/*
 * 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 1.8 2000/05/31 02:26:49 steve Exp $"
#endif

# include  "netlist.h"

NetEvent::NetEvent(const string&n)
: name_(n)
{
      scope_ = 0;
      snext_ = 0;
      probes_ = 0;
      trig_ = 0;
      waitref_ = 0;
      wlist_ = 0;
}

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

string NetEvent::name() const
{
      return name_;
}

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

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;
}

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_;
}

NetEvent* NetEvent::find_similar_event()
{
      if (probes_ == 0)
	    return 0;
#define NCAND 256
      NetEvent*cand[NCAND];
      bool cflg[NCAND];
      unsigned ncand = 0;

      NetEvProbe*cur = probes_;

	/* First locate all the canditate events from the probe
	   objects that are connected to them. */

      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;

	    cand[ncand++] = tmp->event();
	    assert(ncand <= NCAND);
      }

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

	    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 (cand[srch] == tmp->event()) {
			      cflg[srch] = true;
			      break;
			}
	    }

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

		  for (unsigned tmp = idx ;  idx+1 < ncand ;  idx += 1) {
			cflg[tmp] = cflg[tmp+1];
			cand[tmp] = cand[tmp+1];
		  }
		  ncand -= 1;
	    }
      }

      for (unsigned idx = 0 ;  idx < ncand ;  idx += 1) {
	    if (cand[idx]->nprobe() == nprobe())
		  return cand[idx];
      }

      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 1.8  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.
 *
 */