OpenRA.DirectGLES.SPAWN is green: ssim=1.000000, mismatchPixels=0, zero
Fatal{ lines, against a server in a process the client started by name. The
inproc SPLIT arm stays beside it as the control, so "did the transport break
it" and "did the phase break it" remain separately answerable.
Five defects stood between the handshake and that picture. Each one was
silent in its own way, and none of them looked like what it was.
1. THE DOORBELL COULD NOT WAKE ITSELF. SocketDoorbell's one-fd form sends on
the end it polls, so a write is delivered to the PEER - correct for waking
the other process, useless for waking a thread in this one. The server's
control pump posts into the apply thread's mailbox and must ring the bell
that thread parks on. Symptom: every eglInitialize crossed, landed in the
mailbox, and timed out at 5 s. The two-fd form (park on [0], notify on [1])
is restored here, and the bell handover goes from two descriptors to THREE
- the client needs the same split for the same reason. Seven offers now.
2. InitCapabilities HAD NO WIRE KIND. CONTRACT-P6 §2 predicted this exactly
("the request has a live client caller and the codec refuses to encode
it"). SurfaceOpKind gains 11, append-only; the decode range's upper bound
moves with it, or the new tag reads as out-of-range and surfaces as
Fatal{ProtocolCorruption} rather than the missing row it is. The op's name
loses its InprocOnly suffix, which stopped being true here.
3. THE CHILD LOADED NO CONFIG AT ALL. mobilegl_server_main calls
InitServerRoleForSpawn directly, and MG_ConfigLoader::Init is a step of
MobileGL::Initialize - so every MG_Config value in the server was its
static default. MOBILEGL_BACKEND_TYPE survives the launcher's scrub on
purpose and was read by nobody: a DirectVulkan session would have brought
up a DirectGLES server and then disagreed with its client about which
backend the capability mask describes.
4. AND THEREFORE Transport READ AS Monolith, which CONTRACT-P6 §3.1 (D1)
forbids in as many words. a6 measured the cost: 226 live lines test
`Transport != Monolith` to select the SERVER arm, 148 in MG_Backend.
Monolith flips all of them to frontend glue in the one process with no
frontend. Observed precisely as predicted - UnitTexturesByHandle() answered
false, Clear took the legacy arm that dereferences borrowed FRONTEND slot
pointers, and the apply thread took a SIGSEGV inside SyncNeccessaryTextures
on the first Clear record of the trace. It is pinned in-process rather than
through the environment because the environment is where it must NOT be:
LooksLikeAClientEnvironment exits 65 on a surviving MOBILEGL_TRANSPORT, and
that check is anti-recursion catch (b). Dial, not Transport, is that axis.
5. THE LOG WAS CORRUPT, NOT MERELY INTERLEAVED. Two processes opened the same
MOBILEGL_LOG_FILE_PATH with "w" and each carried its OWN file offset, so
they overwrote each other's bytes - half-lines like `ote client: CapsMirror
generation 1 adopted`, and the server's whole startup block vanishing under
the client's later writes. This cost real diagnosis time twice, because a
missing line read as a code path not taken. O_APPEND now; the client still
truncates once so a fresh run is not a pile of old ones, and the server
never does - it would delete the very startup lines a failed session needs.
run_trace_case.cmake's Fatal{ census reads exactly this file, so it was
also reading a lie.
The retrace runner's split assertions become transport-aware: one row per
transport it admits, and a transport with no row is a FATAL rather than a
fall-through, because the fall-through is the accident the block exists to
prevent. The spawn row carries a SECOND sentence and it is the stronger half
- ConfigLoader's marker proves the value RESOLVED, while `spawn ARMED - the
server role runs in pid N` is written only after the launch, the connect and
the handshake all succeeded, and carries a pid that is not this process's.
inproc resolves its own marker while running the server role on a thread
here; nothing on that path can write this one.
G14: one test name added (TheEleventhFramedOpIsInitCapabilitiesAndItCrosses-
TheWire), none removed. The ten-op table keeps its name and its scope rather
than being renamed to eleven.
Two unit failures predate this change and are environmental in this tree:
PipeCatalogue.FrontendNeverTakesAnApplierAddress (the frontend source root
resolves empty) and SessionHandshakeTest.TheAbiFingerprintChangesWhenAnyOf-
ItsInputsDoes (GIT_COMMIT_HASH_SHORT is empty here, which a6 already recorded
as red in this configuration).
- the block looked for Fatal{PipeVerifyDiffer and Fatal{UnmigratedPipeInput only. A
misspelt MOBILEGL_PIPE_VERIFY_CORRUPT / MOBILEGL_PIPE_POISON_OMIT reports
Fatal{PipeVerifyBadKnob, and it was caught only because D2 makes that one abort the
process - which is precisely what MOBILEGL_PIPE_VERIFY_FATAL=0, the supported triage
configuration, takes away. A typo'd knob would have left a negative-control run
looking healthy
- the FATAL_ERROR text now says what each of the three means and where the two
vocabularies live, because that message is the whole diagnosis a `cmake -P` step gets
- A retrace that exports MOBILEGL_PIPE_VERIFY=1 at a library configured without
-DMOBILEGL_PIPE_VERIFY=ON is a no-op: the frames still match their goldens and the
case reports green having compared nothing. run_trace_case.cmake now demands the
evidence whenever the variable is set to anything but 0/false - mobilegl.log must
exist, must carry "MGPipe: verify armed", and must carry neither
Fatal{PipeVerifyDiffer nor Fatal{UnmigratedPipeInput. With the variable unset the
script is byte-for-byte the old one.
- The Fatal scan is not redundant with the replay's exit status:
MOBILEGL_PIPE_VERIFY_FATAL=0 is the supported triage configuration, and there a
divergence is logged and counted rather than aborted, so the run would finish 0
with its own report sitting unread in the log.
- LABELS retrace on both registrations: the lane was selectable only by regex, so
`ctest -L retrace --no-tests=error` - the spelling that reds a lane which
registered nothing - could not be written at all.
- "verify": true on eight cases (the five 180s cases plus minecraft-1.21.4-in-world,
minecraft-1.21.4-fabric-sodium-in-world and improved-transparency-minecraft-26.3),
and --format github-verify-matrix over that subset: 16 entries, against the full
lane's 77. The verify build compares at every verb boundary and again at every
accessor read, which the design budgets at 5-10x, so the per-push job runs the
subset and the full sweep is a phase-exit / workflow_dispatch run.
- The flag is validated in the manifest loader, not at the matrix, so a non-boolean
or a verify case excluded from CI is a loud error in every consumer instead of a
subset that is quietly one case short.
- compare actual output against primary and alternate golden images
- record the matched golden path in trace replay results
- allow APK and Linux retrace fixtures to pass alternate golden paths
- keep nostalgia validation accepting both Mesa and PC goldens
swung0x48