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Sharath Kumar
Sharath Kumar

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What is Synchronization in Java?

#synchronization #java

Synchronization in Java is a mechanism used to control access to shared resources when multiple threads are executing simultaneously. It ensures that only one thread can access a critical section of code at a time, preventing data inconsistency and unexpected results.

In multithreading, when several threads try to modify the same data, problems like race conditions may occur. Synchronization helps maintain data integrity by allowing threads to execute sequentially where required.

🔹 Why is Synchronization Needed?

When multiple threads share the same object or variable:

  • Data may get corrupted
  • Output may become unpredictable
  • Application behavior may become inconsistent

Synchronization solves these issues by locking the resource during execution.

🔹 Example Without Synchronization 

class Counter {
    int count = 0;

    void increment() {
        count++;
    }
}
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If multiple threads call increment(), the value of count may not be accurate because operations overlap.

🔹 Example With Synchronization 

class Counter {
    int count = 0;

    synchronized void increment() {
        count++;
    }
}
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Here, only one thread can execute the increment() method at a time.

🔹 Ways to Achieve Synchronization

  1. Synchronized Method 
synchronized void display() { }
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  1. Synchronized Block 
synchronized(this) {
   // critical section
}
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  1. Static Synchronization Used when locking is required at the class level.

🔹 Advantages of Synchronization

✅ Prevents data inconsistency
✅ Avoids race conditions
✅ Ensures thread safety
✅ Maintains proper execution order

🔹 Disadvantages

❌ Can reduce performance if overused
❌ Threads may wait longer (blocking)

✅ Conclusion

Synchronization is an essential concept in Java multithreading that ensures safe access to shared resources. Proper use of synchronization helps developers build reliable and thread-safe enterprise applications.

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