net_event.cc

/*
 * Copyright (c) 2000 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, or (at your option)
 *    any later version.
 *
 *    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
 */
#if !defined(WINNT) && !defined(macintosh)
#ident "$Id: net_event.cc,v 1.14 2001/03/29 02:52:19 steve Exp $"
#endif

# include  "netlist.h"

NetEvent::NetEvent(const string&n)
: name_(0)
{
      scope_ = 0;
      snext_ = 0;
      probes_ = 0;
      trig_ = 0;
      waitref_ = 0;
      wlist_ = 0;
      name_ = new char[n.length()+1];
      strcpy(name_, n.c_str());
}

NetEvent::~NetEvent()
{
      assert(waitref_ == 0);
      if (scope_) scope_->rem_event(this);
      while (probes_) {
	    NetEvProbe*tmp = probes_->enext_;
	    delete probes_;
	    probes_ = tmp;
      }
      delete[]name_;
}

const char* NetEvent::name() const
{
      return name_;
}

string NetEvent::full_name() const
{
      assert(scope_);
      return scope_->name() + "." + name_;
}

const NetScope* NetEvent::scope() const
{
      assert(scope_);
      return scope_;
}

unsigned NetEvent::nprobe() const
{
      unsigned cnt = 0;
      NetEvProbe*cur = probes_;
      while (cur) {
	    cnt += 1;
	    cur = cur->enext_;
      }

      return cnt;
}

NetEvProbe* NetEvent::probe(unsigned idx)
{
      NetEvProbe*cur = probes_;
      while (cur && idx) {
	    cur = cur->enext_;
	    idx -= 1;
      }
      return cur;
}

const NetEvProbe* NetEvent::probe(unsigned idx) const
{
      NetEvProbe*cur = probes_;
      while (cur && idx) {
	    cur = cur->enext_;
	    idx -= 1;
      }
      return cur;
}

unsigned NetEvent::ntrig() const
{
      unsigned cnt = 0;
      NetEvTrig*cur = trig_;
      while (cur) {
	    cnt += 1;
	    cur = cur->enext_;
      }

      return cnt;
}

unsigned NetEvent::nwait() const
{
      return waitref_;
}

/*
 * A "similar" event is one that has an identical non-nil set of
 * probes.
 */
NetEvent* NetEvent::find_similar_event()
{
      if (probes_ == 0)
	    return 0;

      struct table_s {
	    NetEvent*ev;
	    bool mark;
      } *table;

	//NetEvent**cand;
	//bool*cflg;
      unsigned max_cand = 0, ncand = 0;

      NetEvProbe*cur = probes_;

	/* Get an estimate of the number of candidate events there
	   are. To get it, count the number of probes that are
	   connected to my first probe. Since there is no more then
	   one NetEvent per NetEvProbe, this is the maximum number of
	   similar events possible.

	   Once we get that count, allocate the arrays needed to
	   account for these events. */

      for (NetNode*idx = cur->next_node()
		 ; idx && (idx != cur) ;  idx = idx->next_node()) {
	    NetEvProbe*tmp = dynamic_cast<NetEvProbe*>(idx);
	    if (tmp == 0)
		  continue;
	    if (tmp->edge() != cur->edge())
		  continue;

	    max_cand += 1;
      }

      table = new struct table_s[max_cand];


	/* First, locate all the candidate events from my first
	   probe. Look for all the NetEvProbe objects connected to my
	   probe (that are the same edge) and save the NetEvent that
	   that probe drives. */

      for (NetNode*idx = cur->next_node()
		 ; idx && (idx != cur) ;  idx = idx->next_node()) {
	    NetEvProbe*tmp = dynamic_cast<NetEvProbe*>(idx);
	    if (tmp == 0)
		  continue;
	    if (tmp->edge() != cur->edge())
		  continue;

	    table[ncand++].ev = tmp->event();
	    assert(ncand <= max_cand);
      }


	/* All the events in the cand array are now known to connect
	   through at least one NetEvProbe. Now go through all my
	   remaining probes and check that each candidate event is
	   also connected (through a NetEvProbe) to me.

