xcp-end-sys.h

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// -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*-

/*
 * Copyright (C) 2004 by the University of Southern California
 * Copyright (C) 2004 by USC/ISI
 *               2002 by Dina Katabi
 * $Id: xcp-end-sys.h,v 1.8 2005/09/21 20:52:48 haldar Exp $
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 *
 *
 * The copyright of this module includes the following
 * linking-with-specific-other-licenses addition:
 *
 * In addition, as a special exception, the copyright holders of
 * this module give you permission to combine (via static or
 * dynamic linking) this module with free software programs or
 * libraries that are released under the GNU LGPL and with code
 * included in the standard release of ns-2 under the Apache 2.0
 * license or under otherwise-compatible licenses with advertising
 * requirements (or modified versions of such code, with unchanged
 * license).  You may copy and distribute such a system following the
 * terms of the GNU GPL for this module and the licenses of the
 * other code concerned, provided that you include the source code of
 * that other code when and as the GNU GPL requires distribution of
 * source code.
 *
 * Note that people who make modified versions of this module
 * are not obligated to grant this special exception for their
 * modified versions; it is their choice whether to do so.  The GNU
 * General Public License gives permission to release a modified
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 * possible to release a modified version which carries forward this
 * exception.
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 */

/*
 * $Header: /nfs/jade/vint/CVSROOT/ns-2/xcp/xcp-end-sys.h,v 1.8 2005/09/21 20:52:48 haldar Exp $
 */

#ifndef ns_xcp_end_sys_h
#define ns_xcp_end_sys_h

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>

#include "ip.h"
#include "tcp.h"
#include "flags.h"

#include "agent.h"
#include "packet.h"

#include "flags.h"
#include "tcp-sink.h"

#define XCP_HDR_LEN  20

//-----------  The Congestion Header ------------//
struct hdr_xcp {
    double  throughput_;
    double  rtt_;
    enum {
        XCP_DISABLED = 0,
        XCP_ENABLED,
        XCP_ACK,
    }   xcp_enabled_;       // to indicate that the flow is XCP enabled
    bool    xcp_sparse_;        // flag used with xcp_sparse extension
    int xcpId_;         // Sender's ID (debugging only)
    double  cwnd_;          // The current window (debugging only) 
    double  reverse_feedback_;

    // --- Initialized by source and Updated by Router 
    double delta_throughput_;
    unsigned int controlling_hop_;  // The AQM ID of the controlling router

    static int offset_;     // offset for this header
    inline static int& offset() { return offset_; }
    inline static hdr_xcp* access(Packet* p) {
        return (hdr_xcp*) p->access(offset_);
    }

    /* per-field member functions */
    double& cwnd() { return (cwnd_); }
    double& rtt() { return (rtt_); }
};

/*--------------- Cwnd Shrinking Timer ---------------*
 *  If the cwnd becomes smaller than 1 then we keep it
 *  as one and reduce but delay sending the packet
 *  for s_rtt/cwnd
 * 
 * This code is to be written later!
 */

#define     MAX(a,b)    ((a) > (b) ? (a) : (b))
#define     TP_TO_TICKS MAX(1, (t_srtt_ >> T_SRTT_BITS))

#define TP_AVG_EXP      4   // used for xcp_metered_output_ == true

class XcpAgent;
  
class cwndShrinkingTimer : public TimerHandler {
public: 
    cwndShrinkingTimer(XcpAgent *a) : TimerHandler() { a_ = a; }
protected:
    virtual void expire(Event *e);
    XcpAgent *a_;
};

class XcpAgent : public RenoTcpAgent {
public:
    XcpAgent();

protected:
    
    double time_now()  { return  Scheduler::instance().clock(); };
    void trace_var(char * var_name, double var);
    
    void init_rtt_vars(){
        srtt_estimate_           = 0.0;
    }
    virtual void delay_bind_init_all();
    virtual int delay_bind_dispatch(const char *varName, 
                    const char *localName, 
                    TclObject *tracer);
    
    virtual void output(int seqno, int reason = 0);
    virtual void recv_newack_helper(Packet *); 
    virtual void opencwnd(); 
    virtual void rtt_init(); // called in reset()
    virtual void rtt_update(double tao);
    
    /*--------- Variables --------------*/
    double current_positive_feedback_ ;
    int    tcpId_;
    double srtt_estimate_;
    /* more bits in delta for better precision, just for SRTT */
#define XCP_DELTA_SHIFT     5
#define XCP_EXPO_SHIFT      3
#define XCP_RTT_SHIFT       (XCP_DELTA_SHIFT + XCP_EXPO_SHIFT)  
    /* macros for SRTT calculations */
#define XCP_INIT_SRTT(rtt)                  \
    ((rtt) << XCP_RTT_SHIFT)
       
#define XCP_UPDATE_SRTT(srtt, rtt)              \
    ((srtt) + (((rtt) << XCP_DELTA_SHIFT)           \
           - (((srtt) + (1 << (XCP_EXPO_SHIFT - 1)))    \
              >> XCP_EXPO_SHIFT)))
    long    xcp_srtt_; // srtt estimate using the above macros

    int xcp_sparse_;
    int xcp_sparse_seqno_;

    cwndShrinkingTimer shrink_cwnd_timer_;
};

class XcpSink : public Agent {
public:
    XcpSink(Acker*);
    void recv(Packet* pkt, Handler*);
    void reset();
    int command(int argc, const char*const* argv);
//  TracedInt& maxsackblocks() { return max_sack_blocks_; }
protected:
    void ack(Packet*);
    virtual void add_to_ack(Packet* pkt);

    virtual void delay_bind_init_all();
    virtual int delay_bind_dispatch(const char *varName, 
                    const char *localName, 
                    TclObject *tracer);
    Acker* acker_;
    int ts_echo_bugfix_;
    int ts_echo_rfc1323_;   // conforms to rfc1323 for timestamps echo
    // Added by Andrei Gurtov
    friend void Sacker::configure(TcpSink*);
//  TracedInt max_sack_blocks_; /* used only by sack sinks */
    Packet* save_;      /* place to stash saved packet while delaying */
                /* used by DelAckSink */
    int RFC2581_immediate_ack_;     // Used to generate ACKs immediately
    int bytes_;     // for JOBS
    // for RFC2581-compliant gap-filling.
    double lastreset_;      /* W.N. used for detecting packets
                 * from previous incarnations */
};

#endif /* ns_xcp_end_sys_h */

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