Files
wz-phone/crates/wzp-native/src/lib.rs
Siavash Sameni a37c8b30fe fix(native): add missing bt_active field to stall detector config
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-12 17:25:11 +04:00

428 lines
16 KiB
Rust

//! wzp-native — standalone Android cdylib for all the C++ audio code.
//!
//! Built with `cargo ndk`, NOT `cargo tauri android build`. Loaded at
//! runtime by the Tauri desktop cdylib (`wzp-desktop`) via libloading.
//! See `docs/incident-tauri-android-init-tcb.md` for why the split exists.
//!
//! Phase 2: real Oboe audio backend.
//!
//! Architecture: Oboe runs capture + playout streams on its own high-
//! priority AAudio callback threads inside the C++ bridge. Two SPSC ring
//! buffers (capture and playout) are shared between the C++ callbacks
//! and the Rust side via atomic indices — no locks on the hot path.
//! `wzp-desktop` drains the capture ring into its Opus encoder and fills
//! the playout ring with decoded PCM.
use std::sync::atomic::{AtomicI32, Ordering};
// ─── Phase 1 smoke-test exports (kept for sanity checks) ─────────────────
/// Returns 42. Used by wzp-desktop's setup() to verify dlopen + dlsym
/// work before any audio code runs.
#[unsafe(no_mangle)]
pub extern "C" fn wzp_native_version() -> i32 {
42
}
/// Writes a NUL-terminated string into `out` (capped at `cap`) and
/// returns bytes written excluding the NUL.
#[unsafe(no_mangle)]
pub unsafe extern "C" fn wzp_native_hello(out: *mut u8, cap: usize) -> usize {
const MSG: &[u8] = b"hello from wzp-native\0";
if out.is_null() || cap == 0 {
return 0;
}
let n = MSG.len().min(cap);
unsafe {
core::ptr::copy_nonoverlapping(MSG.as_ptr(), out, n);
*out.add(n - 1) = 0;
}
n - 1
}
// ─── C++ Oboe bridge FFI ─────────────────────────────────────────────────
#[repr(C)]
struct WzpOboeConfig {
sample_rate: i32,
frames_per_burst: i32,
channel_count: i32,
/// When nonzero, capture stream skips setSampleRate and setInputPreset
/// so the system can route to BT SCO at its native rate (8/16kHz).
/// Oboe's SampleRateConversionQuality::Best resamples to 48kHz.
bt_active: i32,
}
#[repr(C)]
struct WzpOboeRings {
capture_buf: *mut i16,
capture_capacity: i32,
capture_write_idx: *mut AtomicI32,
capture_read_idx: *mut AtomicI32,
playout_buf: *mut i16,
playout_capacity: i32,
playout_write_idx: *mut AtomicI32,
playout_read_idx: *mut AtomicI32,
}
// SAFETY: atomics synchronise producer/consumer; raw pointers are owned
// by the AudioBackend singleton below whose lifetime covers all calls.
unsafe impl Send for WzpOboeRings {}
unsafe impl Sync for WzpOboeRings {}
unsafe extern "C" {
fn wzp_oboe_start(config: *const WzpOboeConfig, rings: *const WzpOboeRings) -> i32;
fn wzp_oboe_stop();
fn wzp_oboe_capture_latency_ms() -> f32;
fn wzp_oboe_playout_latency_ms() -> f32;
fn wzp_oboe_is_running() -> i32;
}
// ─── SPSC ring buffer (shared with C++ via AtomicI32) ────────────────────
/// 20 ms @ 48 kHz mono = 960 samples.
const FRAME_SAMPLES: usize = 960;
/// ~160 ms headroom at 48 kHz.
const RING_CAPACITY: usize = 7680;
struct RingBuffer {
buf: Vec<i16>,
capacity: usize,
write_idx: AtomicI32,
read_idx: AtomicI32,
}
// SAFETY: SPSC with atomic read/write cursors; producer and consumer
// are always on different threads.
