Motivation

Paywalls can request several cached images from Swift concurrency tasks during first presentation. DecodedImageCache wrapped NSCache access in a concurrent DispatchQueue using synchronous reads and asynchronous barrier writes. Blocking Swift cooperative pool threads on that GCD queue can starve the pool and deadlock image loading, which can also prevent subscriber actions from running.

Description

• Removed the extra GCD queue from DecodedImageCache and use NSCache directly, since NSCache is thread-safe.
• Added a regression test that launches many unique decoded image loads from Swift concurrency and asserts they complete. This reproduced a deadlock as a timeout without the fix

Slack Thread