使用jstack精确找到异常代码

秒速五厘米 2022-02-28 00:22 113阅读 0赞

一个CPU密集型线程的demo：

package chapter1;

public class FindJavaThreadInTaskManager \{

public static void main(String\[\] args) \{

Thread thread = new Thread(new Worker());

thread.start();

static class Worker implements Runnable \{

@Override

public void run() \{

while (true) \{

System.out.println("Thread Name:" + Thread.currentThread().getName());

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NxaXVjaGVuZw_size_16_color_FFFFFF_t_70][]

找到CPU利用率持续比较高的进程，获取进程号，此处PID为3036

命令：

top

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NxaXVjaGVuZw_size_16_color_FFFFFF_t_70 1][]

找到上述进程中，CPU利用率比较高的线程号TID（十进制数）,此处为3046

命令：

ps p 3036 -L -o pcpu,pid,**tid**,time,tname,cmd

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NxaXVjaGVuZw_size_16_color_FFFFFF_t_70 2][]

找到上述进程中，CPU利用率比较高的线程号TID（十进制数）,此处为3046

将获取的线程号（十进制数）转换成十六进制,此处为0x**b46**

命令：

printf "%x\\n" 3046

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NxaXVjaGVuZw_size_16_color_FFFFFF_t_70 3][]

查看进程PID为3036中

nid为0x**b46**的线程信息

命令：

jstack -l 3036

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NxaXVjaGVuZw_size_16_color_FFFFFF_t_70 4][]

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