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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
 */

# include  "config.h"
# include  "compiler.h"
# include  "netlist.h"

/*
 * NOTE: The name_ is perm-allocated by the caller.
 */
NetEvent::NetEvent(perm_string n)
: name_(n)
{
      scope_ = 0;
      snext_ = 0;
      probes_ = 0;
      trig_ = 0;
      waitref_ = 0;
      exprref_ = 0;
      wlist_ = 0;
}

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

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

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

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_;
}

unsigned NetEvent::nexpr() const
{
      return exprref_;
}

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

      map<NetEvent*,unsigned> event_matches;

      /* First, get a list of all the NetEvProbes that are connected
         to my first probe. Then use that to create a set of
         candidate events. These candidate events are a superset of
         the similar events, so I will be culling this list later. */
      list<NetEvProbe*>first_probes;
      probes_->find_similar_probes(first_probes);

      for (list<NetEvProbe*>::iterator idx = first_probes.begin()
             ; idx != first_probes.end() ;  idx ++) {
          event_matches[ (*idx)->event() ] = 1;
      }

      /* Now scan the remaining probes, in each case ticking the
         candidate event. The events that really are similar to this
         one will turn up in every probe list. */
      unsigned probe_count = 1;
      for (NetEvProbe*cur = probes_->enext_ ; cur ;  cur = cur->enext_) {
          list<NetEvProbe*>similar_probes;
          cur->find_similar_probes(similar_probes);

          for (list<NetEvProbe*>::iterator idx = similar_probes.begin()
                   ; idx != similar_probes.end() ;  idx ++) {
              event_matches[ (*idx)->event() ] += 1;
          }

          probe_count += 1;
      }

      /* Now scan the candidate events. Those events that are
         connected to all my probes (match_count[x] == probe_count)
         are possible. If those events have the same number of
         events, then jackpot. */
      for (map<NetEvent*,unsigned>::iterator idx = event_matches.begin()
             ; idx != event_matches.end() ;  idx ++) {

          NetEvent*tmp = (*idx).first;

          if (tmp == this)
              continue;

              /* For automatic tasks, the VVP runtime holds state for events
                 in the automatically allocated context. This means we can't
                 merge similar events in different automatic tasks. */
            if (scope()->is_auto() && (tmp->scope() != scope()))
                  continue;

          if ((*idx).second != probe_count)
              continue;

          unsigned tcnt = 0;
          for (NetEvProbe*cur = tmp->probes_ ; cur ; cur = cur->enext_)
              tcnt += 1;

          if (tcnt == probe_count)
              event_list .push_back(tmp);
      }

}


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

NexusSet* NetEvent::nex_async_()
{
      /* If there are behavioral trigger statements attached to me,
         then this is not an asynchronous event. */
      if (trig_ != 0)
          return 0;


      NexusSet*tmp = new NexusSet;
      for (NetEvProbe*cur = probes_ ;  cur != 0 ;  cur = cur->enext_) {
          if (cur->edge() != NetEvProbe::ANYEDGE) {
              delete tmp;
              return 0;
          }

          for (unsigned idx = 0 ;  idx < cur->pin_count() ;  idx += 1)
              tmp->add(cur->pin(idx).nexus());

      }

      return tmp;
}

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(NetScope*s, perm_string n, NetEvent*tgt,
                   edge_t t, unsigned p)
: NetNode(s, n, p), event_(tgt), edge_(t)
{
      for (unsigned idx = 0 ;  idx < p ;  idx += 1) {
          pin(idx).set_dir(Link::INPUT);
      }

      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_;
}

/*
 * A similar NetEvProbe is one that is connected to all the same nexa
 * that this probe is connected to, and also is the same edge
 * type. Don't count myself as a similar probe.
 */
void NetEvProbe::find_similar_probes(list<NetEvProbe*>&plist)
{
      Nexus*nex = pin(0).nexus();

      for (Link*lcur = nex->first_nlink(); lcur; lcur = lcur->next_nlink()) {
          NetPins*obj = lcur->get_obj();
          if (obj->pin_count() != pin_count())
              continue;

          NetEvProbe*tmp = dynamic_cast<NetEvProbe*>(obj);
          if (tmp == 0)
              continue;

          if (tmp == this)
              continue;

          if (edge() != tmp->edge())
              continue;

          bool ok_flag = true;
          for (unsigned idx = 1 ;  idx < pin_count() ;  idx += 1)
              if (pin(idx).nexus() != tmp->pin(idx).nexus()) {
                  ok_flag = false;
                  break;
              }

          if (ok_flag == true)
              plist .push_back(tmp);
      }
}

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_;
}


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