Re: notify() and wait()
On Jan 9, 6:28 pm, Patricia Shanahan <p...@acm.org> wrote:
Tom Anderson wrote:
On Sat, 9 Jan 2010, Jack wrote:
I have two threads: thread1 and thread2 and use myObject for
synchronization.
Object myObject = new Object();
If thread1 calls myObject.notify() first, then thread2 calls
myObject.wait(). The wait() still blocks thread2, right?
In general, it is difficult to control the timing of notify() and wait
() call. How to prevent this situation.
I suspect that what you really want is a CountDownLatch:
http://java.sun.com/javase/6/docs/api/java/util/concurrent/CountDownL...
Not necessarily. The original question could have been exactly the same
if, for example, the OP were trying to build a blocking queue from first
principles. I think the first step in building communication between
threads should be to look at java.util.concurrent, without
preconceptions, to see whether any of its classes does the job.
Patricia
Thank you all for your replies.
My application is that: Thread1 wakes up every five hours to do a job;
Thread2 wakes up Thread1 if the application is to be shut down. So
Thread2 is mainly for preventing the program from hanging there.
So the code is like:
Static boolean conditionIsTrue = false;
//For Thread1:
while(conditionIsTrue)
{
doTheJob();
Synchronized(myObject)
{
myObject.wait(//for 5 hours);
}
}
//For Thread2:
shutDown()
{
conditionIsTrue = false;
Synchronized(myObject)
{
myObject.notify();
}
}
Can java.util.concurrent solve my problem?
Thanks.
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