Synchronised Method in Java Meaning

In Java, a synchronized method is a method that can only be accessed by one thread at a time. This means that when one thread is executing a synchronized method for an object, all other threads that try to invoke synchronized methods for the same object will block (suspend execution) until the first thread is done with the object.

A synchronized method in Java provides two key benefits: it ensures that only one thread can access the object's shared state at any given time, and it also establishes a happens-before relationship with any subsequent invocation of a synchronized method for the same object. This means that when one thread is executing a synchronized method, all other threads that try to execute a synchronized method on the same object will wait until the first thread is done.

In Java, synchronization is achieved using the `synchronized` keyword. When a method is declared as `synchronized`, it means that only one thread can access the method at any given time. This ensures that shared mutable variables are accessed in a thread-safe manner.

For example, consider an instance of a class called `SynchronizedCounter`. If we have two threads that increment the counter using synchronized methods, it is not possible for these threads to interleave their executions. This means that one thread will complete its increment operation before another thread starts its increment operation.

In contrast, if we do not use synchronization and multiple threads access a shared mutable variable without synchronizing their access, we can experience race conditions, where the actual result varies with every execution of the code. In this case, it is possible for two threads to read the same current value and then both try to write their new values, resulting in lost writes.

In Java 8, synchronization can be achieved using lambda expressions and new concurrency features. This allows developers to write more concise and efficient multi-threaded code.

Overall, synchronized methods in Java provide a way to ensure thread safety when accessing shared mutable variables from multiple threads. By declaring a method as `synchronized`, we can guarantee that only one thread can access the method at any given time, which ensures that our code is free from race conditions and other concurrency issues.

Synchronised method in java meaning