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MobileGL/docs/Disaggregated/notes/p5e/reports/c0e-v1.md
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swung0x48 aba329cc53 [Docs] (Disaggregated): P6's plan and contract draft; the working notes move from a local directory into the repository
Two things land together: the plan and contract draft P6 needs before it starts, and the
working notes that until now existed on exactly one machine.

1. P6's plan and contract draft (neither started; not one line of code)

     docs/Disaggregated/P6-SPAWN-PLAN.md      the package plan
     docs/Disaggregated/P6-CONTRACT-DRAFT.md  the contract draft (moves to
                                              MG_Remote/CONTRACT-P6.md when c6 lands)

   The three findings that mattered, all written into the documents:

   a. P6 is SMALLER than its roadmap cell suggests. The transport primitives are already in
      the tree and already tested: SocketDoorbell including hangup detection and the two
      lost-wakeup fences (Doorbell.cpp:211-360, four cases in FdPassingTest), SCM_RIGHTS fd
      passing, ShmSegment::Adopt, and the SurfaceOp / WindowKind schema already defined in
      protocol.fbs. inproc uses a real second shm mapping rather than an alias, and
      SessionRings.h:22-28 says that was done so today is not the first time it runs. P6 is
      assembly plus a control plane plus a process, not "write a socket transport".

   b. The evidence for "P6 is only a transport swap" has EXPIRED. It was bought by P5c, whose
      audit found 59 direct memory accesses in a tree that already looked clean. P5e changed
      the tree again. So the first package, a6, is a read-only audit that writes no code, and
      every contract row that depends on it is marked PENDING a6 rather than decided in
      advance.

   c. P6 does not get a game running on the phone. ANativeWindow* is meaningless in the child,
      and protocol.fbs:186-196's own comment says Android transfers the window out of band -
      that band is P12. P6 lands pbuffer / surfaceless / offscreen, which is what HeadlessGL,
      the split-equivalent lane and trace replay need, and which is exactly what P6's own exit
      gate measures. A real window reaching the server is a named refusal. This gets its own
      section because "P6 is done" would otherwise read as "the game runs now".

   The contract adds rule G: a role may not name a process-local handle. It extends P5c's
   rule E (a role may not name the other role's memory) from memory to identity - EGLDisplay /
   EGLSurface / EGLContext / ANativeWindow* / fd number / pid / mapped address either cross as
   a token this contract defines or they do not cross, and a descriptor crosses only through
   SCM_RIGHTS, where the kernel renumbers it.

   What P5e left for P6 gets its own section. The latch semantics are already designed
   (ARCHITECTURE.md:504) and are copied unchanged. What is new is that after run-ahead the
   client no longer waits while the peer process can DIE: the client holds records that were
   published and will never be applied, and Android's freezer suspends the child without
   closing anything. So slow and dead must be distinguishable WITHOUT a timeout threshold.
   That is P6's only new design; everything else is carriage. It shares a predicate with E1's
   outstanding re-specification (ID-122), and the two should be designed together.

   Two gates carried over from P5e's lessons: G2 requires integration-spawn's test-name set to
   match integration-split's name for name, because a differing set means the lane is quietly
   running less; and the arm-proof gate requires every entry to record the child pid and
   transport=spawn in its OWN private log - ID-124 established that this kind of false green
   really happens, and a spawn lane that actually ran monolith would pass every other gate.
   S2's shape must be settled before it is written, and the document says why: E1 is the
   cautionary case.

2. The working notes move into the repository (docs/Disaggregated/notes/, 415 .md files)

   ROADMAP / CURRENT_STAGE_PROGRESS / MEASUREMENTS cite ruling numbers, audit line numbers and
   the provenance of gate figures from ~/w7/notes/, a directory that exists on one machine and
   is under no version control. A record cited hundreds of times that lives only locally is not
   a record, so it moves in whole, with its directory structure intact.

   Only .md moves. Scripts, run logs, census and gate result JSON, patches, APKs and nm dumps
   stay where they are: they are evidence DATA rather than documents - large, regenerated per
   run, and mostly carrying absolute paths and device serials that mean something only on the
   machine that produced them. The mapping and this split are written in
   docs/Disaggregated/notes/README.md.

