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/Users/yzchen/ns/ns-allinone-2.33/ns-2.33/queue/pi.h

00001 /* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
00002 /*
00003  * Copyright (c) 1990-1997 Regents of the University of California.
00004  * All rights reserved.
00005  *
00006  * Redistribution and use in source and binary forms, with or without
00007  * modification, are permitted provided that the following conditions
00008  * are met:
00009  * 1. Redistributions of source code must retain the above copyright
00010  *    notice, this list of conditions and the following disclaimer.
00011  * 2. Redistributions in binary form must reproduce the above copyright
00012  *    notice, this list of conditions and the following disclaimer in the
00013  *    documentation and/or other materials provided with the distribution.
00014  * 3. All advertising materials mentioning features or use of this software
00015  *    must display the following acknowledgement:
00016  *      This product includes software developed by the Computer Systems
00017  *      Engineering Group at Lawrence Berkeley Laboratory.
00018  * 4. Neither the name of the University nor of the Laboratory may be used
00019  *    to endorse or promote products derived from this software without
00020  *    specific prior written permission.
00021  *
00022  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00023  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00024  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00025  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00026  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00027  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00028  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00029  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00030  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00031  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00032  * SUCH DAMAGE.
00033  *
00034  */
00035 
00036 
00037 /*
00038  * Based on PI controller described in:
00039  * C. Hollot, V. Misra, D. Towsley and W. Gong. 
00040  * On Designing Improved Controllers for AQM Routers
00041  * Supporting TCP Flows, 
00042  * INFOCOMM 2001. 
00043  */
00044 
00045 #ifndef ns_pi_h
00046 #define ns_pi_h
00047 
00048 #undef setbit
00049 
00050 #include "queue.h"
00051 #include "trace.h"
00052 #include "timer-handler.h"
00053 
00054 #define DTYPE_NONE      0       /* ok, no drop */
00055 #define DTYPE_FORCED    1       /* a "forced" drop */
00056 #define DTYPE_UNFORCED  2       /* an "unforced" (random) drop */
00057 
00058 // Insert APPLE specific macro here
00059 //
00060 #if defined( __MACH__ ) && defined( __APPLE__ )
00061 #undef setbit
00062 #endif
00063 
00064 /*
00065  * Early drop parameters, supplied by user
00066  */
00067 struct edp_pi {
00068         /*
00069          * User supplied.
00070          */
00071         int mean_pktsize;       /* avg pkt size, linked into Tcl */
00072         int bytes;              /* true if queue in bytes, false if packets */
00073         int setbit;             /* true to set congestion indication bit */
00074         double a, b;             /* parameters to pi controller */
00075         double w;                               /* sampling frequency (# of times per second) */ 
00076         double qref;            /* desired queue size */
00077         edp_pi(): mean_pktsize(0), bytes(0), setbit(0), a(0.0), b(0.0), w(0.0), qref(0.0) { }
00078 };
00079 
00080 /*
00081  * Early drop variables, maintained by PI
00082  */
00083 struct edv_pi {
00084         TracedDouble v_prob;    /* prob. of packet drop before "count". */
00085         int count;              /* # of packets since last drop */
00086         int count_bytes;        /* # of bytes since last drop */
00087         int qold;
00088         edv_pi() : v_prob(0.0), count(0), count_bytes(0), qold(0) { }
00089 };
00090 
00091 class LinkDelay;
00092 class PIQueue ; 
00093 
00094 class PICalcTimer : public TimerHandler {
00095 public:
00096                 PICalcTimer(PIQueue *a) : TimerHandler() { a_ = a; }
00097                 virtual void expire(Event *e);
00098 protected:
00099                 PIQueue *a_;
00100 };
00101 
00102 class PIQueue : public Queue {
00103  
00104  friend class PICalcTimer;
00105  public:        
00106         PIQueue(const char * = "Drop");
00107  protected:
00108         int command(int argc, const char*const* argv);
00109         void enque(Packet* pkt);
00110         virtual Packet *pickPacketForECN(Packet* pkt);
00111         virtual Packet *pickPacketToDrop();
00112         Packet* deque();
00113         void reset();
00114         int drop_early(Packet* pkt, int qlen);
00115         double calculate_p();
00116         PICalcTimer CalcTimer;
00117 
00118         LinkDelay* link_;       /* outgoing link */
00119         int fifo_;              /* fifo queue? */
00120         PacketQueue *q_;        /* underlying (usually) FIFO queue */
00121                 
00122         int qib_;       /* bool: queue measured in bytes? */
00123         NsObject* de_drop_;     /* drop_early target */
00124 
00125         //added to be able to trace EDrop Objects - ratul
00126         //the other events - forced drop, enque and deque are traced by a different mechanism.
00127         NsObject * EDTrace;    //early drop trace
00128         char traceType[20];    //the preferred type for early drop trace. 
00129                                //better be less than 19 chars long
00130         Tcl_Channel tchan_;     /* place to write trace records */
00131         TracedInt curq_;        /* current qlen seen by arrivals */
00132         void trace(TracedVar*); /* routine to write trace records */
00133 
00134         edp_pi edp_;    /* early-drop params */
00135         edv_pi edv_;            /* early-drop variables */
00136 
00137         int first_reset_;       /* first time reset() is called */
00138 
00139 };
00140 
00141 #endif

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