From 23047e0d498501dc95bb58b010ed3c11f8cb3cf8 Mon Sep 17 00:00:00 2001
From: James Newton-King <james@newtonking.com>
Date: Wed, 16 Nov 2022 15:10:09 +0800
Subject: [PATCH] Change channel transport property to readonly (#1947)

---
 .../Balancer/Internal/ConnectionManager.cs     |  2 +-
 src/Grpc.Net.Client/Balancer/Subchannel.cs     | 18 ++++++++++++------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/Grpc.Net.Client/Balancer/Internal/ConnectionManager.cs b/src/Grpc.Net.Client/Balancer/Internal/ConnectionManager.cs
index 79715adea..ba61330f3 100644
--- a/src/Grpc.Net.Client/Balancer/Internal/ConnectionManager.cs
+++ b/src/Grpc.Net.Client/Balancer/Internal/ConnectionManager.cs
@@ -103,7 +103,7 @@ public void ConfigureBalancer(Func<IChannelControlHelper, LoadBalancer> configur
     Subchannel IChannelControlHelper.CreateSubchannel(SubchannelOptions options)
     {
         var subchannel = new Subchannel(this, options.Addresses);
-        subchannel.Transport = _subchannelTransportFactory.Create(subchannel);
+        subchannel.SetTransport(_subchannelTransportFactory.Create(subchannel));
 
         lock (_subchannels)
         {
diff --git a/src/Grpc.Net.Client/Balancer/Subchannel.cs b/src/Grpc.Net.Client/Balancer/Subchannel.cs
index 9aa1c1b72..7c37d15dd 100644
--- a/src/Grpc.Net.Client/Balancer/Subchannel.cs
+++ b/src/Grpc.Net.Client/Balancer/Subchannel.cs
@@ -46,7 +46,7 @@ public sealed class Subchannel : IDisposable
 {
     internal readonly List<BalancerAddress> _addresses;
     internal readonly object Lock;
-    internal ISubchannelTransport Transport { get; set; } = default!;
+    internal ISubchannelTransport Transport => _transport;
     internal int Id { get; }
 
     /// <summary>
@@ -60,6 +60,7 @@ public sealed class Subchannel : IDisposable
     internal readonly ConnectionManager _manager;
     private readonly ILogger _logger;
 
+    private ISubchannelTransport _transport = default!;
     private ConnectContext? _connectContext;
     private ConnectivityState _state;
     private TaskCompletionSource<object?>? _delayInterruptTcs;
@@ -68,7 +69,7 @@ public sealed class Subchannel : IDisposable
     /// <summary>
     /// Gets the current connected address.
     /// </summary>
-    public BalancerAddress? CurrentAddress => Transport.CurrentAddress;
+    public BalancerAddress? CurrentAddress => _transport.CurrentAddress;
 
     /// <summary>
     /// Gets the metadata attributes.
@@ -88,6 +89,11 @@ internal Subchannel(ConnectionManager manager, IReadOnlyList<BalancerAddress> ad
         SubchannelLog.SubchannelCreated(_logger, Id, addresses);
     }
 
+    internal void SetTransport(ISubchannelTransport transport)
+    {
+        _transport = transport;
+    }
+
     private readonly List<StateChangedRegistration> _stateChangedRegistrations = new List<StateChangedRegistration>();
 
     /// <summary>
@@ -190,7 +196,7 @@ public void UpdateAddresses(IReadOnlyList<BalancerAddress> addresses)
         if (requireReconnect)
         {
             CancelInProgressConnect();
-            Transport.Disconnect();
+            _transport.Disconnect();
             RequestConnection();
         }
     }
@@ -249,7 +255,7 @@ private async Task ConnectTransportAsync()
         // There shouldn't be a previous connect in progress, but cancel the CTS to ensure they're no longer running.
         CancelInProgressConnect();
 
-        var connectContext = _connectContext = new ConnectContext(Transport.ConnectTimeout ?? Timeout.InfiniteTimeSpan);
+        var connectContext = _connectContext = new ConnectContext(_transport.ConnectTimeout ?? Timeout.InfiniteTimeSpan);
 
         var backoffPolicy = _manager.BackoffPolicyFactory.Create();
 
@@ -267,7 +273,7 @@ private async Task ConnectTransportAsync()
                     }
                 }
 
-                if (await Transport.TryConnectAsync(connectContext).ConfigureAwait(false))
+                if (await _transport.TryConnectAsync(connectContext).ConfigureAwait(false))
                 {
                     return;
                 }
@@ -408,7 +414,7 @@ public void Dispose()
         _stateChangedRegistrations.Clear();
 
         CancelInProgressConnect();
-        Transport.Dispose();
+        _transport.Dispose();
     }
 }