/// <summary>
/// Runs a search thread for parallel DFS.
/// (here for potential multi-threading support in the future)
/// </summary>
/// <param name="end">goal method</param>
/// <param name="proctor">the stack "proctor" for all threads</param>
/// <param name="threadId">the ID for this thread (for use with proctor)</param>
/// <param name="cancellationToken">the cancellation token</param>
private void RunSearchThread(Method end,
StackProctor proctor,
int threadId,
CancellationToken cancellationToken)
{
var stack = proctor.GetStack(threadId);
proctor.SetStackWaiting(threadId);
var shouldTerminate = false;
while (!shouldTerminate)
{
if (stack.Count == 0)
{
foreach (var workItem in proctor.PullWork())
{
stack.Push(workItem);
}
}
while (stack.Count != 0)
{
proctor.SetStackRunning(threadId);
DepthFirstSearch(end, stack, cancellationToken);
if (cancellationToken.IsCancellationRequested)
{
AppLogger.Current.Debug(
"Thread with ID: {0} has had its operation cancelled. Terminating.",
threadId);
cancellationToken.ThrowIfCancellationRequested();
return;
}
proctor.SetStackWaiting(threadId);
foreach (var workItem in proctor.PullWork())
{
stack.Push(workItem);
}
}
shouldTerminate = proctor.IsCompleted;
Thread.Sleep(50);
}
AppLogger.Current.Debug(
"Terminating thread with ID: {0}",
threadId);
}
/// <summary>
/// Constructs the partial paths which forms the sub-graph of solution nodes
/// </summary>
/// <param name="start">starting method</param>
/// <param name="end">ending method</param>
/// <param name="cancellationToken">cancellation token</param>
/// <returns>void Task</returns>
public async Task ConstructPartialPaths(Method start,
Method end,
CancellationToken cancellationToken)
{
this.partialPaths = new List <CodePath>();
this.visited = new HashSet <Method>();
this.pathSolutionMap = new Dictionary <Method, List <CodePath> >();
this.solutionMethods = new HashSet <Method>();
this.completedMethods = new HashSet <Method>();
// left for potential future multi-threading support
var proctor = new StackProctor(1);
var stack = proctor.GetStack(0);
stack.Push(CodePath.FromSingleMethod(start));
await Task.Run(() => RunSearchThread(end, proctor, 0, cancellationToken));
}