Synchronization Block in Java

A synchronization block in Java is a specific section of code that is synchronized to allow only one thread to execute it at a time. This provides a way to control access to shared resources and ensure thread safety in multi-threaded environments.

Key Points on Synchronization Block:

• Granular Control: Synchronization blocks allow you to lock only specific parts of your code rather than entire methods, providing more granular control over synchronization.
• Object Locking: You can synchronize on any object, not just the instance of the class. This is useful for synchronizing access to resources that are shared across multiple threads.
• Improved Performance: By limiting the scope of synchronization, you can reduce the performance overhead associated with locking and increase concurrency.
• Preventing Deadlock: Careful design of synchronization blocks can help prevent deadlock situations when multiple threads are trying to acquire locks.

Syntax of Synchronization Block:

The basic syntax of a synchronization block is as follows:

synchronized (object) {
            // Code to be synchronized
        }

Example of Synchronization Block:

This example demonstrates how to use a synchronization block to increment a shared counter safely:

class Counter {
            private int count = 0;
        
            public void increment() {
                synchronized (this) { // Synchronizing on the current instance
                    count++;
                }
            }
        
            public int getCount() {
                return count;
            }
        }
        
        public class SynchronizationBlockExample {
            public static void main(String[] args) {
                Counter counter = new Counter();
        
                // Creating multiple threads to increment the counter
                Thread thread1 = new Thread(() -> {
                    for (int i = 0; i < 1000; i++) {
                        counter.increment();
                    }
                });
        
                Thread thread2 = new Thread(() -> {
                    for (int i = 0; i < 1000; i++) {
                        counter.increment();
                    }
                });
        
                thread1.start();
                thread2.start();
        
                try {
                    thread1.join();
                    thread2.join();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
        
                System.out.println("Final Count: " + counter.getCount());
            }
        }

Output:

Conclusion:

Synchronization blocks are a powerful feature in Java for managing access to shared resources in multi-threaded applications. By carefully designing synchronization blocks, developers can enhance the performance and safety of their applications while minimizing the risk of thread interference.

Best Practices:

• Use Lock Objects: Consider using specific lock objects instead of using this to synchronize if you want to prevent other methods in the same object from being synchronized unintentionally.
• Minimize Synchronized Code: Keep synchronized blocks as small as possible to reduce contention and increase throughput.
• Document Locking Strategy: Clearly document the locking strategy in your code to make it easier for others (or yourself) to understand the synchronization logic later.