Remove indirection in DependencyInjection (#52140)

- Remove indirection
- Get rid of scope state and lock on ResolvedServices
- Don't run customer code under the lock
- No public API changes

src/libraries/Microsoft.Extensions.DependencyInjection/src/DependencyInjectionEventSource.cs

@@ -67,15 +67,6 @@ public void ServiceRealizationFailed(string? exceptionMessage)
             WriteEvent(6, exceptionMessage);
         }
 
-        [NonEvent]
-        public void ScopeDisposed(ServiceProviderEngine engine, ScopeState state)
-        {
-            if (IsEnabled(EventLevel.Verbose, EventKeywords.All))
-            {
-                ScopeDisposed(engine.GetHashCode(), state.ResolvedServicesCount, state.DisposableServicesCount);
-            }
-        }
-
         [NonEvent]
         public void ServiceResolved(Type serviceType)
         {

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceCollectionContainerBuilderExtensions.cs

@@ -58,23 +58,7 @@ public static ServiceProvider BuildServiceProvider(this IServiceCollection servi
                 throw new ArgumentNullException(nameof(options));
             }
 
-            IServiceProviderEngine engine;
-
-#if !NETSTANDARD2_1
-            engine = new DynamicServiceProviderEngine(services);
-#else
-            if (RuntimeFeature.IsDynamicCodeCompiled)
-            {
-                engine = new DynamicServiceProviderEngine(services);
-            }
-            else
-            {
-                // Don't try to compile Expressions/IL if they are going to get interpreted
-                engine = new RuntimeServiceProviderEngine(services);
-            }
-#endif
-
-            return new ServiceProvider(services, engine, options);
+            return new ServiceProvider(services, options);
         }
     }
 }

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/CallSiteRuntimeResolver.cs

@@ -12,6 +12,12 @@ namespace Microsoft.Extensions.DependencyInjection.ServiceLookup
 {
     internal sealed class CallSiteRuntimeResolver : CallSiteVisitor<RuntimeResolverContext, object>
     {
+        public static CallSiteRuntimeResolver Instance { get; } = new();
+
+        private CallSiteRuntimeResolver()
+        {
+        }
+
         public object Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
         {
             return VisitCallSite(callSite, new RuntimeResolverContext
@@ -66,7 +72,7 @@ protected override object VisitRootCache(ServiceCallSite callSite, RuntimeResolv
             }
 
             var lockType = RuntimeResolverLock.Root;
-            ServiceProviderEngineScope serviceProviderEngine = context.Scope.Engine.Root;
+            ServiceProviderEngineScope serviceProviderEngine = context.Scope.RootProvider.Root;
 
             lock (callSite)
             {
@@ -91,7 +97,7 @@ protected override object VisitScopeCache(ServiceCallSite callSite, RuntimeResol
         {
             // Check if we are in the situation where scoped service was promoted to singleton
             // and we need to lock the root
-            return context.Scope == context.Scope.Engine.Root ?
+            return context.Scope.IsRootScope ?
                 VisitRootCache(callSite, context) :
                 VisitCache(callSite, context, context.Scope, RuntimeResolverLock.Scope);
         }
@@ -149,7 +155,7 @@ protected override object VisitServiceProvider(ServiceProviderCallSite servicePr
 
         protected override object VisitServiceScopeFactory(ServiceScopeFactoryCallSite serviceScopeFactoryCallSite, RuntimeResolverContext context)
         {
-            return context.Scope.Engine;
+            return serviceScopeFactoryCallSite.Value;
         }
 
         protected override object VisitIEnumerable(IEnumerableCallSite enumerableCallSite, RuntimeResolverContext context)

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/CompiledServiceProviderEngine.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
-using System.Collections.Generic;
 
 namespace Microsoft.Extensions.DependencyInjection.ServiceLookup
 {
@@ -14,21 +13,11 @@ internal abstract class CompiledServiceProviderEngine : ServiceProviderEngine
         public ExpressionResolverBuilder ResolverBuilder { get; }
 #endif
 
