Observer callback under lock

Code reviewConcurrencySenior–Staff~30 min

Review this Java cache that notifies observers under its lock.

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.

0:00 of about 30 min

Mark a line and say what kind of problem it is.0 findings

1public class StateStore {

2 private final Object lock = new Object();

3 private final Map<String, String> state = new HashMap<>();

4 private final List<Observer> observers = new ArrayList<>();

6 public void put(String k, String v) {

7 synchronized (lock) {

8 state.put(k, v);

9 for (Observer o : observers) o.onChange(k, v);

10 }

11 }

12}

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.