Github user nkalmar commented on a diff in the pull request:
https://github.com/apache/zookeeper/pull/563#discussion_r201258688
--- Diff: src/java/test/org/apache/zookeeper/test/ThrottleRaceTest.java ---
@@ -0,0 +1,156 @@
+/**
+ * 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.
+ */
+
+package org.apache.zookeeper.test;
+
+import static org.apache.zookeeper.test.ClientBase.CONNECTION_TIMEOUT;
+import static org.apache.zookeeper.test.ClientBase.verifyThreadTerminated;
+
+import org.apache.zookeeper.AsyncCallback.StatCallback;
+import org.apache.zookeeper.KeeperException;
+import org.apache.zookeeper.ZKTestCase;
+import org.apache.zookeeper.TestableZooKeeper;
+import org.apache.zookeeper.WatchedEvent;
+import org.apache.zookeeper.data.Stat;
+import org.apache.zookeeper.test.ClientBase.CountdownWatcher;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ThrottleRaceTest extends ZKTestCase {
+ private static final Logger LOG =
LoggerFactory.getLogger(ThrottleRaceTest.class);
+
+ private QuorumBase qb = new QuorumBase();
+
+ private volatile boolean bang;
+
+ public void setUp() throws Exception {
+ qb.setUp();
+ }
+
+ public void tearDown() throws Exception {
+ LOG.info("Test clients shutting down");
+ qb.tearDown();
+ }
+
+ /**
+ * Send exists /zookeeper requests asynchronously, max 30 outstanding
+ */
+ class HammerThreadExists extends Thread implements StatCallback {
+ private static final int MAX_OUTSTANDING = 30;
+
+ private TestableZooKeeper zk;
+ private int outstanding;
+
+ private volatile boolean failed = false;
+
+ public HammerThreadExists(String name) {
+ super(name);
+ }
+
+ public void run() {
+ try {
+ CountdownWatcher watcher = new CountdownWatcher();
+ zk = new TestableZooKeeper(qb.hostPort, CONNECTION_TIMEOUT,
+ watcher);
+ watcher.waitForConnected(CONNECTION_TIMEOUT);
+ while(bang) {
+ incOutstanding(); // before create otw race
+ zk.exists("/zookeeper", false, this, null);
+ }
+ } catch (InterruptedException e) {
+ if (bang) {
+ LOG.error("sanity check Assert.failed!!!"); // sanity
check
+ return;
+ }
+ } catch (Exception e) {
+ LOG.error("Client create operation Assert.failed", e);
+ return;
+ } finally {
+ if (zk != null) {
+ try {
+ if (!zk.close(CONNECTION_TIMEOUT)) {
+ failed = true;
+ LOG.error("Client did not shutdown");
+ }
+ } catch (InterruptedException e) {
+ LOG.info("Interrupted", e);
+ }
+ }
+ }
+ }
+
+ private synchronized void incOutstanding() throws
InterruptedException {
+ outstanding++;
+ while(outstanding > MAX_OUTSTANDING) {
+ wait();
+ }
+ }
+
+ private synchronized void decOutstanding() {
+ outstanding--;
+ Assert.assertTrue("outstanding >= 0", outstanding >= 0);
+ notifyAll();
+ }
+
+ public void process(WatchedEvent event) {
+ // ignore for purposes of this test
+ }
+
+ public void processResult(int rc, String path, Object ctx, Stat
stat) {
+ if (rc != KeeperException.Code.OK.intValue()) {
+ if (bang) {
+ failed = true;
+ LOG.error("Exists Assert.failed for 0x"
+ + Long.toHexString(zk.getSessionId())
+ + "with rc:" + rc + " path:" + path);
+ }
+ decOutstanding();
+ return;
+ }
+ decOutstanding();
+ }
+ }
+
+ @Test
+ public void testExistsHammer() throws Exception {
+ System.setProperty("zookeeper.globalOutstandingLimit", "1");
+ setUp();
+ bang = true;
+ LOG.info("Starting hammers");
+ HammerThreadExists[] hammers = new HammerThreadExists[100];
+ for (int i = 0; i < hammers.length; i++) {
+ hammers[i] = new HammerThreadExists("HammerThread-" + i);
+ hammers[i].start();
+ }
+ LOG.info("Started hammers");
+ Thread.sleep(30000); // allow the clients to run for max 5sec
--- End diff --
nit: This is 3 seconds not five as in the comment
---
