/// <summary>
/// The local function of each process running Improved MultiCore Tarjan algorithm
/// </summary>
/// <returns></returns>
public void localImprovedTarjanGeldenhuysValmari()
{
//local data for on-the-fly and Tarjan algorithm
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
StringDictionary <int[]> dfsData = new StringDictionary <int[]>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(1024);
Stack <LocalPair> callStack = new Stack <LocalPair>(5000);
Stack <LocalPair> currentStack = new Stack <LocalPair>(1024);
int counter = 0;
string goal = null;
int[] goalData = new int[2] {
-2, 0
};
//--------------------------
//create initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
//create random variable for each process
Random rand = null;
lock (MultiCoreLock)
{
rand = new Random(MultiCoreSeed);
MultiCoreSeed++;
}
//put all initial states to callStack in different order & init data
int[] initPermutation = generatePermutation(initialStates.Count, rand);
for (int i = 0; i < initPermutation.Length; i++)
{
//get data from initialStates
LocalPair tmp = initialStates[initPermutation[i]];
callStack.Push(tmp);
string tmpID = tmp.GetCompressedState();
dfsData.Add(tmpID, new int[] { VISITED_NOPREORDER, 0 });
outgoingTransitionTable.Add(tmpID, new List <string>(8));
}
//start loop
while (callStack.Count > 0)
{
//cancel if too long action
if (CancelRequested || StopMutliCoreThreads)
{
return;
}
//get the top of callStack
LocalPair pair = callStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
//get local data of the top
List <string> outgoing = outgoingTransitionTable[v];
int[] vData = dfsData.GetContainsKey(v);
//if not expended then expend to next states from v
if (!expendedNodes.ContainsKey(v))
{
//create next states of v
ConfigurationBase[] nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
List <LocalPair> nextStates = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, nextStates);
//update outgoing of v and set initial data for successors
//no need to use inverse for statement and use nextStates
foreach (LocalPair next in nextStates)
{
string w = next.GetCompressedState();
outgoing.Add(w);
if (!dfsData.ContainsKey(w))
{
dfsData.Add(w, new int[] { VISITED_NOPREORDER, 0 });
outgoingTransitionTable.Add(w, new List <string>(8));
}
}
}
//get successors of v
List <LocalPair> successors = expendedNodes[v];
//process if v is not numbered yet
if (vData[0] == VISITED_NOPREORDER)
{
vData[0] = counter;
vData[1] = counter;
counter = counter + 1;
//push to currentStack
currentStack.Push(pair);
//check whether v is accepting
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
goal = v;
goalData = vData;
}
//update lowlink according to successors in currentStack
//remove already visited successors
//no need random because consider all successors
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
int[] wData = dfsData.GetContainsKey(w);
if (wData[0] >= 0 && !foundSCCTarjanGeldenhuysValmari.ContainsKey(w))
{
//update & remove from expendedNodes(v)
vData[1] = Math.Min(vData[1], wData[0]);
successors.RemoveAt(i);
//check for report accepting cycle
if (vData[1] <= goalData[0])
{
//REPORT COUNTEREXAMPLE
localReportAcceptingCycle(succ, callStack, dfsData, outgoingTransitionTable);
return;
}
}
}
}
//check if there is any successor not numbered & not visited by other threads
//choose random
bool completed = true;
LocalPair firstUnnumbered = null;
for (int i = successors.Count - 1; i >= 0; i--)
{
int randIndex = rand.Next(successors.Count);
LocalPair succ = successors[randIndex];
string w = succ.GetCompressedState();
int[] wData = dfsData.GetContainsKey(w);
//only check states not in foundSCCTarjanGeldenhuysValmari
if (wData[0] == VISITED_NOPREORDER && !foundSCCTarjanGeldenhuysValmari.ContainsKey(w))
{
completed = false;
firstUnnumbered = succ;
successors.RemoveAt(randIndex);
break;
}
else
{
successors.RemoveAt(randIndex);
}
}
// if there at least one unnumbered successor
if (!completed)
{
callStack.Push(firstUnnumbered);
}
else //all successors are numbered
{
//check for loop at an accepting & deadlock state
if (LTSState.IsDeadLock && pair.state.EndsWith(Constants.ACCEPT_STATE))
{
//report AcceptingCycle
localReportAcceptingCycle(pair, callStack, dfsData, outgoingTransitionTable);
return;
}
if (vData[0] == vData[1])
{
//find the root -> mark as local and global for all processes
LocalPair tmp = null;
string tmpID = null;
//pop currentStack and update SCC_FOUND and add to global memory until v
do
{
//local
tmp = currentStack.Pop();
tmpID = tmp.GetCompressedState();
int[] tmpData = dfsData.GetContainsKey(tmpID);
tmpData[0] = SCC_FOUND;
//global
foundSCCTarjanGeldenhuysValmari.GetOrAdd(tmpID, true);
} while (!tmpID.Equals(v));
//pop callStack
callStack.Pop();
}
else
{
//pop callStack & update the parent
LocalPair pop = callStack.Pop();
LocalPair top = callStack.Peek();
string popID = pop.GetCompressedState();
string topID = top.GetCompressedState();
int[] popData = dfsData.GetContainsKey(popID);
int[] topData = dfsData.GetContainsKey(topID);
topData[1] = Math.Min(topData[1], popData[1]);
}
}
}
}
/// <summary>
/// Improved Nested DFS
/// A Note on On-The-Fly Verification Algorithms - TACAS 2005
/// Blue DFS
/// </summary>
public void BlueDFS()
{
VerificationOutput.CounterExampleTrace = null;
//on-the-fly data
Stack <LocalPair> blueStack = new Stack <LocalPair>(5000);
Dictionary <string, Color> dfsColor = new Dictionary <string, Color>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(5000);
//initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
//check valid result
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
//push initial states to call stack
foreach (LocalPair tmp in initialStates)
{
blueStack.Push(tmp);
}
//start loop
while (blueStack.Count > 0)
{
//cancel if take long time
if (CancelRequested)
{
VerificationOutput.NoOfStates = dfsColor.Count;
return;
}
//get top of call stack
LocalPair pair = blueStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
//get successors
List <LocalPair> successors = null;
if (expendedNodes.ContainsKey(v))
{
successors = expendedNodes[v];
}
else
{
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
successors = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, successors);
}
//if v is white
if (!dfsColor.ContainsKey(v))
{
//set v cyan
Color vColor = new Color();
vColor.setCyan();
dfsColor.Add(v, vColor);
//early cycle detection
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is cyan and (v or w is accepting)
if (dfsColor.ContainsKey(w))
{
Color wColor = dfsColor[w];
if (wColor.isCyan() && (succ.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE)))
{
//REPORT COUNTEREXAMPLE
GetLoopCounterExample(w, blueStack, dfsColor);
return;
}
}
}
}
//check if there is an unnumbered successor
bool isBlueCompleted = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is white
if (!dfsColor.ContainsKey(w))
{
blueStack.Push(succ);
isBlueCompleted = false;
break;
}
}
//if there is no unnumbered successor
if (isBlueCompleted)
{
Color vColor = dfsColor[v];
//if v is accepting
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
//if v is deadlock
if (LTSState.IsDeadLock)
{
//REPORT COUNTEREXAMPLE
GetDeadlockCounterExample(blueStack, dfsColor);
return;
}
else
{
bool stop = RedDFS(pair, blueStack, dfsColor, expendedNodes);
if (stop)
{
return;
}
}
//set v pink
vColor.setPink();
}
else
{
vColor.setBlue();
}
//pop blue stack
blueStack.Pop();
}
}
//no counter example
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = dfsColor.Count;
return;
}
/// <summary>
/// Local Tarjan in each thread to find SCC
/// </summary>
/// <param name="o"></param>
public void LocalImprovedFairTarjan(object o)
{
//order of this thread
int order = (int)o;
Random rand = new Random(order);
//on-the-fly data
Stack <LocalPair> localCallStack = new Stack <LocalPair>(5000);
Stack <LocalPair> localCurrentStack = new Stack <LocalPair>(1024);
Stack <LocalPair> localGoalStack = new Stack <LocalPair>(256);
Dictionary <string, int[]> localDFSNumber = new Dictionary <string, int[]>(5000);
int localNumber = 0;
Dictionary <string, List <LocalPair> > localExpendedNodes = new Dictionary <string, List <LocalPair> >(5000);
//initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
//check valid result
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
return;
}
//push local initial states to local call stack
int[] localPerm = Permutation(initialStates.Count, rand);
for (int i = 0; i < initialStates.Count; i++)
{
LocalPair tmp = initialStates[localPerm[i]];
localCallStack.Push(tmp);
}
//start loop
while (localCallStack.Count > 0)
{
//cancel if take long time
if (CancelRequested || isGlobalStop)
{
return;
}
//get top of call stack
LocalPair pair = localCallStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
//get successors
List <LocalPair> successors = null;
if (localExpendedNodes.ContainsKey(v))
{
successors = localExpendedNodes[v];
}
else
{
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
successors = LocalPair.NextLocal(BA, nextLTSStates, BAState);
localExpendedNodes.Add(v, successors);
}
//if v is not number yet
if (!localDFSNumber.ContainsKey(v))
{
//number v
int[] vData = new int[] { localNumber, localNumber };
localDFSNumber.Add(v, vData);
localNumber = localNumber + 1;
//push to currentStack
localCurrentStack.Push(pair);
//check whether v is accepting
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
localGoalStack.Push(pair);
}
//update lowlink for already numbered successors
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
if (localDFSNumber.ContainsKey(w))
{
int[] wData = localDFSNumber[w];
//if w is in current stack
if (wData[0] >= 0)
{
vData[1] = Math.Min(vData[1], wData[0]);
//check for report accepting cycle
if (localGoalStack.Count > 0 && vData[1] <= localDFSNumber[localGoalStack.Peek().GetCompressedState()][0])
