private async Task<AspNetWebSocket> ProcessRequestImplAsync() {
AspNetWebSocket webSocket = null;
try {
// SendResponse and other asynchronous notifications cannot be process by ASP.NET after this point.
_root.WorkerRequest.SuppressSendResponseNotifications();
// A flush is necessary to activate the WebSocket module so that we can get its pointer.
//
// DevDiv #401948: We can't allow a flush failure to propagate out, otherwise the rest of
// this method doesn't run, which could leak resources (by not invoking the user callback)
// or cause weird behavior (by not calling CompleteTransitionToWebSocket, which could corrupt
// server state). If the flush fails, we'll wait to propagate the exception until a safe
// point later in this method.
ExceptionDispatchInfo flushExceptionDispatchInfo = DoFlush();
// Create the AspNetWebSocket. There's a chance that the client disconnected before we
// hit this code. If this is the case, we'll pass a null WebSocketPipe to the
// AspNetWebSocket ctor, which immediately sets the socket into an aborted state.
UnmanagedWebSocketContext unmanagedWebSocketContext = _root.WorkerRequest.GetWebSocketContext();
WebSocketPipe pipe = (unmanagedWebSocketContext != null) ? new WebSocketPipe(unmanagedWebSocketContext, PerfCounters.Instance) : null;
webSocket = new AspNetWebSocket(pipe, _subProtocol);
// slim down the HttpContext as much as possible to allow the GC to reclaim memory
_httpContext.CompleteTransitionToWebSocket();
// always install a new SynchronizationContext, even if the user is running in legacy SynchronizationContext mode
AspNetSynchronizationContext syncContext = new AspNetSynchronizationContext(this);
_httpContext.SyncContext = syncContext;
bool webSocketRequestSucceeded = false;
try {
// need to keep track of this in the manager so that we can abort if it the AppDomain goes down
AspNetWebSocketManager.Current.Add(webSocket);
// bump up the total count (the currently-executing count is recorded separately)
PerfCounters.IncrementCounter(AppPerfCounter.REQUESTS_TOTAL_WEBSOCKETS);
// Release the reference to the user delegate (which might just be a simple initialization routine) so that
// the GC can claim it. The only thing that needs to remain alive is the Task itself, which we're referencing.
Task task = null;
syncContext.Send(_ => {
task = _userFunc(new AspNetWebSocketContextImpl(new HttpContextWrapper(_httpContext), _root.WorkerRequest, webSocket));
}, null);
// Was there an exception from user code? If so, rethrow (which logs).
ExceptionDispatchInfo exception = syncContext.ExceptionDispatchInfo;
if (exception != null) {
exception.Throw();
}
_userFunc = null;
await task.ConfigureAwait(continueOnCapturedContext: false);
// Was there an exception from the earlier call to DoFlush? If so, rethrow (which logs).
// This needs to occur after the user's callback finishes, otherwise ASP.NET could try
// to complete the request while the callback is still accessing it.
if (flushExceptionDispatchInfo != null) {
flushExceptionDispatchInfo.Throw();
}
// Any final state except Aborted is marked as 'success'.
// It's possible execution never reaches this point, e.g. if the user's
// callback throws an exception. In that case, 'webSocketRequestSucceeded'
// will keep its default value of false, and the performance counter
// will mark this request as having failed.
if (webSocket.State != WebSocketState.Aborted) {
webSocketRequestSucceeded = true;
PerfCounters.IncrementCounter(AppPerfCounter.REQUESTS_SUCCEEDED_WEBSOCKETS);
}
}
finally {
// we need to make sure the user can't call the WebSocket any more after this point
_isProcessingComplete = true;
webSocket.DisposeInternal();
AspNetWebSocketManager.Current.Remove(webSocket);
if (!webSocketRequestSucceeded) {
PerfCounters.IncrementCounter(AppPerfCounter.REQUESTS_FAILED_WEBSOCKETS);
}
}
}
catch (Exception ex) {
// don't let the exception propagate upward; just log it instead
WebBaseEvent.RaiseRuntimeError(ex, null);
}
return webSocket;
}
private async Task <AspNetWebSocket> ProcessRequestImplAsync()
{
AspNetWebSocket webSocket = null;
try {
// SendResponse and other asynchronous notifications cannot be process by ASP.NET after this point.