   Two exceptions are recorded there too: P6's BRIEF has been promoted to a first-class
   document and keeps no copy under notes/, so the two cannot drift apart; and recovered/ holds
   material salvaged from failed workflow runs, which may duplicate the like-named phase
   directories and is kept because a few of those were the only complete version at the time.

   CI's citation lint takes docs/Disaggregated/*.md only (non-recursive), and notes/ is
   deliberately outside it: those notes' file:line citations were written against their own
   code heads, and resolving them against today's HEAD would fail wholesale - which is not an
   error, it is their correct state as a historical record. To check one, use the revision it
   declares (--rev).

3. Inconsistencies fixed in passing

   - README.md's status line still said P5e was in progress while the stage table already said
     closed.
   - CURRENT_STAGE_PROGRESS's next-step item 1 still listed the exit gate as pending, though
     (a) and (b) were run in the previous commit; rewritten to closed plus the one item that
     actually remains (E1).
   - ROADMAP's P6 row still had the pre-phase plan in three of its cells; it now carries the
     package order, the scope boundary and the two new gates.

Checked with check_doc_citations.py: 125 citations across docs/Disaggregated/*.md, 0 problems.
2026-09-18 23:31:39 -04:00

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# c0e — the contract and the wire (P5e). Report v1
Branch `p5e/c0e`, head `a513c53ee3b9fa1497312b8eddb499995e94d16f` (base `2fde7034`), six commits,
35 files, +2276/−195. Everything is INERT: the caps bit is not published, opcode 80 has no route,
bit 13 is not in `kMGPipeWiredSubsystems`, and every new applier entry point and by-handle backend
signature aborts by name. `build` / `unit` / `isplit` / `gens` green; `strict` is the phase's
expected-red baseline, recorded below.
## Gate
| step | result |
|---|---|
| `build` | rc 0 (341 TUs on the first full pass) |
| `unit` | **2205/2205** (`tcache_count=0`; 2203 at base + the two names below) |
| `isplit` | **111/111** |
| `gens` | `gen_pipe --check` up to date; `gen_pipe --self-test` **12** controls (9 at base); `gen_pipe_field_ownership --check` up to date, `--self-test` 15 controls; include-closure 4 probes / 0 problems; dirty-surface `--check` rc 0, `--self-test` 27 controls; doc citations **3 problems at HEAD vs 4 at base** — all three are pre-existing `CONTRACT-P5.md` rows, c0e adds none and incidentally retires one |
| `strict` | 108 failed / 2 skipped / 1 passed out of 111 — **unchanged in shape**: `.github/workflows/test.yml:1199-1206` gates this lane on the run FAILING, and the one pass is `SplitLogPaths.PrivateAndDistinct`, which draws nothing |
### The strict baseline the later packages must shrink
From the 88 private logs under `build-split/MobileGL/MG_IntegrationTest/split-logs/`; 86 carry
`BARRIER-PULLED, MOBILEGL_IPC_STRICT_ERRORS=1`. Each scenario aborts at its FIRST pulled row, so
this is the first-blocker census and not the full pull set.
```
39 Fatal{UnmigratedPipeInput, "GetFramebufferBindingSlot@Clear"} -> fb
14 Fatal{UnmigratedPipeInput, "GetBoundVertexArray@DrawArrays"} -> vi
13 Fatal{UnmigratedPipeInput, "GetImageTextureBinding@BindImageTexture"} -> fb
9 Fatal{UnmigratedPipeInput, "GetTextureUnitObject@Clear"} -> tx2
6 Fatal{UnmigratedPipeInput, "GetTextureObject@CopyImageSubData"} -> sticky, P7 (stays)
3 Fatal{UnmigratedPipeInput, "GetProgramForDispatch@DispatchCompute"} -> pg
