Transport: Fix ServicePoint for WebAssembly (#1445)

* Adding accessor

* webassembly too

* Comment

Microsoft.Azure.Cosmos/src/DocumentClient.cs

@@ -1030,7 +1030,7 @@ internal virtual void Initialize(Uri serviceEndpoint,
  this.ConnectionPolicy = connectionPolicy ?? ConnectionPolicy.Default;
 
 #if !NETSTANDARD16
- ServicePoint servicePoint = ServicePointManager.FindServicePoint(this.ServiceEndpoint);
+ ServicePointAccessor servicePoint = ServicePointAccessor.FindServicePoint(this.ServiceEndpoint);
  servicePoint.ConnectionLimit = this.ConnectionPolicy.MaxConnectionLimit;
 #endif
 

Microsoft.Azure.Cosmos/src/Routing/LocationCache.cs

@@ -565,7 +565,7 @@ private bool CanUseMultipleWriteLocations()
  private void SetServicePointConnectionLimit(Uri endpoint)
  {
 #if !NETSTANDARD16
- ServicePoint servicePoint = ServicePointManager.FindServicePoint(endpoint);
+ ServicePointAccessor servicePoint = ServicePointAccessor.FindServicePoint(endpoint);
  servicePoint.ConnectionLimit = this.connectionLimit;
 #endif
  }

Microsoft.Azure.Cosmos/src/Util/ServicePointAccessor.cs

@@ -0,0 +1,57 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation. All rights reserved.
+//------------------------------------------------------------
+
+namespace Microsoft.Azure.Cosmos
+{
+ using System;
+ using System.Net;
+ using System.Runtime.InteropServices;
+ using Microsoft.Azure.Cosmos.Core.Trace;
+
+ /// <summary>
+ /// While ServicePoint is a NETStandard 2.0 API, not all runtimes support the operations and some Framework implementations might not support it.
+ /// </summary>
+ internal class ServicePointAccessor
+ {
+ // WebAssembly detection
+ private static bool IsBrowser = RuntimeInformation.IsOSPlatform(OSPlatform.Create("BROWSER")) || RuntimeInformation.IsOSPlatform(OSPlatform.Create("WEBASSEMBLY"));
+
+ private readonly ServicePoint servicePoint;
+
+ private ServicePointAccessor(ServicePoint servicePoint)
+ {
+ this.servicePoint = servicePoint ?? throw new ArgumentNullException(nameof(servicePoint));
+ }
+
+ internal static ServicePointAccessor FindServicePoint(Uri endpoint)
+ {
+ return new ServicePointAccessor(ServicePointManager.FindServicePoint(endpoint));
+ }
+
+ public int ConnectionLimit
+ {
+ get => this.servicePoint.ConnectionLimit;
+ set => this.TrySetConnectionLimit(value);
+ }
+
+ private void TrySetConnectionLimit(int connectionLimit)
+ {
+ if (ServicePointAccessor.IsBrowser)
+ {
+ // Workaround for WebAssembly.
+ // WebAssembly currently throws a SynchronizationLockException and not a PlatformNotSupportedException.
+ return; 
+ }
+
+ try
+ {
+ this.servicePoint.ConnectionLimit = connectionLimit;
+ }
+ catch (PlatformNotSupportedException)
+ {
+ DefaultTrace.TraceWarning("ServicePoint.set_ConnectionLimit - Platform does not support feature.");
+ }
+ }
+ }
+}

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/ServicePointAccessorTests.cs

@@ -0,0 +1,27 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation. All rights reserved.
+//------------------------------------------------------------
+
+namespace Microsoft.Azure.Cosmos.Tests
+{
+ using System;
+ using System.Net;
+ using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+ [TestClass]
+ public class ServicePointAccessorTests
+ {
+ private static Uri uri = new Uri("https://localhost");
+
+ [TestMethod]
+ public void ServicePointAccessor_SetConnectionLimit()
+ {
+ int limit = 10;
+ ServicePointAccessor accessor = ServicePointAccessor.FindServicePoint(ServicePointAccessorTests.uri);
+ Assert.IsNotNull(accessor);
+ accessor.ConnectionLimit = limit;
+ ServicePoint servicePoint = ServicePointManager.FindServicePoint(ServicePointAccessorTests.uri);
+ Assert.AreEqual(limit, servicePoint.ConnectionLimit);
+ }
+ }
+}