AI_Assistant/pcbjam
Watch
1
0
Fork
You've already forked pcbjam
 0
Code Issues Pull requests Projects Releases 4 Packages Wiki Activity Actions 2

fix(wx): thread-safe wxString for the AsyncLoad fan-out — CvPcb-open trap solved

Browse source 
The ~1/9 wasm trap on CvPcb open ("index out of bounds" / "indirect call to
null" in a footprint AsyncLoad pool worker, then eeschema aborting on the
broken future — and the eeschema-fp-selector "CI-only" trap family, which was
never llvmpipe-specific) was wxString's UTF-8 build mutating SHARED strings on
read-only access from concurrent pool workers: every iterator ctor/dtor
spliced an intrusive list inside the string object, and torn splices wrote
through dead node pointers into other threads' stack frames. Second defect:
the UTF-8 position cache returned stale offsets when another thread's string
died and its address was reused.

Fixed in the wxwidgets fork (per-thread iterator registry + position cache
disabled under Emscripten) — kicad is untouched and AsyncLoad keeps its full
multi-worker fan-out. Falsified along the way (all perturbation masks, not
fixes): serializing the items, mimalloc vs dlmalloc, pthread stack size,
ASYNCIFY_STACK_SIZE, private-copy EnumFromStr, hot-path logging.

New red-first standalone app tests/apps/standalone/wxstring-mt (+ spec
coroutine-wxstring-mt.spec.ts, wx-chromium + coroutine-firefox): shared-string
compares alternating with wide-literal conversions reproduce the exact editor
trap signatures on the unfixed wx and run 4.7M rounds clean on the fixed one;
the pos-cache address-reuse dance corrupts on the first reuse before and
survives 673 after; two guard modes keep the iterator fix-up feature honest
(incl. an anti-elision liveness check — balanced register/unregister pairs in
tight loops can legally be optimized away, so a naive red test tests nothing).

Verification: wx+coroutine suites 382 passed; in-app AsyncLoad hammer 3x1000
rounds clean (baseline died <10); eeschema-assign-footprints spec 20/20
firefox + 20/20 chromium on the final build; lint:determinism clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Rb9jsqtHsC3tHTaJ45244j
This commit is contained in:
Viktor Vaczi 2026-07-20 11:56:20 +02:00
commit d538b73557
5 changed files with 580 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

13
tests/apps/Makefile.wasm
View file

@ -611,6 +611,19 @@ raytrace-threads: $(S)/raytrace-threads/raytrace_threads_test.html
# Include the raytracer-threading repro in the default `all` build (prereqs accumulate).
all: $(S)/raytrace-threads/raytrace_threads_test.html
# wxString UTF-8 multithreading red/green tests (shared-iterator registry,
# position cache, iterator fix-up) — see the app header for the modes.
$(S)/wxstring-mt/wxstring_mt_test.o: $(S)/wxstring-mt/wxstring_mt_test.cpp
$(CXX) -c $(CXXFLAGS) -pthread $< -o $@
$(S)/wxstring-mt/wxstring_mt_test.html: $(S)/wxstring-mt/wxstring_mt_test.o $(WX_CORE_LIB) $(JS_FILES)
$(CXX) $< $(LDFLAGS_PTHREAD) --pre-js $(JS) --shell-file $(HTML) -o $@
wxstring-mt: $(S)/wxstring-mt/wxstring_mt_test.html
.PHONY: wxstring-mt
all: $(S)/wxstring-mt/wxstring_mt_test.html
# Un-shimmed copy of KiCad's BS::thread_pool: the single-thread #ifdef __EMSCRIPTEN__ shim in
# detach_task is disabled (-> #if 0) so the pool tests exercise REAL multithreading WITHOUT
# modifying the pristine KiCad header and WITHOUT a compile macro. Regenerated at parse time to