2 Fatal{UnmigratedPipeInput, "ValidateProgramName@ShaderStorageBlockBinding"} -> §7 allowlist
```
## What changed, per file
**`MG_Pipe/MGPipeTypes.h`** (+144) — `kCapRunAheadApply` (bit 10) and the pure arm
`MGPipeRunAheadCapBitsFor(BackendType, Bool ready)`; `kMGPipeMaxBufferBindingPoints` (84);
`kMGPipeShaderBufferClass{Uniform,ShaderStorage,AtomicCounter,Count}`; `MGPProgramBindings` (32 B)
+ `MGPProgramSamplerUnit` (8 B) + `MGPProgramStorageOverride` (40 B) + the three declared bounds;
`MGPProgramDesc::LinkStatus`; `kDrawClientArrays` (bit 6).
**`MG_Pipe/MGPipeValueTypes.h`** (+49) — `MGPipeImageAccess` and the three constants, with
`MGPipeDecodeImageAccess` / `MGPipeImageAccessIsValid` / `…Reads` / `…Writes`. Pure: the
include-closure probe stays 0 problems.
**`MG_Impl/Pipe/ImageEmit.h`** — `MGPipeEncodeImageAccess` MOVED out of the emitter's private
section into a free function that names the shared enumerators. Not duplicated: the literals are
gone.
**`MG_Pipe/MGPipe.h`** — `enum MGPipeWaitClass`; `kMGPipeSubsystemBufferBindings` (bit 13);
`kMGPipeSubsystemsMigratedAtP5e` = `0x3fff` with its drift assert.
**`MG_Pipe/PipeCalls.def`** (+220/−…) — the fifth column on all 79 rows plus
`SetProgramBindings` appended as opcode 80 (`kCtxState`, `kVarTail|kHostSpan`, `kWaitNone`), count
79 → 80, `kCtxState` 18 → 19.
**`scripts/gen_pipe.py`** (+127) — the 5-arg `CALL_RE`, `parse_wait_classes()` read out of
`MGPipe.h`, `check_wait_classes_are_known()` (unknown token; `kReplySlot`↔`kWaitReply` BOTH ways),
`kMGPipeWaitClasses[]` + `MGPipeWaitClassFor(op)` + five spot static_asserts in `PipeWire.inc`,
three new `--self-test` controls.
**`MG_Remote/Wire/PipeWireCodec.{h,cpp}`** (+112) — `WireRecordLayout` grows to
`kMaxWireRecordTails = 3`; the `SetProgramBindings` layout arm (three counts refused against their
bounds, three tails always declared, each 8-aligned); the decode arm that validates and DECLINES,
walking the third tail's name spans through `CheckHostSpanIsHonest` itself — they are members of a
40-byte element, so the encoder's blanket second-tail pass would read one span and a quarter of
garbage. The tail cross-check's Fatal line now prints all three tail sizes.
**`MG_Pipe/PipeApply.{h,cpp}`** (+244) — `MGPipeBarriered(op, payload, st)` **implemented** (all
three clauses); `MGPipeApplierCurrentRecordIsBarriered()` + its writer, **implemented**, default
`true`; `MGPipeApplySetShaderBuffers` / `MGPipeApplySetProgramBindings` declared and aborting; the
sb applier window (`BoundShaderBuffers[3][84]`, `ShaderBufferStart/Count/WritableMask[3]`,
`ShaderBuffersSerial`), the pg record tails (`BlockBindings`, `SamplerUnits`, `StorageOverrides`,
`Signature`, `BindingsSerial`) and `MGPipeProgramStorageOverride`; `MGPipeApplierState::
IsTransformFeedbackActive`, mirrored by `MGPipeApplySetContextValues`. `PipeApply.h` now includes
`MGPipe.h` (sibling layer; the closure gate is unchanged).
**`MG_Backend/DirectGLES/Managers.{h,cpp}`** (+120) — eight by-handle seams declared, bodies in
ONE block at the end of `Managers.cpp` calling `MGPipeP5eSeamNotLanded(name, owner, handle)`:
`VertexArrayImpl::ResolveVaoTwin`, `TextureImpl::{SyncTextureToBackendByHandle, ResolveTextureTwin}`,
`BackendTextureObject::SyncMipmapsToBackendByHandle`,
`BackendFramebufferObject::SyncToBackendByHandle`,
`BackendRenderbufferObject::SyncToBackendByHandle`, `PrgramImpl::ResolveProgramTwin`,
`BackendProgramObjectImpl::SyncToBackendByHandle`.
**`MG_Impl/Pipe/{Tracker.h, SetHashSuppressor.h, PipeFill.cpp}`** — bits 15/16/17 → subsystem 13
and `kMGPipeDirtyEmittedAtP5e`; the three `SetShaderBuffers*` suppressor slots and
