Once the Dockerfile rewrites every android24-clang to exec android26-clang,
the linker uses the API-26 NDK sysroot and libstd's pthread_create reference
resolves directly against libc.so's real runtime symbol — no interposition
needed.
The pthread_shim.c approach was actually fighting its own solution: our
shim's dlsym() call bound at link time to libdl.a's STUB dlsym (a
five-line function inside libdl_static.o that just returns NULL and sets
dlerror to "libdl.a is a stub --- use libdl.so instead"). NDK r19 and
glibc 2.34 both replaced libdl.a with empty stubs because dynamic loading
is now part of the main libc/bionic — so no amount of link-order
tinkering can make a static libdl.a dlsym actually work.
Remove pthread_shim.c, the cc::Build::new().file("cpp/pthread_shim.c")
step in build.rs, and the -Wl,--wrap=pthread_create rustc-link-arg. Keep
getauxval_fix.c because that one DOES work at link time (the symbol
override is for a function compiler-rt defines statically, not one that
would depend on the stub libdl.a/libc.a).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Build #11 linked cleanly with --wrap=pthread_create but crashed at launch
on tao::ndk_glue::create with a Rust .expect() panic — meaning the shim's
__wrap_pthread_create successfully intercepted the call but returned
non-zero, triggering std::thread::spawn's Result::expect panic.
Add __android_log_print tracing so logcat shows exactly which resolver
path fired (RTLD_DEFAULT vs dlopen fallback) and what dlerror reports
when they fail. Also try RTLD_DEFAULT first — it's the simplest and
should find libc.so's pthread_create in the process's global symbol
table without any namespace games.
Build #10 failed with:
ld.lld: error: duplicate symbol: pthread_create
>>> defined at pthread_shim.c:30
>>> ... in archive libpthread_shim.a
(the other definition coming from libstd's bundled libc.a stub)
The raw-symbol-override approach was naive: when two static archives
both define the same symbol the linker refuses instead of picking one.
Switch to GNU-ld's `--wrap=pthread_create` mechanism:
- All `pthread_create` references get rewritten to `__wrap_pthread_create`
- Our shim now defines `__wrap_pthread_create` (no symbol clash)
- Inside the shim we `dlopen("libc.so")` + `dlsym("pthread_create")` to
get the real runtime symbol directly, bypassing BOTH the broken static
stub (libstd's libc.a copy) AND libstd's own pthread_create path
- `--real_pthread_create` is deliberately NOT used — it would alias the
same broken stub the wrap exists to avoid
The wrap flag is emitted via `cargo:rustc-link-arg` in build.rs so it
only affects the Android target (the Android-branch of build.rs is the
only place that emits it).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Builds #7, #8 and #9 all crashed at launch with the same SIGSEGV inside
__init_tcb(bionic_tcb*, pthread_internal_t*)+4 called via pthread_create
from std::sys::thread::unix::Thread::new.
Digging further: the problem is NOT the final linker we pass to cargo.
It's that rustup ships a PRE-COMPILED libstd for aarch64-linux-android
which was built statically against an old NDK libc archive. That archive
has a pthread_create stub which calls a static __init_tcb stub that
assumes libc's static init path has set up the TCB — which never happens
in a .so loaded via dlopen. Bumping minSdk to 26 or forcing the
android26-clang linker (903a07c) doesn't rebuild libstd and therefore
doesn't fix the bundled broken stub.
The legacy wzp-android crate dodged this with a getauxval_fix.c shim that
interposes getauxval via RTLD_NEXT. The same trick works for pthread_create
here: define our own `int pthread_create(...)` in cpp/pthread_shim.c that
forwards to `dlsym(RTLD_NEXT, "pthread_create")` — the real, fully working
version exported from libc.so. The linker processes our static lib before
libstd.rlib, so libstd's unresolved pthread_create reference binds to our
symbol, and the broken libc.a stub inside libstd is never pulled in.
build.rs compiles cpp/pthread_shim.c right after cpp/getauxval_fix.c so
both symbol overrides are in place before any Rust code gets linked.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This is the big one — the Tauri Android app now has a real audio stack
capable of full-duplex VoIP, reusing the proven C++ Oboe bridge from the
legacy wzp-android crate.
Architecture:
- desktop/src-tauri/cpp/ — copies of oboe_bridge.{h,cpp}, oboe_stub.cpp,
and getauxval_fix.c from crates/wzp-android/cpp/. build.rs clones
google/oboe@1.8.1 into OUT_DIR and compiles the bridge + all Oboe
sources as "oboe_bridge" static lib, linking against shared libc++
(static would pull broken libc stubs that SIGSEGV in .so libraries).
- src/oboe_audio.rs — Rust side: an SPSC ring buffer matching the C++
bridge's AtomicI32 layout, plus OboeHandle::start() which returns
(capture_ring, playout_ring, owning_handle). The ring exposes the same
(available / read / write) methods as wzp_client::audio_ring::AudioRing
so CallEngine treats both backends interchangeably.
- src/engine.rs — compiled on every platform now. A cfg-switched type
alias picks wzp_client::audio_ring::AudioRing on desktop and
crate::oboe_audio::AudioRing on Android. The audio setup block has
three branches: VPIO/CPAL on macOS, CPAL on Linux/Windows, Oboe on
Android. Send/recv tasks are identical across platforms.
- src/lib.rs — removes all the "step 3 not done" Android stubs. The
engine module is no longer cfg-gated; connect / disconnect / toggle_mic
/ toggle_speaker / get_status are single implementations used by both
desktop and Android. Identity path resolves via app.path().app_data_dir()
from the Tauri setup() callback (already wired in step 1).
Runtime mic permission:
- scripts/build-tauri-android.sh now injects RECORD_AUDIO + MODIFY_AUDIO_
SETTINGS into gen/android/app/src/main/AndroidManifest.xml after init,
and overwrites MainActivity.kt with a version that calls
ActivityCompat.requestPermissions in onCreate. This is idempotent:
every build re-applies the patches so tauri re-init can't regress them.
Cargo.toml:
- cc is now an unconditional build-dep (build.rs runs on the host, so
target-gating build-deps doesn't work).
- wzp-client is now a dep on every platform. On Android it gets default
features only (no "audio"/"vpio") so CPAL isn't dragged in — oboe_audio
provides the capture/playout rings instead.
- tracing-android is added on Android so tracing events flow into logcat.
build.rs also gained embedded git hash (WZP_GIT_HASH) capture, which is
shown under the fingerprint on the home screen — already committed in
7639aaf, reinstated here alongside the Oboe build logic.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
