| 1 | //! A bounded presentation sink for the shared core's stereo PCM. No score, |
| 2 | //! event interpretation or simulation clock lives in the audio player. |
| 3 | use std::io::{self, Write}; |
| 4 | use std::process::{Child, Command, Stdio}; |
| 5 | use std::sync::atomic::{AtomicBool, Ordering}; |
| 6 | use std::sync::{Arc, Mutex, mpsc}; |
| 7 | use std::time::{Duration, Instant}; |
| 8 | |
| 9 | pub const SAMPLE_RATE: usize = 48_000; |
| 10 | pub const MAX_FRAMES: usize = SAMPLE_RATE / 2; |
| 11 | |
| 12 | pub(super) struct Packet { |
| 13 | pub(super) bytes: Vec<u8>, |
| 14 | created: Instant, |
| 15 | } |
| 16 | |
| 17 | #[derive(Default)] |
| 18 | struct Control { |
| 19 | child: Mutex<Option<Child>>, |
| 20 | cancelled: AtomicBool, |
| 21 | failed: AtomicBool, |
| 22 | } |
| 23 | |
| 24 | #[derive(Clone)] |
| 25 | pub struct Target { |
| 26 | tx: mpsc::SyncSender<Packet>, |
| 27 | control: Arc<Control>, |
| 28 | requested: Instant, |
| 29 | } |
| 30 | |
| 31 | impl Target { |
| 32 | pub fn same_stream(&self, other: &Self) -> bool { |
| 33 | Arc::ptr_eq(&self.control, &other.control) |
| 34 | } |
| 35 | |
| 36 | pub fn active(&self) -> bool { |
| 37 | !self.control.cancelled.load(Ordering::Acquire) |
| 38 | && !self.control.failed.load(Ordering::Acquire) |
| 39 | } |
| 40 | |
| 41 | pub fn fail(&self) { |
| 42 | self.control.failed.store(true, Ordering::Release); |
| 43 | } |
| 44 | |
| 45 | pub fn current(&self) -> bool { |
| 46 | self.requested.elapsed() <= Duration::from_millis(500) |
| 47 | } |
| 48 | |
| 49 | /// `Ok` means the samples were valid and the stream is live, not that they |
| 50 | /// were played: a full queue or a stale request drops them. Live audio is |
| 51 | /// a bounded real-time sink — late samples never queue behind the world |
| 52 | /// clock — so an overrun is a dropout, not a stream failure. |
| 53 | pub fn send(&self, channels: [Vec<f32>; 2]) -> Result<(), ()> { |
| 54 | let length = channels[0].len(); |
| 55 | if length > MAX_FRAMES |
| 56 | || channels[1].len() != length |
| 57 | || channels |
| 58 | .iter() |
| 59 | .flatten() |
| 60 | .any(|s| !s.is_finite() || s.abs() > 1.0) |
| 61 | { |
| 62 | self.fail(); |
| 63 | return Err(()); |
| 64 | } |
| 65 | if !self.active() { |
| 66 | return Err(()); |
| 67 | } |
| 68 | if !self.current() { |
| 69 | return Ok(()); |
| 70 | } |
| 71 | let mut bytes = Vec::with_capacity(length * 8); |
| 72 | for (left, right) in channels[0].iter().zip(&channels[1]) { |
| 73 | bytes.extend_from_slice(&left.to_le_bytes()); |
| 74 | bytes.extend_from_slice(&right.to_le_bytes()); |
| 75 | } |
| 76 | match self.tx.try_send(Packet { |
| 77 | bytes, |
| 78 | created: self.requested, |
| 79 | }) { |
| 80 | Ok(()) | Err(mpsc::TrySendError::Full(_)) => Ok(()), |
| 81 | Err(mpsc::TrySendError::Disconnected(_)) => { |
| 82 | self.fail(); |
| 83 | Err(()) |
| 84 | } |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | pub struct Output { |
| 90 | target: Target, |
| 91 | } |
| 92 | |
| 93 | impl Output { |
| 94 | #[cfg(test)] |
| 95 | pub(super) fn capture() -> (Self, mpsc::Receiver<Packet>) { |
| 96 | let (tx, rx) = mpsc::sync_channel(4); |
| 97 | ( |
| 98 | Self { |
| 99 | target: Target { |
| 100 | tx, |
| 101 | control: Arc::new(Control::default()), |
| 102 | requested: Instant::now(), |
| 103 | }, |
| 104 | }, |
| 105 | rx, |
| 106 | ) |
| 107 | } |
| 108 | |
| 109 | #[cfg(not(test))] |
| 110 | pub fn start() -> io::Result<Self> { |