-        public CompiledServiceProviderEngine(IEnumerable<ServiceDescriptor> serviceDescriptors)
-            : base(serviceDescriptors)
+        public CompiledServiceProviderEngine(ServiceProvider provider)
         {
-#if IL_EMIT
-            ResolverBuilder = new ILEmitResolverBuilder(RuntimeResolver, this, Root);
-#else
-            ResolverBuilder = new ExpressionResolverBuilder(RuntimeResolver, this, Root);
-#endif
+            ResolverBuilder = new(provider);
         }
 
-        protected override Func<ServiceProviderEngineScope, object> RealizeService(ServiceCallSite callSite)
-        {
-            Func<ServiceProviderEngineScope, object> realizedService = ResolverBuilder.Build(callSite);
-            RealizedServices[callSite.ServiceType] = realizedService;
-            return realizedService;
-        }
+        public override Func<ServiceProviderEngineScope, object> RealizeService(ServiceCallSite callSite) => ResolverBuilder.Build(callSite);
     }
 }

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/DynamicServiceProviderEngine.cs

@@ -2,19 +2,20 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
-using System.Collections.Generic;
 using System.Threading;
 
 namespace Microsoft.Extensions.DependencyInjection.ServiceLookup
 {
     internal sealed class DynamicServiceProviderEngine : CompiledServiceProviderEngine
     {
-        public DynamicServiceProviderEngine(IEnumerable<ServiceDescriptor> serviceDescriptors)
-            : base(serviceDescriptors)
+        private readonly ServiceProvider _serviceProvider;
+
+        public DynamicServiceProviderEngine(ServiceProvider serviceProvider): base(serviceProvider)
         {
+            _serviceProvider = serviceProvider;
         }
 
-        protected override Func<ServiceProviderEngineScope, object> RealizeService(ServiceCallSite callSite)
+        public override Func<ServiceProviderEngineScope, object> RealizeService(ServiceCallSite callSite)
         {
             int callCount = 0;
             return scope =>
@@ -29,7 +30,7 @@ protected override Func<ServiceProviderEngineScope, object> RealizeService(Servi
 
                 // Resolve the result before we increment the call count, this ensures that singletons
                 // won't cause any side effects during the compilation of the resolve function.
-                var result = RuntimeResolver.Resolve(callSite, scope);
+                var result = CallSiteRuntimeResolver.Instance.Resolve(callSite, scope);
 
                 if (Interlocked.Increment(ref callCount) == 2)
                 {
@@ -46,7 +47,7 @@ protected override Func<ServiceProviderEngineScope, object> RealizeService(Servi
                     {
                         try
                         {
-                            base.RealizeService(callSite);
+                            _serviceProvider.ReplaceServiceAccessor(callSite, base.RealizeService(callSite));
                         }
                         catch (Exception ex)
                         {

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/Expressions/ExpressionResolverBuilder.cs

@@ -44,39 +44,21 @@ internal sealed class ExpressionResolverBuilder : CallSiteVisitor<object, Expres
                     Expression.Call(ScopeParameter, CaptureDisposableMethodInfo, CaptureDisposableParameter),
                     CaptureDisposableParameter);
 
-        private readonly CallSiteRuntimeResolver _runtimeResolver;
-
-        private readonly IServiceScopeFactory _serviceScopeFactory;
-
         private readonly ServiceProviderEngineScope _rootScope;
 
         private readonly ConcurrentDictionary<ServiceCacheKey, Func<ServiceProviderEngineScope, object>> _scopeResolverCache;
 
         private readonly Func<ServiceCacheKey, ServiceCallSite, Func<ServiceProviderEngineScope, object>> _buildTypeDelegate;
 
