add something about thread

Author: CodePrometheus

AQS/AQS.iml

@@ -7,5 +7,6 @@
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="scala-sdk-2.12.12" level="application" />
   </component>
 </module>

Thread/src/create/BothRunnableAndThread.java

@@ -9,11 +9,13 @@
 public class BothRunnableAndThread {
     public static void main(String[] args) {
         Thread thread = new Thread(() -> System.out.println("来自Runnable的方法")) {
+
+            //这里的run方法已经把父类的run方法覆盖
             @Override
             public void run() {
                 System.out.println("来自Thread的方法");
             }
         };
-        thread.start();
+        thread.start();//来自Thread的方法
     }
 }

Thread/src/create/CreateThreadSummary.java

@@ -0,0 +1,28 @@
+package create;
+
+/**
+ * 实现多线程的方法总结
+ *
+ * @Author: zzStar
+ * @Date: 10-13-2020 19:06
+ */
+public class CreateThreadSummary {
+
+    /**
+     * 两种方法！创建新的执行线程
+     *      1.将类声明为子类Thread，重写类的run方法Thread，也即继承Thread类
+     *      2.声明一个实现Runnable接口的类，实现run方法
+     *
+     *   准确地说，创建线程只有一种方式就是构造Thread类，而实现线程的执行单元有两种方式
+     *      1.实现Runnable接口的run方法，并把Runnable实例传给Thread类
+     *      2.重写Thread的run方法（继承Thread类）
+     */
+
+
+    /**
+     * 优先选择Runnable接口
+     *      1.解耦
+     *      2.传入实例可以反复利用同一个线程
+     *      3.Java不支持双继承
+     */
+}

Thread/src/create/ThreadCreate.java

@@ -2,23 +2,27 @@
 
 /**
  * 线程创建的方式
- * 共列举四种
  *
  * @Author: zzStar
  * @Date: 2020-10-07 18:44
  */
 public class ThreadCreate {
     public static void main(String[] args) {
+
         //创建Runnable实现类的实例，并用这个实例作为Thread的target来创建Thread对象，
         //这个Thread对象才是真正的线程对象
+        //最终调用target.run()
         new Thread(new MyThread1(), "thread 1").start();
 
+        //继承所实现的直接start
+        //run()整个都被重写
         new MyThread2("thread 2").start();
     }
 }
 
 /**
  * 通过实现Runnable接口来创建Thread线程,重写run()方法
+ * 优先选择
  */
 class MyThread1 implements Runnable {
     @Override
@@ -32,6 +36,7 @@ public void run() {
  * 这种创建线程的方法不够好，主要是因为其涉及运行机制问题，影响程序性能
  */
 class MyThread2 extends Thread {
+
     //调用super（name）后，getName才会返回你创建新实例时传入的name
     MyThread2(String name) {
         super(name);
@@ -42,3 +47,14 @@ public void run() {
         System.out.println(Thread.currentThread().getName() + "-->run...");
     }
 }
+
+/*
+    //run源码
+    @Override
+    public void run() {
+        if (target != null) {
+            target.run();
+        }
+    }
+*/
+

Thread/src/create/TimerThreadTest.java

@@ -13,6 +13,7 @@
 public class TimerThreadTest {
     public static void main(String[] args) {
         TimerTask task = new TimerTask() { //创建一个新的timer task
+
             @Override
             public void run() { //定时器任务执行的操作
                 Date date = new Date();//创建Date对象

Thread/src/startthread/StartAndRunMethod.java

@@ -0,0 +1,71 @@
+package startthread;
+
+/**
+ * 对比start & run
+ *
+ * 一个线程两次调用start方法时会抛出异常，见源码对线程状态的检查
+ * 调用start才是真正意义上的启动线程，经历线程的各个周期
+ *
+ * @Author: zzStar
+ * @Date: 10-13-2020 20:09
+ */
+public class StartAndRunMethod {
+    public static void main(String[] args) {
+        Runnable runnable = () -> {
+            System.out.println(Thread.currentThread().getName());
+        };
+
+        runnable.run();//main
+
+        new Thread(runnable).start();//Thread-0
+
+    }
+}
+
+/*
+    private volatile int threadStatus;
+
+    public synchronized void start() {
+        */
+/**
+ * This method is not invoked for the main method thread or "system"
+ * group threads created/set up by the VM. Any new functionality added
+ * to this method in the future may have to also be added to the VM.
+ * <p>
+ * A zero status value corresponds to state "NEW".
+ *//*
+
+        //检查线程状态，初始化就是0
+        if (threadStatus != 0)
+            throw new IllegalThreadStateException();
+
+        */
+/* Notify the group that this thread is about to be started
+ * so that it can be added to the group's list of threads
+ * and the group's unstarted count can be decremented. *//*
+
+        //加入线程组
+        group.add(this);
+
+        boolean started = false;
+        try {
+            start0();
+            started = true;
+        } finally {
+            try {
+                if (!started) {
+                    group.threadStartFailed(this);
+                }
+            } catch (Throwable ignore) {
+                */
+/* do nothing. If start0 threw a Throwable then
+                  it will be passed up the call stack *//*
+
+            }
+        }
+    }
+
+    //jdk源码
+    private native void start0();
+*/
+

Thread/src/startthread/StartThreadSummary.java

@@ -0,0 +1,10 @@
+package startthread;
+
+/**
+ * 启动线程总结
+ *
+ * @Author: zzStar
+ * @Date: 10-13-2020 20:09
+ */
+public class StartThreadSummary {
+}