8 MiB window, so a range larger than the window is always imported alone. A
buffer bound across two such ranges then has no import and is copied whole on
every use: PPSA25344 binds a 368 MiB buffer across a 320.75 MiB and a 47.3 MiB
range and copies it on almost every frame.
When UploadFinish meets such a region, it imports the run of the ranges the
region crosses, provided every one of them is larger than the window, and
retires their own imports. It does this before any region of the build
confirms an import, so the retire moves the epoch ahead of every pointer the
build would use. A range that large is registered whole, not grown in 64 KiB
pieces like a heap, so the joined import is not re-imported as a heap grows; it
stands in refreshImports while exactly its ranges stand. A later join that
reaches a joined import takes it in, so two joins that share a range never
retire each other in turn.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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