Fix | Load and resolve retry logic providers into the current AssemblyLoadContext

src/Microsoft.Data.SqlClient.slnx

@@ -175,6 +175,10 @@
     <Project Path="Microsoft.SqlServer.Server/Microsoft.SqlServer.Server.csproj" />
   </Folder>
   <Folder Name="/test/">
+    <Project Path="Microsoft.Data.SqlClient/tests/UnloadableLibrary/UnloadableLibrary.csproj">
+	  <Platform Solution="*|x64" Project="x64" />
+      <Platform Solution="*|x86" Project="x86" />
+	</Project>
     <Project Path="Microsoft.Data.SqlClient/tests/Common/Microsoft.Data.SqlClient.TestCommon.csproj">
       <Platform Solution="*|x64" Project="x64" />
       <Platform Solution="*|x86" Project="x86" />

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/Reliability/SqlConfigurableRetryLogicLoader.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -357,28 +357,30 @@ internal sealed class AssemblyResolutionSubscription : IDisposable
         {
             #if NET
             private bool _isSubscribed;
+            private readonly AssemblyLoadContext _currentAssemblyLoadContext;
             #endif
 
             internal AssemblyResolutionSubscription(bool subscribe)
             {
-            #if NET
+                #if NET
                 if (subscribe)
                 {
-                    AssemblyLoadContext.Default.Resolving += Default_Resolving;
+                    _currentAssemblyLoadContext = AssemblyLoadContext.GetLoadContext(Assembly.GetExecutingAssembly());
+                    _currentAssemblyLoadContext?.Resolving += Default_Resolving;
                     _isSubscribed = true;
                 }
-            #endif
+                #endif
             }
 
             public void Dispose()
             {
-            #if NET
+                #if NET
                 if (_isSubscribed)
                 {
-                    AssemblyLoadContext.Default.Resolving -= Default_Resolving;
+                    _currentAssemblyLoadContext?.Resolving -= Default_Resolving;
                     _isSubscribed = false;
                 }
-            #endif
+                #endif
             }
         }
 
@@ -399,10 +401,11 @@ private static Assembly AssemblyResolver(AssemblyName arg)
             string methodName = nameof(AssemblyResolver);
 
             string fullPath = MakeFullPath(ProbingDirectory, arg.Name);
+            AssemblyLoadContext currentAlc = AssemblyLoadContext.GetLoadContext(Assembly.GetExecutingAssembly());
             SqlClientEventSource.Log.TryTraceEvent("<sc.{0}.{1}|INFO> Looking for '{2}' assembly by '{3}' full path."
                 , TypeName, methodName, arg, fullPath);
 
-            return fullPath == null ? null : AssemblyLoadContext.Default.LoadFromAssemblyPath(fullPath);
+            return fullPath != null && currentAlc != null ? currentAlc.LoadFromAssemblyPath(fullPath) : null;
         }
 
         /// <summary>
@@ -411,8 +414,8 @@ private static Assembly AssemblyResolver(AssemblyName arg)
         /// <remarks>
         /// This handler is only subscribed while a configured retry logic provider is being
         /// resolved and constructed, and only when a custom retry logic type has been configured.
-        /// It must not remain subscribed to <see cref="AssemblyLoadContext.Default"/> after that,
-        /// because doing so changes assembly resolution behavior for the entire application.
+        /// It must not remain subscribed to the calling <see cref="AssemblyLoadContext"/> after that,
+        /// because doing so can change assembly resolution behavior for the entire application.
         /// </remarks>
         private static Assembly Default_Resolving(AssemblyLoadContext arg1, AssemblyName arg2)
         {
@@ -426,8 +429,8 @@ private static Assembly Default_Resolving(AssemblyLoadContext arg1, AssemblyName
         }
 
         /// <summary>
-        /// Performs a case-sensitive search to resolve the specified type name 
-        /// and its related assemblies in default assembly load context if they aren't loaded yet.
+        /// Performs a case-sensitive search to resolve the specified type name and its related
+        /// assemblies in the calling assembly load context if they aren't loaded yet.
         /// </summary>
         /// <returns>Resolved type if it could resolve the type; otherwise, the `SqlConfigurableRetryFactory` type.</returns>
         private static Type LoadType(string fullyQualifiedName)

src/Microsoft.Data.SqlClient/tests/Common/ConfigurableRetryLogic/RetryLogicConfigs.cs