-        public ExpressionResolverBuilder(CallSiteRuntimeResolver runtimeResolver, IServiceScopeFactory serviceScopeFactory, ServiceProviderEngineScope rootScope)
+        public ExpressionResolverBuilder(ServiceProvider serviceProvider)
         {
-            if (runtimeResolver == null)
-            {
-                throw new ArgumentNullException(nameof(runtimeResolver));
-            }
-
+            _rootScope = serviceProvider.Root;
             _scopeResolverCache = new ConcurrentDictionary<ServiceCacheKey, Func<ServiceProviderEngineScope, object>>();
-            _runtimeResolver = runtimeResolver;
-            _serviceScopeFactory = serviceScopeFactory;
-            _rootScope = rootScope;
             _buildTypeDelegate = (key, cs) => BuildNoCache(cs);
         }
 
         public Func<ServiceProviderEngineScope, object> Build(ServiceCallSite callSite)
         {
-            // Optimize singleton case
-            if (callSite.Cache.Location == CallSiteResultCacheLocation.Root)
-            {
-                object value = _runtimeResolver.Resolve(callSite, _rootScope);
-                return scope => value;
-            }
-
             // Only scope methods are cached
             if (callSite.Cache.Location == CallSiteResultCacheLocation.Scope)
             {
@@ -117,7 +99,7 @@ private Expression<Func<ServiceProviderEngineScope, object>> BuildExpression(Ser
 
         protected override Expression VisitRootCache(ServiceCallSite singletonCallSite, object context)
         {
-            return Expression.Constant(_runtimeResolver.Resolve(singletonCallSite, _rootScope));
+            return Expression.Constant(CallSiteRuntimeResolver.Instance.Resolve(singletonCallSite, _rootScope));
         }
 
         protected override Expression VisitConstant(ConstantCallSite constantCallSite, object context)
@@ -132,7 +114,7 @@ protected override Expression VisitServiceProvider(ServiceProviderCallSite servi
 
         protected override Expression VisitServiceScopeFactory(ServiceScopeFactoryCallSite serviceScopeFactoryCallSite, object context)
         {
-            return Expression.Constant(_serviceScopeFactory);
+            return Expression.Constant(serviceScopeFactoryCallSite.Value);
         }
 
         protected override Expression VisitFactory(FactoryCallSite factoryCallSite, object context)

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/Expressions/ExpressionsServiceProviderEngine.cs

@@ -2,23 +2,21 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
-using System.Collections.Generic;
 
 namespace Microsoft.Extensions.DependencyInjection.ServiceLookup
 {
     internal sealed class ExpressionsServiceProviderEngine : ServiceProviderEngine
     {
         private readonly ExpressionResolverBuilder _expressionResolverBuilder;
-        public ExpressionsServiceProviderEngine(IEnumerable<ServiceDescriptor> serviceDescriptors) : base(serviceDescriptors)
+
+        public ExpressionsServiceProviderEngine(ServiceProvider serviceProvider)
         {
-            _expressionResolverBuilder = new ExpressionResolverBuilder(RuntimeResolver, this, Root);
+            _expressionResolverBuilder = new ExpressionResolverBuilder(serviceProvider);
         }
 
-        protected override Func<ServiceProviderEngineScope, object> RealizeService(ServiceCallSite callSite)
+        public override Func<ServiceProviderEngineScope, object> RealizeService(ServiceCallSite callSite)
         {
-            Func<ServiceProviderEngineScope, object> realizedService = _expressionResolverBuilder.Build(callSite);
-            RealizedServices[callSite.ServiceType] = realizedService;
-            return realizedService;
+            return _expressionResolverBuilder.Build(callSite);
         }
     }
 }

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/ILEmit/ILEmitResolverBuilder.cs

@@ -25,7 +25,6 @@ internal sealed class ILEmitResolverBuilder : CallSiteVisitor<ILEmitResolverBuil
 
         private sealed class ILEmitResolverBuilderRuntimeContext
         {
-            public IServiceScopeFactory ScopeFactory;
             public object[] Constants;
             public Func<IServiceProvider, object>[] Factories;
         }
@@ -38,39 +37,21 @@ private struct GeneratedMethod
             public DynamicMethod DynamicMethod;
         }
 
-        private readonly CallSiteRuntimeResolver _runtimeResolver;
-
-        private readonly IServiceScopeFactory _serviceScopeFactory;
-
         private readonly ServiceProviderEngineScope _rootScope;
 
         private readonly ConcurrentDictionary<ServiceCacheKey, GeneratedMethod> _scopeResolverCache;
 
         private readonly Func<ServiceCacheKey, ServiceCallSite, GeneratedMethod> _buildTypeDelegate;
 
