Add analyzer for invalid use of ITimerScheduler inside PreRestart and…

… AroundPreRestart (#85)

src/Akka.Analyzers/AK1000/MustNotUseIWithTimersInPreRestartAnalyzer.cs

@@ -0,0 +1,61 @@
+// -----------------------------------------------------------------------
+//  <copyright file="MustNotUseIWithTimersInPreRestartAnalyzer.cs" company="Akka.NET Project">
+//      Copyright (C) 2013-2024 .NET Foundation <https://github.com/akkadotnet/akka.net>
+//  </copyright>
+// -----------------------------------------------------------------------
+
+using System.Collections.Immutable;
+using Akka.Analyzers.Context;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+namespace Akka.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public class MustNotUseIWithTimersInPreRestartAnalyzer(): AkkaDiagnosticAnalyzer(RuleDescriptors.Ak1007MustNotUseIWithTimersInPreRestart)
+{
+    public override void AnalyzeCompilation(CompilationStartAnalysisContext context, AkkaContext akkaContext)
+    {
+        Guard.AssertIsNotNull(context);
+        Guard.AssertIsNotNull(akkaContext);
+
+        context.RegisterSyntaxNodeAction(ctx =>
+        {
+            var invocationExpr = (InvocationExpressionSyntax)ctx.Node;
+            var semanticModel = ctx.SemanticModel;
+
+            if (semanticModel.GetSymbolInfo(invocationExpr).Symbol is not IMethodSymbol methodInvocationSymbol)
+                return;
+            
+            // Invocation expression must be either `ITimerScheduler.StartPeriodicTimer()` or `ITimerScheduler.StartSingleTimer()`
+            var iWithTimers = akkaContext.AkkaCore.Actor.ITimerScheduler;
+            var refMethods = iWithTimers.StartPeriodicTimer.AddRange(iWithTimers.StartSingleTimer);
+            if (!methodInvocationSymbol.MatchesAny(refMethods))
+                return;
+            
+            // Grab the enclosing method declaration
+            var methodDeclaration = invocationExpr.FirstAncestorOrSelf<MethodDeclarationSyntax>();
+            if (methodDeclaration is null)
+                return;
+
+            var methodDeclarationSymbol = semanticModel.GetDeclaredSymbol(methodDeclaration);
+            if(methodDeclarationSymbol is null)
+                return;
+            
+            // Method declaration must be `ActorBase.PreRestart()` or `ActorBase.AroundPreRestart()`
+            var actorBase = akkaContext.AkkaCore.Actor.ActorBase;
+            refMethods = new[] { actorBase.PreRestart!, actorBase.AroundPreRestart! }.ToImmutableArray();
+            if (!methodDeclarationSymbol.OverridesAny(refMethods))
+                return;
+
+            var diagnostic = Diagnostic.Create(
+                descriptor: RuleDescriptors.Ak1007MustNotUseIWithTimersInPreRestart, 
+                location: invocationExpr.GetLocation(),
+                messageArgs: [methodInvocationSymbol.Name, methodDeclarationSymbol.Name]);
+            ctx.ReportDiagnostic(diagnostic);
+
+        }, SyntaxKind.InvocationExpression);
+    }
+}

src/Akka.Analyzers/Context/Core/Actor/ActorSymbolFactory.cs

@@ -47,4 +47,8 @@ public static class ActorSymbolFactory
     public static INamedTypeSymbol? ActorRefs(Compilation compilation)
         => Guard.AssertIsNotNull(compilation)
             .GetTypeByMetadataName("Akka.Actor.ActorRefs");
+
+    public static INamedTypeSymbol? TimerSchedulerInterface(Compilation compilation)
+        => Guard.AssertIsNotNull(compilation)
+            .GetTypeByMetadataName($"{AkkaActorNamespace}.ITimerScheduler");
 }