@@ -0,0 +1,53 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.Data.SqlClient.Tests.Common.ConfigurableRetryLogic;
+
+/// <summary>
+/// Transport object for retry logic configuration parameters. This is used to pass
+/// values which would ordinarily be part of the SqlConfigurableRetryLogicConnection
+/// or SqlConfigurableRetryLogicCommand section to <see cref="RetryLogicLoaderHelper.CreateLoader"/>
+/// </summary>
+public sealed class RetryLogicConfigs
+{
+    /// <summary>
+    /// Equivalent of the deltaTime value in an app.config file.
+    /// </summary>
+    public TimeSpan DeltaTime { get; set; }
+
+    /// <summary>
+    /// Equivalent of the maxTime value in an app.config file.
+    /// </summary>
+    public TimeSpan MaxTimeInterval { get; set; }
+
+    /// <summary>
+    /// Equivalent of the minTime value in an app.config file.
+    /// </summary>
+    public TimeSpan MinTimeInterval { get; set; }
+
+    /// <summary>
+    /// Equivalent of the numberOfTries value in an app.config file.
+    /// </summary>
+    public int NumberOfTries { get; set; }
+
+    /// <summary>
+    /// Equivalent of the transientErrors value in an app.config file.
+    /// </summary>
+    public string? TransientErrors { get; set; }
+
+    /// <summary>
+    /// Equivalent of the authorizedSqlCondition value in an app.config file.
+    /// </summary>
+    public string? AuthorizedSqlCondition { get; set; }
+
+    /// <summary>
+    /// Equivalent of the retryLogicType value in an app.config file.
+    /// </summary>
+    public string? RetryLogicType { get; set; }
+
+    /// <summary>
+    /// Equivalent of the retryMethod value in an app.config file.
+    /// </summary>
+    public string? RetryMethodName { get; set; }
+}

src/Microsoft.Data.SqlClient/tests/Common/ConfigurableRetryLogic/RetryLogicLoaderHelper.cs

