HTTPCLIENT-726: test for spurious wakeups

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@619610 13f79535-47bb-0310-9956-ffa450edef68

module-client/src/test/java/org/apache/http/impl/conn/tsccm/TestAllTSCCM.java

@@ -45,6 +45,7 @@ public class TestAllTSCCM extends TestCase {
 
         suite.addTest(TestDumbHelpers.suite());
         suite.addTest(TestWaitingThread.suite());
+        suite.addTest(TestSpuriousWakeup.suite());
 
         return suite;
     }

module-client/src/test/java/org/apache/http/impl/conn/tsccm/TestSpuriousWakeup.java

@@ -0,0 +1,196 @@
+/*
+ * $HeadURL$
+ * $Revision$
+ * $Date$
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+
+package org.apache.http.impl.conn.tsccm;
+
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.Condition;
+
+import junit.framework.Test;
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+
+import org.apache.http.HttpHost;
+import org.apache.http.HttpVersion;
+import org.apache.http.conn.ManagedClientConnection;
+import org.apache.http.conn.ClientConnectionManager;
+import org.apache.http.conn.PlainSocketFactory;
+import org.apache.http.conn.Scheme;
+import org.apache.http.conn.SchemeRegistry;
+import org.apache.http.conn.SocketFactory;
+import org.apache.http.conn.routing.HttpRoute;
+import org.apache.http.conn.params.HttpConnectionManagerParams;
+import org.apache.http.params.BasicHttpParams;
+import org.apache.http.params.HttpParams;
+import org.apache.http.params.HttpProtocolParams;
+
+// test imports
+import org.apache.http.impl.conn.GetConnThread;
+
+
+
+/**
+ * Tests for spurious wakeups in <code>WaitingThread</code>.
+ * Requires some wrapping code to get at the lock and condition,
+ * which is required to trigger a wakeup without actually
+ * satisfying the condition.
+ *
+ * @author <a href="mailto:rolandw at apache.org">Roland Weber</a>
+ */
+public class TestSpuriousWakeup extends TestCase {
+
+    public final static
+        HttpHost TARGET = new HttpHost("target.test.invalid");
+    public final static
+        HttpRoute ROUTE = new HttpRoute(TARGET);
+
+
+    public TestSpuriousWakeup(String testName) {
+        super(testName);
+    }
+
+    public static void main(String args[]) {
+        String[] testCaseName = { TestSpuriousWakeup.class.getName() };
+        junit.textui.TestRunner.main(testCaseName);
+    }
+
+    public static Test suite() {
+        return new TestSuite(TestSpuriousWakeup.class);
+    }
+
+
+    /**
+     * An extended connection pool that gives access to some internals.
+     */
+    private static class XConnPoolByRoute extends ConnPoolByRoute {
+
+        /** The last WaitingThread object created. */
+        protected WaitingThread newestWT;
+
+
+        public XConnPoolByRoute(ClientConnectionManager mgr) {
+            super(mgr);
+        }
+
+        protected synchronized
+            WaitingThread newWaitingThread(Condition cond,
+                                           RouteSpecificPool rospl) {
+            WaitingThread wt = super.newWaitingThread(cond, rospl);
+            newestWT = wt;
+            return wt;
+        }
+
+    } // class XConnPoolByRoute
+
+
+    /**
+     * An extended TSCCM that uses XConnPoolByRoute.
+     */
+    private static class XTSCCM extends ThreadSafeClientConnManager {
+
+        /** The extended connection pool. */
+        protected XConnPoolByRoute extendedCPBR;
+
+
+        public XTSCCM(HttpParams params, SchemeRegistry schreg) {
+            super(params, schreg);
+        }
+
+        protected AbstractConnPool createConnectionPool() {
+            extendedCPBR = new XConnPoolByRoute(this);
+            // no connection GC required
+            return extendedCPBR;
+        }
+
+    } // class XTSCCM
+
+
+
+    public void testSpuriousWakeup() throws Exception {
+
+        // parameters with connection limit 1
+        HttpParams params = new BasicHttpParams();
+        HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
+        HttpProtocolParams.setUseExpectContinue(params, false);
+        HttpConnectionManagerParams.setDefaultMaxConnectionsPerHost(params, 1);
+        HttpConnectionManagerParams.setMaxTotalConnections(params, 1);
+
+        SchemeRegistry schreg = new SchemeRegistry();
+        SocketFactory sf = PlainSocketFactory.getSocketFactory();
+        schreg.register(new Scheme("http", sf, 80));
+
+        XTSCCM mgr = new XTSCCM(params, schreg);
+
+        try {
+            // take out the only connection
+            ManagedClientConnection conn = mgr.getConnection(ROUTE);
+            assertNotNull(conn);
+
+            // send a thread waiting
+            GetConnThread gct = new GetConnThread(mgr, ROUTE, 0L);
+            gct.start();
+            Thread.sleep(100); // give extra thread time to block
+
+            assertEquals("thread not waiting",
+                         Thread.State.WAITING, gct.getState());
+
+            // get access to the objects we need
+            Lock      lck = mgr.extendedCPBR.poolLock;
+            Condition cnd = mgr.extendedCPBR.newestWT.getCondition();
+
+            // Now trigger spurious wakeups. We'll do it several times
+            // in a loop, just to be sure the connection manager has a
+            // fair chance of misbehaving, and the gct to register it.
+
+            for (int i=0; i<3; i++) {
+                if (i > 0)
+                    Thread.sleep(333); // don't go too fast
+
+                try {
+                    lck.lock();
+                    cnd.signalAll(); // this is the spurious wakeup
+                } finally {
+                    lck.unlock();
+                }
+
+                // now give the waiting thread some time to register a wakeup
+                Thread.sleep(100);
+
+                assertEquals("thread no longer waiting, iteration " + i,
+                             Thread.State.WAITING, gct.getState());
+            }
+        } finally {
+            // don't worry about releasing the connection, just shut down
+            mgr.shutdown();
+        }
+    } // testSpuriousWakeup
+
+
+} // class TestSpuriousWakeup