public ProgramCounter(ZingMethod method)
{
string name = method.MethodName;
object o = methodNameTable[name];
Hashtable blockTable = null;
if (o == null)
{
methodNameTable[name] = ++methodCounter;
blockTable = new Hashtable();
methodBlockTable[name] = blockTable;
methodNumberTable[methodCounter] = name;
methodNumber = methodCounter;
}
else
{
blockTable = (Hashtable)methodBlockTable[name];
methodNumber = (ushort)o;
}
nextBlock = method.NextBlock;
blockTable[nextBlock] = method.ProgramCounter;
}
public UndoPop(Process p, ZingMethod theFrame)
: base(p)
{
savedStackFrame = theFrame;
}
private void rollbackStackFrames(Stack sules)
{
StackULE ule;
Debug.Assert(stackULEs != null);
Debug.Assert(stackULEs.Count == 0);
if (sules == null)
{
savedTopOfStack = topOfStack;
return;
}
while (sules.Count > 0)
{
ule = (StackULE)sules.Pop();
ule.Undo();
}
savedTopOfStack = topOfStack;
}
private void doPush(ZingMethod method)
{
method.Caller = topOfStack;
topOfStack = method;
if (stackULEs == null)
return;
stackULEs.Push(new UndoPush(this));
}
private ZingMethod doPop()
{
if (stackULEs != null)
{
if (stackULEs.Count > 0 && stackULEs.Peek() is UndoPush)
stackULEs.Pop();
else
{
Debug.Assert(topOfStack == savedTopOfStack);
stackULEs.Push(new UndoPop(this, topOfStack));
savedTopOfStack = topOfStack.Caller;
}
}
ZingMethod oldTop = topOfStack;
topOfStack = topOfStack.Caller;
return oldTop;
}
private Stack checkInStackFrames()
{
// this is the first time we checked in
if (stackULEs == null)
{
stackULEs = new Stack();
for (savedTopOfStack = topOfStack;
savedTopOfStack != null;
savedTopOfStack = savedTopOfStack.Caller)
savedTopOfStack.DoCheckIn();
savedTopOfStack = topOfStack;
return null;
}
object zmULE = null;
if (savedTopOfStack != null)
zmULE = savedTopOfStack.DoCheckIn();
// small optimization when no changes was made in the
// current transition
if (stackULEs.Count == 0 && zmULE == null)
{
Debug.Assert(savedTopOfStack == topOfStack);
return null;
}
// the result
Stack resStack = stackULEs;
stackULEs = new Stack();
ZingMethod stackFrame = topOfStack;
// move newly pushed frames away from the result, save
// them temporarily in stackULEs; while doing that, we
// checkIn every newly pushed node
while (resStack.Count > 0 && resStack.Peek() is UndoPush)
{
//object sfULE =
// this would be the first time we check in these
// freshly pushed nodes. so we discard their undo log
// entries
stackFrame.DoCheckIn();
stackULEs.Push(resStack.Pop());
stackFrame = stackFrame.Caller;
}
// everything below should be UndoPop's or UndoResetLastFunctionCompleted,
// and if anything is to be saved, it should be right there at stackFrame
Debug.Assert(resStack.Count == 0 || resStack.Peek() is UndoPop
|| resStack.Peek() is UndoResetLastFunctionCompleted);
Debug.Assert(savedTopOfStack == stackFrame);
// insert zmULE between UndoPop objects and UndoPush
// objects
if (zmULE != null)
resStack.Push(new UndoUpdate(this, zmULE));
// move undoPush objects back into the result
while (stackULEs.Count > 0)
resStack.Push(stackULEs.Pop());
savedTopOfStack = topOfStack;
return resStack;
}
//the following is used during application of effects
public void UpdateDirectLastFunctionCompleted(ZingMethod method)
{
lastFunctionCompleted = method;
}
internal OutputVars(ZingMethod zm)
{
stackFrame = zm;
}
public void RaiseZingException(int exception)
{
this.lastFunctionCompleted = null;
doPop();
while (topOfStack != null)
{
