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maolan_engine/workers/
hw_worker.rs

1use crate::{
2    hw::config,
3    hw::traits::{HwMidiHub, HwWorkerDriver},
4    message::{HwMidiEvent, Message},
5    mutex::UnsafeMutex,
6};
7#[cfg(unix)]
8use nix::libc;
9use std::sync::{Arc, Condvar, Mutex};
10use std::thread::JoinHandle;
11use std::time::{Duration, Instant};
12use tokio::sync::mpsc::{Receiver, Sender};
13use tracing::error;
14
15pub trait Backend: Send + Sync + 'static {
16    type Driver: HwWorkerDriver + Send + 'static;
17    type MidiHub: HwMidiHub + Send + 'static;
18
19    const LABEL: &'static str;
20    const WORKER_THREAD_NAME: &'static str;
21    const ASSIST_THREAD_NAME: &'static str;
22    const ASSIST_AUTONOMOUS_ENV: &'static str;
23    const ASSIST_STEP_REQUIRES_REQUEST_CYCLE: bool = false;
24}
25
26#[derive(Debug)]
27pub struct HwWorker<B: Backend> {
28    driver: Arc<UnsafeMutex<B::Driver>>,
29    midi_hub: Arc<UnsafeMutex<B::MidiHub>>,
30    rx: Receiver<Message>,
31    tx: Sender<Message>,
32    cycle_frames: u32,
33    pending_midi_out_events: Vec<HwMidiEvent>,
34    midi_in_events: Vec<HwMidiEvent>,
35    pending_midi_out_sorted: bool,
36}
37
38#[derive(Debug, Default)]
39struct AssistState {
40    shutdown: bool,
41    request_seq: u64,
42    done_seq: u64,
43    init_complete: bool,
44    last_error: Option<String>,
45}
46
47#[cfg(unix)]
48const RT_POLICY: i32 = libc::SCHED_FIFO;
49const RT_PRIORITY_WORKER: i32 = 18;
50const RT_PRIORITY_ASSIST: i32 = 12;
51const PROFILE_INTERVAL: Duration = Duration::from_secs(1);
52
53#[derive(Debug)]
54struct AssistProfiler {
55    report_at: Instant,
56    cycle_count: u64,
57    cycle_err_count: u64,
58    cycle_time_ns: u128,
59    step_count: u64,
60    step_work_count: u64,
61    step_err_count: u64,
62    step_time_ns: u128,
63    wait_count: u64,
64    wait_time_ns: u128,
65}
66
67impl AssistProfiler {
68    fn new() -> Self {
69        Self {
70            report_at: Instant::now() + PROFILE_INTERVAL,
71            cycle_count: 0,
72            cycle_err_count: 0,
73            cycle_time_ns: 0,
74            step_count: 0,
75            step_work_count: 0,
76            step_err_count: 0,
77            step_time_ns: 0,
78            wait_count: 0,
79            wait_time_ns: 0,
80        }
81    }
82
83    fn maybe_report(&mut self, cycle_samples: usize, sample_rate: i32, label: &str) {
84        let now = Instant::now();
85        if now < self.report_at {
86            return;
87        }
88        let cycle_avg_us = if self.cycle_count > 0 {
89            (self.cycle_time_ns / self.cycle_count as u128) as f64 / 1_000.0
90        } else {
91            0.0
92        };
93        let step_avg_us = if self.step_count > 0 {
94            (self.step_time_ns / self.step_count as u128) as f64 / 1_000.0
95        } else {
96            0.0
97        };
98        let wait_avg_us = if self.wait_count > 0 {
99            (self.wait_time_ns / self.wait_count as u128) as f64 / 1_000.0
100        } else {
101            0.0
102        };
103        let expected_cycles_per_sec = if cycle_samples > 0 && sample_rate > 0 {
104            sample_rate as f64 / cycle_samples as f64
105        } else {
106            0.0
107        };
108        error!(
109            "{} profile: expected_cps={:.1} cycles={} cycle_err={} cycle_avg_us={:.1} steps={} steps_work={} step_err={} step_avg_us={:.1} waits={} wait_avg_us={:.1}",
110            label,
111            expected_cycles_per_sec,
112            self.cycle_count,
113            self.cycle_err_count,
114            cycle_avg_us,
115            self.step_count,
116            self.step_work_count,
117            self.step_err_count,
118            step_avg_us,
119            self.wait_count,
120            wait_avg_us
121        );
122        self.report_at = now + PROFILE_INTERVAL;
123        self.cycle_count = 0;
124        self.cycle_err_count = 0;
125        self.cycle_time_ns = 0;
126        self.step_count = 0;
127        self.step_work_count = 0;
128        self.step_err_count = 0;
129        self.step_time_ns = 0;
