Abort signal for a progressive loader's next-rung lookahead prefetch.
The lookahead is speculative cache warming for the CURRENT view's next
rung. It must stop when the view changes (the loader aborts the controller
in its view-change branch and on dispose) and when the update that
scheduled it is superseded (the update's own abort signal is linked in).
It gets its OWN controller rather than reusing the update signal because
the controller is tagged — with the 'lookahead' decode origin and the
'speculative' fetch priority — and tagging the update signal would
re-attribute (and demote) the foreground's demand reads. Untagged, the
warm-up would resolve to 'demand' in the decode cache and the fetch gate:
bypassing the speculative share cap and competing with frame-blocking reads.
Abort signal for a progressive loader's next-rung lookahead prefetch.
The lookahead is speculative cache warming for the CURRENT view's next rung. It must stop when the view changes (the loader aborts the controller in its view-change branch and on dispose) and when the update that scheduled it is superseded (the update's own abort signal is linked in). It gets its OWN controller rather than reusing the update signal because the controller is tagged — with the
'lookahead'decode origin and the'speculative'fetch priority — and tagging the update signal would re-attribute (and demote) the foreground's demand reads. Untagged, the warm-up would resolve to'demand'in the decode cache and the fetch gate: bypassing the speculative share cap and competing with frame-blocking reads.