Program: 74959
Project: 74959
Buggy source:
/** 
 * Check whether a rendezvous can be formed starting from the given two-dimensional array of receivers. If a rendezvous can be formed, the ready set contains all the receivers participating in the rendezvous after the call, and true is returned; Otherwise, the ready set is not meaningful.
 * @param receivers The initial two-dimensional array of receivers on an actor.
 * @param isPut Whether the request is put.
 * @param beingChecked The set of receivers that are being checked by previous recursive calls.
 * @param ready The set of receivers that are ready for a rendezvous.
 * @param notReady The set of receivers that are not ready for a rendezvous.
 * @param symmetricReceivers The set of symmetric receivers that have been visited during the traversal.
 * @param isSymmetricGet Whether the previous recursive call is from the other side (the get side) of a Merge or Barrier.
 * @param isSymmetricPut Whether the previous recursive call is from the other side (the put side) of a Merge or Barrier.
 * @param farSideReceiver The receiver that is being checked on the far side, or null if this method is not called from the far side.
 * @return Whether a rendezvous can be formed.
 */
private static boolean _checkRendezvous(Receiver[][] receivers,boolean isPut,Set beingChecked,Set ready,Set notReady,Set symmetricReceivers,boolean isSymmetricGet,boolean isSymmetricPut,Receiver farSideReceiver){
  if (receivers.length == 0) {
    return isPut;
  }
  boolean isConditional=_isConditional(receivers,isPut);
  boolean branchReady=false;
  int selectedBranch=_getSelectedBranch(receivers,beingChecked,ready);
  for (int i=0; i < receivers.length; i++) {
    if (receivers[i] == null) {
      continue;
    }
    if (isConditional && farSideReceiver != null) {
      boolean found=false;
      for (int j=0; j < receivers[i].length; j++) {
        if (receivers[i][j] == farSideReceiver) {
          found=true;
          break;
        }
      }
      if (!found) {
        continue;
      }
    }
    if (isConditional && selectedBranch >= 0 && selectedBranch != i) {
      continue;
    }
    branchReady=true;
    for (int j=0; j < receivers[i].length; j++) {
      RendezvousReceiver receiver=(RendezvousReceiver)receivers[i][j];
      if (receiver == null) {
        continue;
      }
      if (symmetricReceivers.contains(receiver)) {
        return false;
      }
      if (beingChecked.contains(receiver) || ready.contains(receiver)) {
      }
 else       if (notReady.contains(receiver)) {
        branchReady=false;
        break;
      }
 else       if ((receiver._putWaiting == null) || (receiver._getWaiting == null)) {
        branchReady=false;
        notReady.add(receiver);
        break;
      }
 else {
        Receiver[][] farSideReceivers=isPut ? receiver._getReceivers : receiver._putReceivers;
        beingChecked.add(receiver);
        symmetricReceivers.add(receiver);
        if (!_checkRendezvous(farSideReceivers,!isPut,beingChecked,ready,notReady,new HashSet(),false,false,receiver)) {
          branchReady=false;
        }
        Receiver[][] symmetric=receiver._symmetricGetReceivers;
        if (branchReady && !isSymmetricPut && symmetric != null) {
          if (!_checkRendezvous(symmetric,false,beingChecked,ready,notReady,symmetricReceivers,true,false,null)) {
            branchReady=false;
          }
        }
        symmetric=receiver._symmetricPutReceivers;
        if (branchReady && !isSymmetricGet && symmetric != null) {
          if (!_checkRendezvous(symmetric,true,beingChecked,ready,notReady,symmetricReceivers,false,true,null)) {
            branchReady=false;
          }
        }
        beingChecked.remove(receiver);
        symmetricReceivers.remove(receiver);
        if (branchReady) {
          ready.add(receiver);
        }
 else {
          notReady.add(receiver);
          break;
        }
      }
    }
    if ((isConditional && branchReady) || (!isConditional && !branchReady)) {
      break;
    }
  }
  return branchReady;
}

Fixed version (ground truth):
/** 
 * Check whether a rendezvous can be formed starting from the given two-dimensional array of receivers. If a rendezvous can be formed, the ready set contains all the receivers participating in the rendezvous after the call, and true is returned; Otherwise, the ready set is not meaningful.