`SetProgramBindings`; `SubsystemForEmitter`'s and `EmittedCallSuppliesTheWholeField`'s new arms,
three pairing asserts, and the `kMGPipeMaxBufferBindingPoints == BufferBindingPointCount` pin.
**`MG_Pipe/{Coverage.def, FieldOwnership.def, PipeFields.def}`** — the shape-only
`GetBufferBindingPoint → SetShaderBuffers` emitted row; the seven object-class rows re-annotated to
`"P5e (Espryt unbarriered), P7 (Magma)"`; `F(LinkStatus)` and the three new verify payloads (82).
**`Config.h` / `ConfigLoader.cpp` / `MG_Backend/Init.cpp`** — `RunAhead`, `PresentCredit`, the log
line, the `PipeVerify` force, the push default `0x3fff`, `kMGPipeP5eRunAheadReady = false` and the
caps arm.
**Tests** — `PipeCatalogueTest` (macro arity, the sizes, opcode 80, the null-route pins, the draw
flag, and the new wait-class case); `MagmaPipeIdentityTest` (new case + its pull-build skip twin);
`TrackerTest`; `FieldOwnershipTest`'s strict string. **Docs** — the P5E contract, the ROADMAP row,
`CURRENT_STAGE_PROGRESS` §1 and §6.
## Red-once evidence (verbatim)
1. **Flip one row's `WaitClass`, do not regenerate** (`GenerateMipmap` `kWaitApplied`→`kWaitNone`):
`gen_pipe: OUT OF DATE: MobileGL/MG_Pipe/generated/PipeWire.inc`, rc 1. Reverted → `gen_pipe:
generated files are up to date`.
2. **The same flip, regenerated** (the stronger half — this is what the contract-vs-def case buys):
`PipeCatalogue.EveryRowCarriesTheWaitClassTheContractGivesIt ***Failed`,
`PipeCatalogueTest.cpp:747: Failure … Expected equality of these values: MGPipeWaitClassFor(op)
… kWaitApplied … GenerateMipmap`. Reverted → 34/34.
3. **`sizeof(MGPProgramBindings)` 32 → 40** (a `Uint64 Pad1` plus the matching `MGP_ASSERT_POD`):
`PipeCatalogue.LateArrivalsAreAppendedWithoutRenumbering ***Failed`, `Expected equality of these
values: sizeof(MGPProgramBindings) Which is: 40 / 32u Which is: 32`. Reverted → 34/34.
4. **Publish bit 10 on the Magma arm** (`MGPipeRunAheadCapBitsFor` stops testing the backend type):
`MagmaPipeIdentityTest.AMagmaServerNeverPublishesTheRunAheadCapBit ***Failed`,
`MagmaPipeIdentityTest.cpp:241: Failure … MG_Pipe::MGPipeRunAheadCapBitsFor(BackendType::
DirectVulkan, true) & kCapRunAheadApply Which is: 1024 / 0u Which is: 0`. Reverted → 5/5.
## G1 / G2 / G14
- **G2/G14, new ctest names (both added, none removed):**
`PipeCatalogue.EveryRowCarriesTheWaitClassTheContractGivesIt` (compiles in both flavours) and
`MagmaPipeIdentityTest.AMagmaServerNeverPublishesTheRunAheadCapBit` (in
`MGL_MAGMA_PIPE_IDENTITY_TEST_LIST`, so the pull build declares its skip twin).
- **G1: NOT MEASURED HERE** — no pull-build baseline `.so` exists on this machine and the gate
wrapper has no pull flavour. The deltas to shared code, named:
(a) `MGPipeScreen`/`MGPipeContext` each gain one function-pointer member and the three generated
per-opcode arrays each gain one entry — **the identical delta P5b (five opcodes) and P5c (three)
made, both of which measured 0/0/0/0**;
(b) `MGPProgramDesc` 192 → 200 bytes — the payload is instantiated only under
`MOBILEGL_PIPE_PUSH` (`PipeApply.cpp`, `PipeRoute.cpp`, `MG_Impl/Pipe/ProgramEmit.h` and the
codec are all push-only sources), so the pull build holds none;
(c) `MGPipeValueTypes.h` gains four `constexpr` functions and an enum — no symbol unless
odr-used, and the pull build uses none of them;
(d) `Config.h`'s `IpcTable` grows two `Uint32` — `IpcTable` is inside
`#if MOBILEGL_BUILD_DISAGGREGATED`, so the pull build does not compile it at all.
