jstack的使用
作者:互联网
概述
有些时候我们需要查看下JVM中的线程执行情况,比如:发现服务器的CPU的负载突然增高了,出现了死锁,死循环等;
由于程序是正常运行的,没有任何的输出,从日志方面也看不出问题,所以就需要看下JVM的内部线程的执行情况,然后在进行分析查找出原因;
这个时候,就需要借助jstack命令了,jstack的作用是将正在运行的JVM的线程情况进行快照,并且打印出来;
使用命令【jstack 进程号】
E:\北大青鸟\Y2\JVM\文件>jstack 17656 2020-03-03 16:54:24 Full thread dump Java HotSpot(TM) Client VM (25.73-b02 mixed mode): "http-bio-8080-exec-6" #34 daemon prio=5 os_prio=0 tid=0x15535c00 nid=0x33ac waiting on condition [0x16f2f000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x0a270340> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039) at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:104) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:32) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) "http-bio-8080-exec-5" #33 daemon prio=5 os_prio=0 tid=0x15535800 nid=0x27d0 waiting on condition [0x16e9f000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x0a270340> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039) at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:104) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:32) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) "http-bio-8080-exec-4" #32 daemon prio=5 os_prio=0 tid=0x15538400 nid=0xa2c waiting on condition [0x16e0f000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x0a270340> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039) at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:104) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:32) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) "http-bio-8080-exec-3" #31 daemon prio=5 os_prio=0 tid=0x15535000 nid=0x4bf4 waiting on condition [0x16d7f000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x0a270340> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039) at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:104) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:32) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) "http-bio-8080-exec-2" #30 daemon prio=5 os_prio=0 tid=0x15537400 nid=0x4010 waiting on condition [0x16cef000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x0a270340> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039) at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:104) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:32) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) "http-bio-8080-exec-1" #29 daemon prio=5 os_prio=0 tid=0x15537000 nid=0x2478 waiting on condition [0x1635f000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x0a270340> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039) at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:104) at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:32) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) "ajp-bio-8009-AsyncTimeout" #26 daemon prio=5 os_prio=0 tid=0x15537c00 nid=0x3ddc waiting on condition [0x162cf000] java.lang.Thread.State: TIMED_WAITING (sleeping) at java.lang.Thread.sleep(Native Method) at org.apache.tomcat.util.net.JIoEndpoint$AsyncTimeout.run(JIoEndpoint.java:152) at java.lang.Thread.run(Thread.java:745) "ajp-bio-8009-Acceptor-0" #25 daemon prio=5 os_prio=0 tid=0x15536800 nid=0x51a0 runnable [0x1623f000] java.lang.Thread.State: RUNNABLE at java.net.DualStackPlainSocketImpl.accept0(Native Method) at java.net.DualStackPlainSocketImpl.socketAccept(DualStackPlainSocketImpl.java:131) at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:199) - locked <0x0a1352a8> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:545) at java.net.ServerSocket.accept(ServerSocket.java:513) at org.apache.tomcat.util.net.DefaultServerSocketFactory.acceptSocket(DefaultServerSocketFactory.java:60) at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:222) at java.lang.Thread.run(Thread.java:745) "http-bio-8080-AsyncTimeout" #24 daemon prio=5 os_prio=0 tid=0x15538800 nid=0x2390 waiting on condition [0x161af000] java.lang.Thread.State: TIMED_WAITING (sleeping) at