/// <summary>
/// Replays the transition of the counter example with the zero-baesd <paramref name="transitionIndex" />.
/// </summary>
/// <param name="choiceResolver">The choice resolver that should be used to resolve nondeterministic choices.</param>
/// <param name="transitionIndex">The zero-based index of the transition that should be replayed.</param>
internal unsafe void Replay(ChoiceResolver choiceResolver, int transitionIndex)
{
if (StepCount == 0)
{
return;
}
choiceResolver.Clear();
choiceResolver.PrepareNextState();
choiceResolver.SetChoices(ReplayInfo[transitionIndex]);
fixed(byte *state = States[transitionIndex])
RuntimeModel.Deserialize(state);
foreach (var fault in RuntimeModel.NondeterministicFaults)
{
fault.Reset();
}
if (transitionIndex == 0)
{
RuntimeModel.ExecuteInitialStep();
}
else
{
RuntimeModel.ExecuteStep();
}
RuntimeModel.NotifyFaultActivations();
}
/// <summary>
/// Generates the replay information for the <paramref name="trace" />.
/// </summary>
/// <param name="choiceResolver">The choice resolver that should be used to resolve nondeterministic choices.</param>
/// <param name="trace">The trace the replay information should be generated for.</param>
/// <param name="endsWithException">Indicates whether the trace ends with an exception being thrown.</param>
private int[][] GenerateReplayInformation(ChoiceResolver choiceResolver, byte[][] trace, bool endsWithException)
{
var info = new int[trace.Length - 1][];
var targetState = stackalloc byte[StateVectorSize];
// We have to generate the replay info for all transitions
for (var i = 0; i < trace.Length - 1; ++i)
{
choiceResolver.Clear();
choiceResolver.PrepareNextState();
// Try all transitions until we find the one that leads to the desired state
while (true)
{
try
{
if (!choiceResolver.PrepareNextPath())
{
break;
fixed(byte *sourceState = trace[i])
Deserialize(sourceState);
foreach (var fault in NondeterministicFaults)
{
fault.Reset();
}
if (i == 0)
{
ExecuteInitialStep();
}
else
{
ExecuteStep();
}
if (endsWithException && i == trace.Length - 2)
continue; }
}
catch (Exception)
{
Requires.That(endsWithException, "Unexpected exception.");
Requires.That(i == trace.Length - 2, "Unexpected exception.");
info[i] = choiceResolver.GetChoices().ToArray();
break;
}
NotifyFaultActivations();
Serialize(targetState);
// Compare the target states; if they match, we've found the correct transition
var areEqual = true;
for (var j = StateHeaderBytes; j < StateVectorSize; ++j)
{
areEqual &= targetState[j] == trace[i + 1][j];
}
if (!areEqual)
{
continue;
}
info[i] = choiceResolver.GetChoices().ToArray();
break;
}
Requires.That(info[i] != null, $"Unable to generate replay information for step {i + 1} of {trace.Length}.");
}
return(info);
}