@@ -0,0 +1,128 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Reflection;
+
+namespace Microsoft.Data.SqlClient.Tests.Common.ConfigurableRetryLogic;
+
+/// <summary>
+/// Contains helper methods for creating and configuring instances of
+/// SqlConfigurableRetryLogicLoader and its associated configuration objects without needing
+/// to populate an app.config file.
+/// </summary>
+public static class RetryLogicLoaderHelper
+{
+    private const string ConfigurationLoaderTypeName = "Microsoft.Data.SqlClient.SqlConfigurableRetryLogicLoader";
+    private const string InterfaceCnnCfgTypeName = "Microsoft.Data.SqlClient.ISqlConfigurableRetryConnectionSection";
+    private const string InterfaceCmdCfgTypeName = "Microsoft.Data.SqlClient.ISqlConfigurableRetryCommandSection";
+    private const string CnnCfgTypeName = "Microsoft.Data.SqlClient.SqlConfigurableRetryConnectionSection";
+    private const string CmdCfgTypeName = "Microsoft.Data.SqlClient.SqlConfigurableRetryCommandSection";
+    private const string DefaultTransientErrors = "1204, 1205, 1222, 49918, 49919, 49920, 4060, 4221, 40143, 40613, 40501, 40540, 40197, 42108, 42109, 10929, 10928, 10060, 10054, 10053, 997, 233, 64, 20, 0, -2, 207, 102, 2812";
+
+    private static readonly Random s_random = new();
+
+    private static readonly Assembly s_sqlClientAssembly = typeof(SqlConnection).Assembly;
+    private static readonly Type s_configurationLoaderType = s_sqlClientAssembly.GetType(ConfigurationLoaderTypeName)!;
+    private static readonly Type s_interfaceCnnCfgType = s_sqlClientAssembly.GetType(InterfaceCnnCfgTypeName)!;
+    private static readonly Type s_interfaceCmdCfgType = s_sqlClientAssembly.GetType(InterfaceCmdCfgTypeName)!;
+    private static readonly Type s_cnnCfgType = s_sqlClientAssembly.GetType(CnnCfgTypeName)!;
+    private static readonly Type s_cmdCfgType = s_sqlClientAssembly.GetType(CmdCfgTypeName)!;
+
+    private static readonly Type[] s_cfgLoaderParamsType =
+        [
+            s_interfaceCnnCfgType,
+            s_interfaceCmdCfgType,
+            typeof(string), typeof(string)
+        ];
+    private static readonly ConstructorInfo s_loaderCtorInfo = s_configurationLoaderType.GetConstructor(s_cfgLoaderParamsType)!;
+
+    /// <summary>
+    /// Creates and returns an instance of SqlConfigurableRetryLogicLoader with the specified
+    /// connection and command retry logic configurations.
+    /// </summary>
+    /// <param name="cnnConfig">The configuration for the connection retry logic.</param>
+    /// <param name="cmdConfig">The configuration for the command retry logic.</param>
+    /// <returns>The created loader instance.</returns>
+    public static object CreateLoader(RetryLogicConfigs cnnConfig, RetryLogicConfigs cmdConfig)
+    {
+        object cnnCfgObj = Activator.CreateInstance(s_cnnCfgType)!;
+        SetValue(cnnCfgObj, s_cnnCfgType, "DeltaTime", cnnConfig.DeltaTime);
+        SetValue(cnnCfgObj, s_cnnCfgType, "MinTimeInterval", cnnConfig.MinTimeInterval);
+        SetValue(cnnCfgObj, s_cnnCfgType, "MaxTimeInterval", cnnConfig.MaxTimeInterval);
+        SetValue(cnnCfgObj, s_cnnCfgType, "NumberOfTries", cnnConfig.NumberOfTries);
+        SetValue(cnnCfgObj, s_cnnCfgType, "AuthorizedSqlCondition", cnnConfig.AuthorizedSqlCondition);
+        SetValue(cnnCfgObj, s_cnnCfgType, "TransientErrors", cnnConfig.TransientErrors);
+        SetValue(cnnCfgObj, s_cnnCfgType, "RetryLogicType", cnnConfig.RetryLogicType);
+        SetValue(cnnCfgObj, s_cnnCfgType, "RetryMethod", cnnConfig.RetryMethodName);
+
+        object cmdCfgObj = Activator.CreateInstance(s_cmdCfgType)!;
+        SetValue(cmdCfgObj, s_cmdCfgType, "DeltaTime", cmdConfig.DeltaTime);
+        SetValue(cmdCfgObj, s_cmdCfgType, "MinTimeInterval", cmdConfig.MinTimeInterval);
+        SetValue(cmdCfgObj, s_cmdCfgType, "MaxTimeInterval", cmdConfig.MaxTimeInterval);
+        SetValue(cmdCfgObj, s_cmdCfgType, "NumberOfTries", cmdConfig.NumberOfTries);
+        SetValue(cmdCfgObj, s_cmdCfgType, "AuthorizedSqlCondition", cmdConfig.AuthorizedSqlCondition);
+        SetValue(cmdCfgObj, s_cmdCfgType, "TransientErrors", cmdConfig.TransientErrors);
+        SetValue(cmdCfgObj, s_cmdCfgType, "RetryLogicType", cmdConfig.RetryLogicType);
+        SetValue(cmdCfgObj, s_cmdCfgType, "RetryMethod", cmdConfig.RetryMethodName);
+
+        return s_loaderCtorInfo.Invoke([cnnCfgObj, cmdCfgObj, default!, default!]);
+    }
+
+    /// <summary>
+    /// Creates and returns an instance of SqlConfigurableRetryLogicLoader with the specified
+    /// connection and command retry logic configurations, and also retrieves the associated
+    /// connection and command providers.
+    /// </summary>
+    /// <param name="cnnCfg">The configuration for the connection retry logic.</param>
+    /// <param name="cmdCfg">The configuration for the command retry logic.</param>
+    /// <param name="cnnProvider">When this method returns, contains the connection provider.</param>
+    /// <param name="cmdProvider">When this method returns, contains the command provider.</param>
+    /// <returns>The created loader instance.</returns>
+    public static object ReturnLoaderAndProviders(RetryLogicConfigs cnnCfg, RetryLogicConfigs cmdCfg, out SqlRetryLogicBaseProvider cnnProvider, out SqlRetryLogicBaseProvider cmdProvider)
+    {
+        object loaderObj = CreateLoader(cnnCfg, cmdCfg);
+
+        cnnProvider = GetValue<SqlRetryLogicBaseProvider>(loaderObj, s_configurationLoaderType, "ConnectionProvider");
+        cmdProvider = GetValue<SqlRetryLogicBaseProvider>(loaderObj, s_configurationLoaderType, "CommandProvider");
+        return loaderObj;
+    }
+
+    /// <summary>
+    /// Creates a RetryLogicConfigs object with random values for its properties, optionally specifying
+    /// default values for certain mandatory properties.
+    /// </summary>
+    /// <param name="method">The retry method to use.</param>
+    /// <param name="authorizedSqlCondition">The authorized SQL condition.</param>
+    /// <param name="transientErrors">The transient errors.</param>
+    /// <returns>The created retry logic configuration.</returns>
+    public static RetryLogicConfigs CreateRandomConfig(string? method, string? authorizedSqlCondition = null, string transientErrors = DefaultTransientErrors)
+    {
+        TimeSpan start = TimeSpan.Zero;
+        TimeSpan end = TimeSpan.FromSeconds(60);
+        TimeSpan min = GenerateTimeSpan(start, end);
+
+        return new RetryLogicConfigs()
+        {
+            DeltaTime = GenerateTimeSpan(start, end),
+            MinTimeInterval = min,
+            MaxTimeInterval = GenerateTimeSpan(min, end),
+            NumberOfTries = s_random.Next(1, 60),
+            AuthorizedSqlCondition = authorizedSqlCondition,
+            TransientErrors = transientErrors,
+            RetryMethodName = method
+        };
+    }
+
+    private static T GetValue<T>(object obj, Type type, string propName, BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance) =>
+        (T)type.GetProperty(propName, flags)?.GetValue(obj)!;
+
+    private static void SetValue<T>(object obj, Type type, string propName, T value, BindingFlags flags = BindingFlags.Public | BindingFlags.Instance) =>
+        type.GetProperty(propName, flags)?.SetValue(obj, value);
+
+    private static TimeSpan GenerateTimeSpan(TimeSpan start, TimeSpan end)
+    {
+        int max = (int)(end - start).TotalSeconds;
+        return start.Add(TimeSpan.FromSeconds(s_random.Next(max)));
+    }
+}