src/Akka.Analyzers/Context/Core/Actor/AkkaCoreActorContext.cs

@@ -22,6 +22,7 @@ public sealed class EmptyAkkaCoreActorContext : IAkkaCoreActorContext
     public INamedTypeSymbol? GracefulStopSupportType => null;
     public INamedTypeSymbol? ITellSchedulerType => null;
     public INamedTypeSymbol? ActorRefsType => null;
+    public INamedTypeSymbol? ITimerSchedulerType => null;
 
     public IGracefulStopSupportContext GracefulStopSupportSupport => EmptyGracefulStopSupportContext.Instance;
     public IIndirectActorProducerContext IIndirectActorProducer => EmptyIndirectActorProducerContext.Instance;
@@ -31,6 +32,7 @@ public sealed class EmptyAkkaCoreActorContext : IAkkaCoreActorContext
     public IPropsContext Props => EmptyPropsContext.Instance;
     public ITellSchedulerInterfaceContext ITellScheduler => EmptyTellSchedulerInterfaceContext.Instance;
     public IActorRefsContext ActorRefs => EmptyActorRefsContext.Empty;
+    public ITimerSchedulerContext ITimerScheduler => EmptyTimerSchedulerContext.Instance;
 }
 
 public sealed class AkkaCoreActorContext : IAkkaCoreActorContext
@@ -44,6 +46,8 @@ public sealed class AkkaCoreActorContext : IAkkaCoreActorContext
     private readonly Lazy<INamedTypeSymbol?> _lazyGracefulStopSupportType;
     private readonly Lazy<INamedTypeSymbol?> _lazyTellSchedulerInterface;
     private readonly Lazy<INamedTypeSymbol?> _lazyActorRefsType;
+    private readonly Lazy<INamedTypeSymbol?> _lazyITimerSchedulerType;
+
     private readonly Lazy<IGracefulStopSupportContext> _lazyGracefulStopSupport;
     private readonly Lazy<IIndirectActorProducerContext> _lazyIIndirectActorProducer;
     private readonly Lazy<IReceiveActorContext> _lazyReceiveActor;
@@ -62,6 +66,8 @@ private AkkaCoreActorContext(Compilation compilation)
         _lazyGracefulStopSupportType = new Lazy<INamedTypeSymbol?>(() => ActorSymbolFactory.GracefulStopSupport(compilation));
         _lazyTellSchedulerInterface = new Lazy<INamedTypeSymbol?>(() => ActorSymbolFactory.TellSchedulerInterface(compilation));
         _lazyActorRefsType = new Lazy<INamedTypeSymbol?>(() => ActorSymbolFactory.ActorRefs(compilation));
+        _lazyITimerSchedulerType = new Lazy<INamedTypeSymbol?>(() => ActorSymbolFactory.TimerSchedulerInterface(compilation));
+
         _lazyGracefulStopSupport = new Lazy<IGracefulStopSupportContext>(() => GracefulStopSupportContext.Get(this));
         _lazyIIndirectActorProducer = new Lazy<IIndirectActorProducerContext>(() => IndirectActorProducerContext.Get(this));
         _lazyReceiveActor = new Lazy<IReceiveActorContext>(() => ReceiveActorContext.Get(this));
@@ -70,6 +76,7 @@ private AkkaCoreActorContext(Compilation compilation)
         _lazyProps = new Lazy<IPropsContext>(() => PropsContext.Get(this));
         ITellScheduler = TellSchedulerInterfaceContext.Get(compilation);
         ActorRefs = ActorRefsContext.Get(this);
+        ITimerScheduler = TimerSchedulerContext.Get(this);
     }
 