| 111 | Self::spawn(player_command()?) |
| 112 | } |
| 113 | |
| 114 | #[cfg(test)] |
| 115 | pub fn start() -> io::Result<Self> { |
| 116 | // Product/library tests never open the user's audio output. |
| 117 | Err(io::Error::new( |
| 118 | io::ErrorKind::Unsupported, |
| 119 | "audio disabled in tests", |
| 120 | )) |
| 121 | } |
| 122 | |
| 123 | fn spawn(mut command: Command) -> io::Result<Self> { |
| 124 | let (tx, rx) = mpsc::sync_channel(4); |
| 125 | let control = Arc::new(Control::default()); |
| 126 | let thread_control = Arc::clone(&control); |
| 127 | std::thread::Builder::new() |
| 128 | .name("pet-audio".into()) |
| 129 | .spawn(move || { |
| 130 | let result = play(&mut command, rx, &thread_control); |
| 131 | if result.is_err() && !thread_control.cancelled.load(Ordering::Acquire) { |
| 132 | thread_control.failed.store(true, Ordering::Release); |
| 133 | } |
| 134 | let child = thread_control |
| 135 | .child |
| 136 | .lock() |
| 137 | .ok() |
| 138 | .and_then(|mut slot| slot.take()); |
| 139 | if let Some(mut child) = child { |
| 140 | let _ = child.kill(); |
| 141 | let _ = child.wait(); |
| 142 | } |
| 143 | })?; |
| 144 | Ok(Self { |
| 145 | target: Target { |
| 146 | tx, |
| 147 | control, |
| 148 | requested: Instant::now(), |
| 149 | }, |
| 150 | }) |
| 151 | } |
| 152 | |
| 153 | pub fn target(&self) -> Target { |
| 154 | Target { |
| 155 | requested: Instant::now(), |
| 156 | ..self.target.clone() |
| 157 | } |
| 158 | } |
| 159 | pub fn failed(&self) -> bool { |
| 160 | self.target.control.failed.load(Ordering::Acquire) |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | impl Drop for Output { |
| 165 | fn drop(&mut self) { |
| 166 | self.target.control.cancelled.store(true, Ordering::Release); |
| 167 | // Closing or muting Watch interrupts even a blocked pipe write. Reaping |
| 168 | // happens in the audio thread, never in the terminal event loop. |
| 169 | if let Ok(mut slot) = self.target.control.child.lock() |
| 170 | && let Some(child) = slot.as_mut() |
| 171 | { |
| 172 | let _ = child.kill(); |
| 173 | } |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | /// The pet's PCM player: `ffplay` from a fixed install prefix, never from the |
| 178 | /// ambient `PATH` (see [`crate::notify::audio::trusted_system_executable`]). A player |
| 179 | /// that is not installed there fails the start and Watch reports audio as |
| 180 | /// unavailable. |
| 181 | fn player_command() -> io::Result<Command> { |
| 182 | let mut command = Command::new(crate::notify::audio::trusted_system_executable("ffplay")?); |
| 183 | command.args([ |
| 184 | "-nodisp", |
| 185 | "-autoexit", |
| 186 | "-loglevel", |
| 187 | "error", |
| 188 | "-probesize", |
| 189 | "32", |
| 190 | "-analyzeduration", |
| 191 | "0", |
| 192 | "-f", |
| 193 | "f32le", |
| 194 | "-sample_rate", |
| 195 | "48000", |
| 196 | "-ch_layout", |
| 197 | "stereo", |
| 198 | "-i", |
| 199 | "pipe:0", |
| 200 | ]); |
| 201 | #[cfg(windows)] |
| 202 | { |
| 203 | use std::os::windows::process::CommandExt; |
| 204 | command.creation_flags(0x08000000); // CREATE_NO_WINDOW |
| 205 | } |
| 206 | Ok(command) |
| 207 | } |
| 208 | |
| 209 | fn play(command: &mut Command, rx: mpsc::Receiver<Packet>, control: &Control) -> io::Result<()> { |
| 210 | if control.cancelled.load(Ordering::Acquire) { |
| 211 | return Ok(()); |
| 212 | } |
| 213 | let mut child = command |
| 214 | .stdin(Stdio::piped()) |
