countpriosched.cc

COPE the first practical network coding scheme which is developped on click

// -*- c-basic-offset: 4 -*-
/*
 * priosched.{cc,hh} -- priority scheduler element
 * Robert Morris, Eddie Kohler
 *
 * Copyright (c) 1999-2000 Massachusetts Institute of Technology
 * Copyright (c) 2003 International Computer Science Institute
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, subject to the conditions
 * listed in the Click LICENSE file. These conditions include: you must
 * preserve this copyright notice, and you cannot mention the copyright
 * holders in advertising related to the Software without their permission.
 * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
 * notice is a summary of the Click LICENSE file; the license in that file is
 * legally binding.
 */

#include <click/config.h>
#include <click/error.hh>
#include <click/straccum.hh>
#include "countpriosched.hh"
CLICK_DECLS

CountPrioSched::CountPrioSched()
    : PrioSched(), _signals(0)
{
    for (int i = 0; i < 3; i++)
	_pulls[i] = 0;
}

CountPrioSched::~CountPrioSched()
{
}

/*
void
PrioSched::notify_ninputs(int i)
{
    set_ninputs(i);
}
*/

int 
CountPrioSched::initialize(ErrorHandler *errh)
{
    if (!(_signals = new NotifierSignal[ninputs()]))
	return errh->error("out of memory!");
    for (int i = 0; i < ninputs(); i++)
	_signals[i] = Notifier::upstream_empty_signal(this, i, 0);
    return 0;
}

void *
CountPrioSched::cast(const char *n)
{
    if (strcmp(n, "CountPrioSched") == 0)
        return (CountPrioSched *)this;
    else
        return PrioSched::cast(n);
}

void
CountPrioSched::cleanup(CleanupStage)
{
    delete[] _signals;
}

Packet *
CountPrioSched::pull(int)
{
    Packet *p;
    for (int i = 0; i < ninputs(); i++) {
	_pulls[i]++;
	if (_signals[i] && (p = input(i).pull())) 
	    return p;
    }
    return 0;
}

String
CountPrioSched::stats(Element *e, void *)
{
  StringAccum sa;
  CountPrioSched *sched = static_cast<CountPrioSched *>(e);
  sa << "pulls: " << sched->_pulls[0] << ", " << sched->_pulls[1] << ", " << sched->_pulls[2] << "\n";
  click_chatter("%{element}: statistics ----------", sched);
  return sa.take_string();
}

int
CountPrioSched::static_clear(const String &arg, Element *e,
                        void *, ErrorHandler *errh)
{
  CountPrioSched *sched = static_cast<CountPrioSched *>(e);

  bool b;

  if (!cp_bool(arg, &b))
    return errh->error("`clear' must be a boolean");

  if (b) {
      for (int i = 0; i<3; i++)
	  sched->_pulls[i] = 0;
      click_chatter("%{element}: statistics cleared\n", sched);
  }

  return 0;
}

void 
CountPrioSched::add_handlers()
{
  add_read_handler("stats", stats, (void *)0);
  add_write_handler("clear", static_clear, 0);
}

CLICK_ENDDECLS
EXPORT_ELEMENT(CountPrioSched)