     public INamedTypeSymbol? ActorBaseType => _lazyActorBaseType.Value;
@@ -81,6 +88,8 @@ private AkkaCoreActorContext(Compilation compilation)
     public INamedTypeSymbol? ITellSchedulerType => _lazyTellSchedulerInterface.Value;
     public INamedTypeSymbol? ActorRefsType => _lazyActorRefsType.Value;
     public INamedTypeSymbol? GracefulStopSupportType => _lazyGracefulStopSupportType.Value;
+    public INamedTypeSymbol? ITimerSchedulerType => _lazyITimerSchedulerType.Value;
+
     public IGracefulStopSupportContext GracefulStopSupportSupport => _lazyGracefulStopSupport.Value;
     public IIndirectActorProducerContext IIndirectActorProducer => _lazyIIndirectActorProducer.Value;
     public IReceiveActorContext ReceiveActor => _lazyReceiveActor.Value;
@@ -89,6 +98,7 @@ private AkkaCoreActorContext(Compilation compilation)
     public IPropsContext Props => _lazyProps.Value;
     public ITellSchedulerInterfaceContext ITellScheduler { get; }
     public IActorRefsContext ActorRefs { get; }
+    public ITimerSchedulerContext ITimerScheduler { get; }
 
     public static IAkkaCoreActorContext Get(Compilation compilation)
         => new AkkaCoreActorContext(compilation);

src/Akka.Analyzers/Context/Core/Actor/BaseActorContext.cs

@@ -11,27 +11,91 @@ namespace Akka.Analyzers.Context.Core.Actor;
 
 public interface IActorBaseContext
 {
+    #region Properties
+
     public IPropertySymbol? Self { get; }
+
+    #endregion
+
+    #region Methods
+
+    public IMethodSymbol? AroundPreRestart { get; }
+    public IMethodSymbol? AroundPreStart { get; }
+    public IMethodSymbol? PreStart { get; }
+    public IMethodSymbol? AroundPostRestart { get; }
+    public IMethodSymbol? PreRestart { get; }
+    public IMethodSymbol? PostRestart { get; }
+    public IMethodSymbol? AroundPostStop { get; }
+    public IMethodSymbol? PostStop { get; }
+
+    #endregion
 }
 
 public sealed class EmptyActorBaseContext : IActorBaseContext
 {
     public static readonly EmptyActorBaseContext Instance = new();
     private EmptyActorBaseContext() { }
     public IPropertySymbol? Self => null;
+    public IMethodSymbol? AroundPreRestart => null;
+    public IMethodSymbol? AroundPreStart => null;
+    public IMethodSymbol? PreStart => null;
+    public IMethodSymbol? AroundPostRestart => null;
+    public IMethodSymbol? PreRestart => null;
+    public IMethodSymbol? PostRestart => null;
+    public IMethodSymbol? AroundPostStop => null;
+    public IMethodSymbol? PostStop => null;
 }
 
 public sealed class ActorBaseContext : IActorBaseContext
 {
     private readonly Lazy<IPropertySymbol> _lazySelf;
+    private readonly Lazy<IMethodSymbol> _lazyAroundPreRestart;
+    private readonly Lazy<IMethodSymbol> _lazyAroundPreStart;
+    private readonly Lazy<IMethodSymbol> _lazyPreStart;
+    private readonly Lazy<IMethodSymbol> _lazyAroundPostRestart;
+    private readonly Lazy<IMethodSymbol> _lazyPreRestart;
+    private readonly Lazy<IMethodSymbol> _lazyPostRestart;
+    private readonly Lazy<IMethodSymbol> _lazyAroundPostStop;
+    private readonly Lazy<IMethodSymbol> _lazyPostStop;
 