{
//------------------------------------
//get SCC
Dictionary <string, LocalPair> newSCC = new Dictionary <string, LocalPair>();
Dictionary <string, List <string> > newOutgoingTransitionTable = new Dictionary <string, List <string> >();
LocalPair[] callArray = localCallStack.ToArray();
for (int j = 0; j < callArray.Length; j++)
{
LocalPair state = callArray[i];
string stateID = state.GetCompressedState();
newSCC.Add(stateID, state);
List <string> outgoing = new List <string>(8);
List <LocalPair> nextStates = localExpendedNodes[stateID];
foreach (LocalPair next in nextStates)
{
string nextID = next.GetCompressedState();
outgoing.Add(nextID);
}
newOutgoingTransitionTable.Add(stateID, outgoing);
if (stateID.Equals(w))
{
break;
}
}
Dictionary <string, LocalPair> fairSCC = IsFair(newSCC, newOutgoingTransitionTable);
if (fairSCC != null)
{
//REPORT COUNTEREXAMPLE
GetLocalLoopCounterExample(w, localCallStack);
return;
}
return;
}
}
}
}
}
//------------------------------------------------------------------------
//filter successors
List <int> unvisitedIndexs = new List <int>(successors.Count);//not numbered and not global found
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is not cyan and not global red
if (!localDFSNumber.ContainsKey(w) && !globalFoundSCCs.ContainsKey(w))
{
unvisitedIndexs.Add(i);
}
}
//------------------------------------------------------------------------
//get random unvisited successors
if (unvisitedIndexs.Count > 0)
{
bool isFresh = false;
List <int> unFreshIndexs = new List <int>();
while (unvisitedIndexs.Count > 0)
{
int r = rand.Next(unvisitedIndexs.Count);
LocalPair succ = successors[unvisitedIndexs[r]];
string w = succ.GetCompressedState();
//if w is fresh successor
if (!allVisitedStates.ContainsKey(w))
{
localCallStack.Push(succ);
allVisitedStates.GetOrAdd(w, 0);
allVisitedStates[w]++;
isFresh = true;
break;
}
else
{
unFreshIndexs.Add(unvisitedIndexs[r]);
unvisitedIndexs.RemoveAt(r);
}
}
if (!isFresh)
{
int r = rand.Next(unFreshIndexs.Count);
LocalPair succ = successors[unFreshIndexs[r]];
string w = succ.GetCompressedState();
localCallStack.Push(succ);
allVisitedStates.GetOrAdd(w, 0);
allVisitedStates[w]++;
}
}
else
{
//update global
globalFoundSCCs.GetOrAdd(v, true);
int[] vData = localDFSNumber[v];
//if v is root
if (vData[0] == vData[1])
{
// check selfLoop
bool selfLoop = false;
foreach (LocalPair succ in successors)
{
string w = succ.GetCompressedState();
if (v.Equals(w))
{
selfLoop = true;
break;
}
}
//remove states from current stack and goal stack
//updata global
bool isBuchiFair = false;
Dictionary <string, LocalPair> newSCC = new Dictionary <string, LocalPair>(1024);
List <ConfigurationBase> cycle = new List <ConfigurationBase>(1024);
LocalPair tmp = null;
string tmpID = null;
do
{
//get states in SCC
tmp = localCurrentStack.Pop();
if (!isBuchiFair && tmp.state.EndsWith(Constants.ACCEPT_STATE))
{
isBuchiFair = true;
}
tmpID = tmp.GetCompressedState();
newSCC.Add(tmpID, tmp);
cycle.Insert(0, tmp.configuration);
//local
localDFSNumber[tmpID][0] = SCC_FOUND;
} while (tmp != pair);
//local check fairness
if (isBuchiFair && (selfLoop || newSCC.Count > 1 || LTSState.IsDeadLock))
{
//------------------------------------
//get outgoing transition table
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(newSCC.Count);
foreach (KeyValuePair <string, LocalPair> kv in newSCC)
{
string s = kv.Key;
List <LocalPair> nextStates = localExpendedNodes[s];
List <string> outgoing = new List <string>(nextStates.Count);
foreach (LocalPair next in nextStates)
{
string n = next.GetCompressedState();
outgoing.Add(n);
}
outgoingTransitionTable.Add(s, outgoing);
}
//------------------------------------
Dictionary <string, LocalPair> fairSCC = IsFair(newSCC, outgoingTransitionTable);
if (fairSCC != null)
{
//REPORT COUNTEREXAMPLE
GetLocalFairCounterExample(localCallStack, cycle, LTSState.IsDeadLock);
return;
}
}
//pop call stack
localCallStack.Pop();
}
else
{
//pop call stack and update lowlink of top
LocalPair pop = localCallStack.Pop();
LocalPair top = localCallStack.Peek();
string popID = pop.GetCompressedState();
string topID = top.GetCompressedState();
int[] popData = localDFSNumber[popID];
int[] topData = localDFSNumber[topID];
topData[1] = Math.Min(topData[1], popData[1]);
}
}
}
}
// Blue DFS
public void localBlueDFSNestedDFSSharedRed(object o)
{
// get order
int order = (int)o;
// local data for on-the-fly Nested DFS
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
Stack <LocalPair> blueStack = new Stack <LocalPair>(5000);
Dictionary <string, Color> colorData = new Dictionary <string, Color>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(1024);
// create initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
return;
}
// create random variable for each thread
Random rand = new Random(order);
// push initial states to blueStack in random order & initialize data
int[] permutation = generatePermutation(initialStates.Count, rand);
for (int i = 0; i < initialStates.Count; i++)
{
LocalPair tmp = initialStates[permutation[i]];
blueStack.Push(tmp);
string ID = tmp.GetCompressedState();
colorData.Add(ID, new Color());
outgoingTransitionTable.Add(ID, new List <string>(8));
}
// start loop
while (blueStack.Count > 0)
{
// cancel if too long action or couterexample reported
if (CancelRequested || isStop)
{
return;
}
// get the top of blueStack
LocalPair pair = blueStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
// local data of the top
List <string> outgoing = outgoingTransitionTable[v];
Color vColor = colorData[v];
// if v is not expended then expend successors of v
if (!expendedNodes.ContainsKey(v))
{
// create next states from v & add to expendedNodes
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
List <LocalPair> nextStates = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, nextStates);
// add to visitedTimes in this thread
//visitedTimes.GetOrAdd(v, 0);
//visitedTimes[v]++;
// update outgoing of v and set initial data for successors
// no need to use inverse for statement and use nextStates
foreach (LocalPair next in nextStates)
{
string w = next.GetCompressedState();
outgoing.Add(w);
if (!colorData.ContainsKey(w))
{
colorData.Add(w, new Color());
outgoingTransitionTable.Add(w, new List <string>(8));
}
}
}
// get successor of v
List <LocalPair> successors = expendedNodes[v];
// visit v & early accepting cycle detection
if (vColor.isWhite())
{
vColor.setCyan();
// early cycle detection
// use reverse order to remove visited states
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
Color wColor = colorData[w];
// if successor is not white then remove from expendedNodes
if (wColor.isCyan())
{
if (succ.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE))
{
localBlueReportAcceptinCycle(succ, blueStack, outgoingTransitionTable);
return;
}
else
{
successors.RemoveAt(i);
}
}
}
}
// traverse all sucessors in a random order
bool blueDone = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
int randIndex = rand.Next(successors.Count);
LocalPair succ = successors[randIndex];
string w = succ.GetCompressedState();
// only visite white & not red globally successors
if (colorData[w].isWhite() && !sharedRedStates.ContainsKey(w))
{
blueStack.Push(succ);
successors.RemoveAt(randIndex);
blueDone = false;
break;
}
else // remove already visited states in expendedNodes
{
successors.RemoveAt(randIndex);
}
}
// if all successors are visited by blue DFS
if (blueDone)
{
// check loop at an accepting & deadlock state
if (pair.state.EndsWith(Constants.ACCEPT_STATE) && LTSState.IsDeadLock)
{
lock (reportLocker)
{
isStop = true;
Dictionary <string, LocalPair> acceptingCycle = new Dictionary <string, LocalPair>();
acceptingCycle.Add(v, pair);
blueStack.Pop();
finalLocalTaskStack = blueStack;
finalAcceptingCycle = acceptingCycle;
finalOutgoingTransitionTable = outgoingTransitionTable;
return;
}
}
// check whether all successors of v are already red
// also right for deadlock state
bool isAllRed = true;
foreach (string w in outgoing)
{
if (!sharedRedStates.ContainsKey(w))
{
isAllRed = false;
break;
}
}
// if all sucessors are red then v also red
if (isAllRed)
{
sharedRedStates.GetOrAdd(v, true);
}
// if v is accepting states
else if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
// increase count red of v by 1
sharedAcceptingCountRedDFS.GetOrAdd(v, 0);
sharedAcceptingCountRedDFS[v]++;
// initialize red DFS at v
bool stop = localRedDFSNestedDFSSharedRed(pair, blueStack, colorData, outgoingTransitionTable, rand);
if (stop)
{
return;
}
}
// set v to blue
colorData[v].setBlue();
//pop v out of blueStack
blueStack.Pop();
}
}
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
// local function of each thread
public void localQueueTarjanFairnessChecking(object o)
{
// get order
int order = (int)o;
// local data for on-the-fly and Tarjan algorithm
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
Stack <LocalPair> callStack = new Stack <LocalPair>(5000);
Stack <LocalPair> currentStack = new Stack <LocalPair>(1024);
Dictionary <string, int[]> dfsData = new Dictionary <string, int[]>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(1024);
int counter = 0;
//--------------------------
// create initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
return;
}
// create random variable for each process
Random rand = new Random(order);
// push all initial states to callStack in different order & init data
int[] initPermutation = generatePermutation(initialStates.Count, rand);
for (int i = 0; i < initPermutation.Length; i++)
{
//get data from initialStates
LocalPair tmp = initialStates[initPermutation[i]];
callStack.Push(tmp);
string tmpID = tmp.GetCompressedState();
dfsData.Add(tmpID, new int[] { VISITED_NOPREORDER, 0 });
outgoingTransitionTable.Add(tmpID, new List <string>(8));
}