java.lang.Thread.sleep(Native Method) at org.apache.tomcat.util.net.JIoEndpoint$AsyncTimeout.run(JIoEndpoint.java:152) at java.lang.Thread.run(Thread.java:745) "http-bio-8080-Acceptor-0" #23 daemon prio=5 os_prio=0 tid=0x154e4000 nid=0x3d3c runnable [0x1611f000] java.lang.Thread.State: RUNNABLE at java.net.DualStackPlainSocketImpl.accept0(Native Method) at java.net.DualStackPlainSocketImpl.socketAccept(DualStackPlainSocketImpl.java:131) at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:199) - locked <0x0a135390> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:545) at java.net.ServerSocket.accept(ServerSocket.java:513) at org.apache.tomcat.util.net.DefaultServerSocketFactory.acceptSocket(DefaultServerSocketFactory.java:60) at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:222) at java.lang.Thread.run(Thread.java:745) "ContainerBackgroundProcessor[StandardEngine[Catalina]]" #22 daemon prio=5 os_prio=0 tid=0x154e3c00 nid=0x1774 waiting on condition [0x1608f000] java.lang.Thread.State: TIMED_WAITING (sleeping) at java.lang.Thread.sleep(Native Method) at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1512) at java.lang.Thread.run(Thread.java:745) "GC Daemon" #18 daemon prio=2 os_prio=-2 tid=0x15484800 nid=0x4e2c in Object.wait() [0x15e6f000] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x0a0dd158> (a sun.misc.GC$LatencyLock) at sun.misc.GC$Daemon.run(GC.java:117) - locked <0x0a0dd158> (a sun.misc.GC$LatencyLock) "RMI Scheduler(0)" #14 daemon prio=5 os_prio=0 tid=0x152b4c00 nid=0x617c waiting on condition [0x15aef000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x09dbc780> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039) at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1081) at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:809) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) "RMI TCP Accept-0" #12 daemon prio=5 os_prio=0 tid=0x151ac400 nid=0x252c runnable [0x1583f000] java.lang.Thread.State: RUNNABLE at java.net.DualStackPlainSocketImpl.accept0(Native Method) at java.net.DualStackPlainSocketImpl.socketAccept(DualStackPlainSocketImpl.java:131) at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:199) - locked <0x09eb9b28> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:545) at java.net.ServerSocket.accept(ServerSocket.java:513) at sun.management.jmxremote.LocalRMIServerSocketFactory$1.accept(LocalRMIServerSocketFactory.java:52) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:400) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:372) at java.lang.Thread.run(Thread.java:745) "RMI TCP Accept-1099" #11 daemon prio=5 os_prio=0 tid=0x14e50000 nid=0x4c7c runnable [0x156af000] java.lang.Thread.State: RUNNABLE at java.net.DualStackPlainSocketImpl.accept0(Native Method) at java.net.DualStackPlainSocketImpl.socketAccept(DualStackPlainSocketImpl.java:131) at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:199) - locked <0x09eb9e90> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:545) at java.net.ServerSocket.accept(ServerSocket.java:513) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:400) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:372) at java.lang.Thread.run(Thread.java:745) "RMI TCP Accept-0" #10 daemon prio=5 os_prio=0 tid=0x15198400 nid=0x5d1c runnable [0x1561f000] java.lang.Thread.State: RUNNABLE at java.net.DualStackPlainSocketImpl.accept0(Native Method) at java.net.DualStackPlainSocketImpl.socketAccept(DualStackPlainSocketImpl.java:131) at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:199) - locked <0x09eba190> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:545) at java.net.ServerSocket.accept(ServerSocket.java:513) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:400) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:372) at java.lang.Thread.run(Thread.java:745) "Service Thread" #7 daemon prio=9 os_prio=0 tid=0x14c99c00 nid=0x26f0 