_root.WorkerRequest.SuppressSendResponseNotifications();
// A flush is necessary to activate the WebSocket module so that we can get its pointer.
//
// DevDiv #401948: We can't allow a flush failure to propagate out, otherwise the rest of
// this method doesn't run, which could leak resources (by not invoking the user callback)
// or cause weird behavior (by not calling CompleteTransitionToWebSocket, which could corrupt
// server state). If the flush fails, we'll wait to propagate the exception until a safe
// point later in this method.
ExceptionDispatchInfo flushExceptionDispatchInfo = DoFlush();
// Create the AspNetWebSocket. There's a chance that the client disconnected before we
// hit this code. If this is the case, we'll pass a null WebSocketPipe to the
// AspNetWebSocket ctor, which immediately sets the socket into an aborted state.
UnmanagedWebSocketContext unmanagedWebSocketContext = _root.WorkerRequest.GetWebSocketContext();
WebSocketPipe pipe = (unmanagedWebSocketContext != null) ? new WebSocketPipe(unmanagedWebSocketContext, PerfCounters.Instance) : null;
webSocket = new AspNetWebSocket(pipe, _subProtocol);
// slim down the HttpContext as much as possible to allow the GC to reclaim memory
_httpContext.CompleteTransitionToWebSocket();
// always install a new SynchronizationContext, even if the user is running in legacy SynchronizationContext mode
AspNetSynchronizationContext syncContext = new AspNetSynchronizationContext(this);
_httpContext.SyncContext = syncContext;
bool webSocketRequestSucceeded = false;
try {
// need to keep track of this in the manager so that we can abort if it the AppDomain goes down
AspNetWebSocketManager.Current.Add(webSocket);
// bump up the total count (the currently-executing count is recorded separately)
PerfCounters.IncrementCounter(AppPerfCounter.REQUESTS_TOTAL_WEBSOCKETS);
// Release the reference to the user delegate (which might just be a simple initialization routine) so that
// the GC can claim it. The only thing that needs to remain alive is the Task itself, which we're referencing.
Task task = null;
syncContext.Send(_ => {
task = _userFunc(new AspNetWebSocketContextImpl(new HttpContextWrapper(_httpContext), _root.WorkerRequest, webSocket));
}, null);
// Was there an exception from user code? If so, rethrow (which logs).
ExceptionDispatchInfo exception = syncContext.ExceptionDispatchInfo;
if (exception != null)
{
exception.Throw();
}
_userFunc = null;
await task.ConfigureAwait(continueOnCapturedContext : false);
// Was there an exception from the earlier call to DoFlush? If so, rethrow (which logs).
// This needs to occur after the user's callback finishes, otherwise ASP.NET could try
// to complete the request while the callback is still accessing it.
if (flushExceptionDispatchInfo != null)
{
flushExceptionDispatchInfo.Throw();
}
// Any final state except Aborted is marked as 'success'.
// It's possible execution never reaches this point, e.g. if the user's
// callback throws an exception. In that case, 'webSocketRequestSucceeded'
// will keep its default value of false, and the performance counter
// will mark this request as having failed.
if (webSocket.State != WebSocketState.Aborted)
{
webSocketRequestSucceeded = true;
PerfCounters.IncrementCounter(AppPerfCounter.REQUESTS_SUCCEEDED_WEBSOCKETS);
}
}
finally {
// we need to make sure the user can't call the WebSocket any more after this point
_isProcessingComplete = true;
webSocket.DisposeInternal();
AspNetWebSocketManager.Current.Remove(webSocket);
if (!webSocketRequestSucceeded)
{
PerfCounters.IncrementCounter(AppPerfCounter.REQUESTS_FAILED_WEBSOCKETS);
}
}
}
catch (Exception ex) {
// don't let the exception propagate upward; just log it instead
WebBaseEvent.RaiseRuntimeError(ex, null);
}
return(webSocket);
}
