Multithreading, Locks, Concurrency Hazards, and a Bounded Queue Design

Context: Technical screen for a software engineering role. You are asked to demonstrate understanding of multithreading primitives, concurrency pitfalls, and to implement a thread-safe bounded queue supporting multiple producers and consumers using condition variables.

Tasks

1. Explain how multithreading works and when to use locks.
2. Compare mutexes, semaphores, and read–write locks: pros/cons and appropriate use cases.
3. Identify race conditions, deadlocks, livelocks, and starvation; outline concrete avoidance strategies (e.g., lock ordering, timeouts, backoff, minimizing critical sections).
4. Design and implement a thread-safe bounded queue (multiple producers and consumers) using condition variables.
5. Describe how you would test it for correctness and performance.