public class ThreadLock implements Runnable{ static Object o1 = new Object();
static Object o2 = new Object();
int flag = 1; public void run (){
System.out.println("flag="+flag);
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");
}
}
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) {
// TODO Auto-generated method stub
ThreadLock tl = new ThreadLock();
ThreadLock ty = new ThreadLock();
tl.flag = 1;
ty.flag = 0;
Thread t1 = new Thread(tl);
Thread t2 = new Thread(ty);
t1.start();
t2.start();
}
}
把代码改了一下,估计可以发生public class ThreadLock implements Runnable { static Object o1 = new Object();
static Object o2 = new Object();
int flag = 1; public void run() {
System.out.println("flag=" + flag);
if (flag == 1) {
for(int i=0;i<10;i++) {
synchronized (o1) {
try {
Thread.sleep(100);
}
catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("t1.o1"); synchronized (o2) {
System.out.println("t1.o2");
} }
}
}
if (flag == 0) {
for(int i=0;i<10;i++) {
synchronized (o2) {
try {
Thread.sleep(100);
}
catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("t2.o2"); synchronized (o1) {
System.out.println("t2.o1");
} }
}
}
} public static void main(String[] args) {
// TODO Auto-generated method stub ThreadLock tl = new ThreadLock();
ThreadLock ty = new ThreadLock();
tl.flag = 1;
ty.flag = 0;
Thread t1 = new Thread(tl);
Thread t2 = new Thread(ty); t1.start();
t2.start();
}
}
之所以没有出现死锁,肯定是死锁条件不具备.
synchronized (o1) 与synchronized (o2)中代码块没有涉及到对象的互相堵塞.