1.死鎖代碼

//死鎖：多個(gè)線程互相抱著對(duì)方需要的資源，然后形成僵局 public class DeadLock {public static void main(String[] args) {Makeup girl1 = new Makeup(0,"灰姑娘");Makeup girl2 = new Makeup(1,"白雪公主");girl1.start();girl2.start();}}//口紅 class Lipstick{}//鏡子 class Mirror{}class Makeup extends Thread{//需要的資源只能有一份，用static來(lái)保證只有一份static Lipstick lipstick = new Lipstick();static Mirror mirror = new Mirror();int choice;//選擇String girlName;//使用化妝品的人public Makeup(int choice, String girlName) {this.choice = choice;this.girlName = girlName;}@Overridepublic void run(){try {makeup();//化妝} catch (InterruptedException e) {e.printStackTrace();}}private void makeup() throws InterruptedException {if (choice == 0){synchronized (lipstick){//獲得口紅的鎖System.out.println(this.girlName+"獲得口紅的鎖");Thread.sleep(1000);synchronized (mirror){//一秒鐘后想獲得鏡子System.out.println(this.girlName+"獲取鏡子的鎖");}}}else {synchronized (mirror){//獲得鏡子的鎖System.out.println(this.girlName+"獲得鏡子的鎖");Thread.sleep(2000);synchronized (lipstick){//兩秒鐘后，想獲得口紅System.out.println(this.girlName+"獲取口紅的鎖");}}}} }

關(guān)鍵代碼

private void makeup() throws InterruptedException {if (choice == 0){synchronized (lipstick){//獲得口紅的鎖System.out.println(this.girlName+"獲得口紅的鎖");Thread.sleep(1000);synchronized (mirror){//一秒鐘后想獲得鏡子System.out.println(this.girlName+"獲取鏡子的鎖");}}}else {synchronized (mirror){//獲得鏡子的鎖System.out.println(this.girlName+"獲得鏡子的鎖");Thread.sleep(2000);synchronized (lipstick){//兩秒鐘后，想獲得口紅System.out.println(this.girlName+"獲取口紅的鎖");}}}}

上述代碼解析，當(dāng)一個(gè)線程A鎖住口紅不放，同時(shí)想拿鏡子
但是鏡子被線程B鎖住，線程B要拿到了口紅才會(huì)釋放鏡子
那么線程A就會(huì)一直等待線程B釋放鏡子鎖
但是線程B要拿不到口紅鎖就不會(huì)釋放鏡子鎖
所以兩個(gè)線程互相等待，形成死鎖，程序崩潰
運(yùn)行結(jié)果

2.解決后的代碼

private void makeup() throws InterruptedException {if (choice == 0){synchronized (lipstick){//獲得口紅的鎖System.out.println(this.girlName+"獲得口紅的鎖");Thread.sleep(1000);}synchronized (mirror){//一秒鐘后想獲得鏡子System.out.println(this.girlName+"獲取鏡子的鎖");}}else {synchronized (mirror){//獲得鏡子的鎖System.out.println(this.girlName+"獲得鏡子的鎖");Thread.sleep(2000);}synchronized (lipstick){//兩秒鐘后，想獲得口紅System.out.println(this.girlName+"獲取口紅的鎖");}}}

線程A拿到了口紅鎖，然后釋放了口紅鎖，想拿鏡子鎖
線程B拿到了鏡子鎖，然后釋放了鏡子鎖，再拿口紅鎖
雙方達(dá)成共識(shí)，不會(huì)永久的等待

運(yùn)行結(jié)果

總結(jié)

以上是生活随笔為你收集整理的java线程（16）——死锁讲解，白雪公主与灰姑娘抢口红和镜子的案例的全部?jī)?nèi)容，希望文章能夠幫你解決所遇到的問(wèn)題。

如果覺(jué)得生活随笔網(wǎng)站內(nèi)容還不錯(cuò)，歡迎將生活随笔推薦給好友。