Code Room
Code reviewMedium
Question
Review this Java method using an explicit ReentrantLock.
What concurrency-relevant failure does this have?
What a strong answer looks like
Separate real bugs from style. Rank issues by severity, point at the root cause rather than the symptom, and suggest a concrete fix — specific and kind.
Learn the concepts
class Ledger { private final ReentrantLock lock = new ReentrantLock(); private long total; long applyAndRead(long delta) { lock.lock(); total += delta; long snapshot = expensiveAudit(total); // (1) may throw lock.unlock(); return snapshot; }}Run or narrate your approach, then ask the coach.