The integrator should run the real G1 pair at landing.
## Rows of my "family" (the contract), against `kimi-audit.md`
c0e retires no apply-thread read: it is the inert contract commit. What it DID do for the audit's
benefit is give every row a place to be retired INTO — the wait class that decides whether a row's
apply may read client memory at all, and the eight by-handle signatures the five per-draw families
replace bodies in. The audit's rows stay exactly where they are; the strict census above is the
first-blocker half of that list as measured at this head.
## Rulings I need from the integrator
1. **`MGPShaderBuffers::WritableMask` is a `Uint32` and the window is 84.** The mask can describe
only the first 32 binding points of a class. The contract now records this (§5.6) and hands sb
the choice — narrow the window, widen the field, or declare the bound — but it is a WIRE field,
so it is not sb's to pick. This was not caught in the brief or in S5.
2. **`MGPProgramDesc` grew 192 → 200.** The draft's "in the descriptor's existing pad, size
unchanged" is arithmetically impossible: the fixed head is exactly full at 24 bytes and
`MGPBlobRef` is 8-aligned. I landed the honest version and argued it in the contract and in the
header. If the integrator would rather pay a bit in `StageMask` or shrink
`ReservedNumSamplesOffset`, that is a different record and a different commit.
3. **Consumer bit 13 in `Init.cpp`'s `ConsumedSubsystemsFor`.** I did NOT add it: withholding a
consumer bit is the safe direction (the file says so itself), no emitter exists yet, and
`Init.cpp`'s consumer mask is not in c0e's brief scope. sb must add it in the same commit that
gives `ShaderBufferEmit.h` its wired constant, or the client's R-8 gate will withhold the whole
family. Flagged so it is not discovered at the merge.
## Seams I assumed
- `MGPipeApplySetProgramBindings` takes the three tails PLUS a `const char* const*` of RESOLVED
override names, because the names ride SEG_STAGE and SEG_STAGE retires with the record (rule C).
pg must copy them into the record before the call returns. If pg wants the spans instead, the
signature is mine to change — ask.
- `MGPipeBarriered`'s `payload` may be null and clause 3 then falls through. ra's emit-side caller
must pass the real `MGPDrawInfo` it is about to publish.
- `MGPipeApplierCurrentRecordIsBarriered()` is `thread_local` and defaults `true`. id sets it from
`MGPipeBarriered` at the top of `ApplyOne`; nothing clears it, because every dispatch sets it.
## What I did not do
- **G1 measurement** (above) and the strict lane's *comparison against a base run* — the lane is
expected-red by CI design at this head, so what I recorded is the marker census, not a diff. No
base build exists on this machine.
- **`MOBILEGL_IPC_RUN_AHEAD` / `PRESENT_CREDIT` have no reader yet.** They parse, they log, they
are forced by `PipeVerify`. `ClientSession` is ra's file and c0e does not touch it.
- **`ARCHITECTURE.md` §11/§14/§17 and `README.md`'s knob table** still describe the lockstep and
list neither knob. The brief gives `ARCHITECTURE.md` to ra; `README.md` is nobody's — the
integrator should hand it to ra with the rest.
- **`.github/workflows/test.yml`'s strict step** is untouched (ra's, per BRIEF §2).
- **`MG_Test/Wire/ServerLoopTest.cpp`'s bit-10 pin.** BRIEF §6 names it beside
`MagmaPipeIdentityTest`; the unit case I added covers the arm as a pure function, which is the
half a unit lane can reach. A `ServerLoopTest` pin over a real `CallMask` belongs with ra's
session work.