// start loop
while (callStack.Count > 0)
{
// cancel if too long action or any counterexample is reported
if (CancelRequested || isStop)
{
return;
}
// get the top of callStack
LocalPair pair = callStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
// get local data of the top
List <string> outgoing = outgoingTransitionTable[v];
int[] vData = dfsData[v];
// if not expended then expend to next states from v
if (!expendedNodes.ContainsKey(v))
{
// create next states of v
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
List <LocalPair> nextStates = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, nextStates);
// add to visitedTimes in this thread
//visitedTimes.GetOrAdd(v, 0);
//visitedTimes[v]++;
// update outgoing of v and set initial data for successors
// no need to use inverse for statement and use nextStates
foreach (LocalPair next in nextStates)
{
string w = next.GetCompressedState();
outgoing.Add(w);
if (!dfsData.ContainsKey(w))
{
dfsData.Add(w, new int[] { VISITED_NOPREORDER, 0 });
outgoingTransitionTable.Add(w, new List <string>(8));
}
}
}
// get successors of v
List <LocalPair> successors = expendedNodes[v];
// process if v is not numbered yet
if (vData[0] == VISITED_NOPREORDER)
{
vData[0] = counter;
vData[1] = counter;
counter = counter + 1;
// push to currentStack
currentStack.Push(pair);
// update lowlink according to successors in currentStack
// remove already visited successors
// no need to use random
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
int[] wData = dfsData[w];
if (wData[0] >= 0)
{
// update & remove from expendedNodes(v)
vData[1] = Math.Min(vData[1], wData[0]);
successors.RemoveAt(i);
}
}
}
// check if there is any successor not numbered & not visited by other threads
// choose random
bool completed = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
int randIndex = rand.Next(successors.Count);
LocalPair succ = successors[randIndex];
string w = succ.GetCompressedState();
int[] wData = dfsData[w];
// check states not locally visited & not in global shared found SCC
if (wData[0] == VISITED_NOPREORDER && !sharedSCCStates.ContainsKey(w))
{
callStack.Push(succ);
successors.RemoveAt(randIndex);
completed = false;
break;
}
else
{
successors.RemoveAt(randIndex);
}
}
// if all successors are visited
if (completed)
{
// check root
if (vData[0] == vData[1])
{
Dictionary <string, LocalPair> newSCC = new Dictionary <string, LocalPair>(1024);
// check selfLoop
bool selfLoop = false;
foreach (string w in outgoing)
{
if (v.Equals(w))
{
selfLoop = true;
break;
}
}
// get all states in a SCC & check Buchi fair
bool isBuchiFair = false;
LocalPair tmp = null;
string tmpID = null;
// get from current until v
do
{
tmp = currentStack.Pop();
isBuchiFair = isBuchiFair || tmp.state.EndsWith(Constants.ACCEPT_STATE);
tmpID = tmp.GetCompressedState();
int[] tmpData = dfsData[tmpID];
tmpData[0] = SCC_FOUND;
newSCC.Add(tmpID, tmp);
// update global
sharedSCCStates.GetOrAdd(tmpID, true);
} while (!tmpID.Equals(v));
if (isBuchiFair && (selfLoop || newSCC.Count > 1 || LTSState.IsDeadLock))
{
// queue new SCC to check fairness
localQueueSCC(order, newSCC, callStack, outgoingTransitionTable);
}
//pop callStack
callStack.Pop();
}
else
{
//pop callStack & update the parent
LocalPair pop = callStack.Pop();
LocalPair top = callStack.Peek();
string popID = pop.GetCompressedState();
string topID = top.GetCompressedState();
int[] popData = dfsData[popID];
int[] topData = dfsData[topID];
topData[1] = Math.Min(topData[1], popData[1]);
}
}
}
isStop = true;
}
// Blue DFS
public void localBlueDFSCombinationNestedDFS(object o)
{
// get order
int order = (int)o;
// local data of each thread for on-the-fly Nested DFS algorithm
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
Stack <LocalPair> blueStack = new Stack <LocalPair>(5000);
Dictionary <string, bool> cyanData = new Dictionary <string, bool>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(1024);
// create initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
return;
}
// create random variable for each process
Random rand = new Random(order);
// push initial states to blueStack in random order & init data
int[] permutation = generatePermutation(initialStates.Count, rand);
for (int i = 0; i < initialStates.Count; i++)
{
LocalPair tmp = initialStates[permutation[i]];
blueStack.Push(tmp);
string ID = tmp.GetCompressedState();
cyanData.Add(ID, false);
outgoingTransitionTable.Add(ID, new List <string>(8));
}
// start loop
while (blueStack.Count > 0)
{
// cancel if too long action or couterexample reported
if (CancelRequested || isStop)
{
return;
}
// get the top of blueStack
LocalPair pair = blueStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
// get local data of the top
List <string> outgoing = outgoingTransitionTable[v];
bool isVCyan = cyanData[v];
// if v is not expended then expend successors of v
if (!expendedNodes.ContainsKey(v))
{
// create next states from v & add to expendedNodes
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
List <LocalPair> nextStates = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, nextStates);
// add to visitedTimes in this thread
//visitedTimes.GetOrAdd(v, 0);
//visitedTimes[v]++;
// update outgoing of v and set cyan color false
// no need to use inverse for statement and use nextStates
foreach (LocalPair next in nextStates)
{
string w = next.GetCompressedState();
outgoing.Add(w);
if (!cyanData.ContainsKey(w))
{
cyanData.Add(w, false);
outgoingTransitionTable.Add(w, new List <string>(8));
}
}
}
// get successor of v
List <LocalPair> successors = expendedNodes[v];
// if v is not cyan
if (!isVCyan)
{
cyanData[v] = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
bool isWCyan = cyanData[w];
if (isWCyan)
{
if (succ.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE))
{
localBlueReportAcceptinCycle(succ, blueStack, outgoingTransitionTable);
return;
}
else
{
successors.RemoveAt(i);
}
}
}
}
// traverse all sucessors in a random order to find unvisited state
bool blueDone = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
int randIndex = rand.Next(successors.Count);
LocalPair succ = successors[randIndex];
string w = succ.GetCompressedState();
bool isWCyan = cyanData[w];
// if w is not cyan & not global blue
// if w is in sharedBlueRedStates then w is global Blue
// if sharedBlueRedStates[w] is true then w is also global Red
if (!isWCyan && !sharedBlueRedStates.ContainsKey(w))
{
blueStack.Push(succ);
successors.RemoveAt(randIndex);
blueDone = false;
break;
}
else // remove already visited states in expendedNodes
{
successors.RemoveAt(randIndex);
}
}
// if all successors are visited by blue DFS
if (blueDone)
{
// mark v as global blue & false to indicate not globally red yet
sharedBlueRedStates.GetOrAdd(v, false);
// check loop at an accepting & deadlock state
if (pair.state.EndsWith(Constants.ACCEPT_STATE) && LTSState.IsDeadLock)
{
lock (reportLocker)
{
isStop = true;
Dictionary <string, LocalPair> acceptingCycle = new Dictionary <string, LocalPair>();
acceptingCycle.Add(v, pair);
blueStack.Pop();
finalLocalTaskStack = blueStack;
finalAcceptingCycle = acceptingCycle;
finalOutgoingTransitionTable = outgoingTransitionTable;
return;
}
}
// check whether all successors of v are already red
// also right for deadlock state
bool isAllRed = true;
foreach (string w in outgoing)
{
// not in shareBlueRedStates or in but not yet red
if (!sharedBlueRedStates.ContainsKey(w) || !sharedBlueRedStates[w])
{
isAllRed = false;
break;
}
}
// if all sucessors are red then v also red
if (isAllRed)
{
sharedBlueRedStates[v] = true;
}
// if v is accepting state
else if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
Dictionary <LocalPair, bool> rSet = new Dictionary <LocalPair, bool>(1024);
// initialize red DFS at v
bool stop = localRedDFSCombinationNestedDFS(rSet, pair, blueStack, cyanData, outgoingTransitionTable, rand);
if (stop)
{
return;
}
// wait for all accepting states EXCEPT v in rSet become red
foreach (KeyValuePair <LocalPair, bool> kv in rSet)
{
string s = kv.Key.GetCompressedState();
if (kv.Key.state.EndsWith(Constants.ACCEPT_STATE) && !s.Equals(v))
{
while (!sharedBlueRedStates[s])
{
}
;
}
}
// set all states in rSet to red
// states already blue and in shareBlueRedStates blue
foreach (KeyValuePair <LocalPair, bool> kv in rSet)
{
string kvID = kv.Key.GetCompressedState();
sharedBlueRedStates[kvID] = true;
}
}
//pop v out of blueStack
blueStack.Pop();
// uncyan v
cyanData[v] = false;
}
}
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
/// <summary>
/// The function of each worker in swarm NDFS
/// </summary>
/// <returns></returns>
public void SwarmNestedDFSModelCheckingWorker()
{
Dictionary <string, List <string> > OutgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
List <LocalPair> initials = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initials.Count == 0)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
Stack <LocalPair> BlueStack = new Stack <LocalPair>(5000);
Dictionary <string, StateColor> colorData = new Dictionary <string, StateColor>(5000);
int threadId;
// Create random variable with different seed for each thread
Random rand; // helps different threads access different region of the graph
lock (MultiCoreLock)
{
threadId = MultiCoreSeed;
rand = new Random(MultiCoreSeed);
MultiCoreSeed++;
}
// Create the list of initial states
// May apply randomness here to increase performance
int[] permutation = generatePermutation(initials.Count, rand);
for (int z = 0; z < initials.Count; z++)
{
LocalPair initState = initials[permutation[z]];
BlueStack.Push(initState);
string ID = initState.GetCompressedState();
colorData.Add(ID, new StateColor());
OutgoingTransitionTable.Add(ID, new List <string>(8));
}
//store the expended event step of a node to avoid multiple invocation of the make one move.
