Support resetting state when connecting to a previously monitored app (#8154)

* Support resetting state when connecting to a previously monitored app

* Fix switch build issue

* Fix unit tests

* PR Feedback

* Add exception startup collection enablement

* Fix env check

* PR feedback

* PR feedback

* Use an interlocked many reader single writer to synchronize exceptions threads and pipeline stop calls

* Fixup PR tests

* PR feedback

* PR feedback

Co-authored-by: Justin Anderson <[email protected]>

* Fixup schema

* Unit test

* (test)

---------

Co-authored-by: Justin Anderson <[email protected]>

Author: wiktork

cspell.json

@@ -55,6 +55,7 @@
         "hresult",
         "Hsts",
         "Impls",
+        "inproc",
         "JITID",
         "JWTs",
         "LCID",
@@ -107,6 +108,7 @@
         "ukwn",
         "uninitialize",
         "Uninstallation",
+        "uninstrumented",
         "uniquifier",
         "Unlocalized",
         "Unredacted",

documentation/schema.json

@@ -1123,6 +1123,14 @@
               "$ref": "#/definitions/ExceptionsConfiguration"
             }
           ]
+        },
+        "CollectOnStartup": {
+          "type": [
+            "boolean",
+            "null"
+          ],
+          "description": "[Experimental] Determines if exception collection should begin immediately",
+          "default": true
         }
       }
     },

src/Microsoft.Diagnostics.Monitoring.Options/ExceptionsOptions.cs

@@ -27,5 +27,11 @@ public sealed class ExceptionsOptions :
             ResourceType = typeof(OptionsDisplayStrings),
             Description = nameof(OptionsDisplayStrings.DisplayAttributeDescription_ExceptionsOptions_CollectionFilters))]
         public ExceptionsConfiguration? CollectionFilters { get; set; }
+
+        [Display(
+            ResourceType = typeof(OptionsDisplayStrings),
+            Description = nameof(OptionsDisplayStrings.DisplayAttributeDescription_ExceptionsOptions_CollectOnStartup))]
+        [DefaultValue(ExceptionsOptionsDefaults.CollectOnStartup)]
+        public bool? CollectOnStartup { get; set; }
     }
 }

src/Microsoft.Diagnostics.Monitoring.Options/ExceptionsOptionsDefaults.cs

@@ -8,5 +8,7 @@ internal static class ExceptionsOptionsDefaults
         public const bool Enabled = true;
 
         public const int TopLevelLimit = 20;
+
+        public const bool CollectOnStartup = true;
     }
 }

src/Microsoft.Diagnostics.Monitoring.Options/ExceptionsOptionsExtensions.cs

@@ -14,5 +14,10 @@ public static int GetTopLevelLimit(this ExceptionsOptions options)
         {
             return options.TopLevelLimit.GetValueOrDefault(ExceptionsOptionsDefaults.TopLevelLimit);
         }
+
+        public static bool CollectOnStartup(this ExceptionsOptions options)
+        {
+            return options.CollectOnStartup.GetValueOrDefault(ExceptionsOptionsDefaults.CollectOnStartup);
+        }
     }
 }

src/Microsoft.Diagnostics.Monitoring.Options/OptionsDisplayStrings.Designer.cs

@@ -780,4 +780,7 @@
     <value>Performs a match based on the name of the managed entry point assembly of the process.</value>
     <comment>The description provided for the ManagedEntryPointAssemblyName parameter on ProcessFilterDescriptor.</comment>
   </data>
+  <data name="DisplayAttributeDescription_ExceptionsOptions_CollectOnStartup" xml:space="preserve">
+    <value>[Experimental] Determines if exception collection should begin immediately</value>
+  </data>
 </root>

src/Microsoft.Diagnostics.Monitoring.Options/OptionsDisplayStrings.resx

@@ -23,7 +23,13 @@ internal sealed class DiagnosticsBootstrapper :
         public DiagnosticsBootstrapper()
         {
             _exceptionProcessor = new(ToolIdentifiers.IsEnvVarEnabled(InProcessFeaturesIdentifiers.EnvironmentVariables.Exceptions.IncludeMonitorExceptions));
-            _exceptionProcessor.Start();
+
+            // If collectOnStart is not set, assume the default value (true).
+            string? collectOnStart = Environment.GetEnvironmentVariable(InProcessFeaturesIdentifiers.EnvironmentVariables.Exceptions.CollectOnStartup);
+            if (collectOnStart == null || ToolIdentifiers.IsEnvVarValueEnabled(collectOnStart))
+            {
+                _exceptionProcessor.Start();
+            }
 
             using IDisposable _ = MonitorExecutionContextTracker.MonitorScope();
 