runnable [0x00000000] java.lang.Thread.State: RUNNABLE "C1 CompilerThread0" #6 daemon prio=9 os_prio=2 tid=0x14c91c00 nid=0x950 waiting on condition [0x00000000] java.lang.Thread.State: RUNNABLE "Attach Listener" #5 daemon prio=5 os_prio=2 tid=0x14c91000 nid=0x53e4 waiting on condition [0x00000000] java.lang.Thread.State: RUNNABLE "Signal Dispatcher" #4 daemon prio=9 os_prio=2 tid=0x14cc6400 nid=0x3710 runnable [0x00000000] java.lang.Thread.State: RUNNABLE "Finalizer" #3 daemon prio=8 os_prio=1 tid=0x14c64800 nid=0x4a8c in Object.wait() [0x14eef000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x09eba9d8> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143) - locked <0x09eba9d8> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:164) at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209) "Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x14c63400 nid=0x5984 in Object.wait() [0x047ef000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x09ebab78> (a java.lang.ref.Reference$Lock) at java.lang.Object.wait(Object.java:502) at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:157) - locked <0x09ebab78> (a java.lang.ref.Reference$Lock) "main" #1 prio=5 os_prio=0 tid=0x0028d400 nid=0x10c4 runnable [0x00d2f000] java.lang.Thread.State: RUNNABLE at java.net.DualStackPlainSocketImpl.accept0(Native Method) at java.net.DualStackPlainSocketImpl.socketAccept(DualStackPlainSocketImpl.java:131) at java.net.AbstractPlainSocketImpl.accept(AbstractPlainSocketImpl.java:409) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:199) - locked <0x0a2e50d8> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:545) at java.net.ServerSocket.accept(ServerSocket.java:513) at org.apache.catalina.core.StandardServer.await(StandardServer.java:453) at org.apache.catalina.startup.Catalina.await(Catalina.java:777) at org.apache.catalina.startup.Catalina.start(Catalina.java:723) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:497) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455) "VM Thread" os_prio=2 tid=0x00eddc00 nid=0x3378 runnable "VM Periodic Task Thread" os_prio=2 tid=0x151ad800 nid=0x5988 waiting on condition JNI global references: 266View Code
1.线程的状态
线程的状态一共分为6种:
1.初始态(NEW)
创建一个Thread对象,但未调用start()启动线程时,线程处于初始态;
2.运行态(RUNNABLE)
就绪态
该状态下的线程已经获得执行所需要的所以资源,只要CPU分配执行权就能运行;
所有就绪的线程存放在就绪队列中;
运行态
获得CPU执行权,正在执行的线程;
由于一个CPU同一时刻只能执行一条线程,因此每个CPU每个时刻只有一条运行态的线程;
3.阻塞态(BLOCKED)
当一条正在执行的线程请求某一资源失败时,就会进入阻塞态;
而在java中,阻塞态专指请求锁失败时进入的状态;
由一个阻塞队列存放所有阻塞态的线程;
处于阻塞态的线程会不断请求资源,一旦请求成功,就会进入就绪队列,等待执行;
4.等待态(WAITING)
当前线程中调用wait,join,park函数时,当前线程就会进入等待状态;
也有一个等待队列存放所有等待态的线程;
线程处于等待态表示它需要等待其他线程的指示才能继续运行;
进入等待态的线程会释放CPU执行权,并释放资源;
5.超时等待态(TIMED_WAITING)
当运行中的线程调用sleep(time),wait,join,parkNanos,parkUntil时,就会进入该状态;
它和等待态一样,并不是因为请求不到资源,而是主动进入,并且进入后需要其他线程唤醒;
进入该状态后释放CPU执行权和占有的资源;
与等待态的区别:到了超时时间后自动进入阻塞队列,开始竞争锁;
6.终止态(TERMINATED)
线程执行结束后的状态;
2.死锁问题
如果在生产环境发生了死锁,我们将看到的是部署的程序没有任何反应了,这个时候我们可以借助jstack进行分析;
2.1 构造死锁
编写代码,启动2个线程,Thread1拿到了obj1锁,准备去拿obj2锁时,obj2已经被Thread2锁定,所以发送了死锁;
public class TestDeadLock { private static Object obj1=new Object(); private static Object obj2=new Object(); public static void main(String[] args){ new Thread(new Thread1()).start(); new Thread(new Thread2()).start(); } private static class Thread1 implements Runnable{ @Override public void run() { synchronized (obj1){ System.out.println("Thread1-obj1"); try { Thread.sleep(2000); }catch (InterruptedException e){ e.printStackTrace(); } synchronized (obj2){ System.out.println("Thread1-obj2"); } } } } private static class Thread2 implements Runnable{ @Override public void run() { synchronized (obj2){ System.out.println("Thread2-obj2"); try { Thread.sleep(2000); }catch (InterruptedException e){ e.printStackTrace(); } synchronized (obj1){ System.out.println("Thread2-obj1"); } } } } }
2.2 运行
使用【javac TestDeadLock.java】命令进行编译
使用【java TestDeadLock】命令执行
E:\北大青鸟\Y2\JVM\文件>java TestDeadLock Thread1-obj1 Thread2-obj2
