bug-38708

Main.cs

class MainClass
{
	const int THREADS = 0x5;
	static volatile bool stopTheWorld = false;
	static volatile bool stopped = false;

	public static void trigger ()
	{
		string longstring = "asdflkjasgakjlsdflaksjdfklajsdfalkdjf1337";
		while (longstring.Length < 0x10000)
			longstring += longstring;

		Console.Error.WriteLine ("starting threads...");
		Thread[] threads = new Thread[THREADS];

		for (int j = 0; j < threads.Length; j++) {
			threads [j] = new Thread (delegate () {
				HttpClient c = new HttpClient ();
				c.Timeout = new TimeSpan(0, 0, /* Resources.Numbers.NetworkTimeoutLength */ 5);
				for (int i = 0; i < 0x4ffff; i++) {
					while (stopTheWorld)
						Thread.Sleep (1);
					// 10.0.25.56 runs a http echo service.
					var message = new HttpRequestMessage (new HttpMethod ("POST"), "http://10.0.25.56:8080");
					message.Content = new StringContent (longstring, System.Text.UTF8Encoding.Default, "application/json");
					WebPostMessageReturnResponse (c, message);
				}
			});
			threads [j].Name = "Echo Service " + j;
			threads [j].Start ();
		}
		new Thread (delegate () {
			while (!stopped) {
				stopTheWorld = false;
				Console.Error.WriteLine ("RUN THE WORLD");
				Thread.Sleep (1500);
				stopTheWorld = true;
				Console.Error.WriteLine ("STOP THE WORLD");
				Thread.Sleep (400);
			}
			}).Start ();
		for (int j = 0; j < threads.Length; j++) {
			Console.WriteLine ("wait for thread " + j);
			threads [j].Join ();
		}
		stopped = true;
		Console.WriteLine ("Bye!");
	}

	private static HttpResponseMessage WebPostMessageReturnResponse(HttpClient httpClient, HttpRequestMessage message)
	{
		var response = httpClient.SendAsync (message).Result;
		if (CheckStatusCode(response.StatusCode) == false) {
			Console.Error.WriteLine ("fail: " + response.ToString());
			System.Environment.Exit (2);
		}

		return response;
	}

	private static bool CheckStatusCode(HttpStatusCode statusCode)
	{
		if ((int) statusCode < 200 || (int) statusCode >= 300) {
			Console.Error.WriteLine ("Got bad http status code from insights api server: " + (int) statusCode);
			return false;
		}

		return true;
	}
}

mono.patch

commit 8b15d99c1fda9997240d5b48d617ab508c08770c
Author: Bernhard Urban <bernhard.urban@xamarin.com>
Date:   Mon Mar 28 10:42:50 2016 -0700

    change this to make repro happen faster

diff --git a/mcs/class/System/System.Net/ServicePointManager.cs b/mcs/class/System/System.Net/ServicePointManager.cs
index abd23e6..f7d29c2 100644
--- a/mcs/class/System/System.Net/ServicePointManager.cs
+++ b/mcs/class/System/System.Net/ServicePointManager.cs
@@ -116,7 +116,7 @@ namespace System.Net

                private static ICertificatePolicy policy;
                private static int defaultConnectionLimit = DefaultPersistentConnectionLimit;
-               private static int maxServicePointIdleTime = 100000; // 100 seconds
+               private static int maxServicePointIdleTime = 20; // 0.02 seconds
                private static int maxServicePoints = 0;
                private static int dnsRefreshTimeout = 2 * 60 * 1000;
                private static bool _checkCRL = false;