Final PRs and fix gRPC-Web on v2.54.x

global.json

@@ -1,5 +1,6 @@
 {
   "sdk": {
-    "version": "7.0.201"
+    "version": "7.0.201",
+    "rollForward": "latestFeature"
   }
 }

src/Grpc.AspNetCore.Server/Grpc.AspNetCore.Server.csproj

@@ -30,6 +30,7 @@
     <Compile Include="..\Shared\Server\UnaryServerMethodInvoker.cs" Link="Model\Internal\UnaryServerMethodInvoker.cs" />
     <Compile Include="..\Shared\NullableAttributes.cs" Link="Internal\NullableAttributes.cs" />
     <Compile Include="..\Shared\CodeAnalysisAttributes.cs" Link="Internal\CodeAnalysisAttributes.cs" />
+    <Compile Include="..\Shared\NonCapturingTimer.cs" Link="Internal\NonCapturingTimer.cs" />
   </ItemGroup>
 
   <ItemGroup>

src/Grpc.AspNetCore.Server/Internal/ServerCallDeadlineManager.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -91,12 +91,12 @@ public ServerCallDeadlineManager(HttpContextServerCallContext serverCallContext,
             // Ensures there is no weird situation where the timer triggers
             // before the field is set. Shouldn't happen because only long deadlines
             // will take this path but better to be safe than sorry.
-            _longDeadlineTimer = new Timer(DeadlineExceededLongDelegate, (this, maxTimerDueTime), Timeout.Infinite, Timeout.Infinite);
+            _longDeadlineTimer = NonCapturingTimer.Create(DeadlineExceededLongDelegate, (this, maxTimerDueTime), Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
             _longDeadlineTimer.Change(timerMilliseconds, Timeout.Infinite);
         }
         else
         {
-            _longDeadlineTimer = new Timer(DeadlineExceededDelegate, this, timerMilliseconds, Timeout.Infinite);
+            _longDeadlineTimer = NonCapturingTimer.Create(DeadlineExceededDelegate, this, TimeSpan.FromMilliseconds(timerMilliseconds), Timeout.InfiniteTimeSpan);
         }
     }
 

src/Grpc.Net.Client/Balancer/BalancerAttributes.cs

@@ -17,6 +17,7 @@
 #endregion
 
 #if SUPPORT_LOAD_BALANCING
+using System.Collections;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics.CodeAnalysis;
@@ -29,7 +30,7 @@ namespace Grpc.Net.Client.Balancer;
 /// Note: Experimental API that can change or be removed without any prior notice.
 /// </para>
 /// </summary>
-public sealed class BalancerAttributes : IDictionary<string, object?>
+public sealed class BalancerAttributes : IDictionary<string, object?>, IReadOnlyDictionary<string, object?>
 {
     /// <summary>
     /// Gets a read-only collection of metadata attributes.
@@ -61,22 +62,28 @@ private BalancerAttributes(IDictionary<string, object?> attributes)
             _attributes[key] = value;
         }
     }
+
     ICollection<string> IDictionary<string, object?>.Keys => _attributes.Keys;
     ICollection<object?> IDictionary<string, object?>.Values => _attributes.Values;
     int ICollection<KeyValuePair<string, object?>>.Count => _attributes.Count;
-    bool ICollection<KeyValuePair<string, object?>>.IsReadOnly => ((IDictionary<string, object?>)_attributes).IsReadOnly;
+    bool ICollection<KeyValuePair<string, object?>>.IsReadOnly => _attributes.IsReadOnly;
+    IEnumerable<string> IReadOnlyDictionary<string, object?>.Keys => _attributes.Keys;
+    IEnumerable<object?> IReadOnlyDictionary<string, object?>.Values => _attributes.Values;
+    int IReadOnlyCollection<KeyValuePair<string, object?>>.Count => _attributes.Count;
+    object? IReadOnlyDictionary<string, object?>.this[string key] => _attributes[key];
     void IDictionary<string, object?>.Add(string key, object? value) => _attributes.Add(key, value);
-    void ICollection<KeyValuePair<string, object?>>.Add(KeyValuePair<string, object?> item) => ((IDictionary<string, object?>)_attributes).Add(item);
+    void ICollection<KeyValuePair<string, object?>>.Add(KeyValuePair<string, object?> item) => _attributes.Add(item);
     void ICollection<KeyValuePair<string, object?>>.Clear() => _attributes.Clear();
-    bool ICollection<KeyValuePair<string, object?>>.Contains(KeyValuePair<string, object?> item) => ((IDictionary<string, object?>)_attributes).Contains(item);
+    bool ICollection<KeyValuePair<string, object?>>.Contains(KeyValuePair<string, object?> item) => _attributes.Contains(item);
     bool IDictionary<string, object?>.ContainsKey(string key) => _attributes.ContainsKey(key);
-    void ICollection<KeyValuePair<string, object?>>.CopyTo(KeyValuePair<string, object?>[] array, int arrayIndex) =>
-        ((IDictionary<string, object?>)_attributes).CopyTo(array, arrayIndex);
+    void ICollection<KeyValuePair<string, object?>>.CopyTo(KeyValuePair<string, object?>[] array, int arrayIndex) => _attributes.CopyTo(array, arrayIndex);
     IEnumerator<KeyValuePair<string, object?>> IEnumerable<KeyValuePair<string, object?>>.GetEnumerator() => _attributes.GetEnumerator();
-    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => ((System.Collections.IEnumerable)_attributes).GetEnumerator();
+    IEnumerator System.Collections.IEnumerable.GetEnumerator() => ((System.Collections.IEnumerable)_attributes).GetEnumerator();
     bool IDictionary<string, object?>.Remove(string key) => _attributes.Remove(key);
-    bool ICollection<KeyValuePair<string, object?>>.Remove(KeyValuePair<string, object?> item) => ((IDictionary<string, object?>)_attributes).Remove(item);
+    bool ICollection<KeyValuePair<string, object?>>.Remove(KeyValuePair<string, object?> item) => _attributes.Remove(item);
     bool IDictionary<string, object?>.TryGetValue(string key, out object? value) => _attributes.TryGetValue(key, out value);
+    bool IReadOnlyDictionary<string, object?>.ContainsKey(string key) => _attributes.ContainsKey(key);
+    bool IReadOnlyDictionary<string, object?>.TryGetValue(string key, out object? value) => _attributes.TryGetValue(key, out value);
 
