This is demonstrated in the next screen snapshot.Īny individual thread can be clicked on to see the detailed Threads view. Their display is enabled because the "Threads visualization" checkbox is checked.Īnother useful tab on VisualVM is the "Threads" "Table" view that provides textual overview information on the threads. These colored horizontal bars represent individual threads. The screen snapshot above that showed the "Thread Dump" button also conveniently demonstrates VisualVM's Timeline tab that demonstrates in a live fashion the "live" threads. However, VisualVM provides much more than that for thread analysis. Whether the right-click option is used or the "Thread Dump" button is pressed, VisualVM generates jstack thread dump output file and displays it as shown in the next screen snapshot.Īs discussed and demonstrated, VisualVM allows for easy generation of a stack trace dump with jstack. The first way to do this is to right-click on the appropriate Java process and select the option "Thread Dump." This will generate a thread dump file whose name appears under the selected Java process as shown in the following screen snapshot.Ī second way to get the thread dump generated in VisualVM is to use the "Threads" tab and click on the button "Thread Dump." This button is demonstrated in the next screen snapshot. VisualVM offers the capability to generate and view the jstack-generated stack trace. VisualVM makes it easy to monitor application threads. "VM Periodic Task Thread" prio=10 tid=0x02348c00 nid=0x278 waiting on condition "main" prio=6 tid=0x00209000 nid=0x1134 runnable Īt (Arrays.java:2882)Īt (AbstractStringBuilder.java:100)Īt (AbstractStringBuilder.java:390)Īt (StringBuilder.java:119)Īt .loopProvidedNumberOfTimes(AnalyzableImpl.java:48)Īt .main(AnalyzableImpl.java:80) waiting on (a $Lock)Īt (Object.java:485)Īt $n(Reference.java:116) "Reference Handler" daemon prio=10 tid=0x022f2c00 nid=0x1198 in Object.wait() locked (a $Lock)Īt .remove(ReferenceQueue.java:134)Īt $n(Finalizer.java:159) waiting on (a $Lock)Īt .remove(ReferenceQueue.java:118) "Finalizer" daemon prio=8 tid=0x022f4000 nid=0xd14 in Object.wait() "Signal Dispatcher" daemon prio=10 tid=0x02339c00 nid=0xac runnable "Attach Listener" daemon prio=10 tid=0x02342800 nid=0xf6c waiting on condition "CompilerThread0" daemon prio=10 tid=0x02343000 nid=0x108 waiting on condition "Low Memory Detector" daemon prio=6 tid=0x02348000 nid=0xec4 runnable "RMI TCP Accept-0" daemon prio=6 tid=0x023bfc00 nid=0xa74 runnable Īt (Native Method)Īt (PlainSocketImpl.java:390)Īt (ServerSocket.java:453)Īt (ServerSocket.java:421)Īt $1.accept(LocalRMIServerSocketFactory.java:34)Īt .TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:369)Īt .TCPTransport$n(TCPTransport.java:341) parking to wait for (a .AbstractQueuedSynchronizer$ConditionObject)Īt .LockSupport.park(LockSupport.java:158)Īt .AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:1925)Īt .take(DelayQueue.java:160)Īt $DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:583)Īt $DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:576)Īt .getTask(ThreadPoolExecutor.java:947)Īt $n(ThreadPoolExecutor.java:907) "RMI Scheduler(0)" daemon prio=6 tid=0x04bb4c00 nid=0x126c waiting on condition The output of an entire jstack run looks similar to that which follows: 23:25:26įull thread dump Java HotSpot(TM) Client VM (14.0-b16 mixed mode, sharing): Only the top portion of the generated stack trace information is shown above. It is easy to run jstack as demonstrated in the next screen snapshot: Although jstack (Java Stack Trace) is a useful tool for learning more about a how a Java thread is behaving, VisualVM is an even easier method for obtaining the same type of information.
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