[dotnet] Avoid async void events in CDP Network session (#12486)

Author: nvborisenko

dotnet/src/webdriver/DevTools/DevToolsSession.cs

@@ -429,11 +429,11 @@ private async Task InitializeSession()
             this.domains.Target.TargetDetached += this.OnTargetDetached;
         }
 
-        private async void OnTargetDetached(object sender, TargetDetachedEventArgs e)
+        private void OnTargetDetached(object sender, TargetDetachedEventArgs e)
         {
             if (e.SessionId == this.ActiveSessionId && e.TargetId == this.attachedTargetId)
             {
-                await this.StopSession(false);
+                Task.Run(async () => await this.StopSession(false)).GetAwaiter().GetResult();
             }
         }
 
@@ -524,7 +524,10 @@ private async Task ReceiveMessage()
                             using (var reader = new StreamReader(stream, Encoding.UTF8))
                             {
                                 string message = reader.ReadToEnd();
-                                ProcessIncomingMessage(message);
+
+                                // fire and forget
+                                // TODO: we need implement some kind of queue
+                                Task.Run(() => ProcessIncomingMessage(message));
                             }
                         }
                     }
@@ -583,8 +586,7 @@ private void ProcessIncomingMessage(string message)
 
                 LogTrace("Recieved Event {0}: {1}", method, eventData.ToString());
 
-                // fire and forget
-                Task.Run(() => OnDevToolsEventReceived(new DevToolsEventReceivedEventArgs(methodParts[0], methodParts[1], eventData)));
+                OnDevToolsEventReceived(new DevToolsEventReceivedEventArgs(methodParts[0], methodParts[1], eventData));
 
                 return;
             }

dotnet/src/webdriver/DevTools/Network.cs

@@ -16,7 +16,7 @@
 // limitations under the License.
 // </copyright>
 
-using System;
+using System.Linq;
 using System.Threading.Tasks;
 
 namespace OpenQA.Selenium.DevTools
@@ -29,17 +29,17 @@ public abstract class Network
         /// <summary>
         /// Occurs when a network request requires authorization.
         /// </summary>
-        public event EventHandler<AuthRequiredEventArgs> AuthRequired;
+        public event AsyncEventHandler<AuthRequiredEventArgs> AuthRequired;
 
         /// <summary>
         /// Occurs when a network request is intercepted.
         /// </summary>
-        public event EventHandler<RequestPausedEventArgs> RequestPaused;
+        public event AsyncEventHandler<RequestPausedEventArgs> RequestPaused;
 
         /// <summary>
         /// Occurs when a network response is received.
         /// </summary>
-        public event EventHandler<ResponsePausedEventArgs> ResponsePaused;
+        public event AsyncEventHandler<ResponsePausedEventArgs> ResponsePaused;
 
         /// <summary>
         /// Asynchronously disables network caching.
@@ -152,9 +152,14 @@ public async Task SetUserAgentOverride(string userAgent)
         /// <param name="e">An <see cref="AuthRequiredEventArgs"/> that contains the event data.</param>
         protected virtual void OnAuthRequired(AuthRequiredEventArgs e)
         {
-            if (this.AuthRequired != null)
+            var delegates = AuthRequired?.GetInvocationList();
+
+            if (delegates != null)
             {
-                this.AuthRequired(this, e);
+                foreach (var d in delegates.Cast<AsyncEventHandler<AuthRequiredEventArgs>>())
+                {
+                    Task.Run(async () => await d.Invoke(this, e)).GetAwaiter().GetResult();
+                }
             }
         }
 
@@ -164,9 +169,14 @@ protected virtual void OnAuthRequired(AuthRequiredEventArgs e)
         /// <param name="e">An <see cref="RequestPausedEventArgs"/> that contains the event data.</param>
         protected virtual void OnRequestPaused(RequestPausedEventArgs e)
         {
-            if (this.RequestPaused != null)
+            var delegates = RequestPaused?.GetInvocationList();
+
+            if (delegates != null)
             {
-                this.RequestPaused(this, e);
+                foreach (var d in delegates.Cast<AsyncEventHandler<RequestPausedEventArgs>>())
+                {
+                    Task.Run(async () => await d.Invoke(this, e)).GetAwaiter().GetResult();
+                }
             }
         }
 
@@ -176,10 +186,17 @@ protected virtual void OnRequestPaused(RequestPausedEventArgs e)
         /// <param name="e">An <see cref="ResponsePausedEventArgs"/> that contains the event data.</param>
         protected virtual void OnResponsePaused(ResponsePausedEventArgs e)
         {
-            if (this.ResponsePaused != null)
+            var delegates = ResponsePaused?.GetInvocationList();
+
+            if (delegates != null)
             {
-                this.ResponsePaused(this, e);
+                foreach (var d in delegates.Cast<AsyncEventHandler<ResponsePausedEventArgs>>())
+                {
+                    Task.Run(async () => await d.Invoke(this, e)).GetAwaiter().GetResult();
+                }
             }
         }
+
+        public delegate Task AsyncEventHandler<TEventArgs>(object sender, TEventArgs e);
     }
 }

dotnet/src/webdriver/NetworkManager.cs

@@ -190,7 +190,7 @@ public void ClearResponseHandlers()
             this.responseHandlers.Clear();
         }
 
-        private async void OnAuthRequired(object sender, AuthRequiredEventArgs e)
+        private async Task OnAuthRequired(object sender, AuthRequiredEventArgs e)
         {
             string requestId = e.RequestId;
             Uri uri = new Uri(e.Uri);
@@ -212,7 +212,7 @@ private async void OnAuthRequired(object sender, AuthRequiredEventArgs e)
             }
         }
 
-        private async void OnRequestPaused(object sender, RequestPausedEventArgs e)
+        private async Task OnRequestPaused(object sender, RequestPausedEventArgs e)
         {
             if (this.NetworkRequestSent != null)
             {
@@ -240,7 +240,7 @@ private async void OnRequestPaused(object sender, RequestPausedEventArgs e)
             await this.session.Value.Domains.Network.ContinueRequestWithoutModification(e.RequestData);
         }
 
-        private async void OnResponsePaused(object sender, ResponsePausedEventArgs e)
+        private async Task OnResponsePaused(object sender, ResponsePausedEventArgs e)
         {
             if (e.ResponseData.Headers.Count > 0)
             {