Create Deadlock with Multithreading in Java

Deadlock is a state where one thread waits for another thread to release a resource and the another thread also waits for some resources. This leads to a situation where the threads will wait for infinite time.

This scenario can be created using java code where an object can be treated a common resource.

Example of deadlock in java:

public class SharedResource {

synchronized void method1(SharedResource sr) {

System.out.println("Method 1");

sr.method2(this);

}

synchronized void method2(SharedResource sr) {

System.out.println("Method 2");

sr.method1(this);

}

}

public class TestMain {

public static void main(String[] args) throws InterruptedException {

SharedResource sc1 = new SharedResource();

SharedResource sc2 = new SharedResource();

Thread t1 = new Thread(() -> {

sc1.method1(sc2);

});

Thread t2 = new Thread(() -> {

sc2.method2(sc1);

});

t1.start();

t2.start();

t1.join();

t2.join();

}

}

As you can see in the main method, there are two threads t1 and t2. Both will wait for a common resource to be released by the another thread. But another thread is also waiting for the same resource.