Refactor synchronized block on JmxMonitorRegistry

Netflix · Mar 23, 2016 · 0f7fbe7 · 0f7fbe7
1 parent 059a8c4
commit 0f7fbe7
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Showing 2 changed files with 27 additions and 7 deletions.
diff --git a/servo-core/src/main/java/com/netflix/servo/jmx/JmxMonitorRegistry.java b/servo-core/src/main/java/com/netflix/servo/jmx/JmxMonitorRegistry.java
@@ -50,6 +50,7 @@ public final class JmxMonitorRegistry implements MonitorRegistry {
   private final ConcurrentMap<MonitorConfig, Monitor<?>> monitors;
   private final String name;
   private final ObjectNameMapper mapper;
+  private final ConcurrentMap<ObjectName, Object> locks = new ConcurrentHashMap<>();
 
   private final AtomicBoolean updatePending = new AtomicBoolean(false);
   private final AtomicReference<Collection<Monitor<?>>> monitorList =
@@ -80,7 +81,7 @@ public JmxMonitorRegistry(String name, ObjectNameMapper mapper) {
   }
 
   private void register(ObjectName objectName, DynamicMBean mbean) throws Exception {
-    synchronized (mBeanServer) {
+    synchronized (getLock(objectName)) {
       if (mBeanServer.isRegistered(objectName)) {
         mBeanServer.unregisterMBean(objectName);
       }
@@ -152,4 +153,11 @@ public boolean isRegistered(Monitor<?> monitor) {
     }
     return false;
   }
+
+  private Object getLock(ObjectName objectName) {
+    if (locks.get(objectName) == null) {
+      locks.putIfAbsent(objectName, new Object());
+    }
+    return locks.get(objectName);
+  }
 }
diff --git a/...graphite/src/test/java/com/netflix/servo/publish/graphite/GraphiteMetricObserverTest.java b/...graphite/src/test/java/com/netflix/servo/publish/graphite/GraphiteMetricObserverTest.java
@@ -15,17 +15,19 @@
  */
 package com.netflix.servo.publish.graphite;
 
+
 import com.netflix.servo.Metric;
 import org.testng.annotations.Test;
 
+import java.io.IOException;
 import java.net.InetAddress;
+import java.net.ServerSocket;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.List;
 
 import static org.testng.Assert.assertEquals;
 
-
 public class GraphiteMetricObserverTest {
   private String getLocalHostIp() throws UnknownHostException {
     return InetAddress.getLocalHost().getHostAddress();
@@ -45,13 +47,22 @@ public void testBadAddress2() throws Exception {
   public void testBadAddress3() throws Exception {
     new GraphiteMetricObserver("serverA", "socket://" + getLocalHostIp() + ":808");
   }
+
+  private int getAvailablePort() {
+    try (ServerSocket serverSocket = new ServerSocket(0)) {
+      return serverSocket.getLocalPort();
+    } catch (final IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
 
   @Test
   public void testSuccessfulSend() throws Exception {
-    SocketReceiverTester receiver = new SocketReceiverTester(8082);
+    final int port = getAvailablePort();
+    SocketReceiverTester receiver = new SocketReceiverTester(port);
     receiver.start();
 
-    String host = getLocalHostIp() + ":8082";
+    String host = getLocalHostIp() + ":" + port;
     GraphiteMetricObserver gw = new GraphiteMetricObserver("serverA", host);
 
     try {
@@ -76,10 +87,11 @@ public void testSuccessfulSend() throws Exception {
 
   @Test
   public void testReconnection() throws Exception {
-    SocketReceiverTester receiver = new SocketReceiverTester(8082);
+    final int port = getAvailablePort();
+    SocketReceiverTester receiver = new SocketReceiverTester(port);
     receiver.start();
 
-    String host = getLocalHostIp() + ":8082";
+    String host = getLocalHostIp() + ":" + port;
     GraphiteMetricObserver gw = new GraphiteMetricObserver("serverA", host);
 
     try {
@@ -98,7 +110,7 @@ public void testReconnection() throws Exception {
 
       // restarting the receiver
       receiver.stop();
-      receiver = new SocketReceiverTester(8082);
+      receiver = new SocketReceiverTester(port);
       receiver.start();
 
       // the first write does not trigger exception given how TCP works