Java Multithreading: Race conditions in shared mutable state

Multiple threads update a shared counter, but the final value doesn't match the expected result. Why does this happen, and how do I fix it?

When threads concurrently access and modify shared state without proper synchronization, race conditions occur because operations like count++ are not atomic. It splits into read-modify-write, which can interleave unpredictably GeeksforGeeks+14jenkov.com+14Reddit+14Reddit+3Reddit+3Reddit+3Medium. 🛠️ Solutions • Synchronized methods or blocks: java Copy code public synchronized void increment() { counter++; } public synchronized int getValue() { return counter;} Ensures only one thread can run the operation at onceBaeldung • Use atomic classes like AtomicInteger for built-in thread-safe increments: java Copy code AtomicInteger counter = new AtomicInteger(0); counter.incrementAndGet(); These approaches prevent interleaving and ensure correct final state under concurrency.

🧷 Tags for Posting Use these tags to categorize your post effectively: • Memory leak: java, memory-leaks, garbage-collection, resource-management • Null safety: java, nullpointerexception, null-safety, optional, annotations • Concurrency: java, multithreading, synchronization, race-condition, atomic