| 215 | .stdout(Stdio::null()) |
| 216 | .stderr(Stdio::null()) |
| 217 | .spawn()?; |
| 218 | let Some(mut input) = child.stdin.take() else { |
| 219 | let _ = child.kill(); |
| 220 | let _ = child.wait(); |
| 221 | return Err(io::Error::other("audio pipe unavailable")); |
| 222 | }; |
| 223 | match control.child.lock() { |
| 224 | Ok(mut slot) => *slot = Some(child), |
| 225 | Err(_) => { |
| 226 | let _ = child.kill(); |
| 227 | let _ = child.wait(); |
| 228 | return Err(io::Error::other("audio lock failed")); |
| 229 | } |
| 230 | } |
| 231 | while !control.cancelled.load(Ordering::Acquire) && !control.failed.load(Ordering::Acquire) { |
| 232 | if control |
| 233 | .child |
| 234 | .lock() |
| 235 | .map_err(|_| io::Error::other("audio lock failed"))? |
| 236 | .as_mut() |
| 237 | .is_none_or(|c| c.try_wait().map_or(true, |status| status.is_some())) |
| 238 | { |
| 239 | return Err(io::Error::other("audio player exited")); |
| 240 | } |
| 241 | match rx.recv_timeout(Duration::from_millis(50)) { |
| 242 | Ok(packet) => { |
| 243 | if packet.created.elapsed() > Duration::from_millis(500) { |
| 244 | continue; |
| 245 | } |
| 246 | input.write_all(&packet.bytes)?; |
| 247 | } |
| 248 | Err(mpsc::RecvTimeoutError::Timeout) => {} |
| 249 | Err(mpsc::RecvTimeoutError::Disconnected) => break, |
| 250 | } |
| 251 | } |
| 252 | Ok(()) |
| 253 | } |
| 254 | |
| 255 | #[cfg(test)] |
| 256 | mod tests { |
| 257 | use super::*; |
| 258 | |
| 259 | fn wait_until(mut ready: impl FnMut() -> bool) { |
| 260 | let until = Instant::now() + Duration::from_secs(5); |
| 261 | while !ready() { |
| 262 | assert!(Instant::now() < until, "audio process did not settle"); |
| 263 | std::thread::sleep(Duration::from_millis(5)); |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | fn receiver() -> (Target, mpsc::Receiver<Packet>) { |
| 268 | let (tx, rx) = mpsc::sync_channel(4); |
| 269 | ( |
| 270 | Target { |
| 271 | tx, |
| 272 | control: Arc::new(Control::default()), |
| 273 | requested: Instant::now(), |
| 274 | }, |
| 275 | rx, |
| 276 | ) |
| 277 | } |
| 278 | |
| 279 | #[test] |
| 280 | fn pcm_boundary_preserves_samples_rejects_invalid_input_and_discards_backlog() { |
| 281 | let (target, rx) = receiver(); |
| 282 | target.send([vec![0.125, -0.5], vec![0.25, 0.75]]).unwrap(); |
| 283 | let bytes: Vec<_> = [0.125_f32, 0.25, -0.5, 0.75] |
| 284 | .into_iter() |
| 285 | .flat_map(f32::to_le_bytes) |
| 286 | .collect(); |
| 287 | assert_eq!(rx.recv().unwrap().bytes, bytes); |
| 288 | for channels in [ |
| 289 | [vec![0.0], vec![]], |
| 290 | [vec![f32::NAN], vec![0.0]], |
| 291 | [vec![1.01], vec![0.0]], |
| 292 | [vec![0.0; MAX_FRAMES + 1], vec![0.0; MAX_FRAMES + 1]], |
| 293 | ] { |
| 294 | let (target, rx) = receiver(); |
| 295 | assert!(target.send(channels).is_err()); |
| 296 | assert!(!target.active()); |
| 297 | assert!(rx.try_recv().is_err()); |
| 298 | } |
| 299 | let (mut target, rx) = receiver(); |
| 300 | target.requested = Instant::now() - Duration::from_secs(1); |
| 301 | assert!(target.send([vec![0.0], vec![0.0]]).is_ok()); |
| 302 | assert!(target.active()); |
| 303 | assert!(rx.try_recv().is_err()); |
| 304 | let (target, rx) = receiver(); |
| 305 | for _ in 0..4 { |
| 306 | target.send([vec![0.0], vec![0.0]]).unwrap(); |
| 307 | } |
| 308 | assert!(target.send([vec![0.0], vec![0.0]]).is_ok()); |
| 309 | assert!(target.active()); |
| 310 | assert_eq!(rx.try_iter().count(), 4); |
| 311 | } |