Dictionary <string, List <LocalPair> > ExpendedNode = new Dictionary <string, List <LocalPair> >(1024);
do
{
if (CancelRequested || StopMutliCoreThreads)
{
return;
}
LocalPair pair = BlueStack.Peek();
ConfigurationBase evt = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
List <string> outgoing = OutgoingTransitionTable[v];
StateColor nodeColor = colorData[v];
if (nodeColor.IsWhite())
{
nodeColor.SetCyan();
}
bool blueDone = true;
// Initialize the node if first time visited
if (!ExpendedNode.ContainsKey(v))
{
//ConfigurationBase[] configList = evt.MakeOneMove().ToArray();
IEnumerable <ConfigurationBase> configList = evt.MakeOneMove();
pair.SetEnabled(configList, FairnessType);
List <LocalPair> product = LocalPair.NextLocal(BA, configList, BAState);
ExpendedNode.Add(v, product);
for (int k = product.Count - 1; k >= 0; k--)
{
LocalPair step = product[k];
string tmp = step.GetCompressedState();
//update the incoming and outgoing edges
outgoing.Add(tmp);
if (!colorData.ContainsKey(tmp))
{
colorData.Add(tmp, new StateColor());
OutgoingTransitionTable.Add(tmp, new List <string>(8));
}
}
}
List <LocalPair> list = ExpendedNode[v];
//transverse all neighbour nodes
for (int k = list.Count - 1; k >= 0; k--)
{
int randIndex = rand.Next(list.Count);
//int randIndex = list.Count - 1;
LocalPair step = list[randIndex];
string tmp = step.GetCompressedState();
StateColor neighbourColor = colorData[tmp];
//if the neighbour node is white
if (neighbourColor.IsWhite())
{
if (blueDone)
{
BlueStack.Push(step);
blueDone = false;
list.RemoveAt(randIndex);
break;
}
}
// if the neighbour node is cyan,
// and either this node or the neibour node is the accept state
// then report cycle
else if (neighbourColor.IsCyan())
{
if (step.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE))
{
SwarmNestedDFSReportBlueCycle(step, pair, BlueStack, colorData, OutgoingTransitionTable);
return;
}
else
{
list.RemoveAt(randIndex);
}
}
// if the neighbour node is either blue or red,
// can remove from the list
else
{
list.RemoveAt(randIndex);
}
}
if (blueDone)
{
BlueStack.Pop();
// If the current node is an accept state,
// do the red DFS
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
if (evt.IsDeadLock)
{
lock (MultiCoreLock)
{
StopMutliCoreThreads = true;
Dictionary <string, LocalPair> LoopPairs = new Dictionary <string, LocalPair>();
LoopPairs.Add(v, pair);
MultiCoreLocalTaskStack = BlueStack;
MultiCoreResultedLoop = LoopPairs;
MultiCoreOutgoingTransitionTable = OutgoingTransitionTable;
return;
}
}
bool stop = SwarmNestedDFSDepthFirstSearchRed(pair, BlueStack, OutgoingTransitionTable, colorData);
if (stop)
{
return;
}
nodeColor.SetRed();
}
else
{
nodeColor.SetBlue();
}
}
} while (BlueStack.Count > 0);
StopMutliCoreThreads = true;
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = colorData.Count;
return;
}
/// <summary>
/// Improved Tarjan Algorithm
/// A Note on On-The-Fly Verification Algorithms - TACAS 2005
/// </summary>
public void ImprovedTarjan()
{
VerificationOutput.CounterExampleTrace = null;
//on-the-fly data
Stack <LocalPair> callStack = new Stack <LocalPair>(5000);
Stack <LocalPair> currentStack = new Stack <LocalPair>(5000);
Stack <LocalPair> goalStack = new Stack <LocalPair>(1024);
Dictionary <string, int[]> dfsNumber = new Dictionary <string, int[]>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(5000);
int counter = 0;
//initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
//check valid result
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
//push initial states to call stack
foreach (LocalPair tmp in initialStates)
{
callStack.Push(tmp);
}
//start loop
while (callStack.Count > 0)
{
//cancel if take long time
if (CancelRequested)
{
VerificationOutput.NoOfStates = dfsNumber.Count;
return;
}
//get top of call stack
LocalPair pair = callStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
//get successors
List <LocalPair> successors = null;
if (expendedNodes.ContainsKey(v))
{
successors = expendedNodes[v];
}
else
{
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
successors = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, successors);
}
//if v is not number yet
if (!dfsNumber.ContainsKey(v))
{
//number v
int[] vData = new int[] { counter, counter };
dfsNumber.Add(v, vData);
counter = counter + 1;
//push to currentStack
currentStack.Push(pair);
//check whether v is accepting
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
goalStack.Push(pair);
}
//update lowlink for already numbered successors
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is already numbered
if (dfsNumber.ContainsKey(w))
{
int[] wData = dfsNumber[w];
//if w is in current stack
if (wData[0] >= 0)
{
vData[1] = Math.Min(vData[1], wData[0]);
//check for report accepting cycle
if (goalStack.Count > 0 && vData[1] <= dfsNumber[goalStack.Peek().GetCompressedState()][0])
{
//REPORT COUNTEREXAMPLE
GetLoopCounterExample(w, callStack, dfsNumber);
return;
}
}
}
}
}
//check if there is an unnumbered successor
bool isCompleted = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is not already numbered
if (!dfsNumber.ContainsKey(w))
{
callStack.Push(succ);
isCompleted = false;
break;
}
}
//if there is no unnumbered successor
if (isCompleted)
{
//deadlock at accepting state
if (LTSState.IsDeadLock && pair.state.EndsWith(Constants.ACCEPT_STATE))
{
//REPORT COUNTEREXAMPLE
GetDeadlockCounterExample(callStack, dfsNumber);
return;
}
int[] vData = dfsNumber[v];
//if v is root
if (vData[0] == vData[1])
{
//remove states from current stack and goal stack
LocalPair tmp = null;
string tmpID = null;
do
{
//current stack
tmp = currentStack.Pop();
tmpID = tmp.GetCompressedState();
dfsNumber[tmpID][0] = SCC_FOUND;
//goal stack
if (goalStack.Count > 0 && tmp == goalStack.Peek())
{
goalStack.Pop();
}
} while (tmp != pair);
//pop call stack
callStack.Pop();
}
else
{
//pop call stack and update lowlink of top
LocalPair pop = callStack.Pop();
LocalPair top = callStack.Peek();
string popID = pop.GetCompressedState();
string topID = top.GetCompressedState();
int[] popData = dfsNumber[popID];
int[] topData = dfsNumber[topID];
topData[1] = Math.Min(topData[1], popData[1]);
}
}
}
//no counter example
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = dfsNumber.Count;
return;
}
/// <summary>
/// Local blue DFS in each thread
/// </summary>
/// <param name="o"></param>
public void LocalBlue2(object o)
{
//order of this thread
int order = (int)o;
Random rand = new Random(order);
//on-the-fly data
Stack <LocalPair> localBlueStack = new Stack <LocalPair>(5000);
Dictionary <string, bool> localCyanData = new Dictionary <string, bool>(5000);
Dictionary <string, List <LocalPair> > localExpendedNodes = new Dictionary <string, List <LocalPair> >(5000);
//initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
//check valid result
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
return;
}
//push local initial states to local blue stack
int[] localPerm = Permutation(initialStates.Count, rand);
for (int i = 0; i < initialStates.Count; i++)
{
LocalPair tmp = initialStates[localPerm[i]];
localBlueStack.Push(tmp);
}
//start loop
while (localBlueStack.Count > 0)
{
//cancel if take long time
if (CancelRequested || isGlobalStop)
{
return;
}
//get top of blue stack
LocalPair pair = localBlueStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
//get successors
List <LocalPair> successors = null;
if (localExpendedNodes.ContainsKey(v))
{
successors = localExpendedNodes[v];
}
else
{
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
successors = LocalPair.NextLocal(BA, nextLTSStates, BAState);
localExpendedNodes.Add(v, successors);
}
//if v is not cyan
