thread problem

Posted on 2001-06-18
Medium Priority
Last Modified: 2012-05-04
 i am having a problem with NOTIFY and WAIT. when i create a thread using :
    new ABC().start() ... where ABC class extends Thread.i guess since i am always doing NEW of ABC() for all threads a new instance variable is declared .... so i gues my NOTIFY and WAIT doesn't work .... my NOTIFY and WAIT WORK when i create only one RUNNABLE object and pass the same object to all the threads.
 Now i have figured out that if i create only one instance of Runnable object (i.e ABC() implements Runnable) .... my notify and wait works fine since all the thread share same instance variable and i can lock and realease on the ONLY instace that is shared by all the threads.
 But i have a problem here ... now if i wanna set a parameter for each thread like : new ABC(params ..) ... i will have to do NEW ABC() everythime and i guess my notify and wait will NOT WORK ...

Help please

Question by:pravin_tiwari
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Expert Comment

ID: 6203436
on which object do you wait() and notify()?

why not create a
static Object notifier = new Object();

to have one instance for all ob your Abc Threads to wait on?
LVL 16

Expert Comment

ID: 6203633
From your description, it is not clear that you even need wait/notify synchronization. Synchronization is a methodology that is used to coordinate access by multiple threads to a SHARED resource. As long as your mulitple threads are all using their own (instance) variables, there is no need to synchronize, because they cannot interfere with each other. Again, it is only when there are multiple threads that are all trying to manipulate a single shared variable (or other resource) that there can be a problem which would require synchronization to solve. An instance variable (for instance) is not shared among threads. A static variable (on the other hand) could be.

Perhaps an example of your code would help to clarify things.


Expert Comment

ID: 6957052
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Expert Comment

ID: 6991402
I doubt either of us provided any actual information. I was mostly fishing around trying to solicit some response that would clarify the problem. teast is also obviously guessing.

Accepted Solution

Moondancer earned 0 total points
ID: 7055099
Without Asker's participation in his/her own question, this is tough.  Points refunded, item closed.  I very much appreciate the expert help here, and am always saddened when help is requested/given and then .... nothing....
Moondancer - EE Moderator

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