mirror of
https://github.com/MobileGL-Dev/MobileGL
synced 2026-11-07 10:03:23 +09:00
swung0x48
2d03565f87
- ID-132's finding, diagnosed: with the flip thrown the 70 red lane entries are ONE race
and two debts. The race is the client's residual fill writing gPipeInputs while the apply
thread is inside an earlier UNBARRIERED record. Measured interleaving, verbatim:
`[MobileGLIntegra/ERROR] RA2-PROBE fill verb=DrawElements wireop=81 waitclass=-1
applierInside=1` then `[mgl-srv-apply/ERROR] RA2-PROBE unfresh field=IsCapabilityEnabled
verb=DrawElements serverStamped=0 ownership=RECORD-SUPPLIED` then
`[mgl-srv-apply/FATAL] MGPipe: Fatal{UnmigratedPipeInput, "IsCapabilityEnabled@DrawElements"}`.
The GL thread's MGPipeServerClearVerbBoundary withdrew the applier's own stamp mid-record.
- The marker's verb is the CLIENT's verb, which is what identifies the writer without a
probe at all: the applier can only ever put a verb of MGP_VERB_OP_LIST into the block, and
40 of the 54 unbracketed aborts named a verb that is not in it.
- A/B control on the same binary and the same records: MOBILEGL_IPC_RUN_AHEAD=0 is 8/8 green
where the default arm is 2/6 red, so the defect is in the wait rule and not in a record.
- RefusePipeInputsTouchWhileApplierOwnsIt could not fire on any of it: its run-ahead arm read
`if (isBarrieredFill) return;`, and that sentence is a claim about the FUTURE ("this thread
is about to park behind the record"). The order at the validate point is fill, then emit,
then park. So the arm now tests the fact - `isBarrieredFill && !ApplyThreadIsInsideApplier()`
- and the fill sites MAKE it true first with §2.5's forced wait (QuiesceApplierBeforeFill).
- TWICE PER VERB, because the block is written in two phases that straddle publication: the
serial bump / stamp withdrawal / verb rename run before the fourteen emitters and the
63-field walk of step 4 runs after them, and the records those emitters published are
records whose apply reads the block.
- ClientVerbIsBarriered: MGP_VERB_OP_LIST joins the whole draw family through one row
(DrawVbo -> DrawArrays), so inverting it verb-first answered kOpCount for DrawElements and
eighteen other draw verbs, and the "unknown verb answers barriered" default filled for each
while the record it published was a kWaitNone draw_vbo it never parked behind. The family's
row is applied to the family; every other unknown verb keeps the conservative answer, which
the wait above now makes honest. Measured alone it is worth 112 -> 133 isplit; with the wait
in place the lane is 161 either way, so this half is the PERFORMANCE half - without it every
indexed draw takes a forced drain and run-ahead is lockstep by another name on the draw path.
- Red-once A: put the guard's arm back to `if (isBarrieredFill) return;` and
RemoteGuards.ClientBarrieredFillWhileTheApplierIsInsideUnderRunAheadIsFatalByName exits 0
instead of aborting (`Value of: DiedOfAbort(child) Actual: false`), while its green control
keeps passing. Red-once B: delete the kDraw fallback and
RemoteRunAhead.AnIndexedDrawVerbIsUnbarrieredAndTouchesPipeInputsNotAtAll dies of signal 6
with `Fatal{RoleViolation, "gPipeInputs"} - the GL thread touched gPipeInputs
(MGPipeValidateForVerb) on a RUN-AHEAD session in a barriered fill that did not first wait
for the applier to catch up`.
- Both new cases run in the ordinary unit lane with run-ahead armed by the fixture, which is
what ID-132(1) asks for: the strict lane runs under lockstep and cannot see this class.
- Gate on the flipped head: unit 2256/2256, isplit 161/181 (was 112), gpu 1339/1359 (was 1290),
gens rc=0, flavours rc=0. The remaining 20 are two named debts, not this race: 18 are
`GetBufferBindingSlot@DrawArrays [UNBARRIERED]` on the two indirect multi-draw tiers, whose
retiring phase is P8, and 2 are ID-82's own refusal of client vertex arrays.
- The arm is stated and not inferred (ID-81): WaitForApplyToCatchUp's first test is
`m_runAheadArmed && m_started`, which reduces to Transport != Monolith. Under lockstep,
under monolith and under MOBILEGL_IPC_RUN_AHEAD=0 every line added here is a call that
returns, so those arms are unchanged.