if (!localCyanData.ContainsKey(v))
{
//set v cyan
localCyanData.Add(v, true);
//early cycle detection
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is cyan and (v or w is accepting)
if (localCyanData.ContainsKey(w))
{
bool isWcyan = localCyanData[w];
if (isWcyan && (succ.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE)))
{
//REPORT COUNTEREXAMPLE
GetLocalLoopCounterExample(w, localBlueStack);
return;
}
}
}
}
//------------------------------------------------------------------------
//filter successors and check if all successors are red
bool isAllRed = true;
List <int> unvisitedIndexs = new List <int>(successors.Count);//not visited and not global red
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is not cyan and not global blue
if (!localCyanData.ContainsKey(w) && !globalBlueRedStates.ContainsKey(w))
{
unvisitedIndexs.Add(i);
}
//set all red variable to false if w not global red
if (isAllRed)
{
if (!globalBlueRedStates.ContainsKey(w) || !globalBlueRedStates[w])
{
isAllRed = false;
}
}
}
//------------------------------------------------------------------------
//get random unvisited successors
if (unvisitedIndexs.Count > 0)
{
bool isFresh = false;
List <int> unFreshIndexs = new List <int>();
while (unvisitedIndexs.Count > 0)
{
int r = rand.Next(unvisitedIndexs.Count);
LocalPair succ = successors[unvisitedIndexs[r]];
string w = succ.GetCompressedState();
//if w is fresh successor
if (!allVisitedStates.ContainsKey(w))
{
localBlueStack.Push(succ);
allVisitedStates.GetOrAdd(w, 0);
allVisitedStates[w]++;
isFresh = true;
break;
}
else
{
unFreshIndexs.Add(unvisitedIndexs[r]);
unvisitedIndexs.RemoveAt(r);
}
}
if (!isFresh)
{
int r = rand.Next(unFreshIndexs.Count);
LocalPair succ = successors[unFreshIndexs[r]];
string w = succ.GetCompressedState();
localBlueStack.Push(succ);
allVisitedStates.GetOrAdd(w, 0);
allVisitedStates[w]++;
}
}
else
{
//mark v global blue
globalBlueRedStates.GetOrAdd(v, false);
//deadlock at accepting state
if (pair.state.EndsWith(Constants.ACCEPT_STATE) && LTSState.IsDeadLock)
{
//REPORT COUNTEREXAMPLE
GetLocalDeadlockCounterExample(localBlueStack);
return;
}
//if all successors are global red
if (isAllRed)
{
globalBlueRedStates[v] = true;
}
else if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
Dictionary <LocalPair, bool> rSet = new Dictionary <LocalPair, bool>(1024);
//start local red DFS
bool isStop = LocalRed2(rSet, pair, localBlueStack, localCyanData, rand, localExpendedNodes);
if (isStop)
{
return;
}
//wait for all accepting states EXCEPT v in rSet become red
foreach (KeyValuePair <LocalPair, bool> kv in rSet)
{
string s = kv.Key.GetCompressedState();
if (kv.Key.state.EndsWith(Constants.ACCEPT_STATE) && !s.Equals(v))
{
while (!globalBlueRedStates[s])
{
;
}
}
}
//set all states in rSet to red
foreach (KeyValuePair <LocalPair, bool> kv in rSet)
{
string kvID = kv.Key.GetCompressedState();
globalBlueRedStates[kvID] = true;
}
}
//pop blue stack
localBlueStack.Pop();
//uncyan v
localCyanData[v] = false;
}
}
}
/// <summary>
/// Local Improved Tarjan in each thread
/// </summary>
/// <param name="o"></param>
public void LocalImprovedTarjanSwarm(object o)
{
//order of this thread
int order = (int)o;
Random rand = new Random(order);
//on-the-fly data
Stack <LocalPair> localCallStack = new Stack <LocalPair>(5000);
Stack <LocalPair> localCurrentStack = new Stack <LocalPair>(1024);
Stack <LocalPair> localGoalStack = new Stack <LocalPair>(256);
Dictionary <string, int[]> localDFSNumber = new Dictionary <string, int[]>(5000);
int localNumber = 0;
Dictionary <string, List <LocalPair> > localExpendedNodes = new Dictionary <string, List <LocalPair> >(5000);
//initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
//check valid result
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
return;
}
//push local initial states to local call stack
int[] localPerm = Permutation(initialStates.Count, rand);
for (int i = 0; i < initialStates.Count; i++)
{
LocalPair tmp = initialStates[localPerm[i]];
localCallStack.Push(tmp);
}
//start loop
while (localCallStack.Count > 0)
{
//cancel if take long time
if (CancelRequested || isGlobalStop)
{
return;
}
//get top of call stack
LocalPair pair = localCallStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
//get successors
List <LocalPair> successors = null;
if (localExpendedNodes.ContainsKey(v))
{
successors = localExpendedNodes[v];
}
else
{
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
successors = LocalPair.NextLocal(BA, nextLTSStates, BAState);
localExpendedNodes.Add(v, successors);
}
//if v is not number yet
if (!localDFSNumber.ContainsKey(v))
{
//number v
int[] vData = new int[] { localNumber, localNumber };
localDFSNumber.Add(v, vData);
localNumber = localNumber + 1;
//push to currentStack
localCurrentStack.Push(pair);
//check whether v is accepting
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
localGoalStack.Push(pair);
}
//update lowlink for already numbered successors
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
if (localDFSNumber.ContainsKey(w))
{
int[] wData = localDFSNumber[w];
//if w is in current stack
if (wData[0] >= 0)
{
vData[1] = Math.Min(vData[1], wData[0]);
//check for report accepting cycle
if (localGoalStack.Count > 0 && vData[1] <= localDFSNumber[localGoalStack.Peek().GetCompressedState()][0])
{
//REPORT COUNTEREXAMPLE
GetLocalLoopCounterExample(w, localCallStack);
return;
}
}
}
}
}
//------------------------------------------------------------------------
//filter successors
List <int> unvisitedIndexs = new List <int>(successors.Count);//not numbered and not global found
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is not cyan and not global red
if (!localDFSNumber.ContainsKey(w))
{
unvisitedIndexs.Add(i);
}
}
//------------------------------------------------------------------------
//get random unvisited successors
if (unvisitedIndexs.Count > 0)
{
bool isFresh = false;
List <int> unFreshIndexs = new List <int>();
while (unvisitedIndexs.Count > 0)
{
int r = rand.Next(unvisitedIndexs.Count);
LocalPair succ = successors[unvisitedIndexs[r]];
string w = succ.GetCompressedState();
//if w is fresh successor
if (!allVisitedStates.ContainsKey(w))
{
localCallStack.Push(succ);
allVisitedStates.GetOrAdd(w, 0);
allVisitedStates[w]++;
isFresh = true;
break;
}
else
{
unFreshIndexs.Add(unvisitedIndexs[r]);
unvisitedIndexs.RemoveAt(r);
}
}
if (!isFresh)
{
int r = rand.Next(unFreshIndexs.Count);
LocalPair succ = successors[unFreshIndexs[r]];
string w = succ.GetCompressedState();
localCallStack.Push(succ);
allVisitedStates.GetOrAdd(w, 0);
allVisitedStates[w]++;
}
}
else
{
//deadlock at accepting state
if (LTSState.IsDeadLock && pair.state.EndsWith(Constants.ACCEPT_STATE))
{
//REPORT COUNTEREXAMPLE
GetLocalDeadlockCounterExample(localCallStack);
return;
}
int[] vData = localDFSNumber[v];
//if v is root
if (vData[0] == vData[1])
{
//remove states from current stack and goal stack
LocalPair tmp = null;
string tmpID = null;
do
{
//current stack
tmp = localCurrentStack.Pop();
tmpID = tmp.GetCompressedState();
localDFSNumber[tmpID][0] = SCC_FOUND;
//goal stack
if (localGoalStack.Count > 0 && tmp == localGoalStack.Peek())
{
localGoalStack.Pop();
}
} while (tmp != pair);
//pop call stack
localCallStack.Pop();
}
else
{
//pop call stack and update lowlink of top
LocalPair pop = localCallStack.Pop();
LocalPair top = localCallStack.Peek();
string popID = pop.GetCompressedState();
string topID = top.GetCompressedState();
int[] popData = localDFSNumber[popID];
int[] topData = localDFSNumber[topID];
topData[1] = Math.Min(topData[1], popData[1]);
}
}
}
}
/// <summary>
/// Run the verification and get the result.
