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MobileGL/docs/Disaggregated/notes/p0/BRIEF-P0.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

5.0 KiB

P0 implementation brief (MobileGL disaggregation, plan "MGPipe")

You are one implementer among several working IN PARALLEL on phase P0 of the plan in C:/Users/geekerwan/AndroidStudioProjects/FoldCraftLauncher/MobileGL-disagg/docs/Disaggregated/PLAN.md (that file is being consolidated by another agent right now; if it is missing or mid-rewrite, read PLAN-B-MGPipe.md in the same directory - same content, older numbering). Read the plan's §0 (decisions D-B1..D-B8), §4 (interface MGPipe), §6.2/§6.3 (PipeInputs, residual block), §7 (reverse channel), §8 (inherited transport design), §10.3 (gates) and §11 P0 before touching code. Cite plan sections in your commit body.

Where the code lives and how you build it (WSL "Arch", 28 cores)

  • Reference tree: ~/w7/pipe (branch feat/disaggregated, warm build-linux with clang+ccache, unit + integration tests ON, lavapipe/llvmpipe ICD). DO NOT edit ~/w7/pipe or ~/w7/base - they are read-only references.
  • Make YOUR OWN tree: cp -a ~/w7/pipe ~/w7/p0-<slug> (a few minutes; keeps the warm build dir), then work only there. Single-writer rule: never touch another slug's tree.
  • Run WSL commands from the Windows Bash tool as: MSYS_NO_PATHCONV=1 wsl.exe -d Arch -- bash -lc 'bash /mnt/c/<path-to-a-script>.sh' 2>&1 | tr -d '\0' Put every non-trivial command sequence into a script file under your scratchpad directory (inline quoting through wsl.exe gets mangled). Your scratchpad is C:/Users/GEEKER~1/AppData/Local/Temp/claude/C--Users-geekerwan-AndroidStudioProjects-FoldCraftLauncher-MobileGL/eb1a694b-6a85-4ee7-810d-692eabf8fda6/scratchpad/wf2/p0-<slug>/ (create it; Windows path /mnt/c/Users/geekerwan/AppData/Local/Temp/claude/... from WSL).
  • You may read/edit tree files from Windows through the UNC path //wsl.localhost/Arch/home/swung/w7/p0-<slug>/... with the Read/Edit/Write tools, or edit inside WSL with python/sed from a script. Keep LF line endings.
  • Build: cd ~/w7/p0-<slug> && export CCACHE_BASEDIR=/home/swung/w7 && cmake --build build-linux -j 24 2>&1 | tail -30 (reconfigure with the same cmake line as ~/w7/prep.sh only if you changed CMake files: copy that line, keep -B build-linux).
  • Tests: cd build-linux && ctest -L unit -j 12 --output-on-failure (428 unit tests must stay green) and, when your change touches a backend or MG_State, ctest -L integration-gpu -j 8 (367 scenarios; compare the pass/fail NAME set with the baseline recorded in ~/w7/pipe-itest-baseline.txt if present - a failure that is already in the baseline is not yours). Per the user's rule, run REPRESENTATIVE tests locally, not everything, unless your package says otherwise.
  • Android (only if your package needs it): ~/w7/pipe/build-android is warm; NDK /home/swung/android-sdk/ndk/27.3.13750724, SDK ~/android-sdk, gradle ~/gradle-8.10.2, JDK /usr/lib/jvm/java-21-openjdk.
  • Devices (only if your package needs them): 35d0befa (Xiaomi 24129PN74C, Adreno 830) and 3B159D009VZ00000 (Oppo PLG110, Mali). Both are SHARED with another running campaign. Protocol: acquire an atomic mkdir lock BEFORE any adb use: LOCK="C:/Users/GEEKER~1/AppData/Local/Temp/claude/C--Users-geekerwan-AndroidStudioProjects-FoldCraftLauncher-MobileGL/8ab6b3cb-c783-4826-9fd7-39ff3498af5b/scratchpad/w7/locks/<serial>"; until mkdir "$LOCK" 2>/dev/null; do sleep 60; done; echo "p0-<slug> $(date)" > "$LOCK/owner" ... rm -rf "$LOCK" when done. Hold it at most 25 minutes per acquisition. If a lock is held for more than 60 minutes (check cat "$LOCK/owner"), do NOT break it: report "blocked by device lock" in your result and finish the non-device parts. Always pass -s <serial> to adb. Wake+unlock before launching apps (adb -s X shell input keyevent KEYCODE_WAKEUP; input keyevent 82). Read device logs from /sdcard/MG/latest.log, not logcat.

Rules

  • Commit on a branch named p0/<slug> in YOUR tree (git checkout -b p0/<slug>), one or a few focused commits. Commit message format (mandatory): first line [Type] (Scope): short lowercase description; blank line; then - bullets with the rationale, plan section citations and evidence. Types: Feat / Fix / Test / Docs / Build. NEVER add Co-Authored-By or any AI attribution trailer.
  • Do not push anywhere. The coordinator fetches p0/<slug> from your tree by path.
  • The default ALL target must build; unit tests must be green; no per-draw fprintf/printf instrumentation may be committed (a CI grep gate for that is one of the P0 deliverables).
  • Logging: MGLOG_D for non-critical lines (compiled out in INFO builds), never MGLOG_I for per-frame noise.
  • Do not modify 3rdparty/ contents except adding the flatbuffers submodule where your package says so.
  • Do not touch the fixtures under tools/trace_replay/fixtures/ (they are real binaries in the tree; git checkout would turn them into LFS pointers).
  • When you are done, return: the branch name and tree path, the list of commits (hash + subject), what you tested (exact commands and results), anything you could not finish and why, and any deviation from the plan with justification.