     /// <summary>
     /// Gets the value associated with the specified key.

src/Grpc.Net.Client/Balancer/DnsResolver.cs

@@ -68,7 +68,7 @@ protected override void OnStarted()
 
         if (_refreshInterval != Timeout.InfiniteTimeSpan)
         {
-            _timer = new Timer(OnTimerCallback, null, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
+            _timer = NonCapturingTimer.Create(OnTimerCallback, state: null, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
             _timer.Change(_refreshInterval, _refreshInterval);
         }
     }

src/Grpc.Net.Client/Balancer/Internal/SocketConnectivitySubchannelTransport.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -77,7 +77,7 @@ public SocketConnectivitySubchannelTransport(
         ConnectTimeout = connectTimeout;
         _socketConnect = socketConnect ?? OnConnect;
         _activeStreams = new List<ActiveStream>();
-        _socketConnectedTimer = new Timer(OnCheckSocketConnection, state: null, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
+        _socketConnectedTimer = NonCapturingTimer.Create(OnCheckSocketConnection, state: null, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan);
     }
 
     private object Lock => _subchannel.Lock;

src/Grpc.Net.Client/Balancer/PollingResolver.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -86,7 +86,7 @@ protected PollingResolver(ILoggerFactory loggerFactory, IBackoffPolicyFactory? b
     /// </para>
     /// </summary>
     /// <param name="listener">The callback used to receive updates on the target.</param>
-    public override sealed void Start(Action<ResolverResult> listener)
+    public sealed override void Start(Action<ResolverResult> listener)
     {
         if (listener == null)
         {

src/Grpc.Net.Client/Balancer/Subchannel.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -233,7 +233,21 @@ public void RequestConnection()
             }
         }
 
-        _ = ConnectTransportAsync();
+        // Don't capture the current ExecutionContext and its AsyncLocals onto the connect
+        bool restoreFlow = false;
+        if (!ExecutionContext.IsFlowSuppressed())
+        {
+            ExecutionContext.SuppressFlow();
+            restoreFlow = true;
+        }
+
+        _ = Task.Run(ConnectTransportAsync);
+
+        // Restore the current ExecutionContext
+        if (restoreFlow)
+        {
+            ExecutionContext.RestoreFlow();
+        }
     }
 
     private void CancelInProgressConnect()

src/Grpc.Net.Client/Grpc.Net.Client.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <Description>.NET client for gRPC</Description>
@@ -35,6 +35,7 @@
     <Compile Include="..\Shared\NullableAttributes.cs" Link="Internal\NullableAttributes.cs" />
     <Compile Include="..\Shared\Http2ErrorCode.cs" Link="Internal\Http2ErrorCode.cs" />
     <Compile Include="..\Shared\Http3ErrorCode.cs" Link="Internal\Http3ErrorCode.cs" />
+    <Compile Include="..\Shared\NonCapturingTimer.cs" Link="Internal\NonCapturingTimer.cs" />
     <Compile Include="..\Shared\NonDisposableMemoryStream.cs" Link="Internal\NonDisposableMemoryStream.cs" />
   </ItemGroup>
 

