mirror of
https://github.com/MobileGL-Dev/MobileGL
synced 2026-11-07 01:53:24 +09:00
BZLZHH
4e48702f26
The create window could not collect its deferred answers. The previous commit
diagnosed that as the reply pool being 8 slots deep against 55,903 replies in one
frame, and left a no-reply bit as the way out. This lands that bit, measures it on
the device, and reports that the diagnosis was half wrong.
WHAT LANDED. ClientSession::EmitAndWaitTails takes a second question beside
wantReply: willReadReply. They are not the same question and the window is the case
that separates them - it emits with wantReply=false and READS the answer later, so
its records must still be answered. kRecNoReply (RingRecordFlags bit 5, which
aliases kOptional in the call-flag space; the flag-space asserts were extended and
the alias named) is stamped when willReadReply is false, and the decoder skips
PostReply while keeping every acceptance counter - "nobody reads the answer" is not
"nothing happened". The two illegal combinations are Fatal by name.
Three call sites say it: SetTextureParams for a confirmed object, the respecify
row's fire-and-forget half, and sub-data where MGPipeSubDataWantsItsReply decides.
MEASURED ON THE DEVICE (aikjs4s8cys8ba7l, rebuilt APK + client, both halves new):
server: skipped=50,001 answered=4,521 (a frame's replies: 55,903 -> 4,543)
client: Reply frames received seen=4,501, latest seq=97,181
frame-sent: identical per op, records untouched
create row: by_op 2 = 9,070 (was 4,536) - because the drain's blocking take is
now counted, so the row's number stays honest instead of reading as
"create stopped waiting" while the waiting merely moved
AND THE WINDOW STILL READ BACK NOTHING: readfail 8,951 -> 8,872, i.e. -0.9%.
THE REAL CAUSE, from the miss probe:
P12miss n=1 want=310 replySeq=1504 ring=[1175..1504]
P12miss n=9001 want=310 replySeq=102915 ring=[102866..102915]
want=310 every time. The drain is STRICTLY FIFO and a failed read has no way out -
it retries the same head for ever. Any reply buffer is bounded by design (8 pool
slots, or the 8-frame ring the stream link now keeps), so with 4,536 deferred
answers at least one is overwritten before it is read, and that one wedges the
window permanently. Cutting the churn by two orders of magnitude does not help: it
turns a certainty into a certainty. That is the constraint, not the depth.
THE FIX IS NAMED AND NOT TAKEN (the goal this work ran under stops here on purpose).
On a failed read of the head, abandon it: MGPipeNoteHandleUnpublished +
NoteCreateSuspect + pop - the DECLINE path reused for "unknown". The window then
self-heals through the blocking path and the object merely gets slower. It needs its
own gate: a failed read must let the window ADVANCE.
Gates, all green (172 + 13 + 22 + 103):
PipeWireCodecTest.TheNoReplyBitSkipsTheAnswerAndKeepsTheAcceptanceRecord - the skip,
the kept tally, the answered/skipped split, and the negative control that a record
WITHOUT the bit is still answered (a server that stopped answering everything
would otherwise pass)
RemoteClientControls.ACreateWindowDefersTheAnswersAndTheWindowOffDoesNot - now also
asserts the answers CAME BACK (answers_taken=11, outstanding=1, fallbacks=0 against
12 records). RED-ONCE PROVED: giving the window's creates the literal
"fire-and-forget => skip" predicate makes this case fail.
RingTest - the sixth and last flag alias, and the hand-written exhaustiveness list
extended (with a note that it is only as exhaustive as that list).
Server side: AnsweredRecords()/SkippedAnswers() - the number that made this
debuggable, since a wire change whose effect is invisible is undebuggable.
Client-first is safe: an old server ignores bit 5 and replies as before, so the two
cross-version directions degrade to today's behaviour - this is "both ends must
upgrade to take EFFECT", not "to avoid breaking". Hit that in practice first.
MGPipe：MobileGL 前后端拆分
做什么：在 MobileGL 的前端（处理应用的 GL 调用）和后端（调用 GLES / Vulkan 驱动）之间立一份显式接口——前端把状态变化推给后端，后端不再直接读前端的内存。有了这份接口，前后端可以放在两个线程、两个进程，甚至两台机器上运行。
做到哪了（2026-09-25）：接口与拆分已完成到"两个进程、可经 TCP 跨机"。当前在做 P12：让 Android 上的 server 自己开窗口，把画面直接显示到屏幕上——审查后的主机定向测试和 Redmi 真机七项复测已通过；FCL 与跨机 TCP 两项验收仍未完成。→ CURRENT_STAGE_PROGRESS.md
一张图
应用的 GL 调用
→ 前端 MG_Impl：处理 GL 语义；在每条"做事的命令"（draw、clear…）之前，把状态变化整理成记录
→ MGPipe 接口（两张函数指针表，由调用目录 PipeCalls.def 生成）
→ 三选一：直接调用（单线程）│ 队列 → 另一个线程 │ 队列 → 另一个进程 / 另一台机器
→ 后端 MG_Backend：Espryt（GLES）/ Magma（Vulkan），按记录更新自己的状态并调用驱动
← 反向消息（错误、GPU 写回、窗口尺寸）按顺序回到前端
文档导航
| 想知道 | 看 |
|---|---|
| 现在做到哪、下一步 | CURRENT_STAGE_PROGRESS.md |
| 设计要点与各部分设计 | ARCHITECTURE.md → design/ |
| 分几个阶段、每个阶段做了什么 | ROADMAP.md → notes/<阶段>/ |
| 性能与验证的关键数字 | MEASUREMENTS.md |
| 怎么构建、运行、测试 | guide/build-and-run.md |
| 代码在哪 / 术语 / 工程纪律 | guide/code-map.md、guide/glossary.md、guide/discipline.md |
| 各阶段的原始计划、裁定、报告、证据 | notes/ |
整理记录：2026-09-24 两次整理——顶层只留索引，设计正文拆到 design/，上手与参考放 guide/，阶段细节放 notes/<阶段>/；整理前的版本见提交 1fb18d9。更早的设计竞赛与评审稿在 git 历史（8b31de2f、1794ac94、8349babe、87ee17c6）。