (mac->index_==0) printf("\tBackoffTimer[%d]::handle \ttime %2.9f\n",b_tc_,Scheduler::instance().clock()); //DEBUG
	mac->backoffHandler(b_tc_);
}

void
BackoffTimer::start(int cw, int idle)
{
	Scheduler &s = Scheduler::instance();

	assert(busy_ == 0);

	busy_ = 1;
	paused_ = 0;
	stime = s.clock();


	// IEEE802.11e Draft 4.0 page 66, line 20
	rtime = ((Random::random() % (cw+1))+1) * mac->phymib_->SlotTime;


#ifdef USE_SLOT_TIME
	ROUND_TIME();
#endif
	difs_wait = 0.0;

	//if (mac->index_==0) printf("\tBackoffTimer[%d]::start(%d,%d) \ttime %2.9f\n",b_tc_,cw,idle,stime); //DEBUG
	if(idle == 0)
		paused_ = 1;
	else {
		assert(rtime >= 0.0);
		s.schedule(this, &intr, rtime);
	}
}


void
BackoffTimer::pause()
{
	Scheduler &s = Scheduler::instance();
	
	//if (mac->index_==0) printf("\t\tBackoffTimer[%d]::pause() time %2.9f\n",b_tc_,s.clock()); //DEBUG
	//the caculation below make validation pass for linux though it
	// looks dummy

	double st = s.clock();
	double rt = stime + difs_wait;
	double sr = st - rt;
        double mst = (mac->phymib_->SlotTime);

        int slots = int (sr/mst);

    //int slots = (int) ((s.clock() - (stime + difs_wait)) / mac->phymib_->SlotTime);

	// Se abbiamo atteso più del difs_wait, allora sottraiamo già il tempo di uno slot, secondo l' EDCF del draft 2.0
	//if(slots > 0) slots++;	//TODO: verificare se succede ancora nel Draft 4.0

	if(slots < 0)
		slots = 0;
	assert(busy_ && ! paused_);

	paused_ = 1;
	rtime -= (slots * mac->phymib_->SlotTime);
	
	//assert(rtime >= 0.0);
	// EDCF
	if (rtime < 0.0) { rtime = 0.0; /*printf("****EDCF BackoffTimer WARNING: rtime=0 on pause\n");*/ }

	difs_wait = 0.0;

	s.cancel(&intr);
}


void
BackoffTimer::resume(double difs)
{
	Scheduler &s = Scheduler::instance();
	//if (mac->index_==0) printf("\t\tBackoffTimer[%d]::resume(%f) time %2.9f\n",b_tc_,difs,s.clock()); //DEBUG
	assert(busy_ && paused_);

	paused_ = 0;
	stime = s.clock();

	/*
	 * The media should be idle for DIFS time before we start
	 * decrementing the counter, so I add difs time in here.
	 */
	difs_wait = difs;
	/*
#ifdef USE_SLOT_TIME
	ROUND_TIME();
#endif
	*/
	assert(rtime + difs_wait >= 0.0);
       	s.schedule(this, &intr, rtime + difs_wait);
}


/* ======================================================================
   Beacon Timer
   ====================================================================== */
void
BeaconTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;

	mac->BeaconHandler();
}

/* ======================================================================
   Scheduler Timer
   ====================================================================== */
void
SchedulerTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;

	mac->HCFscheduler(); // The scheduler of polled TXOP
}

//@@ FaZ
void psPollTimer::handle(Event *)
{
	busy_ = 0;
	paused_ = 0;
	stime = 0.0;
	rtime = 0.0;
	
	printf("PS-Poll Timer Expired at %2.9f \n",Scheduler::instance().clock());
	
	mac->schedulerPSPoll();
}
//@ FaZ