public class ThreadLock implements Runnable{ static Object o1 = new Object(); //对象o1
static Object o2 = new Object(); //对象o2
int flag = 1; //标记public void run (){
System.out.println("flag="+flag);
//线程t1
if(flag == 1)
{
synchronized(o1)
{
try{
Thread.sleep(10000); }catch(InterruptedException e){e.printStackTrace();}
System.out.println("t1.o1");
}
synchronized(o2)
{
System.out.println("t1.o2");
}
}
//线程t2
if( flag == 0)
{
synchronized(o2)
{
try{
Thread.sleep(10000); }catch(InterruptedException e){e.printStackTrace();}
System.out.println("t2.o2"); }
synchronized(o1)
{
System.out.println("t2.o1");
}
}
} public static void main(String[] args) {
ThreadLock tl = new ThreadLock();
ThreadLock ty = new ThreadLock();
tl.flag = 1;
ty.flag = 0;
Thread t1 = new Thread(tl); //t1先锁对象o1后再锁对象o2
Thread t2 = new Thread(ty); //t2先锁对象o2后再锁对象o1t1.start();
t2.start();
}
} 请问以上的代码为什么产生不了死锁
public int flag = 1;
static Object o1 = new Object(), o2 = new Object();
public void run() {
System.out.println("flag=" + flag);
if(flag == 1) {
synchronized(o1) {
try {
Thread.sleep(500);
} catch (Exception e) {
e.printStackTrace();
}
synchronized(o2) {
System.out.println("1");
}
}
}
if(flag == 0) {
synchronized(o2) {
try {
Thread.sleep(500);
} catch (Exception e) {
e.printStackTrace();
}
synchronized(o1) {
System.out.println("0");
}
}
}
}
public static void main(String[] args) {
TestDeadLock td1 = new TestDeadLock();
TestDeadLock td2 = new TestDeadLock();
td1.flag = 1;
td2.flag = 0;
Thread t1 = new Thread(td1);
Thread t2 = new Thread(td2);
t1.start();
t2.start();
}
}那为什么以上的代码就产生了死锁的现象?