/// </summary>
/// <returns></returns>
public void ModelCheckingLivenessWithFairness()
{
Dictionary <string, List <string> > OutgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
LocalTaskStack = new Stack <LocalPair>(5000);
VerificationOutput.CounterExampleTrace = null;
List <LocalPair> initials = LocalPair.GetInitialPairsLocal(BA, InitialStep);
StringDictionary <int[]> DFSData = new StringDictionary <int[]>();
if (initials.Count == 0)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
for (int z = 0; z < initials.Count; z++)
{
LocalPair initState = initials[z];
LocalTaskStack.Push(initState);
string ID = initState.GetCompressedState(FairnessType);
DFSData.Add(ID, new int[] { VISITED_NOPREORDER, 0 });
OutgoingTransitionTable.Add(ID, new List <string>(8));
}
Dictionary <string, LocalPair> SCCPairs = new Dictionary <string, LocalPair>(1024);
Stack <LocalPair> stepStack = new Stack <LocalPair>(1024);
int i = 0;
//store the expended event step of a node to avoid multiple invocation of the make one move.
Dictionary <string, List <LocalPair> > ExpendedNode = new Dictionary <string, List <LocalPair> >(1024);
do
{
if (CancelRequested)
{
VerificationOutput.NoOfStates = DFSData.Count; // VisitedWithID.Count;
return;
}
LocalPair pair = LocalTaskStack.Peek();
ConfigurationBase evt = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState(FairnessType);
List <string> outgoing = OutgoingTransitionTable[v];
int[] nodeData = DFSData.GetContainsKey(v);
if (nodeData[0] == VISITED_NOPREORDER)
{
nodeData[0] = i;
i++;
}
bool done = true;
if (ExpendedNode.ContainsKey(v))
{
List <LocalPair> list = ExpendedNode[v];
if (list.Count > 0)
{
//transverse all steps
for (int k = list.Count - 1; k >= 0; k--)
{
LocalPair step = list[k];
//if the step is a unvisited step
string tmp = step.GetCompressedState(FairnessType);
if (DFSData.GetContainsKey(tmp)[0] == VISITED_NOPREORDER)
//if (!preorder.ContainsKey(step.GetCompressedState()))
{
//only add the first unvisited step
//for the second or more unvisited steps, ignore at the monent
if (done)
{
LocalTaskStack.Push(step);
done = false;
list.RemoveAt(k);
}
}
else
{
list.RemoveAt(k);
}
}
}
}
else
{
//ConfigurationBase[] list = evt.MakeOneMove().ToArray();
IEnumerable <ConfigurationBase> list = evt.MakeOneMove();
pair.SetEnabled(list, FairnessType);
List <LocalPair> product = LocalPair.NextLocal(BA, list, BAState);
//count the transitions visited
VerificationOutput.Transitions += product.Count;
for (int k = product.Count - 1; k >= 0; k--)
{
LocalPair step = product[k];
string tmp = step.GetCompressedState(FairnessType);
//if (VisitedWithID.ContainsKey(tmp))
int[] data = DFSData.GetContainsKey(tmp);
if (data != null)
{
//update the incoming and outgoing edges
//int t = VisitedWithID.GetContainsKey(tmp); //DataStore.DataManager.GetID(tmp);
outgoing.Add(tmp);
//if this node is still not visited
if (data[0] == VISITED_NOPREORDER)
{
//step.ID = t;
//only put the first one to the work list stack.
//if there are more than one node to be visited,
//simply ignore them and keep its event step in the list.
if (done)
{
LocalTaskStack.Push(step);
done = false;
product.RemoveAt(k);
}
else
{
product[k] = step;
}
}
//this node is truly visited. can be removed
else
{
product.RemoveAt(k);
}
}
else
{
//int stateID = VisitedWithID.Count;
//VisitedWithID.Add(tmp,false);
DFSData.Add(tmp, new int[] { VISITED_NOPREORDER, 0 });
OutgoingTransitionTable.Add(tmp, new List <string>(8));
//step.ID = stateID;
outgoing.Add(tmp);
//only put the first one into the stack.
if (done)
{
LocalTaskStack.Push(step);
done = false;
product.RemoveAt(k);
}
else
{
product[k] = step;
}
}
}
//create the remaining steps as the expending list for v
ExpendedNode.Add(v, product);
}
if (done)
{
int lowlinkV = nodeData[0]; // preorder[v];
int preorderV = lowlinkV;
bool selfLoop = false;
for (int j = 0; j < outgoing.Count; j++)
{
string w = outgoing[j];
if (w == v)
{
selfLoop = true;
}
int[] wdata = DFSData.GetContainsKey(w);
if (wdata[0] != SCC_FOUND)
{
if (wdata[0] > preorderV)
{
lowlinkV = Math.Min(lowlinkV, wdata[1]);
}
else
{
lowlinkV = Math.Min(lowlinkV, wdata[0]);
}
}
}
nodeData[1] = lowlinkV;
LocalTaskStack.Pop();
if (lowlinkV == preorderV)
{
SCCPairs.Add(v, pair);
nodeData[0] = SCC_FOUND;
//checking for buchi-fair
bool BuchiFair = pair.state.EndsWith(Constants.ACCEPT_STATE);
//while (stepStack.Count > 0 && preorder[stepStack.Peek().GetCompressedState()] > preorderV)
while (stepStack.Count > 0 && DFSData.GetContainsKey(stepStack.Peek().GetCompressedState(FairnessType))[0] > preorderV)
{
LocalPair s = stepStack.Pop();
string k = s.GetCompressedState(FairnessType);
DFSData.GetContainsKey(k)[0] = SCC_FOUND;
SCCPairs.Add(k, s);
if (!BuchiFair && s.state.EndsWith(Constants.ACCEPT_STATE))
{
BuchiFair = true;
}
}
int SCCSize = SCCPairs.Count;
if (BuchiFair && (evt.IsDeadLock || SCCSize > 1 || selfLoop))
{
PrintMessage("A SCC of size " + SCCSize + " is found");
Dictionary <string, LocalPair> value = IsFair(SCCPairs, OutgoingTransitionTable);
if (value != null)
{
PrintMessage("The SCC found is FAIR.");
VerificationOutput.VerificationResult = VerificationResultType.INVALID;
VerificationOutput.NoOfStates = DFSData.Count; // VisitedWithID.Count;
LocalGetCounterExample(value, OutgoingTransitionTable);
return;
}
PrintMessage("The SCC found is NOT fair.");
}
foreach (string componet in SCCPairs.Keys)
{
ExpendedNode.Remove(componet);
OutgoingTransitionTable.Remove(componet);
}
//StronglyConnectedComponets.Clear();
SCCPairs.Clear();
}
else
{
stepStack.Push(pair);
}
}
} while (LocalTaskStack.Count > 0);
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = DFSData.Count; // VisitedWithID.Count;
}
/// <summary>
/// Improve Tarjan-Geldenhuy algorithm
/// Iterative version
/// </summary>
public void ImprovedTarjanGeldenhuysValmari()
{
VerificationOutput.CounterExampleTrace = null;
// data for on-the-fly and Tarjan algorithm
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
Stack <LocalPair> callStack = new Stack <LocalPair>(5000);
Stack <LocalPair> currentStack = new Stack <LocalPair>(1024);
Stack <LocalPair> goalStack = new Stack <LocalPair>(256);
Dictionary <string, int[]> dfsData = new Dictionary <string, int[]>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(1024);
int counter = 0;
//--------------------------
// create initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
// test
//expendedNodesNumber = 0;
// put all initial states to callStack & init data
foreach (LocalPair tmp in initialStates)
{
callStack.Push(tmp);
string tmpID = tmp.GetCompressedState();
dfsData.Add(tmpID, new int[] { VISITED_NOPREORDER, 0 });
outgoingTransitionTable.Add(tmpID, new List <string>(8));
}
// start loop
while (callStack.Count > 0)
{
// cancel if too long action
if (CancelRequested)
{
VerificationOutput.NoOfStates = dfsData.Count;
return;
}
// get the top of callStack
LocalPair pair = callStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
// get data of the top
List <string> outgoing = outgoingTransitionTable[v];
int[] vData = dfsData[v];
// if not expended then expend to next states from v
if (!expendedNodes.ContainsKey(v))
{
// create next states of v & add to expendedNodes
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove(); //.ToArray()
pair.SetEnabled(nextLTSStates, FairnessType);
List <LocalPair> nextStates = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, nextStates);
// increase number of states expended
//expendedNodesNumber++;
// increase transitions visited
VerificationOutput.Transitions += nextStates.Count;
// update outgoing of v and set initial data for successors
// no need to use inverse for statement
foreach (LocalPair next in nextStates)
{
string w = next.GetCompressedState();
outgoing.Add(w);
if (!dfsData.ContainsKey(w))
{
dfsData.Add(w, new int[] { VISITED_NOPREORDER, 0 });
outgoingTransitionTable.Add(w, new List <string>(8));
}
}
}
// get successors of v
List <LocalPair> successors = expendedNodes[v];
// process if v is not numbered yet
if (vData[0] == VISITED_NOPREORDER)
{
vData[0] = counter;
vData[1] = counter;
counter = counter + 1;
// push to currentStack
currentStack.Push(pair);
// check whether v is accepting
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
goalStack.Push(pair);
}
// update lowlink according to successors in currentStack
// remove already visited successors
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
int[] wData = dfsData[w];
if (wData[0] >= 0)
{
// update & remove from expendedNodes(v)
vData[1] = Math.Min(vData[1], wData[0]);
successors.RemoveAt(i);
// check for report accepting cycle
if (goalStack.Count > 0 && vData[1] <= dfsData[goalStack.Peek().GetCompressedState()][0])
{
// REPORT COUNTEREXAMPLE
reportAcceptingCycle(succ, callStack, dfsData, outgoingTransitionTable);
return;
}
}
}
}
// check if there is any successor not numbered
bool completed = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
int[] wData = dfsData[w];
if (wData[0] == VISITED_NOPREORDER)
{
callStack.Push(succ);
successors.RemoveAt(i);
completed = false;
break;
}
else
{
successors.RemoveAt(i);
}
}
// if all successors are visited
if (completed)
{
// check for loop at deadlock & accepting state
if (LTSState.IsDeadLock && pair.state.EndsWith(Constants.ACCEPT_STATE))
{
// report accepting cycle
reportAcceptingCycle(pair, callStack, dfsData, outgoingTransitionTable);
return;
}
if (vData[0] == vData[1])
{
LocalPair tmp = null;
string tmpID = null;
// pop currentStack and update SCC_FOUND until v
do
{
// remove from currentStack
tmp = currentStack.Pop();
tmpID = tmp.GetCompressedState();
int[] tmpData = dfsData[tmpID];
tmpData[0] = SCC_FOUND;
// remove from goalStack
if (goalStack.Count > 0 && tmp == goalStack.Peek())
{
goalStack.Pop();
}
} while (!tmpID.Equals(v));
// pop callStack
callStack.Pop();
}
else
{
// pop callStack & update the parent
LocalPair pop = callStack.Pop();
LocalPair top = callStack.Peek();
string popID = pop.GetCompressedState();
string topID = top.GetCompressedState();
int[] popData = dfsData[popID];
int[] topData = dfsData[topID];
topData[1] = Math.Min(topData[1], popData[1]);
}
}
}
// end while loop
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = dfsData.Count;
return;
}
/// <summary>
/// Run the verification using the Nested DFS algorithm and get the result.