unsafe impl Send for RingBuffer {}
unsafe impl Sync for RingBuffer {}
impl RingBuffer {
fn new(capacity: usize) -> Self {
Self {
buf: vec![0i16; capacity],
capacity,
write_idx: AtomicI32::new(0),
read_idx: AtomicI32::new(0),
}
}
fn available_read(&self) -> usize {
let w = self.write_idx.load(Ordering::Acquire);
let r = self.read_idx.load(Ordering::Relaxed);
let avail = w - r;
if avail < 0 { (avail + self.capacity as i32) as usize } else { avail as usize }
}
fn available_write(&self) -> usize {
self.capacity - 1 - self.available_read()
}
fn write(&self, data: &[i16]) -> usize {
let count = data.len().min(self.available_write());
if count == 0 {
return 0;
}
let mut w = self.write_idx.load(Ordering::Relaxed) as usize;
let cap = self.capacity;
let buf_ptr = self.buf.as_ptr() as *mut i16;
for sample in &data[..count] {
unsafe { *buf_ptr.add(w) = *sample; }
w += 1;
if w >= cap { w = 0; }
}
self.write_idx.store(w as i32, Ordering::Release);
count
}
fn read(&self, out: &mut [i16]) -> usize {
let count = out.len().min(self.available_read());
if count == 0 {
return 0;
}
let mut r = self.read_idx.load(Ordering::Relaxed) as usize;
let cap = self.capacity;
let buf_ptr = self.buf.as_ptr();
for slot in &mut out[..count] {
unsafe { *slot = *buf_ptr.add(r); }
r += 1;
if r >= cap { r = 0; }
}
self.read_idx.store(r as i32, Ordering::Release);
count
}
fn buf_ptr(&self) -> *mut i16 {
self.buf.as_ptr() as *mut i16
}
fn write_idx_ptr(&self) -> *mut AtomicI32 {
&self.write_idx as *const AtomicI32 as *mut AtomicI32
}
fn read_idx_ptr(&self) -> *mut AtomicI32 {
&self.read_idx as *const AtomicI32 as *mut AtomicI32
}
}
// ─── AudioBackend singleton ──────────────────────────────────────────────
//
// There is one global AudioBackend instance because Oboe's C++ side
// holds its own singleton of the streams. The `Box::leak`'d statics own
// the ring buffers for the lifetime of the process — dropping them while
// Oboe is still running would cause use-after-free in the audio callback.
use std::sync::OnceLock;
struct AudioBackend {
capture: RingBuffer,
playout: RingBuffer,
started: std::sync::Mutex<bool>,
/// Per-write logging throttle counter for wzp_native_audio_write_playout.
playout_write_log_count: std::sync::atomic::AtomicU64,
/// Fix A (task #35): the playout ring's read_idx at the last
/// check. If audio_write_playout observes read_idx hasn't
/// advanced after N writes, the Oboe playout callback has
/// stopped firing → restart the streams.
playout_last_read_idx: std::sync::atomic::AtomicI32,
/// Number of writes since the last read_idx advance.
playout_stall_writes: std::sync::atomic::AtomicU32,
}
static BACKEND: OnceLock<&'static AudioBackend> = OnceLock::new();
fn backend() -> &'static AudioBackend {
BACKEND.get_or_init(|| {
Box::leak(Box::new(AudioBackend {
capture: RingBuffer::new(RING_CAPACITY),
playout: RingBuffer::new(RING_CAPACITY),
started: std::sync::Mutex::new(false),
playout_write_log_count: std::sync::atomic::AtomicU64::new(0),
playout_last_read_idx: std::sync::atomic::AtomicI32::new(0),
playout_stall_writes: std::sync::atomic::AtomicU32::new(0),
}))
})
}
// ─── C FFI for wzp-desktop ───────────────────────────────────────────────
/// Start the Oboe audio streams. Returns 0 on success, non-zero on error.
/// Idempotent — calling while already running is a no-op that returns 0.
#[unsafe(no_mangle)]
pub extern "C" fn wzp_native_audio_start() -> i32 {
audio_start_inner(false)
}
/// Start Oboe in Bluetooth SCO mode — skips sample rate and input preset
/// on capture so the system can route to the BT SCO device natively.
