CSHARP-1375: Replaced custom AsyncLock with SemaphoreSlimRequest wrapping a SemaphoreSlim.

Author: rstam

src/MongoDB.Driver.Core.Tests/Core/Async/AsyncLockTests.cs

@@ -52,7 +52,6 @@
     <Reference Include="System.Xml.Linq" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="Core\Async\AsyncLockTests.cs" />
     <Compile Include="Core\Clusters\ElectionIdTests.cs" />
     <Compile Include="Core\Clusters\ReplicaSetConfigTests.cs" />
     <Compile Include="Core\Configuration\ClusterSettingsTests.cs" />

src/MongoDB.Driver.Core.Tests/MongoDB.Driver.Core.Tests.csproj

@@ -52,7 +52,7 @@ internal class BinaryConnection : IConnection
         private DateTime _openedAtUtc;
         private readonly object _openLock = new object();
         private Task _openTask;
-        private readonly AsyncLock _receiveLock;
+        private readonly SemaphoreSlim _receiveLock;
         private readonly SemaphoreSlim _sendLock;
         private readonly ConnectionSettings _settings;
         private readonly InterlockedInt32 _state;
@@ -86,7 +86,7 @@ public BinaryConnection(ServerId serverId, EndPoint endPoint, ConnectionSettings
             _backgroundTaskCancellationToken = _backgroundTaskCancellationTokenSource.Token;
 
             _connectionId = new ConnectionId(serverId);
-            _receiveLock = new AsyncLock();
+            _receiveLock = new SemaphoreSlim(1);
             _sendLock = new SemaphoreSlim(1);
             _state = new InterlockedInt32(State.Initial);
 
@@ -321,7 +321,7 @@ private IByteBuffer ReceiveBuffer()
 
         private IByteBuffer ReceiveBuffer(int responseTo, CancellationToken cancellationToken)
         {
-            using (var receiveLockRequest = _receiveLock.Request(cancellationToken))
+            using (var receiveLockRequest = new SemaphoreSlimRequest(_receiveLock, cancellationToken))
             {
                 var messageTask = _dropbox.GetMessageAsync(responseTo);
                 try
@@ -382,7 +382,7 @@ private async Task<IByteBuffer> ReceiveBufferAsync()
 
         private async Task<IByteBuffer> ReceiveBufferAsync(int responseTo, CancellationToken cancellationToken)
         {
-            using (var receiveLockRequest = _receiveLock.Request(cancellationToken))
+            using (var receiveLockRequest = new SemaphoreSlimRequest(_receiveLock, cancellationToken))
             {
                 var messageTask = _dropbox.GetMessageAsync(responseTo);
                 try