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Concurrent download clients share bounded origin range reads: dispatch order follows consumer arrival rather than client names · case 04

Concurrent download clients share bounded origin range reads: dispatch order follows consumer arrival rather than client names.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

x contains ordered jobs [client,absolute-start,count,cancelled], positive chunk size, and dispatch slot count. Drop canceled and zero-length jobs. Maintain first-appearance client order; each client has FIFO requests. Dispatch at most one chunk per client per round, rotate unfinished clients, split long ranges, and remove exhausted requests. Return [dispatches,pending-jobs], where dispatches are [client,start,count] and pending jobs retain scheduler order. This models range-specific origin request scheduling, without network retries.

Why this case matters

Range responses combine representation identity, conditional requests, framing, and partial-object state.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
client-appearance-order fixture 0	`[[["a", 0, 2], ["a", 2, 2], ["a", 4, 1], ["b", 10, 2]], []]`	`[[["a", 0, 2], ["b", 10, 2], ["a", 2, 2], ["a", 4, 1]], []]`	Failed

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