     private ActorBaseContext(AkkaCoreActorContext context)
     {
+        Guard.AssertIsNotNull(context.ActorBaseType);
+
         _lazySelf = new Lazy<IPropertySymbol>(() => (IPropertySymbol) context.ActorBaseType!.GetMembers("Self").First());
+
+        _lazyAroundPreRestart = new Lazy<IMethodSymbol>(() => (IMethodSymbol) context.ActorBaseType!
+            .GetMembers(nameof(AroundPreRestart)).First());
+        _lazyAroundPreStart = new Lazy<IMethodSymbol>(() => (IMethodSymbol) context.ActorBaseType!
+            .GetMembers(nameof(AroundPreStart)).First());
+        _lazyPreStart = new Lazy<IMethodSymbol>(() => (IMethodSymbol) context.ActorBaseType!
+            .GetMembers(nameof(PreStart)).First());
+        _lazyAroundPostRestart = new Lazy<IMethodSymbol>(() => (IMethodSymbol) context.ActorBaseType!
+            .GetMembers(nameof(AroundPostRestart)).First());
+        _lazyPreRestart = new Lazy<IMethodSymbol>(() => (IMethodSymbol) context.ActorBaseType!
+            .GetMembers(nameof(PreRestart)).First());
+        _lazyPostRestart = new Lazy<IMethodSymbol>(() => (IMethodSymbol) context.ActorBaseType!
+            .GetMembers(nameof(PostRestart)).First());
+        _lazyAroundPostStop = new Lazy<IMethodSymbol>(() => (IMethodSymbol) context.ActorBaseType!
+            .GetMembers(nameof(AroundPostStop)).First());
+        _lazyPostStop = new Lazy<IMethodSymbol>(() => (IMethodSymbol) context.ActorBaseType!
+            .GetMembers(nameof(PostStop)).First());
     }
 
     public IPropertySymbol? Self => _lazySelf.Value;
+    public IMethodSymbol? AroundPreRestart => _lazyAroundPreRestart.Value;
+    public IMethodSymbol? AroundPreStart => _lazyAroundPreStart.Value;
+    public IMethodSymbol? PreStart => _lazyPreStart.Value;
+    public IMethodSymbol? AroundPostRestart => _lazyAroundPostRestart.Value;
+    public IMethodSymbol? PreRestart => _lazyPreRestart.Value;
+    public IMethodSymbol? PostRestart => _lazyPostRestart.Value;
+    public IMethodSymbol? AroundPostStop => _lazyAroundPostStop.Value;
+    public IMethodSymbol? PostStop => _lazyPostStop.Value;
 
     public static ActorBaseContext Get(AkkaCoreActorContext context)
-        => new(context);
+    {
+        Guard.AssertIsNotNull(context);
+
+        return new ActorBaseContext(context);
+    }
 }

src/Akka.Analyzers/Context/Core/Actor/IAkkaCoreActorContext.cs

@@ -21,6 +21,7 @@ public interface IAkkaCoreActorContext
     public INamedTypeSymbol? GracefulStopSupportType { get; }
     public INamedTypeSymbol? ITellSchedulerType { get; }
     public INamedTypeSymbol? ActorRefsType { get; }
+    public INamedTypeSymbol? ITimerSchedulerType { get; } 
 
     public IGracefulStopSupportContext GracefulStopSupportSupport { get; }
     public IIndirectActorProducerContext IIndirectActorProducer { get; }
@@ -30,4 +31,5 @@ public interface IAkkaCoreActorContext
     public IPropsContext Props { get; }
     public ITellSchedulerInterfaceContext ITellScheduler { get; }
     public IActorRefsContext ActorRefs { get; }
+    public ITimerSchedulerContext ITimerScheduler { get; }
 }

