下面的代码是一个简单的死锁问题
如果把Object对象前的static去掉 则死锁问题就不存在了
即把“static Object o1 = new Object(),o2 = new Object();”改为
“Object o1 = new Object(),o2 = new Object();”后 就不存在死锁问题了
请问哪位大虾知道为什么吗 ... ? 谢谢 public class DeadLock { /**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
runLock r1 = new runLock();
runLock r2 = new runLock();
Thread t1 = new Thread(r1);
Thread t2 = new Thread(r2);
r1.flag = 0;
r2.flag = 1;
t1.start();
t2.start();
}}
class runLock implements Runnable
{
int flag = 0;
static Object o1 = new Object(),o2 = new Object();
public void run() {
System.out.println("flag = " + flag);
if(flag == 0)
{
synchronized(o1)
{
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized(o2)
{
System.out.println("flag ===0 Thread...");
}
}
}
if(flag == 1)
{
synchronized(o2)
{
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized(o1)
{
System.out.println("flag ===1 Thread...");
}
} }
}
}
如果把Object对象前的static去掉 则死锁问题就不存在了
即把“static Object o1 = new Object(),o2 = new Object();”改为
“Object o1 = new Object(),o2 = new Object();”后 就不存在死锁问题了
请问哪位大虾知道为什么吗 ... ? 谢谢 public class DeadLock { /**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
runLock r1 = new runLock();
runLock r2 = new runLock();
Thread t1 = new Thread(r1);
Thread t2 = new Thread(r2);
r1.flag = 0;
r2.flag = 1;
t1.start();
t2.start();
}}
class runLock implements Runnable
{
int flag = 0;
static Object o1 = new Object(),o2 = new Object();
public void run() {
System.out.println("flag = " + flag);
if(flag == 0)
{
synchronized(o1)
{
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized(o2)
{
System.out.println("flag ===0 Thread...");
}
}
}
if(flag == 1)
{
synchronized(o2)
{
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
synchronized(o1)
{
System.out.println("flag ===1 Thread...");
}
} }
}
}
2楼的解释更直接
一般来说 用同步是用在类里面的某个需要同步的方法而不是用在对象上