How to Ensure Parallel Task Execution on iOS 15 Using Swift?

Efficient concurrency is vital for high-performance iOS applications. The article addresses parallel execution issues with Swift's async/await and TaskGroup on iOS 15. A puzzle-generating app serves as an example, exhibiting performance discrepancies between iOS versions. On iOS 15, parallel task execution is not working as expected, unlike on iOS 16+. The core problem involves tasks within a `TaskGroup` not utilizing multiple CPU cores simultaneously on the older OS. The `PuzzleGenerator`'s `generatePuzzle()` method simulates CPU-intensive work using random number generation. The article suggests adjusting task priorities using `.userInitiated` for improved performance. Task cancellation should be implemented carefully, canceling tasks only after a result is obtained. The provided code modifications include changes to task creation and cancellation behavior. Testing the performance across different iOS versions is crucial to confirm the adjustments. The article concludes by emphasizing iterative adjustments and monitoring performance metrics to ensure a seamless experience for all users.