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MobileGL/docs/Disaggregated/notes/p5e/TASK-vi.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

4.7 KiB

Package vi — VAO / vertex input / index from records (P5e wave 2)

Read in this order, all of it: PACKAGE-PREAMBLE-P5E.md, INTEGRATOR-DECISIONS-P5E.md (ID-81, ID-82, ID-95 are yours), BRIEF-P5E.md (§0, §1, §2 "vi", §5, §6 rulings 1, 2, 19), CONTRACT-P5E.md §4 and §5.1 (landed by c0e in MobileGL/MG_Remote/; the draft in the notes dir is the same text), your scout report scout-S1.md (all of it), and the VAO / buffer rows of kimi-audit.md (rows 1-34) — your report must say, per row, retired / left barriered / not found. All notes are in //wsl.localhost/Arch/home/swung/w7/notes/p5e/.

Your slug is vi; your tree is ~/w7/p5e-vi (branch p5e/vi, based on the landed id head, already configured and built). The twin resolvers ResolveVaoTwin(MGPipeHandle) and the by-handle registry API are id's and already in your base — use them, do not re-declare.

What "done" means for this family

On the DirectGLES draw path under an active transport, nothing in the VAO / vertex-input / index family reads the frontend: the twin resolves from st.BoundVertexElements, the attribute walk and its dirty repair run over st.VertexBuffers[Start..Start+Count) and the CSO record's Attributes[], the IBO arm resolves st.IndexBuffer.Res, every buffer ensure is EnsureBufferResourceForHandle(nullptr, handle), and the clean stamp uses the server-owned {elementsHandle, elementsSerial, buffersSerial} (+ the new iboSerial) instead of the VAO's config version. The three frontend-keyed scope sites of this family (DirectGLES.cpp:1609, :6729, :6775 at the P5d base — re-resolve) are gone.

Scope (the only regions you may edit; anything else is the integrator's)

MG_Backend/DirectGLES/DirectGLES.cpp: SyncVaoAttributeBuffersByHandle + the IBO arm of SyncNeccessaryBuffers; ResolveVaoTwin / SyncCurrentVAO / SyncCurrentVertexAttributeValues; the VAO lines of PrepareForDraw only; the restart helpers (BoundElementArrayBuffer/...Id); the DrawArrays / MultiDrawArrays client-array arms (monolith-only after your change). MG_Backend/DirectGLES/Managers.h: ResolvedDrawBuffers (Entry::frontend leaves the split arm, iboSerial added) and PendingAttribValueMask's key. Managers.cpp: SyncToBackendFromApplier (signature/entry only — its body is already record-only and is your existence proof), SyncClientSideAttributesForDrawArrays (monolith-only). MG_Remote/Client/EmitTables.cpp: the kDrawClientArrays flag and the run-ahead refusal beside the existing CLIENT_INDICES refusal. Tests: MG_Test/Pipe/VertexInputEmitTest.cpp, a SanityTest.cpp sibling, and the scenario work below.

Rulings that bind you

  • ID-82 / ruling 2: client-memory vertex arrays are not refused today (your scout verified it). Refuse them when run-ahead is armed — kDrawClientArrays on the draw record, a named Fatal{UnmigratedVerb, "DrawArrays+CLIENT_ARRAYS"}-shape refusal on the client. Lockstep keeps today's behaviour exactly. Answer the open question yourself: does any existing scenario (DoublePrecisionScenario?) exercise a client array under split — if none does, add one so the refusal has a red-once.
  • ID-81 / ruling 1: handle arms only under Transport != Monolith; the push-monolith build keeps its frontend arms and its bytes.
  • ID-95 / ruling 19: set_vertex_buffers' window must cover the attributes the CSO declares; pin it with a test in the same validate step (a narrower window is Fatal{ProtocolCorruption, "<row>.Count"}).

Red-once (execute each, revert, quote the evidence line in the report)

  1. Revert ResolveVaoTwin to the frontend lookup → the id guard's Fatal{RoleViolation, "MGPipeSlots"} (use id's test hook to force "unbarriered" — run-ahead is not armed yet).
  2. Publish set_vertex_buffers for A,B, repoint the frontend VAO at C without re-emitting, sync → A,B must be ensured; the revert ensures C.
  3. The same on set_index_buffer / st.IndexBuffer.Res.
  4. glDrawArrays with a client array under the run-ahead flag → the named refusal.

Gate

build, unit, isplit, gens green; one on VertexAttribBindingScenario|VertexArrayEnableDisableScenario|PrimitiveRestartScenario|ResidentIndexScenario|MultiDrawScenario|DrawParametersScenario|HandleRecycleScenario|ObjectSubsystemControlScenario; strict — record which UnmigratedPipeInput markers of this family disappeared vs the c0e baseline in your report (that list is the phase's progress metric). Also answer, with evidence: does any GL-thread path bump CurrentBufferMutationEpoch under a transport (your scout's open question 2) — pin the answer with an assertion or a test rather than an argument.

Trailing (do NOT do): deleting ResolvedDrawBuffers (needs a measurement first), staging client arrays (P8).