#[unsafe(no_mangle)]
pub extern "C" fn wzp_native_audio_start_bt() -> i32 {
audio_start_inner(true)
}
fn audio_start_inner(bt: bool) -> i32 {
let b = backend();
let mut started = match b.started.lock() {
Ok(g) => g,
Err(_) => return -1,
};
if *started {
return 0;
}
let config = WzpOboeConfig {
sample_rate: 48_000,
frames_per_burst: FRAME_SAMPLES as i32,
channel_count: 1,
bt_active: if bt { 1 } else { 0 },
};
let rings = WzpOboeRings {
capture_buf: b.capture.buf_ptr(),
capture_capacity: b.capture.capacity as i32,
capture_write_idx: b.capture.write_idx_ptr(),
capture_read_idx: b.capture.read_idx_ptr(),
playout_buf: b.playout.buf_ptr(),
playout_capacity: b.playout.capacity as i32,
playout_write_idx: b.playout.write_idx_ptr(),
playout_read_idx: b.playout.read_idx_ptr(),
};
let ret = unsafe { wzp_oboe_start(&config, &rings) };
if ret != 0 {
return ret;
}
*started = true;
0
}
/// Stop Oboe. Idempotent. Safe to call from any thread.
#[unsafe(no_mangle)]
pub extern "C" fn wzp_native_audio_stop() {
let b = backend();
if let Ok(mut started) = b.started.lock() {
if *started {
unsafe { wzp_oboe_stop() };
*started = false;
}
}
}
/// Read captured PCM samples from the capture ring. Returns the number
/// of `i16` samples actually copied into `out` (may be less than
/// `out_len` if the ring is empty).
#[unsafe(no_mangle)]
pub unsafe extern "C" fn wzp_native_audio_read_capture(out: *mut i16, out_len: usize) -> usize {
if out.is_null() || out_len == 0 {
return 0;
}
let slice = unsafe { std::slice::from_raw_parts_mut(out, out_len) };
backend().capture.read(slice)
}
/// Write PCM samples into the playout ring. Returns the number of
/// samples actually enqueued (may be less than `in_len` if the ring
/// is nearly full — in practice the caller should pace to 20 ms
/// frames and spin briefly if the ring is full).
#[unsafe(no_mangle)]
pub unsafe extern "C" fn wzp_native_audio_write_playout(input: *const i16, in_len: usize) -> usize {
if input.is_null() || in_len == 0 {
return 0;
}
let slice = unsafe { std::slice::from_raw_parts(input, in_len) };
let b = backend();
// Fix A (task #35): detect playout callback stall. If the
// playout ring's read_idx hasn't advanced in 50+ writes
// (~1 second at 50 writes/sec), the Oboe playout callback
// has stopped firing → restart the streams. This is the
// self-healing behavior that makes rejoin work: teardown +
// rebuild clears whatever HAL state locked up the callback.
let current_read_idx = b.playout.read_idx.load(std::sync::atomic::Ordering::Relaxed);
let last_read_idx = b.playout_last_read_idx.load(std::sync::atomic::Ordering::Relaxed);
if current_read_idx == last_read_idx {
let stall = b.playout_stall_writes.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
if stall >= 50 {
// Callback hasn't drained anything in ~1 second.
// Force a stream restart.
unsafe {
android_log("playout STALL detected (50 writes, read_idx unchanged) — restarting Oboe streams");
}
b.playout_stall_writes.store(0, std::sync::atomic::Ordering::Relaxed);
// Release the started lock, stop, re-start.
// This is the same logic as the Rust-side
// audio_stop() + audio_start() but done inline
// because we can't call the extern "C" fns
// recursively. Just call the C++ side directly.
