Difference between yield and wait method in Java? Answer

Yield vs wait in Java
The yield and wait methods in Java, though both are related to Threads,  are completely different to each other. The main difference between wait and yield in Java is that wait() is used for flow control and inter-thread communication while yield is used just to relinquish CPU to offer an opportunity to another thread for running. In this Java tutorial, we will what are differences between the wait and yield method in Java and when to use wait() and yield(). What is important for a Java programmer is not only to understand the difference between the wait() and yield() method but also to know the implications of using the yield method. 

If your program depends upon the yield method for performance or correctness then its most likely does not work perfectly on all platforms because of platform dependent nature of the yield method which we will see in this Java article along with wait vs yield comparison.

This is the second part of understanding three key methods used to pause threads in Java, Thread.sleep(), Thread.yield() and Object.wait() methods. In our earlier article, we have discussed the difference between the sleep and yield method of the Thread class. If you have not read it already, you should check that out as well.




Difference between wait and yield in Java? Answer

Here is a list of differences between the Yield and wait for method in Java, good to remember for Java interviews :


1. Location
The first difference between the wait vs yield method is that wait() is declared in java.lang.Object class while Yield is declared on java.lang.Thread class.

2. Overloaded
The second difference between wait and yield in Java is that wait is an overloaded method and has two versions of wait, normal and timed wait while yield is not overloaded.

3. Instance method
The third difference between wait and yield is that wait is an instance method while yield is a static method and works on the current thread.

4. How to call
Another Java best practice that differentiates wait and yield is that it's advised to call the wait method inside the loop but the yield is better to be called outside of the loop.

5. Synchronized context
The fifth difference between yield vs wait which is quite important as well is that wait() method must be called from either synchronized block or synchronized method, There is no such requirement for the Yield method.

6. Monitor
Another difference between wait and yield is that When a Thread call waits it releases the monitor. You can further check out these Java Multithreading and Concurrency courses to learn more about the wait, yield, and other important methods of Thread class and Concurrency API in Java. 




That's all on the difference between the wait and yield method in Java. In summary wait and yield are completely different and therefore different purposes. Use wait for inter-thread communication while yield is not just reliable enough even for the mentioned task. prefer Thread.sleep(1) instead of yield.



Other Java Multithreading Tutorials you should check out :
  • What is the difference between notify and notifyAll in Java? (answer)
  • What is the difference between synchronized block vs method in Java? (answer)
  • Difference between Runnable and Callable interface in Java? (answer)
  • How to solve Producer-Consumer Problem using wait and notify in Java? (solution)
  • Difference between Thread and Runnable in Java? (answer)
  • Where to use a volatile variables in Java? (answer)
  • Top 12 Multithreading and Concurrency Interview Questions and Answers (answer)

2 comments:

  1. Did you thought about using busy spinning instead of yield or wait, as part of your wait strategy in Java multithreading? Can you please list down some advantage and disadvantage of using busy spinning over yied or wait() method?

    ReplyDelete

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