src/Akka.Analyzers/Context/Core/Actor/ITimerSchedulerContext.cs

@@ -0,0 +1,50 @@
+// -----------------------------------------------------------------------
+//  <copyright file="ITimerSchedulerContext.cs" company="Akka.NET Project">
+//      Copyright (C) 2013-2024 .NET Foundation <https://github.com/akkadotnet/akka.net>
+//  </copyright>
+// -----------------------------------------------------------------------
+
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+
+namespace Akka.Analyzers.Context.Core.Actor;
+
+public interface ITimerSchedulerContext
+{
+    public ImmutableArray<IMethodSymbol> StartPeriodicTimer { get; }
+    public ImmutableArray<IMethodSymbol> StartSingleTimer { get; }
+}
+
+public sealed class EmptyTimerSchedulerContext : ITimerSchedulerContext
+{
+    public static readonly EmptyTimerSchedulerContext Instance = new();
+    private EmptyTimerSchedulerContext() { }
+    public ImmutableArray<IMethodSymbol> StartPeriodicTimer => ImmutableArray<IMethodSymbol>.Empty;
+    public ImmutableArray<IMethodSymbol> StartSingleTimer => ImmutableArray<IMethodSymbol>.Empty;
+}
+
+public sealed class TimerSchedulerContext : ITimerSchedulerContext
+{
+    private readonly Lazy<ImmutableArray<IMethodSymbol>> _lazyStartPeriodicTimer;
+    private readonly Lazy<ImmutableArray<IMethodSymbol>> _lazyStartSingleTimer;
+
+    private TimerSchedulerContext(AkkaCoreActorContext context)
+    {
+        Guard.AssertIsNotNull(context);
+
+        _lazyStartPeriodicTimer = new Lazy<ImmutableArray<IMethodSymbol>>(() => context.ITimerSchedulerType!
+            .GetMembers(nameof(StartPeriodicTimer)).Select(m => (IMethodSymbol)m).ToImmutableArray());
+        _lazyStartSingleTimer = new Lazy<ImmutableArray<IMethodSymbol>>(() => context.ITimerSchedulerType!
+            .GetMembers(nameof(StartSingleTimer)).Select(m => (IMethodSymbol)m).ToImmutableArray());
+    }
+
+    public ImmutableArray<IMethodSymbol> StartPeriodicTimer => _lazyStartPeriodicTimer.Value;
+    public ImmutableArray<IMethodSymbol> StartSingleTimer => _lazyStartSingleTimer.Value;
+
+    public static TimerSchedulerContext Get(AkkaCoreActorContext context)
+    {
+        Guard.AssertIsNotNull(context);
+
+        return new TimerSchedulerContext(context);
+    }
+}

src/Akka.Analyzers/Utility/CodeAnalysisExtensions.cs

@@ -4,6 +4,7 @@
 // </copyright>
 // -----------------------------------------------------------------------
 
+using System.Collections.Immutable;
 using System.Runtime.CompilerServices;
 using Akka.Analyzers.Context.Core;
 using Microsoft.CodeAnalysis;
@@ -183,4 +184,25 @@ public static bool IsDerivedOrImplements(this ITypeSymbol typeSymbol, ITypeSymbo
         return false;
     }
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool OverridesAny(this IMethodSymbol methodSymbol, IReadOnlyCollection<IMethodSymbol> refMethods)
+    {
+        if (!methodSymbol.IsOverride)
+            return false;
+
+        while (methodSymbol.OverriddenMethod != null)
+            methodSymbol = methodSymbol.OverriddenMethod;
+
+        return methodSymbol.MatchesAny(refMethods);
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool MatchesAny(this IMethodSymbol methodSymbol, IReadOnlyCollection<IMethodSymbol> refMethods)
+    {
+        while (!ReferenceEquals(methodSymbol, methodSymbol.ConstructedFrom))
+            methodSymbol = methodSymbol.ConstructedFrom;
+
+        return refMethods.Any(m => ReferenceEquals(m, methodSymbol));
+    }
+
 }

src/Akka.Analyzers/Utility/RuleDescriptors.cs

@@ -61,6 +61,14 @@ public static class RuleDescriptors
                        "can cause memory leak and unnecessary CPU usage if they are not canceled properly inside PostStop(). " +
                        "Consider implementing the IWithTimers interface and use the Timers.StartSingleTimer() or " +
                        "Timers.StartPeriodicTimer() instead.");
+
+    public static DiagnosticDescriptor Ak1007MustNotUseIWithTimersInPreRestart { get; } = Rule(
+        id: "AK1007",
+        title: "Timers.StartSingleTimer() and Timers.StartPeriodicTimer() must not be used inside AroundPreRestart() or PreRestart()", 
+        category: AnalysisCategory.ActorDesign, 
+        defaultSeverity: DiagnosticSeverity.Error,
+        messageFormat: "Creating timer registration using `{0}()` in `{1}()` will not be honored because they will be " +
+                       "cleared immediately. Move timer creation to `PostRestart()` instead.");
     #endregion
 
     #region AK2000 Rules