-        public ILEmitResolverBuilder(CallSiteRuntimeResolver runtimeResolver, IServiceScopeFactory serviceScopeFactory, ServiceProviderEngineScope rootScope) :
-            base()
+        public ILEmitResolverBuilder(ServiceProvider serviceProvider)
         {
-            if (runtimeResolver == null)
-            {
-                throw new ArgumentNullException(nameof(runtimeResolver));
-            }
-            _runtimeResolver = runtimeResolver;
-            _serviceScopeFactory = serviceScopeFactory;
-            _rootScope = rootScope;
+            _rootScope = serviceProvider.Root;
             _scopeResolverCache = new ConcurrentDictionary<ServiceCacheKey, GeneratedMethod>();
             _buildTypeDelegate = (key, cs) => BuildTypeNoCache(cs);
         }
 
         public Func<ServiceProviderEngineScope, object> Build(ServiceCallSite callSite)
         {
-            // Optimize singleton case
-            if (callSite.Cache.Location == CallSiteResultCacheLocation.Root)
-            {
-                object value = _runtimeResolver.Resolve(callSite, _rootScope);
-                return scope => value;
-            }
-
             return BuildType(callSite).Lambda;
         }
 
@@ -166,7 +147,7 @@ protected override object VisitConstructor(ConstructorCallSite constructorCallSi
 
         protected override object VisitRootCache(ServiceCallSite callSite, ILEmitResolverBuilderContext argument)
         {
-            AddConstant(argument, _runtimeResolver.Resolve(callSite, _rootScope));
+            AddConstant(argument, CallSiteRuntimeResolver.Instance.Resolve(callSite, _rootScope));
             return null;
         }
 
@@ -205,9 +186,7 @@ protected override object VisitServiceProvider(ServiceProviderCallSite servicePr
 
         protected override object VisitServiceScopeFactory(ServiceScopeFactoryCallSite serviceScopeFactoryCallSite, ILEmitResolverBuilderContext argument)
         {
-            // this.ScopeFactory
-            argument.Generator.Emit(OpCodes.Ldarg_0);
-            argument.Generator.Emit(OpCodes.Ldfld, typeof(ILEmitResolverBuilderRuntimeContext).GetField(nameof(ILEmitResolverBuilderRuntimeContext.ScopeFactory)));
+            AddConstant(argument, serviceScopeFactoryCallSite.Value);
             return null;
         }
 
@@ -426,8 +405,7 @@ private ILEmitResolverBuilderRuntimeContext GenerateMethodBody(ServiceCallSite c
             return new ILEmitResolverBuilderRuntimeContext
             {
                 Constants = context.Constants?.ToArray(),
-                Factories = context.Factories?.ToArray(),
-                ScopeFactory = _serviceScopeFactory
+                Factories = context.Factories?.ToArray()
             };
         }
 

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/ILEmit/ILEmitServiceProviderEngine.cs

@@ -2,23 +2,20 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
-using System.Collections.Generic;
 
 namespace Microsoft.Extensions.DependencyInjection.ServiceLookup
 {
     internal sealed class ILEmitServiceProviderEngine : ServiceProviderEngine
     {
         private readonly ILEmitResolverBuilder _expressionResolverBuilder;
-        public ILEmitServiceProviderEngine(IEnumerable<ServiceDescriptor> serviceDescriptors) : base(serviceDescriptors)
+        public ILEmitServiceProviderEngine(ServiceProvider serviceProvider)
         {
-            _expressionResolverBuilder = new ILEmitResolverBuilder(RuntimeResolver, this, Root);
+            _expressionResolverBuilder = new ILEmitResolverBuilder(serviceProvider);
         }
 
-        protected override Func<ServiceProviderEngineScope, object> RealizeService(ServiceCallSite callSite)
+        public override Func<ServiceProviderEngineScope, object> RealizeService(ServiceCallSite callSite)
         {
-            Func<ServiceProviderEngineScope, object> realizedService = _expressionResolverBuilder.Build(callSite);
-            RealizedServices[callSite.ServiceType] = realizedService;
-            return realizedService;
+            return _expressionResolverBuilder.Build(callSite);
         }
     }
 }