src/user/lossclp1.c

   1 #include "in1out.h"
   2 /////////////////////////////////////////////////////////////////////////////
   3 // LossCLP1
   4 // Module, which discards CLP=1 data items with prob PLOSS
   5 // it does not support Start/Stop protocol
   6 // LossCLP1 <name>:
   7 //    PLOSS=<double>,   // loss probability
   8 //    LOOSECLP0=0|1,    // loose also CLP=0 cells
   9 //    BURSTLEN=<int>,   // loose bursts of this size
  10 //    OUT=<suc>;
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 class lossclp1: public in1out
  14 {
  15    typedef in1out baseclass;
  16    public:
  17
  18       double ploss;     // loss probability
  19       int LooseClp0;    // loose also CLP0 cells
  20       int BurstLen;     // loose Bursts of this length
  21       int Loosing;      // am I loosing now
  22       int CurrentLen;   // data items currently lost or served
  23       int StartLoosing; // when to start with Loosing
  24       int received;     // received data items
  25
  26       double uniform(){return my_rand() / (32767.0+1.0);} // interval = [0,1) !
  27       void init();
  28       rec_typ REC(data *, int);
  29
  30 };
  31
  32 CONSTRUCTOR(Lossclp1, lossclp1);
  33 USERCLASS("LossCLP1",Lossclp1);
  34
  35 /////////////////////////////////////////////////////////////////////////////
  36 // init()
  37 /////////////////////////////////////////////////////////////////////////////
  38 void lossclp1::init(void)
  39 {
  40    skip(CLASS);
  41    name = read_id(NULL);
  42    skip(':');
  43
  44    ploss = read_double("PLOSS");
  45    if(ploss < 0 || ploss > 1)
  46       syntax0("PLOSS must be >=0 and <=1");
  47    skip(',');
  48
  49    LooseClp0 = read_int("LOOSECLP0");
  50    if(LooseClp0 != 0 && LooseClp0 != 1)
  51       syntax0("LOOSECLP0 must be 0 or 1");
  52    skip(',');
  53
  54    BurstLen = read_int("BURSTLEN");
  55    if(BurstLen < 1)
  56       syntax0("BURSTLEN must be >=1");
  57    skip(',');
  58
  59    if(test_word("STARTLOOSING"))
  60    {
  61       StartLoosing = read_int("STARTLOOSING");
  62       if(StartLoosing < 1)
  63          syntax0("STARTLOOSING must be >=1");
  64       skip(',');
  65    }
  66    else
  67       StartLoosing = 1;
  68
  69    output("OUT");
  70    stdinp();
  71
  72    CurrentLen = 0;
  73    Loosing = 0;
  74    if(uniform() < ploss)
  75       Loosing = 1;
  76
  77    received = 0;
  78
  79 } // lossclp1:init()
  80
  81 /////////////////////////////////////////////////////////////////////////////
  82 // rec()
  83 /////////////////////////////////////////////////////////////////////////////
  84 rec_typ lossclp1::REC(data *pd,int)
  85 {
  86
  87    received++;
  88
  89    // serve CLP=0 items (if not LosseCLP0 is set)
  90    if(received < StartLoosing || (pd->clp == 0 && !LooseClp0))
  91    {
  92       suc->rec(pd, shand);
  93       return ContSend;
  94    }
  95
  96    // now, we have a low priority cell
  97    // if the Burstlen for CLP=1 is over, decide, if to drop
  98    CurrentLen++;
  99    if(CurrentLen >= BurstLen)
 100    {
 101       CurrentLen = 0;
 102       Loosing = 0;
 103
 104       if(uniform() < ploss)
 105          Loosing = 1;
 106    }
 107
 108    if( Loosing)
 109       delete pd;
 110    else
 111       suc->rec(pd, shand);
 112
 113    return ContSend;
 114
 115 } // lossclp1::REC()