MobileGL/docs/archive/notes/p0/BRIEF-P0.md

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.