Explain deadlock cases and how to prevent them
Company: Microsoft
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: medium
Interview Round: Technical Screen
You are asked in an interview to discuss deadlocks in concurrent programming.
1) What is a deadlock?
2) What conditions must hold for a deadlock to be possible?
3) Give several concrete examples of deadlock scenarios (e.g., two threads and two locks), including at least one involving more than two locks or a circular wait.
4) How can deadlocks be prevented, avoided, detected, and/or recovered from in practice? Provide common engineering techniques and trade-offs.
Quick Answer: This question evaluates understanding of deadlocks, concurrency control, and resource synchronization in concurrent programming, testing competency in identifying the necessary conditions for deadlock, analyzing concrete scenarios including circular waits, and considering engineering approaches for prevention, detection, and recovery.