Make ConditionalProxy shut down the WebSocket proxy much faster when the app is shutting down

SteveSandersonMS · SteveSandersonMS · commit b2c1062dd190 · 2017-10-25T15:56:08.000+01:00
diff --git a/src/Microsoft.AspNetCore.SpaServices.Extensions/Proxying/ConditionalProxy.cs b/src/Microsoft.AspNetCore.SpaServices.Extensions/Proxying/ConditionalProxy.cs
@@ -249,8 +249,26 @@ private static async Task PumpWebSocket(WebSocket source, WebSocket destination,
 
 while (true)
{
- var result = await source.ReceiveAsync(new ArraySegment<byte>(buffer), cancellationToken);
+ // Because WebSocket.ReceiveAsync doesn't work well with CancellationToken (it doesn't
+ // actually exit when the token notifies, at least not in the 'server' case), use
+ // polling. The perf might not be ideal, but this is a dev-time feature only.
+ var resultTask = source.ReceiveAsync(new ArraySegment<byte>(buffer), cancellationToken);
+ while (true)
+{
+ if (cancellationToken.IsCancellationRequested)
+{
+ return;
+ }
+
+ if (resultTask.IsCompleted)
+{
+ break;
+ }
+
+ await Task.Delay(250);
+ }
 
+ var result = resultTask.Result; // We know it's completed already
 if (result.MessageType == WebSocketMessageType.Close)
{
 if (destination.State == WebSocketState.Open || destination.State == WebSocketState.CloseReceived)

-Original file line number
+Diff line change
 while(true)
+{
 -varresult=awaitsource.ReceiveAsync(newArraySegment<byte>(buffer),cancellationToken);
 +// Because WebSocket.ReceiveAsync doesn't work well with CancellationToken (it doesn't
 +// actually exit when the token notifies, at least not in the 'server' case), use
 +// polling. The perf might not be ideal, but this is a dev-time feature only.
 +varresultTask=source.ReceiveAsync(newArraySegment<byte>(buffer),cancellationToken);
 +while(true)
 +{
 +if(cancellationToken.IsCancellationRequested)
 +{
 +return;
 +}
++
 +if(resultTask.IsCompleted)
 +{
 +break;
 +}
++
 +awaitTask.Delay(250);
 +}
 +varresult=resultTask.Result;// We know it's completed already
 if(result.MessageType==WebSocketMessageType.Close)
+{
 if(destination.State==WebSocketState.Open||destination.State==WebSocketState.CloseReceived)