Concurrency and Multithreading

Practice 25 Concurrency and Multithreading interview questions with detailed answers. Part of the Concurrency And Multithreading track on Java Interview Hub.

• How would you ensure that a shared resource is accessed safely by multiple threads?
• Explain the synchronized keyword in Java. How does it work?
• What are the differences between using synchronized on a method versus on a block of code?
• What is the significance of the volatile keyword in Java concurrency?
• How does the introduction of Lambda expressions change the way Java handles concurrency?
• Explain the Java concurrency model.
• What are the challenges associated with Java’s thread management?
• Can volatile variables be used as a replacement for synchronization?
• Can a deadlock occur with a single thread?
• What is a synchronized collection, and how does it differ from a concurrent collection?
• How does Java handle multi-threading?
• What are the differences between Runnable and Callable in Java concurrency?
• How do you handle thread interruption in Java?
• How do you check if a Thread holds a lock or not?
• What are use cases of ThreadLocal variables in Java?
• What is the role of ExecutorService in the Executor Framework? What methods does it provide?
• What is the difference between submit() and execute() methods in the Executor Framework?
• What is the RejectedExecutionHandler in ThreadPoolExecutor? How can you customize it?
• How does ConcurrentHashMap work internally?
• Difference Between synchronized and ReentrantLock?
• What happens when an exception occurs inside a synchronized block?
• How do you get a thread dump in Java?
• How to get a thread dump in Java?
• What are the different ways to achieve synchronization in Java?
• What is the difference between synchronized method and synchronized block?