如下代码,应该会 死 锁的,为啥 不会死锁?
public class TestDeadLock implements Runnable
{
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(200);
}
catch(Exception e)
{
e.printStackTrace();
}
}
synchronized(o2)
{
System.out.println("1");
}
}
if(flag == 0)
{
synchronized(o2)
{
try
{
Thread.sleep(200);
}
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();
}
}
public class TestDeadLock implements Runnable
{
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(200);
}
catch(Exception e)
{
e.printStackTrace();
}
}
synchronized(o2)
{
System.out.println("1");
}
}
if(flag == 0)
{
synchronized(o2)
{
try
{
Thread.sleep(200);
}
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();
}
}
t2.start();写错了吗?
t1.run();
t2.run();
Thread.sleep(1000);
{
System.out.println("1");
}把上面的代码放在synchronized(o1)代码块里面试试。
if(flag == 1)
{
synchronized(o1)
{
try
{
Thread.sleep(200);
}
catch(Exception e)
{
e.printStackTrace();
}
synchronized(o2) //在synchronized(o1)里面。
{
System.out.println("1");
}
}
}
{
synchronized(o1)
{
try
{
Thread.sleep(200);
}
catch(Exception e)
{
e.printStackTrace();
}
}
synchronized(o2)
{
System.out.println("1");
}
}
写错了
这样
if(flag == 1)
{
synchronized(o1)
{
try
{
Thread.sleep(200);
}
catch(Exception e)
{
e.printStackTrace();
}
synchronized(o2)
{
System.out.println("1");
} }
估计会死
if (flag == 1) {
synchronized (o1) {
try {
Thread.sleep(200);
} catch (Exception e) {
e.printStackTrace();
} synchronized (o2) {
System.out.println("1");
}
}
}
哥们儿 别人用的是线程 当然是用start();
如果用run的话只是单纯的调用方法 没有多线程的作用