src/Grpc.Net.Client/GrpcChannel.cs

@@ -54,8 +54,7 @@ public sealed class GrpcChannel : ChannelBase, IDisposable
     private readonly Dictionary<MethodKey, MethodConfig>? _serviceConfigMethods;
     private readonly bool _isSecure;
     private readonly List<CallCredentials>? _callCredentials;
-    // Internal for testing
-    internal readonly HashSet<IDisposable> ActiveCalls;
+    private readonly HashSet<IDisposable> _activeCalls;
 
     internal Uri Address { get; }
     internal HttpMessageInvoker HttpInvoker { get; }
@@ -165,7 +164,7 @@ internal GrpcChannel(Uri address, GrpcChannelOptions channelOptions) : base(addr
         ThrowOperationCanceledOnCancellation = channelOptions.ThrowOperationCanceledOnCancellation;
         UnsafeUseInsecureChannelCallCredentials = channelOptions.UnsafeUseInsecureChannelCallCredentials;
         _createMethodInfoFunc = CreateMethodInfo;
-        ActiveCalls = new HashSet<IDisposable>();
+        _activeCalls = new HashSet<IDisposable>();
         if (channelOptions.ServiceConfig is { } serviceConfig)
         {
             RetryThrottling = serviceConfig.RetryThrottling != null ? CreateChannelRetryThrottling(serviceConfig.RetryThrottling) : null;
@@ -490,15 +489,15 @@ internal void RegisterActiveCall(IDisposable grpcCall)
                 throw new ObjectDisposedException(nameof(GrpcChannel));
             }
 
-            ActiveCalls.Add(grpcCall);
+            _activeCalls.Add(grpcCall);
         }
     }
 
     internal void FinishActiveCall(IDisposable grpcCall)
     {
         lock (_lock)
         {
-            ActiveCalls.Remove(grpcCall);
+            _activeCalls.Remove(grpcCall);
         }
     }
 
@@ -749,9 +748,9 @@ public void Dispose()
                 return;
             }
 
-            if (ActiveCalls.Count > 0)
+            if (_activeCalls.Count > 0)
             {
-                activeCallsCopy = ActiveCalls.ToArray();
+                activeCallsCopy = _activeCalls.ToArray();
             }
 
             Disposed = true;
@@ -807,6 +806,15 @@ internal int GetRandomNumber(int minValue, int maxValue)
         }
     }
 
+    // Internal for testing
+    internal IDisposable[] GetActiveCalls()
+    {
+        lock (_lock)
+        {
+            return _activeCalls.ToArray();
+        }
+    }
+
 #if SUPPORT_LOAD_BALANCING
     private sealed class SubChannelTransportFactory : ISubchannelTransportFactory
     {

src/Grpc.Net.Client/Internal/GrpcCall.cs

@@ -838,7 +838,7 @@ public Exception CreateFailureStatusException(Status status)
                 GrpcCallLog.StartingDeadlineTimeout(Logger, timeout.Value);
 
                 var dueTime = CommonGrpcProtocolHelpers.GetTimerDueTime(timeout.Value, Channel.MaxTimerDueTime);
-                _deadlineTimer = new Timer(DeadlineExceededCallback, null, dueTime, Timeout.Infinite);
+                _deadlineTimer = NonCapturingTimer.Create(DeadlineExceededCallback, state: null, TimeSpan.FromMilliseconds(dueTime), Timeout.InfiniteTimeSpan);
             }
         }
 

src/Shared/NonCapturingTimer.cs

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Grpc.Shared;
+
+// A convenience API for interacting with System.Threading.Timer in a way
+// that doesn't capture the ExecutionContext. We should be using this (or equivalent)
+// everywhere we use timers to avoid rooting any values stored in asynclocals.
+internal static class NonCapturingTimer
+{
+    public static Timer Create(TimerCallback callback, object? state, TimeSpan dueTime, TimeSpan period)
+    {
+        if (callback is null)
+        {
+            throw new ArgumentNullException(nameof(callback));
+        }
+
+        // Don't capture the current ExecutionContext and its AsyncLocals onto the timer
+        bool restoreFlow = false;
+        try
+        {
+            if (!ExecutionContext.IsFlowSuppressed())
+            {
+                ExecutionContext.SuppressFlow();
+                restoreFlow = true;
+            }
+
+            return new Timer(callback, state, dueTime, period);
+        }
+        finally
+        {
+            // Restore the current ExecutionContext
+            if (restoreFlow)
+            {
+                ExecutionContext.RestoreFlow();
+            }
+        }
+    }
+}

test/FunctionalTests/Balancer/BalancerHelpers.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -185,74 +185,6 @@ public static async Task<GrpcChannel> CreateChannel(
         return channel;
     }
 