注意:这里发生了死锁,程序将一直等待下去;
2.3 使用jstack进行分析
E:\北大青鸟\Y2\JVM\文件>jps 15956 16548 Main 22292 RemoteMavenServer 4452 17656 Bootstrap 2536 Jps 10524 Launcher 8828 TestDeadLock E:\北大青鸟\Y2\JVM\文件>jstack 8828 2020-03-03 17:50:16 Full thread dump Java HotSpot(TM) Client VM (25.73-b02 mixed mode): "DestroyJavaVM" #10 prio=5 os_prio=0 tid=0x031bc400 nid=0x2628 waiting on condition [0x00000000] java.lang.Thread.State: RUNNABLE "Thread-1" #9 prio=5 os_prio=0 tid=0x1588dc00 nid=0x35a4 waiting for monitor entry [0x15f0f000] java.lang.Thread.State: BLOCKED (on object monitor) at TestDeadLock$Thread2.run(TestDeadLock.java:37) - waiting to lock <0x052e39d8> (a java.lang.Object) - locked <0x052e39e0> (a java.lang.Object) at java.lang.Thread.run(Thread.java:745) "Thread-0" #8 prio=5 os_prio=0 tid=0x1588d400 nid=0x2e40 waiting for monitor entry [0x15e7f000] java.lang.Thread.State: BLOCKED (on object monitor) at TestDeadLock$Thread1.run(TestDeadLock.java:20) - waiting to lock <0x052e39e0> (a java.lang.Object) - locked <0x052e39d8> (a java.lang.Object) at java.lang.Thread.run(Thread.java:745) "Service Thread" #7 daemon prio=9 os_prio=0 tid=0x15825400 nid=0x4dec runnable [0x00000000] java.lang.Thread.State: RUNNABLE "C1 CompilerThread0" #6 daemon prio=9 os_prio=2 tid=0x157d3800 nid=0x1df0 waiting on condition [0x00000000] java.lang.Thread.State: RUNNABLE "Attach Listener" #5 daemon prio=5 os_prio=2 tid=0x157d0000 nid=0x2680 waiting on condition [0x00000000] java.lang.Thread.State: RUNNABLE "Signal Dispatcher" #4 daemon prio=9 os_prio=2 tid=0x157cf400 nid=0x2170 runnable [0x00000000] java.lang.Thread.State: RUNNABLE "Finalizer" #3 daemon prio=8 os_prio=1 tid=0x157a6c00 nid=0x200c in Object.wait() [0x15abf000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x05206458> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143) - locked <0x05206458> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:164) at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209) "Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x0310e800 nid=0x17bc in Object.wait() [0x15a2f000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x05205f50> (a java.lang.ref.Reference$Lock) at java.lang.Object.wait(Object.java:502) at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:157) - locked <0x05205f50> (a java.lang.ref.Reference$Lock) "VM Thread" os_prio=2 tid=0x0310bc00 nid=0x1c18 runnable "VM Periodic Task Thread" os_prio=2 tid=0x15887400 nid=0x2338 waiting on condition JNI global references: 6 Found one Java-level deadlock: ============================= "Thread-1": waiting to lock monitor 0x157a56a4 (object 0x052e39d8, a java.lang.Object), which is held by "Thread-0" "Thread-0": waiting to lock monitor 0x157a63c4 (object 0x052e39e0, a java.lang.Object), which is held by "Thread-1" Java stack information for the threads listed above: =================================================== "Thread-1": at TestDeadLock$Thread2.run(TestDeadLock.java:37) - waiting to lock <0x052e39d8> (a java.lang.Object) - locked <0x052e39e0> (a java.lang.Object) at java.lang.Thread.run(Thread.java:745) "Thread-0": at TestDeadLock$Thread1.run(TestDeadLock.java:20) - waiting to lock <0x052e39e0> (a java.lang.Object) - locked <0x052e39d8> (a java.lang.Object) at java.lang.Thread.run(Thread.java:745) Found 1 deadlock.
在输出的信息中,已经看到了,发送一个死锁,关键看这个:
"Thread-1": at TestDeadLock$Thread2.run(TestDeadLock.java:37) - waiting to lock <0x052e39d8> (a java.lang.Object) - locked <0x052e39e0> (a java.lang.Object) at java.lang.Thread.run(Thread.java:745) "Thread-0": at TestDeadLock$Thread1.run(TestDeadLock.java:20) - waiting to lock <0x052e39e0> (a java.lang.Object) - locked <0x052e39d8> (a java.lang.Object) at java.lang.Thread.run(Thread.java:745)
可以清晰的看到:
Thread2获取了<0x052e39e0>的锁,等待获取<0x052e39d8>这个锁
Thread1获取了<0x052e39d8>的锁,等待获取<0x052e39e0>这个锁
由此可见,发生了死锁;
标签:lang,java,prio,Thread,jstack,util,使用,run 来源: https://www.cnblogs.com/wnwn/p/12403680.html