LibretroAdmin 2b4bc98676 Input: hand the sensor snapshot over in three slots, not a seqlock ...

The shader backends read gyro, accelerometer and rest each frame from
the video thread. They were published under a seqlock, whose reader
started over - spinning - while the poll was mid-publication, and
whose nine floats went through nine atomic stores and loads.

They are now three slots of nine floats: the poll writes its own and
hands it over with one exchange for the middle slot; the reader, when
the middle is new, exchanges its slot for it and reads the floats
where they lie. Neither side ever waits or retries, and a read never
mixes two polls. The exchange lives in input_sensor_snap.h so a test
can drive the same code.

sensor_snap_test publishes as fast as it can from one thread while
another reads, and checks no read is mixed or goes backwards and the
newest is read once the writer stops; CI runs it under ASan, TSan and
Wine. The frontend harness's idle lane counts publications instead of
the sequence.

2026-10-20 16:27:49 +02:00

..

Makefile

Input: hand the sensor snapshot over in three slots, not a seqlock

2026-10-20 16:27:49 +02:00

sensor_snap_test.c

Input: hand the sensor snapshot over in three slots, not a seqlock

2026-10-20 16:27:49 +02:00