-    public static Task WaitForChannelStateAsync(ILogger logger, GrpcChannel channel, ConnectivityState state, int channelId = 1)
-    {
-        return WaitForChannelStatesAsync(logger, channel, new[] { state }, channelId);
-    }
-
-    public static async Task WaitForChannelStatesAsync(ILogger logger, GrpcChannel channel, ConnectivityState[] states, int channelId = 1)
-    {
-        var statesText = string.Join(", ", states.Select(s => $"'{s}'"));
-        logger.LogInformation($"Channel id {channelId}: Waiting for channel states {statesText}.");
-
-        var currentState = channel.State;
-
-        while (!states.Contains(currentState))
-        {
-            logger.LogInformation($"Channel id {channelId}: Current channel state '{currentState}' doesn't match expected states {statesText}.");
-
-            await channel.WaitForStateChangedAsync(currentState).DefaultTimeout();
-            currentState = channel.State;
-        }
-
-        logger.LogInformation($"Channel id {channelId}: Current channel state '{currentState}' matches expected states {statesText}.");
-    }
-
-    public static async Task<Subchannel> WaitForSubchannelToBeReadyAsync(ILogger logger, GrpcChannel channel, Func<SubchannelPicker?, Subchannel[]>? getPickerSubchannels = null)
-    {
-        var subChannel = (await WaitForSubchannelsToBeReadyAsync(logger, channel, 1)).Single();
-        return subChannel;
-    }
-
-    public static async Task<Subchannel[]> WaitForSubchannelsToBeReadyAsync(ILogger logger, GrpcChannel channel, int expectedCount, Func<SubchannelPicker?, Subchannel[]>? getPickerSubchannels = null)
-    {
-        if (getPickerSubchannels == null)
-        {
-            getPickerSubchannels = (picker) =>
-            {
-                return picker switch
-                {
-                    RoundRobinPicker roundRobinPicker => roundRobinPicker._subchannels.ToArray(),
-                    PickFirstPicker pickFirstPicker => new[] { pickFirstPicker.Subchannel },
-                    EmptyPicker emptyPicker => Array.Empty<Subchannel>(),
-                    null => Array.Empty<Subchannel>(),
-                    _ => throw new Exception("Unexpected picker type: " + picker.GetType().FullName)
-                };
-            };
-        }
-
-        logger.LogInformation($"Waiting for subchannel ready count: {expectedCount}");
-
-        Subchannel[]? subChannelsCopy = null;
-        await TestHelpers.AssertIsTrueRetryAsync(() =>
-        {
-            var picker = channel.ConnectionManager._picker;
-            subChannelsCopy = getPickerSubchannels(picker);
-            logger.LogInformation($"Current subchannel ready count: {subChannelsCopy.Length}");
-            for (var i = 0; i < subChannelsCopy.Length; i++)
-            {
-                logger.LogInformation($"Ready subchannel: {subChannelsCopy[i]}");
-            }
-
-            return subChannelsCopy.Length == expectedCount;
-        }, "Wait for all subconnections to be connected.");
-
-        logger.LogInformation($"Finished waiting for subchannel ready.");
-
-        Debug.Assert(subChannelsCopy != null);
-        return subChannelsCopy;
-    }
-
     public static T? GetInnerLoadBalancer<T>(GrpcChannel channel) where T : LoadBalancer
     {
         var balancer = (ChildHandlerLoadBalancer)channel.ConnectionManager._balancer!;

test/FunctionalTests/Balancer/ConnectionTests.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -352,7 +352,7 @@ Task<HelloReply> UnaryMethod(HelloRequest request, ServerCallContext context)
 
         await channel.ConnectAsync().DefaultTimeout();
 
-        await BalancerHelpers.WaitForSubchannelsToBeReadyAsync(Logger, channel, 2).DefaultTimeout();
+        await BalancerWaitHelpers.WaitForSubchannelsToBeReadyAsync(Logger, channel, 2).DefaultTimeout();
 
         var client = TestClientFactory.Create(channel, endpoint1.Method);
 

test/FunctionalTests/Balancer/LeastUsedBalancerTests.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -67,7 +67,7 @@ async Task<HelloReply> UnaryMethod(HelloRequest request, ServerCallContext conte
 
         var channel = await BalancerHelpers.CreateChannel(LoggerFactory, new LoadBalancingConfig("least_used"), new[] { endpoint1.Address, endpoint2.Address }, connect: true);
 
-        await BalancerHelpers.WaitForSubchannelsToBeReadyAsync(
+        await BalancerWaitHelpers.WaitForSubchannelsToBeReadyAsync(
             Logger,
             channel,
             expectedCount: 2,