implemented DnsRefreshTimeout to ServicePointManager and adjusted behavior of ServicePoint.HostEntry property.

simplified some calls as requested

3 files changed, 51 insertions, 26 deletions

diff --git a/mcs/class/System/System.Net/ServicePoint.cs b/mcs/class/System/System.Net/ServicePoint.cs
index d3a3dd507be..ebac3e9cf1d 100644
--- a/mcs/class/System/System.Net/ServicePoint.cs
+++ b/mcs/class/System/System.Net/ServicePoint.cs
@@ -47,6 +47,7 @@ namespace System.Net
 		int maxIdleTime;
 		int currentConnections;
 		DateTime idleSince;
+		DateTime lastDnsResolve;
 		Version protocolVersion;
 		X509Certificate certificate;
 		X509Certificate clientCertificate;
@@ -339,37 +340,30 @@ namespace System.Net
 			CheckAvailableForRecycling (out dummy);
 		}
 
+		private bool HasTimedOut
+		{
+			get {
+				int timeout = ServicePointManager.DnsRefreshTimeout;
+				return timeout != Timeout.Infinite &&
+					(lastDnsResolve + TimeSpan.FromMilliseconds (timeout)) < DateTime.UtcNow;
+			}
+		}
+
 		internal IPHostEntry HostEntry
 		{
 			get {
 				lock (hostE) {
-					if (host != null)
-						return host;
-
 					string uriHost = uri.Host;
 
-					// There is no need to do DNS resolution on literal IP addresses
-					if (uri.HostNameType == UriHostNameType.IPv6 ||
-						uri.HostNameType == UriHostNameType.IPv4) {
+					if (host == null || HasTimedOut) {
+						lastDnsResolve = DateTime.UtcNow;
 
-						if (uri.HostNameType == UriHostNameType.IPv6) {
-							// Remove square brackets
-							uriHost = uriHost.Substring(1,uriHost.Length-2);
+						try {
+							host = Dns.GetHostEntry (uriHost);
+						}
+						catch (Exception) {
+							return null;
 						}
-
-						// Creates IPHostEntry
-						host = new IPHostEntry();
-						host.AddressList = new IPAddress[] { IPAddress.Parse(uriHost) };
-
-						return host;
-					}
-
-					// Try DNS resolution on host names
-					try  {
-						host = Dns.GetHostByName (uriHost);
-					} 
-					catch {
-						return null;
 					}
 				}
 
diff --git a/mcs/class/System/System.Net/ServicePointManager.cs b/mcs/class/System/System.Net/ServicePointManager.cs
index dc7412d725a..9f0ae0b1d9f 100644
--- a/mcs/class/System/System.Net/ServicePointManager.cs
+++ b/mcs/class/System/System.Net/ServicePointManager.cs
@@ -134,6 +134,7 @@ namespace System.Net
 		private static int defaultConnectionLimit = DefaultPersistentConnectionLimit;
 		private static int maxServicePointIdleTime = 100000; // 100 seconds
 		private static int maxServicePoints = 0;
+		private static int dnsRefreshTimeout = 2 * 60 * 1000;
 		private static bool _checkCRL = false;
 		private static SecurityProtocolType _securityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls;
 
@@ -218,14 +219,13 @@ namespace System.Net
 			return new NotImplementedException ();
 		}
 		
-		[MonoTODO]
 		public static int DnsRefreshTimeout
 		{
 			get {
-				throw GetMustImplement ();
+				return dnsRefreshTimeout;
 			}
 			set {
-				throw GetMustImplement ();
+				dnsRefreshTimeout = Math.Max (-1, value);
 			}
 		}
 		
diff --git a/mcs/class/System/Test/System.Net/ServicePointTest.cs b/mcs/class/System/Test/System.Net/ServicePointTest.cs
index 8c564e24658..cb6a705905a 100644
--- a/mcs/class/System/Test/System.Net/ServicePointTest.cs
+++ b/mcs/class/System/Test/System.Net/ServicePointTest.cs
@@ -13,6 +13,7 @@ using System;
 using System.Collections;

 using System.IO;

 using System.Net;

+using System.Reflection;
 using System.Threading;

 

 namespace MonoTests.System.Net

@@ -205,6 +206,36 @@ public class ServicePointTest
 		}

 	}

 

+
+	[Test]
+	public void DnsRefreshTimeout ()
+	{
+		const int dnsRefreshTimeout = 2;
+
+		ServicePoint sp;
+		IPHostEntry host0, host1, host2;
+		Uri uri;
+		PropertyInfo hostEntryProperty;
+
+		ServicePointManager.DnsRefreshTimeout = dnsRefreshTimeout;
+
+		uri = new Uri ("http://ww.google.com/");
+		sp = ServicePointManager.FindServicePoint (uri);
+
+		hostEntryProperty = typeof (ServicePoint).GetProperty ("HostEntry", BindingFlags.NonPublic | BindingFlags.Instance);
+
+		host0 = hostEntryProperty.GetValue (sp, null) as IPHostEntry;
+		host1 = hostEntryProperty.GetValue (sp, null) as IPHostEntry;
+
+		Assert.AreEqual (host0, host1, "HostEntry should result in the same IPHostEntry object.");
+
+		Thread.Sleep (dnsRefreshTimeout);
+		host2 = hostEntryProperty.GetValue (sp, null) as IPHostEntry;
+
+		Assert.AreNotEqual(host0, host2, "HostEntry should result in a new IPHostEntry " +
+				"object when DnsRefreshTimeout is reached.");
+	}
+
 // Debug code not used now, but could be useful later

 /*

 	private void WriteServicePoint (string label, ServicePoint sp)