Jprofile 的 Thread History 功能

快来打我* 2022-09-09 14:50 155阅读 0赞

# 一 点睛 #

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16][]

线程分析主要关心三个方面：

1 web 容器的线程最大数。比如： Tomcat 的线程容量应该略大于最大并发数。

2 线程阻塞

3 线程死锁

# 二 使用 Jprofile 内置的 JDBC demo 进行说明 #

## 1 Thread History ##

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16 1][]

## 2 线程 dump ##

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16 2][]

显示结果如下

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16 3][]

# 三 线程死锁 #

## 1 代码 ##

package chaper02;
    
    /**
    * @className: ThreadDeadLock
    * @description: 线程死锁
    * @date: 2021/8/22
    */
    public class ThreadDeadLock {
        public static void main(String[] args) {
            StringBuilder s1 = new StringBuilder();
            StringBuilder s2 = new StringBuilder();
            new Thread() {
                public void run() {
                    synchronized (s1) {
                        s1.append("a");
                        s2.append("1");
    
                        try {
                            Thread.sleep(100);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
    
                        synchronized (s2) {
                            s1.append("b");
                            s2.append("2");
    
                            System.out.println(s1);
                            System.out.println(s2);
                        }
                    }
                }
            }.start();
    
            new Thread() {
                public void run() {
                    synchronized (s2) {
                        s1.append("c");
                        s2.append("3");
    
                        try {
                            Thread.sleep(100);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
    
                        synchronized (s1) {
                            s1.append("d");
                            s2.append("4");
                            System.out.println(s1);
                            System.out.println(s2);
                        }
                    }
                }
            }.start();
        }
    }

## 2 死锁显示 ##

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16 3][]

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16]: /images/20220829/dce0f08d641f4560ae39ff360073a187.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16 1]: /images/20220829/77c7eaaeee5646229cf56db2af2801e3.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16 2]: /images/20220829/dfb6c3d2c5264033b3981c6170bfda6d.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16 3]: /images/20220829/f6ad1540d62949419aaca82b8e49becf.png