	   By the time I finish this scan, only NetEvents that have
	   equivilent NetEvProbes remain. These are candidates. The
	   events may have *more* NetEvProbes then me, I'll catch
	   those later. */

      for (cur = cur->enext_ ;  cur && ncand ;  cur = cur->enext_) {
	    for (unsigned idx = 0 ;  idx < ncand ;  idx += 1)
		  table[idx].mark = false;

	      /* For this probe, look for other probes connected to it
		 and find the event connected to it. Mark that event
		 as connected to this probe. */

	    for (NetNode*idx = cur->next_node()
		       ; idx && (idx != cur) ;  idx = idx->next_node()) {
		  NetEvProbe*tmp = dynamic_cast<NetEvProbe*>(idx);
		  if (tmp == 0)
			continue;
		  if (tmp->edge() != cur->edge())
			continue;

		  for (unsigned srch = 0 ;  srch < ncand ;  srch += 1)
			if (table[srch].ev == tmp->event()) {
			      table[srch].mark = true;
			      break;
			}
	    }

	      /* Look for all the candidates that did not connect to
		 this probe (cflg is false) and eliminate them. */

	    for (unsigned idx = 0 ;  idx < ncand ;  ) {
		  if (table[idx].mark) {
			idx += 1;
			continue;
		  }

		  for (unsigned tmp = idx ;  (tmp+1) < ncand ;  tmp += 1)
			table[tmp] = table[tmp+1];

		  ncand -= 1;
	    }
      }


	/* Scan the remaining candidates for a similar
	   NetEvent. Eliminate NetEvent objects that have more
	   NetEvProbe objects then I, because those have a proper
	   superset of my probes and were not eliminated by the
	   previous scan.

	   As soon as we find a similar event, we're done. */

      for (unsigned idx = 0 ;  idx < ncand ;  idx += 1) {
	    if (table[idx].ev->nprobe() == nprobe()) {
		  NetEvent*res = table[idx].ev;
		  delete[]table;
		  return res;
	    }
      }


	/* Oops, fell off the list without finding a result. return nil. */
      delete[]table;
      return 0;
}

void NetEvent::replace_event(NetEvent*that)
{
      while (wlist_) {
	    wlist_->obj->replace_event(this, that);
      }
}

NetEvTrig::NetEvTrig(NetEvent*ev)
: event_(ev)
{
      enext_ = event_->trig_;
      event_->trig_ = this;
}

NetEvTrig::~NetEvTrig()
{
      if (event_->trig_ == this) {
	    event_->trig_ = enext_;

      } else {
	    NetEvTrig*cur = event_->trig_;
	    while (cur->enext_ != this) {
		  assert(cur->enext_);
		  cur = cur->enext_;
	    }

	    cur->enext_ = this->enext_;
      }
}

const NetEvent* NetEvTrig::event() const
{
      return event_;
}

NetEvProbe::NetEvProbe(const string&n, NetEvent*tgt,
		       edge_t t, unsigned p)
: NetNode(n, p), event_(tgt), edge_(t)
{
      for (unsigned idx = 0 ;  idx < p ;  idx += 1) {
	    pin(idx).set_dir(Link::INPUT);
	    pin(idx).set_name("P", idx);
      }

      enext_ = event_->probes_;
      event_->probes_ = this;
}

NetEvProbe::~NetEvProbe()
{
      if (event_->probes_ == this) {
	    event_->probes_ = enext_;

      } else {
	    NetEvProbe*cur = event_->probes_;
	    while (cur->enext_ != this) {
		  assert(cur->enext_);
		  cur = cur->enext_;
	    }

	    cur->enext_ = this->enext_;
      }
}

NetEvProbe::edge_t NetEvProbe::edge() const
{
      return edge_;
}

NetEvent* NetEvProbe::event()
{
      return event_;
}

const NetEvent* NetEvProbe::event() const
{
      return event_;
}

NetEvWait::NetEvWait(NetProc*pr)
: statement_(pr), nevents_(0), events_(0)
{
}

NetEvWait::~NetEvWait()
{
      if (events_) {
	    for (unsigned idx = 0 ;  idx < nevents_ ;  idx += 1) {
		  NetEvent*tgt = events_[idx];
		  tgt->waitref_ -= 1;

		  struct NetEvent::wcell_*tmp = tgt->wlist_;
		  if (tmp->obj == this) {
			tgt->wlist_ = tmp->next;
			delete tmp;
		  } else {
			assert(tmp->next);
			while (tmp->next->obj != this) {
			      tmp = tmp->next;
			      assert(tmp->next);
			}
			tmp->next = tmp->next->next;
			delete tmp;
		  }
	    }
	    delete[]events_;
      }
      delete statement_;
}

void NetEvWait::add_event(NetEvent*tgt)
{
      assert(tgt);
      if (nevents_ == 0) {
	    events_ = new NetEvent*[1];

