The only guide you’ll need on concurrency & multithreading for senior engineers. Pressure test your skills with real-world practice problems from top companies.

Concurrency in Java is one of the most complex and advanced topics brought up during senior engineering interviews. Knowledge of concurrency and multithreading can put interviewees at a considerable advantage. This course lays the foundations of advanced concurrency and multithreading and explains concepts such as Monitors and Deferred Callbacks in depth. It also builds simple and complete solutions to popular concurrency problems that can be asked about in interviews like the Reader-Writer Problem and the Dining Philosopher Problem. While prior knowledge of concurrency is not required to follow through with this course, familiarity with the very basics of concurrency would be helpful.

Java Multithreading for Senior Engineering Interviews

## Lock Fairness

We'll briefly touch on the topic of fairness in locks since its out of scope for this course. When locks get acquired by threads, there's no guarantee of the order in which threads are granted access to a lock. A thread requesting lock access more frequently may be able to acquire the lock unfairly greater number of times than other locks. Java locks can be turned into fair locks by passing in the fair constructor parameter. However, fair locks exhibit lower throughput and are slower compared to their unfair counterparts.

 ## Thread Pools
 
Imagine an application that creates threads to undertake short-lived tasks. The application would incur a performance penalty for first creating hundreds of threads and then tearing down the allocated resources for each thread at the ends of its life. The general way programming frameworks solve this problem is by creating a pool of threads, which are handed out to execute each concurrent task and once completed, the thread is returned to the pool
Java offers thread pools via its Executor Framework. The framework includes classes such as the <code class="b_blue">ThreadPoolExecutor</code> for creating thread pools.

# Lock Fairness

We'll briefly touch on the topic of fairness in locks since its out of scope for this course. When locks get acquired by threads, there's no guarantee of the order in which threads are granted access to a lock. A thread requesting lock access more frequently may be able to acquire the lock unfairly greater number of times than other locks. Java locks can be turned into fair locks by passing in the fair constructor parameter. However, fair locks exhibit lower throughput and are slower compared to their unfair counterparts.

 ## Thread Pools
 
Imagine an application that creates threads to undertake short-lived tasks. The application would incur a performance penalty for first creating hundreds of threads and then tearing down the allocated resources for each thread at the ends of its life. The general way programming frameworks solve this problem is by creating a pool of threads, which are handed out to execute each concurrent task and once completed, the thread is returned to the pool
Java offers thread pools via its Executor Framework. The framework includes classes such as the <code class="b_blue">ThreadPoolExecutor</code> for creating thread pools.

# Lock Fairness

We'll briefly touch on the topic of fairness in locks since its out of scope for this course. When locks get acquired by threads, there's no guarantee of the order in which threads are granted access to a lock. A thread requesting lock access more frequently may be able to acquire the lock unfairly greater number of times than other locks. Java locks can be turned into fair locks by passing in the fair constructor parameter. However, fair locks exhibit lower throughput and are slower compared to their unfair counterparts.

 ## Thread Pools
 
Imagine an application that creates threads to undertake short-lived tasks. The application would incur a performance penalty for first creating hundreds of threads and then tearing down the allocated resources for each thread at the ends of its life. The general way programming frameworks solve this problem is by creating a pool of threads, which are handed out to execute each concurrent task and once completed, the thread is returned to the pool
Java offers thread pools via its Executor Framework. The framework includes classes such as the <code>ThreadPoolExecutor</code> for creating thread pools.

The Basics

Multithreading in Java

Java's Memory Model

Interview Practice Problems

Bonus Questions

Beyond the Interview

Java Concurrency Reference

Revision & Quizzes

Miscellaneous Topics

Lock Fairness