Using Jstack to detect deadlocks under Linux in Java

First, write a deadlock program

1  Packagedeadlock;2 3  Public classTestjstack {4     Final StaticObject resource_1 =NewObject ();5     Final StaticObject resource_2 =NewObject ();6 7      Public Static voidMain (string[] args) {8Thread T1 =NewThread ("T1") {9              Public voidrun () {Ten                 synchronized(resource_1) { One                     Try { AThread.Sleep (3000); -}Catch(interruptedexception e) { -                     } theSystem.out.println ("Locked Resource_1"); -                     synchronized(resource_2) { -SYSTEM.OUT.PRINTLN ("Thread T1 done.")); -                     } +                 } -             } +         }; A  atThread t2 =NewThread ("T2") { -              Public voidrun () { -                 synchronized(resource_2) { -System.out.println ("Locked resource_2"); -                     synchronized(resource_1) { -System.out.println ("Thread T2 done.")); in                     } -                 } to             } +         }; - T1.start (); the T2.start (); *     } $}

The result of the program operation is:

Lock Resource_2lock Resource_1

Next, enter the JSP in the terminal to view the currently running Java program:

7480 testjstack13420 Jps

Gets the Testjstack process ID of 7480. Then use the command:

Jstack-l 7480 >deadlock.jstack

Put the Jstack detection results into the file deadlock.jstack. Use Vim to view the file:

Java.lang.Thread.State:RUNNABLE Locked ownable synchronizers:-None Java.lang.Thread.State:RUNNABLE Java.lang.Thread.State:BLOCKED (on object monitor) at testjstack$
    2.run (testjstack.java:29)        -Waiting to lock <0x8c087670>(a java.lang.Object)-Locked <0x8c087678>(a Java.lang.Object) Java.lang.Thread.State:BLOCKED (on Object Monitor) at testjstack$1.run (testjstack.java:15) Locked ownable synchronizers:-None Java.lang.Thread.State:RUNNABLE Locked ownable synchronizers:-None Java.lang.Thread.State:RUNNABLE Locked ownable Synchronizers:java.lang.Thread.State:RUNNABLE Java.lan G.thread.state:waiting (on object monitor) at java.lang.Object.wait (Native Method)-Locked <0x8c050b30>(a java.lang.ref.referencequeue$lock) Locked ownable synchronizers:-None-Waiting on <0x8c050a30>(a java.lang.ref.reference$lock) at java.lang.Object.wait (Object.java:485)        -Locked <0x8c050a30>(a java.lang.ref.reference$lock) Locked ownable synchronizers:"VM Thread" prio=10 tid=0x0807e800 nid=0x260cRunnablejni Global References:576Found One Java-Level Deadlock:============================= "T2": Which is held by"T1" "T1": Which is held by"T2"Java Stack Information forThe threads listed above:=================================================== "T2": at testjstack$2.run (testjstack.java:29)        -Waiting to lock <0x8c087670>(a java.lang.Object)-Locked <0x8c087678>(a java.lang.Object)"T1": at testjstack$1.run (testjstack.java:15)        -Waiting to lock <0x8c087678>(a java.lang.Object)-Locked <0x8c087670>(a java.lang.Object) Found1 deadlock.

Using Jstack to detect deadlocks under Linux in Java