📚 Main Topics

1. Java Lock Interface

   • Represents a lock to guard critical sections.
   • Ensures that only one thread can access a critical section at a time.

2. Reentrant Lock

   • A class that implements the Lock interface.
   • Allows a thread to lock the same lock multiple times without blocking itself.

3. Synchronized Blocks vs. Locks

   • Comparison of using synchronized blocks and locks for thread synchronization.
   • Differences in reentrance, fairness, and method spanning.

4. Locking Mechanisms

   • Use of try-finally blocks for safe locking and unlocking.
   • Methods like lock(), unlock(), tryLock(), and lockInterruptibly().

5. Fairness in Locks

   • Explanation of fairness and starvation in thread scheduling.
   • How to implement fairness in reentrant locks.

✨ Key Takeaways

• Critical Section ManagementLocks are essential for managing access to critical sections in concurrent programming.
• ReentranceReentrant locks allow a thread to acquire the same lock multiple times, preventing deadlock scenarios.
• Thread BlockingWhile one thread holds a lock, other threads attempting to acquire the same lock will be blocked until it is released.
• FairnessLocks can be configured to ensure fairness, preventing starvation where a thread may never get access to the lock.
• Error HandlingAlways use try-finally blocks when locking to ensure that locks are released even if an exception occurs.

🧠 Lessons Learned

• Use Locks WiselyUnderstanding when to use locks versus synchronized blocks can lead to better performance and fewer concurrency issues.
• Implementing FairnessWhen many threads are competing for a lock, enabling fairness can help avoid starvation and ensure that all threads get a chance to execute.
• Thread SafetyAlways ensure that shared resources are accessed in a thread-safe manner to prevent data corruption and unexpected behavior.
• Performance ConsiderationsFairness comes with a performance cost; assess whether it is necessary based on the application's concurrency requirements.