A child abort controller that follows its parent signal.
A pass that starts several reads at once (a pinned pass's concurrent rungs)
sometimes has to cancel SOME of them without cancelling the pass: the
residency brake keeps rung k and drops k+1..n. Each read therefore runs under
its own child controller, which aborts when the parent does and can also be
aborted alone.
The child inherits the parent's fetch-priority cell (shared, so a later
raise on the parent reaches the child) and decode-origin tag: a child is the
same request class as its parent, and an untagged child would silently
resolve to the default 'demand' priority.
A child abort controller that follows its parent signal.
A pass that starts several reads at once (a pinned pass's concurrent rungs) sometimes has to cancel SOME of them without cancelling the pass: the residency brake keeps rung k and drops k+1..n. Each read therefore runs under its own child controller, which aborts when the parent does and can also be aborted alone.
The child inherits the parent's fetch-priority cell (shared, so a later
raiseon the parent reaches the child) and decode-origin tag: a child is the same request class as its parent, and an untagged child would silently resolve to the default'demand'priority.