What is the Thread.yield() function in Java?

The static function Thread.yield() interrupts the scheduler that the current thread is willing to yield the CPUCentral Processing Unit utilization.

Yield is a heuristic or triggering of the CPU to improve the relative progression between two threads or processes. Otherwise, CPU over-utilization occurs.

Note: Programmers use this method, especially for testing and debugging purposes.

Syntax

static void yield()

Return value

This function does not return any value(s).

Code example

The code snippet given below demonstrates how the yield() function works:

// Demo program to check yield() method

// Edpresso class which is implementing Thread class

class Edpresso extends Thread {

   public void run() {

      int i=0;

      while(i!= 2){

         // After calling yield(), it will stop Edpresso execution

         Thread.yield(); 

         System.out.println("Edpresso thread started:" + Thread.currentThread().getName());

         i++;

      }

      System.out.println("Edpresso thread ended:" + Thread.currentThread().getName());

   }

}

// Main class to create another thread.

class Main {

   public static void main(String[] args) {

      Edpresso thread = new Edpresso();

      // starting Edpresso thread execution

      thread.start();

      int i=0;

      while(i!= 2) {

         System.out.println("Main thread started:" + Thread.currentThread().getName());

         i++;

      }

      System.out.println("Main thread ended:" + Thread.currentThread().getName());

   }

}

Code explanation

  • Line 3: We inherit the Edpresso class from the Thread class.
  • Line 8: We invoke the yield() function on the current thread.
  • Line 18: We create a new thread instance of the Edpresso type.
  • Line 20: We start the thread that we created in line 18 to test the working of the yield() function.

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