Error Handling and Cancellation

When subtasks run concurrently, errors can happen in any branch. Structured concurrency gives you a disciplined way to propagate those failures up to the parent.

This lesson covers exceptions, cancellation, interruption, and timeouts.

A subtask that throws does not crash your program immediately. The exception is captured on its Subtask handle. Where it surfaces depends on the policy:

• ShutdownOnFailure: at throwIfFailed()
• ShutdownOnSuccess: at result() if none succeeded