Canceling

This status propagates instantly through all lifetime's children graph when LifetimeDefinition.terminate is invoked. Lifetime is in consistent state (no resources are terminated) but termination process is already began. All background activities that block termination (e.g. started with Lifetime.executeOrThrow, should be interrupted as fast as possible. That's why background activities must check Lifetime.isAlive or Lifetime.throwIfNotAlive quite ofter (200 ms is a good reference value).

Some methods in this status still works, e.g. Lifetime.onTermination others do nothing (Lifetime.executeIfAlive) or throw CancellationException (Lifetime.executeOrThrow, Lifetime.bracketOrThrow)