/// Based on:
/// A Note on On-The-Fly Verification Algorithms
/// http://dl.acm.org/citation.cfm?id=2140670
/// Stefan Schwoon and Javier Esparza
/// Proceeding TACAS'05 Proceedings of the 11th international conference on
/// Tools and Algorithms for the Construction and Analysis of Systems
/// Springer-Verlag Berlin, Heidelberg, 2005
/// </summary>
/// <returns></returns>
public void NestedDFSModelChecking()
{
Dictionary <string, List <string> > OutgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
VerificationOutput.CounterExampleTrace = null;
List <LocalPair> initials = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initials.Count == 0)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
Stack <LocalPair> BlueStack = new Stack <LocalPair>(5000);
StringDictionary <StateColor> colorData = new StringDictionary <StateColor>(5000);
for (int z = 0; z < initials.Count; z++)
{
LocalPair initState = initials[z];
BlueStack.Push(initState);
string ID = initState.GetCompressedState();
colorData.Add(ID, new StateColor());
OutgoingTransitionTable.Add(ID, new List <string>(8));
}
//store the expended event step of a node to avoid multiple invocation of the make one move.
Dictionary <string, List <LocalPair> > ExpendedNode = new Dictionary <string, List <LocalPair> >(1024);
do
{
if (CancelRequested)
{
VerificationOutput.NoOfStates = colorData.Count; // VisitedWithID.Count;
return;
}
LocalPair pair = BlueStack.Peek();
ConfigurationBase evt = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
List <string> outgoing = OutgoingTransitionTable[v];
StateColor nodeColor = colorData.GetContainsKey(v);
if (nodeColor.IsWhite())
{
nodeColor.SetCyan();
}
bool blueDone = true;
if (ExpendedNode.ContainsKey(v))
{
List <LocalPair> list = ExpendedNode[v];
if (list.Count > 0)
{
//transverse all neighbour nodes
for (int k = list.Count - 1; k >= 0; k--)
{
LocalPair step = list[k];
string tmp = step.GetCompressedState();
StateColor neighbourColor = colorData.GetContainsKey(tmp);
//if the neighbour node is white
if (neighbourColor.IsWhite())
{
//only add the first unvisited node
//for the second or more unvisited steps, ignore at the monent
if (blueDone)
{
BlueStack.Push(step);
blueDone = false;
list.RemoveAt(k);
}
}
// if the neighbour node is cyan,
// and either this node or the neibour node is the accept state
// then report cycle
else if (neighbourColor.IsCyan())
{
if (step.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE))
{
// Report cycle
ReportBlueCycle(step, pair, BlueStack, colorData, OutgoingTransitionTable);
return;
}
else
{
list.RemoveAt(k);
}
}
// if the neighbour node is either blue or red,
// can remove from the list
else
{
list.RemoveAt(k);
}
}
}
}
else
{
//ConfigurationBase[] list = evt.MakeOneMove().ToArray();
IEnumerable <ConfigurationBase> list = evt.MakeOneMove();
pair.SetEnabled(list, FairnessType);
List <LocalPair> product = LocalPair.NextLocal(BA, list, BAState);
//count the transitions visited
VerificationOutput.Transitions += product.Count;
for (int k = product.Count - 1; k >= 0; k--)
{
LocalPair step = product[k];
string tmp = step.GetCompressedState();
StateColor neighbourColor = colorData.GetContainsKey(tmp);
if (neighbourColor != null)
{
//update the incoming and outgoing edges
outgoing.Add(tmp);
//if this node is still not visited
if (neighbourColor.IsWhite())
{
//only add the first unvisited node
//for the second or more unvisited steps, ignore at the monent
if (blueDone)
{
BlueStack.Push(step);
blueDone = false;
product.RemoveAt(k);
}
}
// if the neighbour node is cyan,
// and either this node or the neibour node is the accept state
// then report cycle
else if (neighbourColor.IsCyan())
{
if (step.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE))
{
// Report cycle
ReportBlueCycle(step, pair, BlueStack, colorData, OutgoingTransitionTable);
return;
}
else
{
product.RemoveAt(k);
}
}
// if the neighbour node is either blue or red,
// can remove from the list
else
{
product.RemoveAt(k);
}
}
// If the node is not initiated
else
{
colorData.Add(tmp, new StateColor());
OutgoingTransitionTable.Add(tmp, new List <string>(8));
outgoing.Add(tmp);
if (blueDone)
{
BlueStack.Push(step);
blueDone = false;
product.RemoveAt(k);
}
}
}
//create the remaining steps as the expending list for v
ExpendedNode.Add(v, product);
}
if (blueDone)
{
BlueStack.Pop();
// If the current node is an accept state,
// do the red DFS
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
if (evt.IsDeadLock)
{
VerificationOutput.VerificationResult = VerificationResultType.INVALID;
VerificationOutput.NoOfStates = colorData.Count;
Dictionary <string, LocalPair> LoopPairs = new Dictionary <string, LocalPair>();
LoopPairs.Add(v, pair);
LocalTaskStack = BlueStack;
LocalGetCounterExample(LoopPairs, OutgoingTransitionTable);
return;
}
bool stop = DepthFirstSearchRed(pair, BlueStack, OutgoingTransitionTable, colorData);
if (stop)
{
return;
}
nodeColor.SetRed();
}
else
{
nodeColor.SetBlue();
}
}
} while (BlueStack.Count > 0);
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = colorData.Count;
return;
}
// local function of each thread
public void TarjanFairnessChecking()
{
// local data for on-the-fly and Tarjan algorithm
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
Stack <LocalPair> callStack = new Stack <LocalPair>(5000);
Stack <LocalPair> currentStack = new Stack <LocalPair>(1024);
Dictionary <string, int[]> dfsData = new Dictionary <string, int[]>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(1024);
int counter = 0;
//--------------------------
// create initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
// put all initial states to callStack & init data
foreach (LocalPair tmp in initialStates)
{
callStack.Push(tmp);
string tmpID = tmp.GetCompressedState();
dfsData.Add(tmpID, new int[] { VISITED_NOPREORDER, 0 });
outgoingTransitionTable.Add(tmpID, new List <string>(8));
}
// start loop
while (callStack.Count > 0)
{
// cancel if too long action or any counterexample is reported
if (CancelRequested)
{
VerificationOutput.NoOfStates = dfsData.Count;
return;
}
// get the top of callStack
LocalPair pair = callStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
// get local data of the top
List <string> outgoing = outgoingTransitionTable[v];
int[] vData = dfsData[v];
// if not expended then expend to next states from v
if (!expendedNodes.ContainsKey(v))
{
// create next states of v
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
List <LocalPair> nextStates = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, nextStates);
// add to visitedTimes in this thread
//visitedTimes.GetOrAdd(v, 0);
//visitedTimes[v]++;
// update outgoing of v and set initial data for successors
// no need to use inverse for statement and use nextStates
foreach (LocalPair next in nextStates)
{
string w = next.GetCompressedState();
outgoing.Add(w);
if (!dfsData.ContainsKey(w))
{
dfsData.Add(w, new int[] { VISITED_NOPREORDER, 0 });
outgoingTransitionTable.Add(w, new List <string>(8));
}
}
}
// get successors of v
List <LocalPair> successors = expendedNodes[v];
// process if v is not numbered yet
if (vData[0] == VISITED_NOPREORDER)
{
vData[0] = counter;
vData[1] = counter;
counter = counter + 1;
// push to currentStack
currentStack.Push(pair);
// update lowlink according to successors in currentStack
// remove already visited successors
// no need to use random
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
int[] wData = dfsData[w];
if (wData[0] >= 0)
{
// update & remove from expendedNodes(v)
vData[1] = Math.Min(vData[1], wData[0]);
successors.RemoveAt(i);
}
}
}
// check if there is any successor not numbered
bool completed = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
int[] wData = dfsData[w];
if (wData[0] == VISITED_NOPREORDER)
{
callStack.Push(succ);
successors.RemoveAt(i);
completed = false;
break;
}
else
{
successors.RemoveAt(i);
}
}
// if all successors are visited
if (completed)
{
// check root
if (vData[0] == vData[1])
{
//pop callStack
callStack.Pop();
Dictionary <string, LocalPair> newSCC = new Dictionary <string, LocalPair>(1024);
// check selfLoop
bool selfLoop = false;
foreach (string w in outgoing)
{
if (v.Equals(w))
{
selfLoop = true;
break;
}
}
// get all states in a SCC & check Buchi fair
bool isBuchiFair = false;
LocalPair tmp = null;
string tmpID = null;
// get from current until v
do
{
tmp = currentStack.Pop();
isBuchiFair = isBuchiFair || tmp.state.EndsWith(Constants.ACCEPT_STATE);
tmpID = tmp.GetCompressedState();
int[] tmpData = dfsData[tmpID];
tmpData[0] = SCC_FOUND;
newSCC.Add(tmpID, tmp);
} while (!tmpID.Equals(v));
if (isBuchiFair && (selfLoop || newSCC.Count > 1 || LTSState.IsDeadLock))
{
Dictionary <string, LocalPair> fairSCC = IsFair(newSCC, outgoingTransitionTable);
if (fairSCC != null)
{
// get the path to accepting cycle
VerificationOutput.VerificationResult = VerificationResultType.INVALID;
VerificationOutput.NoOfStates = dfsData.Count;
LocalTaskStack = callStack;
LocalGetCounterExample(fairSCC, outgoingTransitionTable);
return;
}
}
}
else
{
//pop callStack & update the parent
LocalPair pop = callStack.Pop();
LocalPair top = callStack.Peek();
string popID = pop.GetCompressedState();
string topID = top.GetCompressedState();
int[] popData = dfsData[popID];
int[] topData = dfsData[topID];
topData[1] = Math.Min(topData[1], popData[1]);
}
}
}
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = dfsData.Count;
}
/// <summary>
/// Tarjan algorithm with farness checking
/// </summary>
public void FairTarjan()
{
VerificationOutput.CounterExampleTrace = null;
//on-the-fly data
Stack <LocalPair> callStack = new Stack <LocalPair>(5000);
Stack <LocalPair> currentStack = new Stack <LocalPair>(5000);
Stack <LocalPair> goalStack = new Stack <LocalPair>(1024);
Dictionary <string, int[]> dfsNumber = new Dictionary <string, int[]>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(5000);
int number = 0;
Random rand = new Random();
//initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
//check valid result
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
//push initial states to call stack
foreach (LocalPair tmp in initialStates)
{
callStack.Push(tmp);
}
//start loop
while (callStack.Count > 0)
{
//cancel if take long time
if (CancelRequested)
{
VerificationOutput.NoOfStates = dfsNumber.Count;
return;
}
//get top of call stack
LocalPair pair = callStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
//get successors
List <LocalPair> successors = null;
if (expendedNodes.ContainsKey(v))
{
successors = expendedNodes[v];
}
else
{
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
successors = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, successors);
}
//if v is not number yet
if (!dfsNumber.ContainsKey(v))
{
//number v
int[] vData = new int[] { number, number };
dfsNumber.Add(v, vData);
number = number + 1;
//push to currentStack
currentStack.Push(pair);
//update lowlink for already numbered successors
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is already numbered
if (dfsNumber.ContainsKey(w))
{
int[] wData = dfsNumber[w];
//if w is in current stack
if (wData[0] >= 0)
{
vData[1] = Math.Min(vData[1], wData[0]);
}
}
}
}
//------------------------------------------------------------------------
//check if there is an unnumbered successor
List <int> unvisitedIndexs = new List <int>(successors.Count);//not visited
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is not already numbered
if (!dfsNumber.ContainsKey(w))
{
unvisitedIndexs.Add(i);
}
}
//------------------------------------------------------------------------
//get random unvisited successors
if (unvisitedIndexs.Count > 0)
{
int r = rand.Next(unvisitedIndexs.Count);
LocalPair succ = successors[unvisitedIndexs[r]];
callStack.Push(succ);
}
else
{
int[] vData = dfsNumber[v];
//if v is root
if (vData[0] == vData[1])
{
// check selfLoop
bool selfLoop = false;
foreach (LocalPair succ in successors)
{
string w = succ.GetCompressedState();
if (v.Equals(w))
{
selfLoop = true;
break;
}
}
//remove states from current stack and goal stack
Dictionary <string, LocalPair> newSCC = new Dictionary <string, LocalPair>(1024);
List <ConfigurationBase> cycle = new List <ConfigurationBase>(1024);
bool isBuchiFair = false;
LocalPair tmp = null;
string tmpID = null;
do
{
//current stack
tmp = currentStack.Pop();
if (!isBuchiFair && tmp.state.EndsWith(Constants.ACCEPT_STATE))
{
isBuchiFair = true;
}
tmpID = tmp.GetCompressedState();
newSCC.Add(tmpID, tmp);
cycle.Insert(0, tmp.configuration);
//mark visited
dfsNumber[tmpID][0] = SCC_FOUND;
} while (tmp != pair);
//check fairness
if (isBuchiFair && (selfLoop || newSCC.Count > 1 || LTSState.IsDeadLock))
{
//get outgoing transition table
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(newSCC.Count);
foreach (KeyValuePair <string, LocalPair> kv in newSCC)
{
string s = kv.Key;
List <LocalPair> nextStates = expendedNodes[s];
List <string> outgoing = new List <string>(nextStates.Count);
foreach (LocalPair next in nextStates)
{
string n = next.GetCompressedState();
outgoing.Add(n);
}
outgoingTransitionTable.Add(s, outgoing);
}
Dictionary <string, LocalPair> fairSCC = IsFair(newSCC, outgoingTransitionTable);
if (fairSCC != null)
{
//REPORT COUNTEREXAMPLE
GetFairCounterExample(callStack, cycle, dfsNumber, LTSState.IsDeadLock);
return;
}
}
//pop call stack
callStack.Pop();
}
else
{
//pop call stack and update lowlink of top
LocalPair pop = callStack.Pop();
LocalPair top = callStack.Peek();
string popID = pop.GetCompressedState();
string topID = top.GetCompressedState();
int[] popData = dfsNumber[popID];
int[] topData = dfsNumber[topID];
topData[1] = Math.Min(topData[1], popData[1]);
}
}
}
//no counter example
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = dfsNumber.Count;
return;
}
/// <summary>
/// The function of each worker in MultiCore Tarjan Model Checking
/// </summary>
/// <returns></returns>
public void MultiCoreWithSharedMemoryTarjanModelCheckingWorker()
{
Dictionary <string, List <string> > OutgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
Stack <LocalPair> TaskStack = new Stack <LocalPair>(5000);
List <LocalPair> initials = LocalPair.GetInitialPairsLocal(BA, InitialStep);
Dictionary <string, int[]> DFSData = new Dictionary <string, int[]>(5000);
if (initials.Count == 0)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
int threadId;
// Create random variable with different seed for each thread
Random rand; // helps different threads access different region of the graph
lock (MultiCoreLock)
{
threadId = MultiCoreSeed;
rand = new Random(MultiCoreSeed);
MultiCoreSeed++;
}
// Create the list of initial states
// May apply randomness here to increase performance
int[] permutation = generatePermutation(initials.Count, rand);
for (int z = 0; z < initials.Count; z++)
{
LocalPair initState = initials[permutation[z]];
TaskStack.Push(initState);
string ID = initState.GetCompressedState();
DFSData.Add(ID, new int[] { VISITED_NOPREORDER, 0 });
OutgoingTransitionTable.Add(ID, new List <string>(8));
}
Dictionary <string, LocalPair> SCCPairs = new Dictionary <string, LocalPair>(1024);
Stack <LocalPair> stepStack = new Stack <LocalPair>(1024);
// Preorder counter
int i = 0;
int numSCCs = 0;
//store the expended event step of a node to avoid multiple invocation of the make one move.
