Merge pull request #219 from OmniSharp/fix/cancellation

if cancellation was not found, place in a cancelled cts

Author: david-driscoll

src/JsonRpc/RequestRouterBase.cs

@@ -92,13 +92,22 @@ public virtual async Task<ErrorResponse> RouteRequest(TDescriptor descriptor, Re
  var mediator = scope.ServiceProvider.GetRequiredService<IMediator>();
 
  var id = GetId(request.Id);
- var cts = new CancellationTokenSource();
+ if (!_requests.TryGetValue(id, out var cts))
+ {
+ cts = new CancellationTokenSource();
+ _requests.TryAdd(id, cts);
+ }
  token.Register(cts.Cancel);
- _requests.TryAdd(id, cts);
 
  // TODO: Try / catch for Internal Error
  try
  {
+ if (cts.IsCancellationRequested)
+ {
+ _logger.LogDebug("Request {Id} was cancelled", id);
+ return new RequestCancelled();
+ }
+
  // To avoid boxing, the best way to compare generics for equality is with EqualityComparer<T>.Default.
  // This respects IEquatable<T> (without boxing) as well as object.Equals, and handles all the Nullable<T> "lifted" nuances.
  // https://stackoverflow.com/a/864860
@@ -176,13 +185,17 @@ public virtual async Task<ErrorResponse> RouteRequest(TDescriptor descriptor, Re
 
  public void CancelRequest(object id)
  {
- if (_requests.TryGetValue(GetId(id), out var cts))
+ var idValue = GetId(id);
+ if (_requests.TryGetValue(idValue, out var cts))
  {
  cts.Cancel();
  }
  else
  {
- _logger.LogDebug("Request {Id} was not found to cancel", id);
+ cts = new CancellationTokenSource();
+ _requests.TryAdd(idValue, cts);
+ cts.Cancel();
+ _logger.LogDebug("Request {Id} was not found to cancel, stubbing it in.", id);
  }
  }