（转）JVM问题诊断常用命令：jinfo,jmap,jstack

"CompilerThread0" daemon prio=10 tid=0x08143c58 nid=0x6 waiting on condition [0x00000000..0xfb5fd798]

"Signal Dispatcher" daemon prio=10 tid=0x08142f08 nid=0x5 waiting on condition [0x00000000..0x00000000]

"Finalizer" daemon prio=10 tid=0x08137ca0 nid=0x4 in Object.wait() [0xfbeed000..0xfbeeddb8]



写了个代码， 100 个线程同时往控制台输出，代码如下： ?
my.start();

}



}

} ?

通过jstack pid,得到如下部分结果：

?

java.lang.Thread.State: BLOCKED (on object monitor)
at java.io.PrintStream.println(PrintStream.java:755)
- waiting to lock <0x805782c0> (a java.io.PrintStream)
at org.jtester.service.MyThread.run(MyThread.java:15)

"thrad75" prio=10 tid=0x096ccc00 nid=0x4304 runnable [0x7a2d1000]
java.lang.Thread.State: RUNNABLE
at java.io.PrintStream.write(PrintStream.java:428)
- locked <0x805782c0> (a java.io.PrintStream)
at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:202)
at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:272)
at sun.nio.cs.StreamEncoder.flushBuffer(StreamEncoder.java:85)
- locked <0x805783c8> (a java.io.OutputStreamWriter)
at java.io.OutputStreamWriter.flushBuffer(OutputStreamWriter.java:168)
at java.io.PrintStream.write(PrintStream.java:477)
- locked <0x805782c0> (a java.io.PrintStream)
at java.io.PrintStream.print(PrintStream.java:619)
at java.io.PrintStream.println(PrintStream.java:756)
- locked <0x805782c0> (a java.io.PrintStream)
at org.jtester.service.MyThread.run(MyThread.java:15)

"thrad74" prio=10 tid=0x096cb000 nid=0x4303 waiting for monitor entry [0x7a322000]
java.lang.Thread.State: BLOCKED (on object monitor)
at java.io.PrintStream.println(PrintStream.java:755)
- waiting to lock <0x805782c0> (a java.io.PrintStream)
at org.jtester.service.MyThread.run(MyThread.java:15) ?

?