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Thread.Sleep

 
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Found this on a mock exam......
public synchronized void someMethod()
{
//lots of code
try
{
Thread.sleep(500);
}
catch(InterruptedException e)
{ }

}
1. The code causes compilation error - sleep cannot be called inside synchronized methods.
2. The code causes compilation error - sleep is not a static method of java.lang.Thread
3. The Thread sleeps for at least 500 milliseconds in this method if not interrupted.
4. When the thread "goes to sleep" it releases the lock on the object.
5. The "sleeping" Threads always have the lock on the Object.
The answer given is 3 & 5. I didn't find this correct.... I think the answer is 3 & 4 as a Thread does give up the lock on an object if it goes to sleep.
Can somebody please verify this..???
Thanks,
Shafeeq
 
Wanderer
Posts: 18671
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Nope. A thread will give up a lock when it calls the wait() method, but not for sleep().
 
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..and what about the yeild() method? Does it give up the lock in the synchronized code? I think it does.

Originally posted by Jim Yingst:
Nope. A thread will give up a lock when it calls the wait() method, but not for sleep().


 
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IMHO
Nope, Thread.yield() does NOT give up the monitor either!
 
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Yup, yield() will only let another thread work on, has nothing to do with the lock on the object.
Regards,
Khalid
 
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