Honor property Maximum pool size per route.

Author: claudiamurialdo

dotnet/src/dotnetframework/GxClasses/Core/gxconfig.cs

@@ -1449,13 +1449,14 @@ internal static bool SingletonHttpClient()
 		{
 			if (singletonHttpClient == -1)
 			{
-				if (Config.GetValueOf("SingletonHttpClient", out string sValue) && int.TryParse(sValue, out int value))
+				if (Config.GetValueOrEnvironmentVarOf("SINGLETON_HTTPCLIENT", out string sValue) && int.TryParse(sValue, out int value))
 					singletonHttpClient = value;
+				else
+					singletonHttpClient = 1;
 			}
 			return singletonHttpClient==1;
-}
-
-	internal static string CorsAllowedOrigins()
+		}
+		internal static string CorsAllowedOrigins()
 		{
 			if (Config.GetValueOf("CORS_ALLOW_ORIGIN", out string corsOrigin))
 				return corsOrigin;
@@ -1504,7 +1505,7 @@ public static int GetHttpClientMaxConnectionPerRoute()
 				try
 				{
 					string strmax;
-					if (Config.GetValueOf("HTTPCLIENT_MAX_PER_ROUTE", out strmax))
+					if (Config.GetValueOrEnvironmentVarOf("HTTPCLIENT_MAX_PER_ROUTE", out strmax))
 					{
 						httpclient_max_per_route = Convert.ToInt32(strmax);
 					}

dotnet/src/dotnetframework/GxClasses/Domain/GxHttpClient.cs

@@ -151,7 +151,7 @@ internal byte[] ReceiveData
 
 #if NETCORE
 		private const int POOLED_CONNECTION_LIFETIME_MINUTES = 2;
-		private static ConcurrentDictionary<string, HttpClient> _httpClientInstances = new ConcurrentDictionary<string, HttpClient>();
+		internal static ConcurrentDictionary<string, HttpClient> _httpClientInstances = new ConcurrentDictionary<string, HttpClient>();
 		private static HttpClient GetHttpClientInstance(Uri URI, int timeout, ArrayList authCollection, ArrayList authProxyCollection, X509Certificate2Collection certificateCollection, List<string> fileCertificateCollection, string proxyHost, int proxyPort, out bool disposableInstance)
 		{
 			if (CacheableInstance(authCollection, authProxyCollection))
@@ -209,8 +209,13 @@ private static SocketsHttpHandler GetHandler(Uri URI, ArrayList authCollection,
 		{
 			SocketsHttpHandler handler = new SocketsHttpHandler()
 			{
-				PooledConnectionLifetime = TimeSpan.FromMinutes(POOLED_CONNECTION_LIFETIME_MINUTES)
+				PooledConnectionLifetime = TimeSpan.FromMinutes(POOLED_CONNECTION_LIFETIME_MINUTES),
 			};
+			int maxConnections = Preferences.GetHttpClientMaxConnectionPerRoute();
+			if (maxConnections != 0)
+			{
+				handler.MaxConnectionsPerServer = maxConnections;
+			}
 			handler.Credentials = getCredentialCache(URI, authCollection);
 
 			if (ServicePointManager.ServerCertificateValidationCallback != null)
@@ -1015,11 +1020,13 @@ public void HttpClientExecute(string method, string name)
 		internal void LoadResponseHeaders(HttpResponseMessage resp)
 		{
 			_respHeaders = new NameValueCollection();
-			foreach (KeyValuePair<string, IEnumerable<string>> header in resp.Headers)
+			HttpResponseHeaders headers = resp.Headers;
+			foreach (KeyValuePair<string, IEnumerable<string>> header in headers)
 			{
 				_respHeaders.Add(header.Key, String.Join(",", header.Value));
 			}
-			foreach (KeyValuePair<string, IEnumerable<string>> header in resp.Content.Headers)
+			HttpContentHeaders contentHeaders = resp.Content.Headers;
+			foreach (KeyValuePair<string, IEnumerable<string>> header in contentHeaders)
 			{
 				_respHeaders.Add(header.Key, String.Join(",", header.Value));
 			}

dotnet/test/DotNetUnitTest/Domain/GxHttpClientTest.cs

@@ -1,6 +1,10 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Net;
+using System.Net.Http;
+using System.Threading.Tasks;
 using GeneXus.Application;
 using GeneXus.Http.Client;
 using Xunit;
@@ -14,6 +18,10 @@ namespace xUnitTesting
 
 	public class GxHttpClientTest
 	{
+		const int MAX_CONNECTIONS= 5;
+		public GxHttpClientTest() {
+			Environment.SetEnvironmentVariable("GX_HTTPCLIENT_MAX_PER_ROUTE", MAX_CONNECTIONS.ToString(), EnvironmentVariableTarget.Process);
+		}
 		[Fact]
 		public void AddHeaderWithSpecialCharactersDoesNotThrowException()
 		{
@@ -70,8 +78,64 @@ public void HttpClientCookieHeader()
 				Assert.NotEqual(((int)HttpStatusCode.InternalServerError), oldHttpclient.StatusCode);
 			}
 		}
+#if NETCORE
+		[Fact(Skip = "For local testing only")]
+		public void TestHttpClientMaxPoolSize()
+		{
+			HttpClientMaxPoolSize().Wait();
+		}
+		async Task HttpClientMaxPoolSize() {
+			GxContext context = new GxContext();
+			string baseUrl = "http://localhost:8082/HttpClientTestNETSQLServer/testcookies.aspx";
+
+			var tasks = new List<Task>();
+
+			for (int i = 0; i < MAX_CONNECTIONS * 10; i++)
+			{
+				string url = $"{baseUrl}?id=" + i;
+				tasks.Add(Task.Run(() => ExecuteGet(url)));
+			}
+			await Task.WhenAll(tasks);
+
+			Assert.Single(GxHttpClient._httpClientInstances);
+
+			HttpClient c = GxHttpClient._httpClientInstances.First().Value;
+			Assert.NotNull(c);
+
+			Assert.True(pendingRequestsCount <= MAX_CONNECTIONS, $"Active connections ({pendingRequestsCount}) exceed MaxConnectionsPerServer ({MAX_CONNECTIONS})");
+		}
+		static private int pendingRequestsCount = 0;
+		static private readonly object syncObject = new object();
+		static private void IncrementPendingRequestsCount()
+		{
+			lock (syncObject)
+			{
+				pendingRequestsCount++;
+			}
+		}
 
-		[Fact(Skip ="For local testing only")]
+		static private void DecrementPendingRequestsCount()
+		{
+			lock (syncObject)
+			{
+				pendingRequestsCount--;
+			}
+		}
+		private string ExecuteGet(string url)
+		{
+			GxContext context = new GxContext();
+			using (GxHttpClient httpclient = new GxHttpClient(context))
+			{
+				IncrementPendingRequestsCount();
+				httpclient.HttpClientExecute("GET", url);
+				Assert.Equal((int)HttpStatusCode.OK, httpclient.StatusCode); //When failed, turn on log.config to see server side error.
+				DecrementPendingRequestsCount();
+				return httpclient.ToString();
+			}
+		}
+
+#endif
+		[Fact(Skip = "For local testing only")]
 		public void HttpClientCookiesTest()
 		{
 			GxContext context = new GxContext();