| 312 | |
| 313 | /// Only a test subprocess with this explicit environment enters the sink. |
| 314 | /// Ordinary library/nextest runs return without launching or playing audio. |
| 315 | #[test] |
| 316 | fn pet_audio_fake_player() { |
| 317 | let Some(path) = std::env::var_os("CODEWHALE_TEST_PET_AUDIO_OUTPUT") else { |
| 318 | return; |
| 319 | }; |
| 320 | let mut file = std::fs::File::create(path).unwrap(); |
| 321 | if std::env::var_os("CODEWHALE_TEST_PET_AUDIO_HOLD").is_some() { |
| 322 | std::thread::sleep(Duration::from_secs(30)); |
| 323 | } else { |
| 324 | std::io::copy(&mut std::io::stdin().lock(), &mut file).unwrap(); |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | fn fake_player(path: &std::path::Path, hold: bool) -> Command { |
| 329 | let module = module_path!().split_once("::").unwrap().1; |
| 330 | let mut command = Command::new(std::env::current_exe().unwrap()); |
| 331 | command |
| 332 | .args([ |
| 333 | "--exact", |
| 334 | &format!("{module}::pet_audio_fake_player"), |
| 335 | "--nocapture", |
| 336 | ]) |
| 337 | .env("CODEWHALE_TEST_PET_AUDIO_OUTPUT", path); |
| 338 | if hold { |
| 339 | command.env("CODEWHALE_TEST_PET_AUDIO_HOLD", "1"); |
| 340 | } |
| 341 | command |
| 342 | } |
| 343 | |
| 344 | #[test] |
| 345 | fn muting_reaps_the_player_even_with_a_retained_target_and_blocked_pipe() { |
| 346 | for hold in [false, true] { |
| 347 | let dir = tempfile::tempdir().unwrap(); |
| 348 | let path = dir.path().join("received.f32"); |
| 349 | let output = Output::spawn(fake_player(&path, hold)).unwrap(); |
| 350 | wait_until(|| path.exists()); |
| 351 | let target = output.target(); |
| 352 | let control = Arc::clone(&target.control); |
| 353 | target |
| 354 | .send([vec![0.125; MAX_FRAMES], vec![-0.25; MAX_FRAMES]]) |
| 355 | .unwrap(); |
| 356 | if !hold { |
| 357 | wait_until(|| std::fs::metadata(&path).unwrap().len() == (MAX_FRAMES * 8) as u64); |
| 358 | } |
| 359 | drop(output); |
| 360 | assert!(!target.active()); |
| 361 | assert!(target.send([vec![0.0], vec![0.0]]).is_err()); |
| 362 | // Only this test and the deliberately retained target remain. The |
| 363 | // player thread must have returned after killing and reaping it. |
| 364 | wait_until(|| Arc::strong_count(&control) == 2); |
| 365 | assert!(control.child.lock().unwrap().is_none()); |
| 366 | } |
| 367 | } |
| 368 | |
| 369 | /// U06-06: the player is an absolute path from a trusted prefix or it is |
| 370 | /// refused — never a bare name the ambient `PATH` resolves, where an empty |
| 371 | /// or repository-local entry would run a workspace-planted `ffplay`. |
| 372 | #[test] |
| 373 | fn pet_player_is_never_resolved_through_path() { |
| 374 | match player_command() { |
| 375 | Ok(command) => assert!( |
| 376 | std::path::Path::new(command.get_program()).is_absolute(), |
| 377 | "player resolved through PATH: {:?}", |
| 378 | command.get_program() |
| 379 | ), |
| 380 | Err(error) => assert_eq!(error.kind(), io::ErrorKind::NotFound), |
| 381 | } |
| 382 | } |
| 383 | |
| 384 | #[test] |
| 385 | fn missing_player_fails_without_opening_a_device_or_blocking_the_caller() { |
| 386 | assert!(Output::start().is_err()); |
| 387 | let dir = tempfile::tempdir().unwrap(); |
| 388 | let output = Output::spawn(Command::new(dir.path().join("missing-player"))).unwrap(); |
| 389 | wait_until(|| output.failed()); |
| 390 | assert!(!output.target().active()); |
| 391 | } |
| 392 | } |
| 393 |