Dictionary <string, List <LocalPair> > ExpendedNode = new Dictionary <string, List <LocalPair> >(1024);
do
{
if (CancelRequested || StopMutliCoreThreads)
{
return;
}
LocalPair pair = TaskStack.Peek();
ConfigurationBase evt = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
List <string> outgoing = OutgoingTransitionTable[v];
int[] nodeData = DFSData[v];
if (nodeData[0] == VISITED_NOPREORDER)
{
nodeData[0] = i;
i++;
}
bool done = true;
// Initialize the states if first time visited
if (!ExpendedNode.ContainsKey(v))
{
List <LocalPair> product;
//lock (MultiCoreLock)
//{
ConfigurationBase[] configList = evt.MakeOneMove();
pair.SetEnabled(configList, FairnessType);
product = LocalPair.NextLocal(BA, configList, BAState);
int[] randomPermutation = generatePermutation(product.Count, rand);
List <LocalPair> randomProduct = new List <LocalPair>();
for (int k = 0; k < product.Count; k++)
{
randomProduct.Add(product[randomPermutation[k]]);
}
ExpendedNode.Add(v, randomProduct);
//}
for (int k = product.Count - 1; k >= 0; k--)
{
LocalPair step = product[k];
string tmp = step.GetCompressedState();
//update the incoming and outgoing edges
outgoing.Add(tmp);
if (!DFSData.ContainsKey(tmp))
{
DFSData.Add(tmp, new int[] { VISITED_NOPREORDER, 0 });
OutgoingTransitionTable.Add(tmp, new List <string>(8));
}
}
}
List <LocalPair> list = ExpendedNode[v];
//transverse all neighbour nodes
for (int k = list.Count - 1; k >= 0; k--)
{
//int randIndex = rand.Next(list.Count);
int randIndex = k;
LocalPair step = list[randIndex];
string tmp = step.GetCompressedState();
int[] neighbourDFSData = DFSData[tmp];
//if the step is a unvisited step
if (neighbourDFSData[0] == VISITED_NOPREORDER && !SharedSCCFoundStatesMultiCoreTarjan.ContainsKey(tmp))
{
if (done)
{
TaskStack.Push(step);
done = false;
list.RemoveAt(randIndex);
break;
}
}
else
{
list.RemoveAt(randIndex);
}
}
if (done)
{
TaskStack.Pop();
int lowlinkV = nodeData[0];
int preorderV = lowlinkV;
bool selfLoop = false;
for (int j = 0; j < outgoing.Count; j++)
{
string w = outgoing[j];
if (w == v)
{
selfLoop = true;
}
int[] wdata = DFSData[w];
if (wdata[0] != SCC_FOUND && !SharedSCCFoundStatesMultiCoreTarjan.ContainsKey(w))
{
if (wdata[0] > preorderV)
{
lowlinkV = Math.Min(lowlinkV, wdata[1]);
}
else
{
lowlinkV = Math.Min(lowlinkV, wdata[0]);
}
}
}
nodeData[1] = lowlinkV;
if (lowlinkV == preorderV)
{
bool stopCheckSCC = false;
SCCPairs.Add(v, pair);
nodeData[0] = SCC_FOUND;
//if (!SharedSCCFoundStatesMultiCoreTarjan.ContainsKey(v))
//{
lock (MultiCoreLock)
{
if (!SharedSCCFoundStatesMultiCoreTarjan.ContainsKey(v))
{
numSCCs++;
SharedSCCFoundStatesMultiCoreTarjan.Add(v, true);
}
else
{
stopCheckSCC = true;
}
}
//}
//else
//{
// stopCheckSCC = true;
//}
//checking for buchi-fair
bool BuchiFair = pair.state.EndsWith(Constants.ACCEPT_STATE);
while (stepStack.Count > 0 && DFSData[stepStack.Peek().GetCompressedState()][0] > preorderV)
{
LocalPair stepStackNode = stepStack.Pop();
string stepStackNodeID = stepStackNode.GetCompressedState();
DFSData[stepStackNodeID][0] = SCC_FOUND;
if (!stopCheckSCC)
{
SCCPairs.Add(stepStackNodeID, stepStackNode);
//if (!SharedSCCFoundStatesMultiCoreTarjan.ContainsKey(stepStackNodeID))
//{
lock (MultiCoreLock)
{
if (!SharedSCCFoundStatesMultiCoreTarjan.ContainsKey(stepStackNodeID))
{
SharedSCCFoundStatesMultiCoreTarjan.Add(stepStackNodeID, true);
}
}
//}
if (!BuchiFair && stepStackNode.state.EndsWith(Constants.ACCEPT_STATE))
{
BuchiFair = true;
}
}
else
{
ExpendedNode.Remove(stepStackNodeID);
OutgoingTransitionTable.Remove(stepStackNodeID);
}
}
int SCCSize = SCCPairs.Count;
if (!stopCheckSCC && BuchiFair && (evt.IsDeadLock || SCCSize > 1 || selfLoop))
{
Dictionary <string, LocalPair> value = IsFair(SCCPairs, OutgoingTransitionTable);
if (value != null)
{
lock (MultiCoreLock)
{
StopMutliCoreThreads = true;
MultiCoreResultedLoop = value;
MultiCoreOutgoingTransitionTable = OutgoingTransitionTable;
MultiCoreLocalTaskStack = TaskStack;
}
return;
}
}
// Avoid access to found SCCs
foreach (string componet in SCCPairs.Keys)
{
ExpendedNode.Remove(componet);
OutgoingTransitionTable.Remove(componet);
}
//StronglyConnectedComponets.Clear();
SCCPairs.Clear();
}
else
{
stepStack.Push(pair);
}
}
} while (TaskStack.Count > 0);
//Console.WriteLine("Thread {0} has traversed {1} SCCs", threadId, numSCCs);
}
/// <summary>
/// Local blue DFS in each thread
/// </summary>
/// <param name="o"></param>
public void LocalBlueSwarm(object o)
{
//order of this thread
int order = (int)o;
Random rand = new Random(order);
//on-the-fly data
Stack <LocalPair> localBlueStack = new Stack <LocalPair>(5000);
Dictionary <string, Color> localDFSColor = new Dictionary <string, Color>(5000);
Dictionary <string, List <LocalPair> > localExpendedNodes = new Dictionary <string, List <LocalPair> >(5000);
//initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
//check valid result
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
return;
}
//push local initial states to local blue stack
int[] localPerm = Permutation(initialStates.Count, rand);
for (int i = 0; i < initialStates.Count; i++)
{
LocalPair tmp = initialStates[localPerm[i]];
localBlueStack.Push(tmp);
}
//start loop
while (localBlueStack.Count > 0)
{
//cancel if take long time
if (CancelRequested || isGlobalStop)
{
return;
}
//get top of blue stack
LocalPair pair = localBlueStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
//get successors
List <LocalPair> successors = null;
if (localExpendedNodes.ContainsKey(v))
{
successors = localExpendedNodes[v];
}
else
{
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
successors = LocalPair.NextLocal(BA, nextLTSStates, BAState);
localExpendedNodes.Add(v, successors);
}
//if v is white
if (!localDFSColor.ContainsKey(v))
{
//set v cyan
Color vColor = new Color();
vColor.setCyan();
localDFSColor.Add(v, vColor);
//early cycle detection
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is cyan and (v or w is accepting)
if (localDFSColor.ContainsKey(w))
{
Color wColor = localDFSColor[w];
if (wColor.isCyan() && (succ.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE)))
{
//REPORT COUNTEREXAMPLE
GetLocalLoopCounterExample(w, localBlueStack);
return;
}
}
}
}
//------------------------------------------------------------------------
//filter successors
List <int> unvisitedIndexs = new List <int>(successors.Count);
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
//if w is white and not global red
if (!localDFSColor.ContainsKey(w))
{
unvisitedIndexs.Add(i);
}
}
//------------------------------------------------------------------------
//get random unvisited successors
if (unvisitedIndexs.Count > 0)
{
bool isFresh = false;
List <int> unFreshIndexs = new List <int>();
while (unvisitedIndexs.Count > 0)
{
int r = rand.Next(unvisitedIndexs.Count);
LocalPair succ = successors[unvisitedIndexs[r]];
string w = succ.GetCompressedState();
//if w is fresh successor
if (!allVisitedStates.ContainsKey(w))
{
localBlueStack.Push(succ);
allVisitedStates.GetOrAdd(w, 0);
allVisitedStates[w]++;
isFresh = true;
break;
}
else
{
unFreshIndexs.Add(unvisitedIndexs[r]);
unvisitedIndexs.RemoveAt(r);
}
}
if (!isFresh)
{
int r = rand.Next(unFreshIndexs.Count);
LocalPair succ = successors[unFreshIndexs[r]];
string w = succ.GetCompressedState();
localBlueStack.Push(succ);
allVisitedStates.GetOrAdd(w, 0);
allVisitedStates[w]++;
}
}
else
{
Color vColor = localDFSColor[v];
//if v is accepting
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
//if v is deadlock
if (LTSState.IsDeadLock)
{
//REPORT COUNTEREXAMPLE
GetLocalDeadlockCounterExample(localBlueStack);
return;
}
else
{
bool isStop = LocalRedSwarm(pair, localBlueStack, localDFSColor, rand, localExpendedNodes);
if (isStop)
{
return;
}
}
//set v pink
vColor.setPink();
}
else
{
vColor.setBlue();
}
//pop v out of blueStack
localBlueStack.Pop();
}
}
}
/// <summary>
/// Improved Nested DFS
/// A Note on On-The-Fly Verification Algorithms - TACAS 2005
/// Stefan Schwoon and Javier Esparza
/// </summary>
public void ImprovedNestedDFS()
{
// data for on-the-fly Nested DFS
Dictionary <string, List <string> > outgoingTransitionTable = new Dictionary <string, List <string> >(Ultility.Ultility.MC_INITIAL_SIZE);
Stack <LocalPair> blueStack = new Stack <LocalPair>(5000);
Dictionary <string, Color> colorData = new Dictionary <string, Color>(5000);
Dictionary <string, List <LocalPair> > expendedNodes = new Dictionary <string, List <LocalPair> >(1024);
// create initial states
List <LocalPair> initialStates = LocalPair.GetInitialPairsLocal(BA, InitialStep);
if (initialStates.Count == 0 || !BA.HasAcceptState)
{
VerificationOutput.VerificationResult = VerificationResultType.VALID;
return;
}
// test
//expendedNodesNumber = 0;
for (int i = 0; i < initialStates.Count; i++)
{
LocalPair tmp = initialStates[i];
blueStack.Push(tmp);
string ID = tmp.GetCompressedState();
colorData.Add(ID, new Color());
outgoingTransitionTable.Add(ID, new List <string>(8));
}
while (blueStack.Count > 0)
{
// cancel if too long action or couterexample reported
if (CancelRequested)
{
VerificationOutput.NoOfStates = colorData.Count;
return;
}
// get the top of blueStack
LocalPair pair = blueStack.Peek();
ConfigurationBase LTSState = pair.configuration;
string BAState = pair.state;
string v = pair.GetCompressedState();
// local data of the top
List <string> outgoing = outgoingTransitionTable[v];
Color vColor = colorData[v];
// if v is not expended then expend successors of v
if (!expendedNodes.ContainsKey(v))
{
// create next states from v & add to expendedNodes
IEnumerable <ConfigurationBase> nextLTSStates = LTSState.MakeOneMove();
pair.SetEnabled(nextLTSStates, FairnessType);
List <LocalPair> nextStates = LocalPair.NextLocal(BA, nextLTSStates, BAState);
expendedNodes.Add(v, nextStates);
// increase number of states expended
//expendedNodesNumber++;
// update outgoing of v and set initial data for successors
// no need to use inverse for statement and use nextStates
foreach (LocalPair next in nextStates)
{
string w = next.GetCompressedState();
outgoing.Add(w);
if (!colorData.ContainsKey(w))
{
colorData.Add(w, new Color());
outgoingTransitionTable.Add(w, new List <string>(8));
}
}
}
// get successor of v
List <LocalPair> successors = expendedNodes[v];
// visit v & early accepting cycle detection
if (vColor.isWhite())
{
vColor.setCyan();
// early cycle detection
// use reverse order to remove visited states
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
Color wColor = colorData[w];
// if successor is not white then remove from expendedNodes
if (wColor.isCyan())
{
if (succ.state.EndsWith(Constants.ACCEPT_STATE) || pair.state.EndsWith(Constants.ACCEPT_STATE))
{
blueReportAcceptinCycle(succ, blueStack, colorData, outgoingTransitionTable);
return;
}
else
{
successors.RemoveAt(i);
}
}
}
}
// find unvisited successor
bool blueDone = true;
for (int i = successors.Count - 1; i >= 0; i--)
{
LocalPair succ = successors[i];
string w = succ.GetCompressedState();
if (colorData[w].isWhite())
{
blueStack.Push(succ);
successors.RemoveAt(i);
blueDone = false;
break;
}
else
{
successors.RemoveAt(i);
}
}
// if there is no unvisited successor
if (blueDone)
{
// if v is accepting
if (pair.state.EndsWith(Constants.ACCEPT_STATE))
{
if (LTSState.IsDeadLock)
{
blueReportAcceptinCycle(pair, blueStack, colorData, outgoingTransitionTable);
return;
}
else // start red DFS
{
bool stop = redDFSImprovedNestedDFS(pair, blueStack, colorData, outgoingTransitionTable);
if (stop)
{
return;
}
}
// SET PINK FOR ACCEPTING STATE
vColor.setPink();
}
else // v is not accepting
{
vColor.setBlue();
}
// pop blueStack
blueStack.Pop();
}
}
// report no couterexample
VerificationOutput.VerificationResult = VerificationResultType.VALID;
VerificationOutput.NoOfStates = colorData.Count;
return;
}