      } else {
	    NetEvent**tmp = new NetEvent*[nevents_+1];
	    for (unsigned idx = 0 ;  idx < nevents_ ;  idx += 1) {
		  tmp[idx] = events_[idx];
		  assert(tmp[idx] != tgt);
	    }
	    delete[]events_;
	    events_ = tmp;
      }

      events_[nevents_] = tgt;
      nevents_ += 1;

	// Remember to tell the NetEvent that there is someone
	// pointing to it.
      tgt->waitref_ += 1;

      struct NetEvent::wcell_*tmp = new NetEvent::wcell_;
      tmp->obj = this;
      tmp->next = tgt->wlist_;
      tgt->wlist_ = tmp;
}

void NetEvWait::replace_event(NetEvent*src, NetEvent*repl)
{
      unsigned idx;
      for (idx = 0 ;  idx < nevents_ ;  idx += 1) {
	    if (events_[idx] == src)
		  break;
      }

      assert(idx < nevents_);

	/* First, remove me from the list held by the src NetEvent. */
      assert(src->waitref_ > 0);
      src->waitref_ -= 1;
      struct NetEvent::wcell_*tmp = src->wlist_;
      if (tmp->obj == this) {
	    src->wlist_ = tmp->next;
	    delete tmp;
      } else {
	    assert(tmp->next);
	    while (tmp->next->obj != this) {
		  tmp = tmp->next;
		  assert(tmp->next);
	    }
	    tmp->next = tmp->next->next;
	    delete tmp;
      }

      events_[idx] = repl;

	// Remember to tell the replacement NetEvent that there is
	// someone pointing to it.
      repl->waitref_ += 1;

      tmp = new NetEvent::wcell_;
      tmp->obj = this;
      tmp->next = repl->wlist_;
      repl->wlist_ = tmp;

}

unsigned NetEvWait::nevents() const
{
      return nevents_;
}

const NetEvent* NetEvWait::event(unsigned idx) const
{
      assert(idx < nevents_);
      return events_[idx];
}

NetEvent* NetEvWait::event(unsigned idx)
{
      assert(idx < nevents_);
      return events_[idx];
}

NetProc* NetEvWait::statement()
{
      return statement_;
}

/*
 * $Log: net_event.cc,v $
 * Revision 1.14  2001/03/29 02:52:19  steve
 *  Add const probe method to NetEvent.
 *
 * Revision 1.13  2001/03/28 06:07:39  steve
 *  Add the ivl_event_t to ivl_target, and use that to generate
 *  .event statements in vvp way ahead of the thread that uses it.
 *
 * Revision 1.12  2000/12/15 17:45:07  steve
 *  Remove limits from the similar events search.
 *
 * Revision 1.11  2000/10/04 16:30:39  steve
 *  Use char8 instead of string to store name.
 *
 * Revision 1.10  2000/09/19 03:00:36  steve
 *  Typo stepping ot next probe in delete.
 *
 * Revision 1.9  2000/07/29 03:55:38  steve
 *  fix problem coalescing events w/ probes.
 *
 * Revision 1.8  2000/05/31 02:26:49  steve
 *  Globally merge redundant event objects.
 *
 * Revision 1.7  2000/05/27 19:33:23  steve
 *  Merge similar probes within a module.
 *
 * Revision 1.6  2000/04/18 04:50:20  steve
 *  Clean up unneeded NetEvent objects.
 *
 * Revision 1.5  2000/04/16 23:32:18  steve
 *  Synthesis of comparator in expressions.
 *
 *  Connect the NetEvent and related classes
 *  together better.
 *
 * Revision 1.4  2000/04/12 20:02:53  steve
 *  Finally remove the NetNEvent and NetPEvent classes,
 *  Get synthesis working with the NetEvWait class,
 *  and get started supporting multiple events in a
 *  wait in vvm.
 *
 * Revision 1.3  2000/04/12 04:23:58  steve
 *  Named events really should be expressed with PEIdent
 *  objects in the pform,
 *
 *  Handle named events within the mix of net events
 *  and edges. As a unified lot they get caught together.
 *  wait statements are broken into more complex statements
 *  that include a conditional.
 *
 *  Do not generate NetPEvent or NetNEvent objects in
 *  elaboration. NetEvent, NetEvWait and NetEvProbe
 *  take over those functions in the netlist.
 *
 * Revision 1.2  2000/04/10 05:26:06  steve
 *  All events now use the NetEvent class.
 *
 * Revision 1.1  2000/04/04 03:20:15  steve
 *  Simulate named event trigger and waits.
 *
 */