@@ -35,6 +41,17 @@ public DiagnosticsBootstrapper()
                     SharedInternals.MessageDispatcher = new MessageDispatcher.MonitorMessageDispatcher(
                         new MessageDispatcher.ProfilerMessageSource(CommandSet.StartupHook));
                     ToolIdentifiers.EnableEnvVar(InProcessFeaturesIdentifiers.EnvironmentVariables.AvailableInfrastructure.ManagedMessaging);
+
+                    SharedInternals.MessageDispatcher.RegisterCallback<EmptyPayload>(StartupHookCommand.StopAllFeatures, (IpcMessage) =>
+                    {
+                        _exceptionProcessor.Stop();
+                        _parameterCapturingService?.RequestStopAll();
+                    });
+
+                    SharedInternals.MessageDispatcher.RegisterCallback<EmptyPayload>(StartupHookCommand.StartAllFeatures, (IpcMessage) =>
+                    {
+                        _exceptionProcessor.Start();
+                    });
                 }
 
                 if (ToolIdentifiers.IsEnvVarEnabled(InProcessFeaturesIdentifiers.EnvironmentVariables.ParameterCapturing.Enable))

src/Microsoft.Diagnostics.Monitoring.StartupHook/DiagnosticsBootstrapper.cs

@@ -14,10 +14,10 @@ internal sealed class CurrentAppDomainExceptionProcessor : IDisposable
         private readonly ExceptionIdSource _idSource = new();
 
         private readonly CurrentAppDomainFirstChanceExceptionSource _firstChanceSource;
-        private readonly ExceptionPipeline _firstChancePipeline;
+        private ExceptionPipeline _firstChancePipeline;
 
         private readonly CurrentAppDomainUnhandledExceptionSource _unhandledSource;
-        private readonly ExceptionPipeline _unhandledPipeline;
+        private ExceptionPipeline _unhandledPipeline;
 
         private readonly bool _includeMonitorExceptions;
 
@@ -35,7 +35,23 @@ public CurrentAppDomainExceptionProcessor(bool includeMonitorExceptions)
         public void Start()
         {
             _firstChancePipeline.Start();
+            _firstChanceSource.Start();
+
             _unhandledPipeline.Start();
+            _unhandledSource.Start();
+        }
+
+        public void Stop()
+        {
+            // Stop all exception flow from the sources. This will allow draining the pipelines.
+            _firstChanceSource.Stop();
+            _unhandledSource.Stop();
+            _firstChancePipeline.Stop();
+            _unhandledPipeline.Stop();
+
+            // We reset the pipelines entirely to allow their cache to be cleared
+            _firstChancePipeline = new(_firstChanceSource, ConfigureFirstChancePipeline);
+            _unhandledPipeline = new(_unhandledSource, ConfigureUnhandledPipeline);
         }
 
         private void ConfigureFirstChancePipeline(ExceptionPipelineBuilder builder)

src/Microsoft.Diagnostics.Monitoring.StartupHook/Exceptions/CurrentAppDomainExceptionProcessor.cs

@@ -15,11 +15,16 @@ internal sealed class CurrentAppDomainFirstChanceExceptionSource :
     {
         private long _disposedState;
 
-        public CurrentAppDomainFirstChanceExceptionSource()
+        public override void Start()
         {
             AppDomain.CurrentDomain.FirstChanceException += CurrentDomain_FirstChanceException;
         }
 
+        public override void Stop()
+        {
+            AppDomain.CurrentDomain.FirstChanceException -= CurrentDomain_FirstChanceException;
+        }
+
         private void CurrentDomain_FirstChanceException(object? sender, FirstChanceExceptionEventArgs e)
         {
             RaiseExceptionGuarded(e.Exception);