8219904: ClassCastException when calling FlightRecorderMXBean#getRecordings()

Reviewed-by: egahlin, mseledtsov

src/jdk.management.jfr/share/classes/jdk/management/jfr/RecordingInfo.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -51,7 +51,7 @@ public final class RecordingInfo {
     private final String state;
     private final boolean dumpOnExit;
     private final long size;
-    private final boolean disk;
+    private final boolean toDisk;
     private final long maxAge;
     private final long maxSize;
     private final long startTime;
@@ -67,7 +67,7 @@ public final class RecordingInfo {
         state = recording.getState().toString();
         dumpOnExit = recording.getDumpOnExit();
         size = recording.getSize();
-        disk = recording.isToDisk();
+        toDisk = recording.isToDisk();
 
         Duration d = recording.getMaxAge();
         if (d == null) {
@@ -87,12 +87,17 @@ public final class RecordingInfo {
     }
 
     private RecordingInfo(CompositeData cd) {
-        id = (int) cd.get("id");
+        id = (long) cd.get("id");
         name = (String) cd.get("name");
         state = (String) cd.get("state");
         dumpOnExit = (boolean) cd.get("dumpOnExit");
         size = (long) cd.get("size");
-        disk = (boolean) cd.get("disk");
+        if(cd.containsKey("toDisk")){
+            toDisk = (boolean) cd.get("toDisk");
+        } else {
+            // Before JDK-8219904 was fixed, the element name was disk, so for compatibility
+            toDisk = (boolean) cd.get("disk");
+        }
         maxAge = (Long) cd.get("maxAge");
         maxSize = (Long) cd.get("maxSize");
         startTime = (Long) cd.get("startTime");
@@ -290,7 +295,7 @@ public final class RecordingInfo {
      * @return {@code true} if recording is to disk, {@code false} otherwise
      */
     public boolean isToDisk() {
-        return disk;
+        return toDisk;
     }
 
     /**
@@ -342,7 +347,7 @@ public final class RecordingInfo {
      * <td>{@code Long}</td>
      * </tr>
      * <tr>
-     * <th scope="row">disk</th>
+     * <th scope="row">toDisk</th>
      * <td>{@code Boolean}</td>
      * </tr>
      * <tr>

test/jdk/jdk/jfr/jmx/JmxHelper.java

@@ -36,6 +36,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import com.sun.tools.attach.VirtualMachine;
 import jdk.jfr.EventType;
 import jdk.jfr.FlightRecorder;
 import jdk.jfr.Recording;
@@ -52,7 +53,15 @@ import jdk.test.lib.Utils;
 import jdk.test.lib.jfr.CommonHelper;
 import jdk.test.lib.jfr.Events;
 
+import javax.management.JMX;
+import javax.management.MBeanServerConnection;
+import javax.management.ObjectName;
+import javax.management.remote.JMXConnector;
+import javax.management.remote.JMXConnectorFactory;
+import javax.management.remote.JMXServiceURL;
+
 public class JmxHelper {
+    private static final String LOCAL_CONNECTION_ADDRESS = "com.sun.management.jmxremote.localConnectorAddress";
 
     public static RecordingInfo getJmxRecording(long recId) {
         for (RecordingInfo r : getFlighteRecorderMXBean().getRecordings()) {
@@ -279,4 +288,18 @@ public class JmxHelper {
         return ManagementFactory.getPlatformMXBean(FlightRecorderMXBean.class);
     }
 
+    public static long getPID(){
+        return ManagementFactory.getRuntimeMXBean().getPid();
+    }
+
+    public static FlightRecorderMXBean getFlighteRecorderMXBean(long pid) throws Exception {
+        VirtualMachine targetVM = VirtualMachine.attach("" + pid);
+        String jmxServiceUrl = targetVM.getAgentProperties().getProperty(LOCAL_CONNECTION_ADDRESS);
+        JMXServiceURL jmxURL = new JMXServiceURL(jmxServiceUrl);
+        JMXConnector connector = JMXConnectorFactory.connect(jmxURL);
+        MBeanServerConnection connection = connector.getMBeanServerConnection();
+
+        ObjectName objectName = new ObjectName("jdk.management.jfr:type=FlightRecorder");
+        return JMX.newMXBeanProxy(connection, objectName, FlightRecorderMXBean.class);
+    }
 }

test/jdk/jdk/jfr/jmx/TestGetRecordings.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -35,7 +35,7 @@ import jdk.management.jfr.RecordingInfo;
  * @key jfr
  * @requires vm.hasJFR
  * @library /test/lib /test/jdk
- * @run main/othervm jdk.jfr.jmx.TestGetRecordings
+ * @run main/othervm -Djdk.attach.allowAttachSelf=true -Dcom.sun.management.jmxremote jdk.jfr.jmx.TestGetRecordings
  */
 public class TestGetRecordings {
     public static void main(String[] args) throws Throwable {
@@ -46,5 +46,11 @@ public class TestGetRecordings {
         JmxHelper.verifyNotExists(recId, preCreateRecordings);
         bean.closeRecording(recId);
         JmxHelper.verifyNotExists(recId, bean.getRecordings());
+
+        long selfPID = JmxHelper.getPID();
+        FlightRecorderMXBean remoteBean = JmxHelper.getFlighteRecorderMXBean(selfPID);
+        long remoteRecId = remoteBean.newRecording();
+        remoteBean.getRecordings();
+        remoteBean.closeRecording(remoteRecId);
     }
 }