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The leak you can read

An event handler nobody unsubscribes, and a static cache that only grows.

Beginner15 min on the clock4 graded checks · 100 pointsResources and Concurrency

Graded by reading your code against the checklist below.

What you build

Unsubscribe from the event when the object is finished with
Give the class somewhere for that unsubscription to live
Replace the unbounded static dictionary with something that evicts
Leave no static collection that can only grow

Done means

The handler is unsubscribed, and nothing left in the class can grow without limit.

How it is graded

Published in full, before you start — every point is one of these and there is nothing else.

The handler is unsubscribed+30Leaks you can see in the source
There is somewhere for the unsubscribe to happen+25Giving resources back
The cache evicts+25Leaks you can see in the source
No static collection left that only grows+20Leaks you can see in the source

What it teaches

Leaks you can see in the sourcebeginner

Finding a leak needs a profiler, but causing one is a code choice: an event handler never unsubscribed keeps the subscriber alive for the life of the publisher, and a static collection that only grows never gives anything back.

Giving resources backbeginner

A file handle or socket you opened is yours to release — the Dispose pattern is how a caller gets to say "I am finished with this" instead of waiting for a collection that may never come.

The rest of Resources and Concurrency

Giving the handle backBeginner · 15 min What you lock onIntermediate · 15 min The permit you never gave backIntermediate · 18 min The app that stops answeringIntermediate · 18 min A deadline and a request to stopAdvanced · 20 min The scoped thing inside the singletonAdvanced · 20 min