Activate hotreload session on both OnAfterLaunchAsync in ProjectLaunchTargetsProvider (#9813)

* Enhance Hot Reload session management by updating ActivateSessionAsync method signature and adding process termination details

* Refactor OnComplete method to ensure proper execution of OnAfterLaunchAsync for IDebugProfileLaunchTargetsProvider4

* Fix XML documentation for launchedProcess parameter in ActivateSessionAsync method

* Remove unused using directive for Microsoft.VisualStudio.Debugger.Contracts in ProjectLaunchTargetsProvider.cs

Author: LittleLittleCloud

src/Microsoft.VisualStudio.ProjectSystem.Managed.VS/ProjectSystem/VS/Debug/LaunchProfilesDebugLaunchProvider.cs

@@ -149,9 +149,8 @@ public void OnComplete(int hr, uint debugTargetCount, VsDebugTargetProcessInfo[]
 
             if (targetsProvider is IDebugProfileLaunchTargetsProvider4 targetsProvider4)
             {
-                threadingService.ExecuteSynchronously(() => targetsProvider4.OnAfterLaunchAsync(launchOptions, activeProfile, processInfoArray));
-
                 IVsLaunchedProcess? vsLaunchedProcess = null;
+
                 lock (_launchedProcesses)
                 {
                     if (_launchedProcesses.Count == 1)
@@ -167,6 +166,10 @@ public void OnComplete(int hr, uint debugTargetCount, VsDebugTargetProcessInfo[]
                 {
                     threadingService.ExecuteSynchronously(() => targetsProvider5.OnAfterLaunchAsync(launchOptions, activeProfile, debugLaunchSettings[0], vsLaunchedProcess, processInfoArray[0]));
                 }
+                else
+                {
+                    threadingService.ExecuteSynchronously(() => targetsProvider4.OnAfterLaunchAsync(launchOptions, activeProfile, processInfoArray));
+                }
             }
             else if (targetsProvider is not null)
             {

src/Microsoft.VisualStudio.ProjectSystem.Managed.VS/ProjectSystem/VS/Debug/ProjectLaunchTargetsProvider.cs

@@ -110,9 +110,11 @@ Task IDebugProfileLaunchTargetsProvider.OnAfterLaunchAsync(DebugLaunchOptions la
         throw new InvalidOperationException($"Wrong overload of {nameof(OnAfterLaunchAsync)} called.");
     }
 
-    public Task OnAfterLaunchAsync(DebugLaunchOptions launchOptions, ILaunchProfile profile, IReadOnlyList<VsDebugTargetProcessInfo> processInfos)
+    public async Task OnAfterLaunchAsync(DebugLaunchOptions launchOptions, ILaunchProfile profile, IReadOnlyList<VsDebugTargetProcessInfo> processInfos)
     {
-        return Task.CompletedTask;
+        var configuredProjectForDebug = await GetConfiguredProjectForDebugAsync();
+        var hotReloadSessionManager = configuredProjectForDebug.GetExportedService<IProjectHotReloadSessionManager>();
+        await hotReloadSessionManager.ActivateSessionAsync(null, processInfos[0]);
     }
 
     public async Task OnAfterLaunchAsync(

src/Microsoft.VisualStudio.ProjectSystem.Managed.VS/ProjectSystem/VS/HotReload/IProjectHotReloadSessionManager.cs

@@ -29,6 +29,11 @@ Task<bool> TryCreatePendingSessionAsync(
 
     /// <summary>
     /// Activates the pending Hot Reload session and associates it with the specified process.
+    /// The <paramref name="launchedProcess"/> and/or <paramref name="vsDebugTargetProcessInfo"/> provide the launch information of the process.
+    /// When the session is terminated, the <paramref name="launchedProcess"/> will be used to terminate the process if it is not null.
+    /// Otherwise, the PID from <paramref name="vsDebugTargetProcessInfo"/> will be used to terminate the process.
     /// </summary>
-    Task ActivateSessionAsync(IVsLaunchedProcess launchedProcess, VsDebugTargetProcessInfo vsDebugTargetProcessInfo);
+    /// <param name="launchedProcess">if not null, it will be used to terminate the process.</param>
+    /// <param name="vsDebugTargetProcessInfo">The process information of the launched process.</param>
+    Task ActivateSessionAsync(IVsLaunchedProcess? launchedProcess, VsDebugTargetProcessInfo vsDebugTargetProcessInfo);
 }

src/Microsoft.VisualStudio.ProjectSystem.Managed.VS/ProjectSystem/VS/HotReload/ProjectHotReloadSessionManager.cs

@@ -192,7 +192,7 @@ async Task ApplyHotReloadUpdateInternalAsync()
         }
     }
 
-    public Task ActivateSessionAsync(IVsLaunchedProcess launchedProcess, VsDebugTargetProcessInfo vsDebugTargetProcessInfo)
+    public Task ActivateSessionAsync(IVsLaunchedProcess? launchedProcess, VsDebugTargetProcessInfo vsDebugTargetProcessInfo)
     {
         Assumes.True(_pendingSessionState is not null, "No pending hot reload session to activate.");
 
@@ -261,11 +261,34 @@ public async Task<bool> StopProjectAsync(CancellationToken cancellationToken)
                 return true;
             }
 
-            // need to call on UI thread
-            await threadingService.SwitchToUIThread(cancellationToken);
+            // prefer to terminate launched process first if we have it
+            if (LaunchedProcess is not null)
+            {
+                // need to call on UI thread
+                await threadingService.SwitchToUIThread(cancellationToken);
 
-            // Ignore the debug option launching flags since we're just terminating the process, not the entire debug session
-            LaunchedProcess.Terminate(ignoreLaunchFlags: 1);
+                // Ignore the debug option launching flags since we're just terminating the process, not the entire debug session
+                LaunchedProcess.Terminate(ignoreLaunchFlags: 1);
+            }
+            else
+            {
+                // stop the process by killing it
+                try
+                {
+                    if (Process is not null && !Process.HasExited)
+                    {
+                        // First try to close the process nicely and if that doesn't work kill it.
+                        if (!Process.CloseMainWindow())
+                        {
+                            Process.Kill();
+                        }
+                    }
+                }
+                catch (InvalidOperationException)
+                {
+                    // Process has already exited.
+                }
+            }
 
             if (Session is not null)
             {