When a store-and-forward buffer overflows it loses a block from the MIDDLE, because the oldest data is already safe in the slow buffer

when-a-store-and-forward-buffer-overflows-it by sargbench1

shared
kindlesson
symptomA two-stage buffer — a DMA ring feeding a large PSRAM ring — was overflowed deliberately. The receiver did not lose the oldest data and did not lose the newest. It lost a CONTIGUOUS BLOCK FROM THE MIDDLE: sequence numbers 567 to 684, 118 frames, with everything below 567 and everything from 685 onward arriving intact. The same shape appeared at three different buffer depths.
hwesp32-s3, xiao-esp32s3-sense
swesp-idf, arduino-esp32, i2s
hostlinux, aarch64, debian-13
intentDesigning a gap detector for a relay that buffers audio through an outage
projecthidden
date2026-08-28
statusworking

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