{
if let Ok(mut started) = b.started.lock() {
if *started {
unsafe { wzp_oboe_stop() };
*started = false;
}
}
}
// Clear the rings so the restart doesn't read stale data
b.playout.write_idx.store(0, std::sync::atomic::Ordering::Relaxed);
b.playout.read_idx.store(0, std::sync::atomic::Ordering::Relaxed);
b.capture.write_idx.store(0, std::sync::atomic::Ordering::Relaxed);
b.capture.read_idx.store(0, std::sync::atomic::Ordering::Relaxed);
// Re-start (stall detector — always non-BT mode)
let config = WzpOboeConfig {
sample_rate: 48_000,
frames_per_burst: FRAME_SAMPLES as i32,
channel_count: 1,
bt_active: 0,
};
let rings = WzpOboeRings {
capture_buf: b.capture.buf_ptr(),
capture_capacity: b.capture.capacity as i32,
capture_write_idx: b.capture.write_idx_ptr(),
capture_read_idx: b.capture.read_idx_ptr(),
playout_buf: b.playout.buf_ptr(),
playout_capacity: b.playout.capacity as i32,
playout_write_idx: b.playout.write_idx_ptr(),
playout_read_idx: b.playout.read_idx_ptr(),
};
let ret = unsafe { wzp_oboe_start(&config, &rings) };
if ret == 0 {
if let Ok(mut started) = b.started.lock() {
*started = true;
}
unsafe { android_log("playout restart OK — Oboe streams rebuilt"); }
} else {
unsafe { android_log(&format!("playout restart FAILED: {ret}")); }
}
b.playout_last_read_idx.store(0, std::sync::atomic::Ordering::Relaxed);
return 0; // caller will retry on next frame
}
} else {
// read_idx advanced — callback is alive, reset counter
b.playout_stall_writes.store(0, std::sync::atomic::Ordering::Relaxed);
b.playout_last_read_idx.store(current_read_idx, std::sync::atomic::Ordering::Relaxed);
}
let before_w = b.playout.write_idx.load(std::sync::atomic::Ordering::Relaxed);
let before_r = b.playout.read_idx.load(std::sync::atomic::Ordering::Relaxed);
let written = b.playout.write(slice);
// First few writes: log ring state + sample range so we can compare what
// engine.rs hands us to what the C++ playout callback reads.
let first_writes = b.playout_write_log_count.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
if first_writes < 3 || first_writes % 50 == 0 {
let (mut lo, mut hi, mut sumsq) = (i16::MAX, i16::MIN, 0i64);
for &s in slice.iter() {
if s < lo { lo = s; }
if s > hi { hi = s; }
sumsq += (s as i64) * (s as i64);
}
let rms = (sumsq as f64 / slice.len() as f64).sqrt() as i32;
let avail_w_after = b.playout.available_write();
let avail_r_after = b.playout.available_read();
let msg = format!(
"playout WRITE #{first_writes}: in_len={} written={} range=[{lo}..{hi}] rms={rms} before_w={before_w} before_r={before_r} avail_read_after={avail_r_after} avail_write_after={avail_w_after}",
slice.len(), written
);
unsafe {
android_log(msg.as_str());
}
}
written
}
// Minimal android logcat shim so we can print from the cdylib without pulling
// in android_logger crate (which would add another dep that has to build with
// cargo-ndk). Uses libc's __android_log_print via extern linkage.
#[cfg(target_os = "android")]
unsafe extern "C" {
fn __android_log_write(prio: i32, tag: *const u8, text: *const u8) -> i32;
}
#[cfg(target_os = "android")]
unsafe fn android_log(msg: &str) {
// ANDROID_LOG_INFO = 4. Tag and text must be NUL-terminated.
let tag = b"wzp-native\0";
let mut buf = Vec::with_capacity(msg.len() + 1);
buf.extend_from_slice(msg.as_bytes());
buf.push(0);
unsafe { __android_log_write(4, tag.as_ptr(), buf.as_ptr()); }
}
#[cfg(not(target_os = "android"))]
#[allow(dead_code)]
unsafe fn android_log(_msg: &str) {}
/// Current capture latency reported by Oboe, in milliseconds. Returns
/// NaN / 0.0 if the stream isn't running.
#[unsafe(no_mangle)]
pub extern "C" fn wzp_native_audio_capture_latency_ms() -> f32 {
unsafe { wzp_oboe_capture_latency_ms() }
}
/// Current playout latency reported by Oboe, in milliseconds.
#[unsafe(no_mangle)]
pub extern "C" fn wzp_native_audio_playout_latency_ms() -> f32 {
unsafe { wzp_oboe_playout_latency_ms() }
}
/// Non-zero if both Oboe streams are currently running.
#[unsafe(no_mangle)]
pub extern "C" fn wzp_native_audio_is_running() -> i32 {
unsafe { wzp_oboe_is_running() }
}