src/Microsoft.Data.SqlClient/tests/FunctionalTests/SqlConfigurableRetryLogicTest.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -86,11 +86,10 @@ public void ValidateRetryParameters()
 #if NET
         /// <summary>
         /// Regression test: triggering the configurable retry logic loader through its normal
-        /// entry points must not leave a process-wide
-        /// <see cref="System.Runtime.Loader.AssemblyLoadContext.Default"/> resolving handler
-        /// installed. Such a handler participates in resolution of every assembly the host
-        /// application fails to find, and serves them out of this component's probing directory,
-        /// which can load code from an unintended location.
+        /// entry points must not leave a resolving handler subscribed to the current
+        /// <see cref="System.Runtime.Loader.AssemblyLoadContext" />. Such a handler participates
+        /// in resolution of every assembly the host application fails to find, and serves them
+        /// out of this component's probing directory, which can load code from an unintended location.
         /// </summary>
         [Fact]
         public void RetryLogicProviderDoesNotLeaveAssemblyProbingEnabled()

src/Microsoft.Data.SqlClient/tests/ManualTests/Microsoft.Data.SqlClient.ManualTests.csproj

@@ -103,6 +103,7 @@
 
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/Common/Microsoft.Data.SqlClient.TestCommon.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/CustomConfigurableRetryLogic/CustomRetryLogicProvider.csproj" />
+    <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/UnloadableLibrary/UnloadableLibrary.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/TestUdts/Address/Address.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/TestUdts/Circle/Circle.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/TestUdts/Shapes/Shapes.csproj" />
@@ -134,6 +135,7 @@
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/TestUdts/Shapes/Shapes.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/TestUdts/Utf8String/Utf8String.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/CustomConfigurableRetryLogic/CustomRetryLogicProvider.csproj" />
+    <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/UnloadableLibrary/UnloadableLibrary.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/tools/Microsoft.Data.SqlClient.TestUtilities/Microsoft.Data.SqlClient.TestUtilities.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/tools/TDS/TDS/TDS.csproj" />
     <ProjectReference Include="$(RepoRoot)src/Microsoft.Data.SqlClient/tests/tools/TDS/TDS.EndPoint/TDS.EndPoint.csproj" />