[dotnet] Fix the issue when service wants to write into disposed stream

dotnet/src/webdriver/DriverService.cs

@@ -255,14 +255,16 @@ public void Start()
         DriverProcessStartingEventArgs eventArgs = new DriverProcessStartingEventArgs(this.driverServiceProcess.StartInfo);
         this.OnDriverProcessStarting(eventArgs);
 
+        // Important: Start the process and immediately begin reading the output and error streams to avoid IO deadlocks.
         this.driverServiceProcess.Start();
+        this.driverServiceProcess.BeginOutputReadLine();
+        this.driverServiceProcess.BeginErrorReadLine();
+
         bool serviceAvailable = this.WaitForServiceInitialization();
+
         DriverProcessStartedEventArgs processStartedEventArgs = new DriverProcessStartedEventArgs(this.driverServiceProcess);
         this.OnDriverProcessStarted(processStartedEventArgs);
 
-        this.driverServiceProcess.BeginOutputReadLine();
-        this.driverServiceProcess.BeginErrorReadLine();
-
         if (!serviceAvailable)
         {
             throw new WebDriverException($"Cannot start the driver service on {this.ServiceUrl}");
@@ -286,6 +288,12 @@ protected virtual void Dispose(bool disposing)
             if (disposing)
             {
                 this.Stop();
+
+                if (this.driverServiceProcess is not null)
+                {
+                    this.driverServiceProcess.OutputDataReceived -= this.OnDriverProcessDataReceived;
+                    this.driverServiceProcess.ErrorDataReceived -= this.OnDriverProcessDataReceived;
+                }
             }
 
             this.isDisposed = true;

dotnet/src/webdriver/Firefox/FirefoxDriverService.cs

@@ -250,7 +250,6 @@ protected override void OnDriverProcessStarting(DriverProcessStartingEventArgs e
     /// </summary>
     /// <param name="sender">The sender of the event.</param>
     /// <param name="args">The data received event arguments.</param>
-    /// <param name="isError">A value indicating whether the data received is from the error stream.</param>
     protected override void OnDriverProcessDataReceived(object sender, DataReceivedEventArgs args)
     {
         if (string.IsNullOrEmpty(args.Data))
@@ -279,13 +278,13 @@ protected override void OnDriverProcessDataReceived(object sender, DataReceivedE
     /// </remarks>
     protected override void Dispose(bool disposing)
     {
+        base.Dispose(disposing);
+
         if (logWriter != null && disposing)
         {
             logWriter.Dispose();
             logWriter = null;
         }
-
-        base.Dispose(disposing);
     }
 
     /// <summary>