Simple delay function in java code#
maximum 5 resources can exist inside ‘taskQueue’ at any given time.īelow is the code for producer thread based on our requirements : Consumer thread takes 1 seconds to process consumed resource from ‘taskQueue’.Producer thread produce a new resource in every 1 second and put it in ‘taskQueue’.
To keep program simple and to keep focus on usage of wait() and notify() methods, we will involve only one producer and one consumer thread. In this exercise, we will solve producer consumer problem using wait() and notify() methods.
Simple delay function in java how to#
How to use with wait(), notify() and notifyAll() methods Let’s write a small program to understand how wait(), notify(), notifyall() methods should be used to get desired results. It is on developer’s hand to specify the condition to be checked before calling wait() or notify(). The wait-and-notify mechanism does not specify what the specific condition/ variable value is.
When another thread establishes the condition (typically by setting the same variable), it calls the notify() method. In general, a thread that uses the wait() method confirms that a condition does not exist (typically by checking a variable) and then calls the wait() method. Other things are same as notify() method above. The highest priority thread will run first in most of the situation, though not guaranteed. It wakes up all the threads that called wait() on the same object. General syntax for calling notify() method is like this:
So, if a notifier calls notify() on a resource but the notifier still needs to perform 10 seconds of actions on the resource within its synchronized block, the thread that had been waiting will need to wait at least another additional 10 seconds for the notifier to release the lock on the object, even though notify() had been called. However, the lock is not actually given up until the notifier’s synchronized block has completed. It tells a waiting thread that that thread can wake up. It should be noted that calling notify() does not actually give up a lock on a resource. It wakes up one single thread that called wait() on the same object. General syntax for calling wait() method is like this: In other words, it is not possible for us to implement the wait() method purely in Java. The wait() method is actually tightly integrated with the synchronization lock, using a feature not available directly from the synchronization mechanism. The wait() method releases the lock prior to waiting and reacquires the lock prior to returning from the wait() method. It tells the calling thread to give up the lock and go to sleep until some other thread enters the same monitor and calls notify(). The Object class in Java has three final methods that allow threads to communicate about the locked status of a resource. What are wait(), notify() and notifyAll() methods? Read more : Difference between wait() and sleep() in Java 1. We will understand the difference between wait and notify. In this tutorial, I am discussing the purpose of wait() notify() notifyall() in Java. A good knowledge around these methods will help you in such situation when arrived. I will also recommend to use these newer APIs over synchronization yourself, BUT many times we are required to do so for various reasons e.g. Programmers using concurrency classes will feel a lot more confident than programmers directly handling synchronization stuff using wait(), notify() and notifyAll() method calls. Java 5, introduced some classes like BlockingQueue and Executors which take away some of the complexity by providing easy to use APIs. Java concurrency is pretty complex topic and requires a lot of attention while writing application code dealing with multiple threads accessing one/more shared resources at any given time.
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