this.atomicityLevel = this.topOfStack.SavedAtomicityLevel;
// If we find a handler, we're done
if (this.topOfStack.RaiseZingException(exception))
return;
doPop();
}
throw new ZingUnhandledExceptionException(exception);
}
public void DoCheckout(object currentUle)
{
ProcessULE pULE = (ProcessULE)currentUle;
// cloned components
atomicityLevel = pULE.atomicityLevel;
middleOfTransition = pULE.middleOfTransition;
choicePending = pULE.choicePending;
lastFunctionCompleted = pULE.lastFunctionCompleted;
// undoable ones -- do nothing
}
/*
public static ZingAttribute PredicateContext
{
get { return predicateContext; }
set { predicateContext = value; }
}
*/
public bool CallPredicateMethod(ZingMethod predicateMethod)
{
if (runningPredicateMethod[MyThreadId])
{
Debugger.Break();
throw new Exception("Predicate !");
}
Process dummyProc = new Process(this.StateImpl, predicateMethod, string.Empty, 0);
Exception savedException = this.StateImpl.Exception;
this.StateImpl.Exception = null;
while (dummyProc.TopOfStack != null)
{
runningPredicateMethod[MyThreadId] = true;
this.StateImpl.RunBlocks(dummyProc);
runningPredicateMethod[MyThreadId] = false;
if (this.StateImpl.Exception != null)
{
if (savedException == null)
{
this.StateImpl.Exception = new Exception("Predicate");
throw this.StateImpl.Exception;
}
else
{
// If we already have a pending exception on the state, just
// return false and restore the original exception.
this.StateImpl.Exception = savedException;
return false;
}
}
if (dummyProc.choicePending)
throw new Exception("Predicate");
}
this.StateImpl.Exception = savedException;
return predicateMethod.BooleanReturnValue;
}
public void Call(ZingMethod method)
{
// method.StateImpl = this.StateImpl;
method.SavedAtomicityLevel = this.atomicityLevel;
doPush(method);
}
public Process(StateImpl stateObj, ZingMethod entryPoint, string name, uint id, int threadID)
: this(stateObj, entryPoint, name, id)
{
this.MyThreadId = threadID;
}
// <summary>
// Constructor
// </summary>
// <param name="entryPoint"></param>
// <param name="name"></param>
// <param name="id"></param>
public Process(StateImpl stateObj, ZingMethod entryPoint, string name, uint id)
{
this.StateImpl = stateObj;
this.entryPoint = entryPoint;
this.name = name;
this.id = id;
this.Call(entryPoint);
}
internal LocalVars(ZingMethod zm)
{
stackFrame = zm;
}
protected override void doUndo()
{
savedStackFrame.Caller = process.topOfStack;
process.topOfStack = process.savedTopOfStack = savedStackFrame;
savedStackFrame = null;
process.topOfStack.DoRevert();
}
public UndoResetLastFunctionCompleted(Process p, ZingMethod l)
: base(p)
{
savedLastFunctionCompleted = l;
}
public void Return(ZingSourceContext context, ZingAttribute contextAttribute)
{
ZingMethod returningMethod = doPop();
this.atomicityLevel = returningMethod.SavedAtomicityLevel;
// Keep a ref to the completed function so the caller can access
// the return value and output parameters.
if (topOfStack != null)
lastFunctionCompleted = returningMethod;
else
{
lastFunctionCompleted = null;
middleOfTransition = false;
}
if (this.topOfStack == null && ZingerConfiguration.ExecuteTraceStatements && (this.name != null && this.name.Length != 0))
{
if (ZingerConfiguration.DegreeOfParallelism == 1)
{
this.StateImpl.ReportEvent(new TerminateProcessEvent(context, contextAttribute));
}
else
{
this.StateImpl.ReportEvent(new TerminateProcessEvent(context, contextAttribute, this.MyThreadId));
}
}
}
