red.h

我自己写的 RED改进算法的代码

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 *
 *
 * Here is one set of parameters from one of my simulations:
 * 
 * ed [ q_weight=0.002 thresh=5 linterm=30 maxthresh=15
 *         mean_pktsize=500 dropmech=random-drop queue-size=60
 *         plot-file=none bytes=false doubleq=false dqthresh=50 
 *	   wait=true ]
 * 
 * 1/"linterm" is the max probability of dropping a packet. 
 * There are different options that make the code
 * more messy that it would otherwise be.  For example,
 * "doubleq" and "dqthresh" are for a queue that gives priority to
 *   small (control) packets, 
 * "bytes" indicates whether the queue should be measured in bytes 
 *   or in packets, 
 * "dropmech" indicates whether the drop function should be random-drop 
 *   or drop-tail when/if the queue overflows, and 
 *   the commented-out Holt-Winters method for computing the average queue 
 *   size can be ignored.
 * "wait" indicates whether the gateway should wait between dropping
 *   packets.
 *
 * @(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/red.h,v 1.24 2000/11/17 22:10:33 ratul Exp $ (LBL)
 */

#ifndef ns_red_h
#define ns_red_h

#include "queue.h"

#include "trace.h"
class LinkDelay;

/*
 * Early drop parameters, supplied by user
 */
struct edp {
	/*
	 * User supplied.
	 */
	int mean_pktsize;	/* avg pkt size, linked into Tcl */
	int bytes;		/* true if queue in bytes, false if packets */
	int wait;		/* true for waiting between dropped packets */
	int setbit;		/* true to set congestion indication bit */
	int gentle;		/* true to increases dropping prob. slowly *
				 * when ave queue exceeds maxthresh. */
	double th_min;		/* minimum threshold of average queue size */
	double th_max;		/* maximum threshold of average queue size */
	double max_p_inv;	/* 1/max_p, for max_p = maximum prob.  */
	double q_w;		/* queue weight given to cur q size sample */

	/*
	 * Computed as a function of user supplied paramters.
	 */
	double ptc;		/* packet time constant in packets/second */
};

/*
 * Early drop variables, maintained by RED
 */
struct edv {
	TracedDouble v_ave;	/* average queue size */
	TracedDouble v_prob1;	/* prob. of packet drop before "count". */
	double v_slope;		/* used in computing average queue size */
				/* obsolete */
	double v_prob;		/* prob. of packet drop */
	double v_a;		/* v_prob = v_a * v_ave + v_b */
	double v_b;
	double v_c;		/* used for "gentle" mode */
	double v_d;		/* used for "gentle" mode */
	int count;		/* # of packets since last drop */
	int count_bytes;	/* # of bytes since last drop */
	int old;		/* 0 when average queue first exceeds thresh */

	edv() : v_ave(0.0), v_prob1(0.0), v_slope(0.0), v_prob(0.0),
		v_a(0.0), v_b(0.0), count(0), count_bytes(0), old(0) { }
};

class REDQueue : public Queue {
 public:	
	/*	REDQueue();*/
	REDQueue(const char * = "Drop");
 protected:
	int command(int argc, const char*const* argv);
	void enque(Packet* pkt);
	virtual Packet *pickPacketForECN(Packet* pkt);
	virtual Packet *pickPacketToDrop();
	Packet* deque();
	void reset();
	void run_estimator(int nqueued, int m);	/* Obsolete */
	double estimator(int nqueued, int m, double ave, double q_w);
	int drop_early(Packet* pkt);
	double modify_p(double p, int count, int count_bytes, int bytes,
		int mean_pktsize, int wait, int size);
 double calculate_p(double v_ave, double th_max, int gentle, 
			   double v_a, double v_b, double v_c, double v_d, double max_p_inv);
	virtual void reportDrop(Packet *) {}  //pushback
 double calculate_pos(double th_max, double th_min, double para_modi);
	LinkDelay* link_;	/* outgoing link */
	int fifo_;		/* fifo queue? */
        PacketQueue *q_; 	/* underlying (usually) FIFO queue */
		
	int bcount_;	/* byte count */
	int qib_;	/* bool: queue measured in bytes? */
	NsObject* de_drop_;	/* drop_early target */

	//added to be able to trace EDrop Objects - ratul
	//the other events - forced drop, enque and deque are traced by a different mechanism.
	NsObject * EDTrace;    //early drop trace
	char traceType[20];    //the preferred type for early drop trace. 
	                       //better be less than 19 chars long

	Tcl_Channel tchan_;	/* place to write trace records */
	TracedInt curq_;	/* current qlen seen by arrivals */
	void trace(TracedVar*);	/* routine to write trace records */

	/*
	 * Static state.
	 */
	int drop_tail_;		/* drop-tail */
	int drop_front_;	/* drop-from-front */
	int drop_rand_;		/* drop-tail, or drop random? */
	int ns1_compat_;	/* for ns-1 compatibility, bypass a */
				/*   small bugfix */

	edp edp_;	/* early-drop params */
	int doubleq_;	/* for experiments with priority for small packets */
	int dqthresh_;	/* for experiments with priority for small packets */

	/*
	 * Dynamic state.
	 */
	int idle_;		/* queue is idle? */
	double idletime_;	/* if so, since this time */
	edv edv_;		/* early-drop variables */
	int first_reset_;       /* first time reset() is called */

	void print_edp();	// for debugging
	void print_edv();	// for debugging
	double  pos_dis;
	double  para_modi;
	double  cou_grn;
	double  cou_red;
	void reset_cou();
  double getupdatedtokens();
	double tokens_; //acumulated tokens
	double rate_; //token bucket rate
	int bucket_; //bucket depth
	int qlen_;
	double lastupdatetime_;
};

#endif