 * @param receivers The initial two-dimensional array of receivers on an actor.
 * @param isPut Whether the request is put.
 * @param beingChecked The set of receivers that are being checked by previous recursive calls.
 * @param ready The set of receivers that are ready for a rendezvous.
 * @param notReady The set of receivers that are not ready for a rendezvous.
 * @param symmetricReceivers The set of symmetric receivers that have been visited during the traversal.
 * @param isSymmetricGet Whether the previous recursive call is from the other side (the get side) of a Merge or Barrier.
 * @param isSymmetricPut Whether the previous recursive call is from the other side (the put side) of a Merge or Barrier.
 * @param farSideReceiver The receiver that is being checked on the far side, or null if this method is not called from the far side.
 * @return Whether a rendezvous can be formed.
 */
private static boolean _checkRendezvous(Receiver[][] receivers,boolean isPut,Set beingChecked,Set ready,Set notReady,Set symmetricReceivers,boolean isSymmetricGet,boolean isSymmetricPut,Receiver farSideReceiver){
  if (receivers.length == 0) {
    return isPut;
  }
  boolean isConditional=_isConditional(receivers,isPut);
  boolean branchReady=false;
  int selectedBranch=_getSelectedBranch(receivers,beingChecked,ready);
  for (int i=0; i < receivers.length; i++) {
    if (receivers[i] == null) {
      continue;
    }
    if (isConditional && farSideReceiver != null) {
      boolean found=false;
      for (int j=0; j < receivers[i].length; j++) {
        if (receivers[i][j] == farSideReceiver) {
          found=true;
          break;
        }
      }
      if (!found) {
        continue;
      }
    }
    if (isConditional && selectedBranch >= 0 && selectedBranch != i) {
      continue;
    }
    branchReady=true;
    for (int j=0; j < receivers[i].length; j++) {
      RendezvousReceiver receiver=(RendezvousReceiver)receivers[i][j];
      if (receiver == null) {
        continue;
      }
      if (symmetricReceivers.contains(receiver)) {
        return false;
      }
      if (beingChecked.contains(receiver) || ready.contains(receiver)) {
      }
 else       if (notReady.contains(receiver)) {
        branchReady=false;
        break;
      }
 else       if ((receiver._putWaiting == null) || (receiver._getWaiting == null)) {
        branchReady=false;
        notReady.add(receiver);
        break;
      }
 else {
        Receiver[][] farSideReceivers=isPut ? receiver._getReceivers : receiver._putReceivers;
        beingChecked.add(receiver);
        symmetricReceivers.add(receiver);
        Receiver[][] symmetric=receiver._symmetricGetReceivers;
        if (branchReady && !isSymmetricPut && symmetric != null) {
          if (!_checkRendezvous(symmetric,false,beingChecked,ready,notReady,symmetricReceivers,true,false,null)) {
            branchReady=false;
          }
        }
        symmetric=receiver._symmetricPutReceivers;
        if (branchReady && !isSymmetricGet && symmetric != null) {
          if (!_checkRendezvous(symmetric,true,beingChecked,ready,notReady,symmetricReceivers,false,true,null)) {
            branchReady=false;
          }
        }
        if (branchReady && !_checkRendezvous(farSideReceivers,!isPut,beingChecked,ready,notReady,new HashSet(),false,false,receiver)) {
          branchReady=false;
        }
        beingChecked.remove(receiver);
        symmetricReceivers.remove(receiver);
        if (branchReady) {
          ready.add(receiver);
        }
 else {
          notReady.add(receiver);
          break;
        }
      }
    }
    if ((isConditional && branchReady) || (!isConditional && !branchReady)) {
      break;
    }
  }
  return branchReady;
}