487
技術社區[雲棲]
java線程的6種狀態以及相互轉換
線程狀態
1、java線程有6中狀態，分別為NEW，RUNNABLE，BLOCKED，WAITING，TIMED_WAITING，TERMINATED詳解java.lang.Thread$State枚舉類
2、線程初始化為NEW狀態，該狀態表示還未調用start方法
3、執行線程調用start方法，線程狀態轉換為RUNNABLE（包括競爭到CPU時間真正意義的執行和沒有競爭到CPU時間等待下一個CPU時間的狀態）
4、BLOCKED狀態為鎖競爭，沒有競爭到鎖為BLOCKED，等待擁有鎖的線程釋放鎖，進入RUNNABLE狀態
5、WAITING狀態為競爭到鎖，執行wait方法，又釋放鎖，本線程進入WAITING，等待其他線程喚醒notify，notifyall，如果不喚醒，將一直處於WAITING狀態
6、TIMED_WAITING為執行sleep join或者有時限的等待
7、線程執行完畢，線程處於TERMINATED狀態
線程狀態變化
package com.rcl.platform.demo;
import java.util.concurrent.TimeUnit;
public class ThreadState {
public static void main( String[] args ) throws InterruptedException {
System.out.println("-------------NEW-------------");
Thread thread = new Thread();
System.out.println(thread.getState() + ":" + (thread.getState() == Thread.State.NEW));
System.out.println("-------------分割線-------------");
System.out.println("-------------RUNNABLE、TERMINATED-------------");
thread = new Thread(new Runnable() {
public void run() {
System.out.println(Thread.currentThread().getState() + ":" + (Thread.currentThread().getState() == Thread.State.RUNNABLE));
}
});
thread.start();
TimeUnit.SECONDS.sleep(1);
System.out.println(thread.getState() + ":" + (thread.getState() == Thread.State.TERMINATED));
System.out.println("-------------分割線-------------");
System.out.println("-------------RUNNABLE、TIMED_WAITING-------------");
thread = new Thread(new Runnable() {
public void run() {
System.out.println(Thread.currentThread().getState() + ":" + (Thread.currentThread().getState() == Thread.State.RUNNABLE));
System.out.println("sleep 進入 TIMED_WAITING");
try {
TimeUnit.SECONDS.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
thread.start();
TimeUnit.SECONDS.sleep(1);
System.out.println(thread.getState() );
TimeUnit.SECONDS.sleep(2);
System.out.println("-------------分割線-------------");
System.out.println("-------------RUNNABLE、TIMED_WAITING-------------");
final Thread mainThread = Thread.currentThread();
thread = new Thread(new Runnable() {
public void run() {
System.out.println(Thread.currentThread().getState() + ":" + (Thread.currentThread().getState() == Thread.State.RUNNABLE));
try {
System.out.println("join 進入 TIMED_WAITING");
System.out.println("mainThread: " + mainThread.getState());
TimeUnit.SECONDS.timedJoin(mainThread, 2);//先執行mainthread
System.out.println("mainThread: " + mainThread.getState());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
thread.start();
TimeUnit.SECONDS.sleep(1);
System.out.println("testThread: " + thread.getState() );
System.out.println("-------------分割線-------------");
System.out.println("-------------RUNNABLE、WAITING-------------");
Object lock = new Object();
final Thread mainThread1 = Thread.currentThread();
thread = new Thread(new Runnable() {
public void run() {
synchronized (lock) {
try {
System.out.println("wait 進入 WAITING");
lock.wait();
System.out.println("mainThread1: " + mainThread1.getState() );
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
thread.start();
TimeUnit.SECONDS.sleep(1);
System.out.println("testThread: " + thread.getState() );
synchronized (lock) {
lock.notifyAll();
}
TimeUnit.SECONDS.sleep(1);
System.out.println("-------------分割線-------------");
Thread thread1 = new Thread(new Runnable() {
public void run() {
synchronized (lock) {
try {
TimeUnit.SECONDS.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
thread1.start();
Thread thread2 = new Thread(new Runnable() {
public void run() {
synchronized (lock) {
}
}
});
thread2.start();
TimeUnit.SECONDS.sleep(1);
System.out.println("thread2: " + thread2.getState() );
}
}
執行結果
-------------NEW-------------
NEW:true
-------------分割線-------------
-------------RUNNABLE、TERMINATED-------------
RUNNABLE:true
TERMINATED:true
-------------分割線-------------
-------------RUNNABLE、TIMED_WAITING-------------
RUNNABLE:true
sleep 進入 TIMED_WAITING
TIMED_WAITING
-------------分割線-------------
-------------RUNNABLE、TIMED_WAITING-------------
RUNNABLE:true
join 進入 TIMED_WAITING
mainThread: TIMED_WAITING
testThread: TIMED_WAITING
-------------分割線-------------
-------------RUNNABLE、WAITING-------------
wait 進入 WAITING
mainThread: TIMED_WAITING
testThread: WAITING
mainThread1: TIMED_WAITING
-------------分割線-------------
thread2: BLOCKED
最後更新：2017-10-28 12:04:04