130        self.wait_count = 0;
131        self.wait_time_ns = 0;
132    }
133}
134
135impl<B: Backend> HwWorker<B> {
136    fn profile_enabled() -> bool {
137        config::env_flag(config::HW_PROFILE_ENV)
138    }
139
140    fn assist_autonomous_enabled() -> bool {
141        config::env_flag(B::ASSIST_AUTONOMOUS_ENV)
142    }
143
144    fn configure_rt_thread(name: &str, priority: i32) -> Result<(), String> {
145        #[cfg(unix)]
146        {
147            let thread = unsafe { libc::pthread_self() };
148            #[cfg(any(target_os = "linux", target_os = "freebsd", target_os = "openbsd"))]
149            let c_name = std::ffi::CString::new(name).map_err(|e| e.to_string())?;
150            #[cfg(target_os = "linux")]
151            unsafe {
152                let _ = libc::pthread_setname_np(thread, c_name.as_ptr());
153            }
154            #[cfg(any(target_os = "freebsd", target_os = "openbsd"))]
155            unsafe {
156                libc::pthread_set_name_np(thread, c_name.as_ptr());
157            }
158
159            let param = unsafe {
160                let mut p = std::mem::zeroed::<libc::sched_param>();
161                p.sched_priority = priority;
162                p
163            };
164            let rc = unsafe { libc::pthread_setschedparam(thread, RT_POLICY, &param) };
165            if rc != 0 {
166                return Err(format!(
167                    "pthread_setschedparam({}, prio {}) failed with errno {}",
168                    name, priority, rc
169                ));
170            }
171
172            let mut actual_policy = 0_i32;
173            let mut actual_param = unsafe { std::mem::zeroed::<libc::sched_param>() };
174            let rc = unsafe {
175                libc::pthread_getschedparam(thread, &mut actual_policy, &mut actual_param)
176            };
177            if rc != 0 {
178                return Err(format!(
179                    "pthread_getschedparam({}) failed with errno {}",
180                    name, rc
181                ));
182            }
183            if actual_policy != RT_POLICY || actual_param.sched_priority != priority {
184                return Err(format!(
185                    "realtime verification failed for {}: policy {}, prio {}",
186                    name, actual_policy, actual_param.sched_priority
187                ));
188            }
189            Ok(())
190        }
191        #[cfg(not(unix))]
192        {
193            let _ = name;
194            let _ = priority;
195            Err("Realtime thread priority is not supported on this platform".to_string())
196        }
197    }
198
199    fn lock_memory_pages() -> Result<(), String> {
200        #[cfg(unix)]
201        {
202            let rc = unsafe { libc::mlockall(libc::MCL_CURRENT | libc::MCL_FUTURE) };
203            if rc == 0 {
204                Ok(())
205            } else {
206                Err(format!(
207                    "mlockall(MCL_CURRENT|MCL_FUTURE) failed: {}",
208                    std::io::Error::last_os_error()
209                ))
210            }
211        }
212        #[cfg(not(unix))]
213        {
214            Err("mlockall is not supported on this platform".to_string())
215        }
216    }
217
218    pub fn new(
219        driver: Arc<UnsafeMutex<B::Driver>>,
220        midi_hub: Arc<UnsafeMutex<B::MidiHub>>,
221        rx: Receiver<Message>,
222        tx: Sender<Message>,
223    ) -> Self {
224        let cycle_frames = {
225            let d = driver.lock();
226            d.cycle_samples() as u32
227        };
228        Self {
229            driver,
230            midi_hub,
231            rx,
232            tx,
233            cycle_frames,
234            pending_midi_out_events: vec![],
235            midi_in_events: Vec::with_capacity(64),
236            pending_midi_out_sorted: true,
237        }
238    }
239
240    pub async fn work(mut self) {
241        if let Err(e) = Self::lock_memory_pages() {
242            error!("{} worker memory lock not enabled: {}", B::LABEL, e);
243        }
244        if let Err(e) = Self::configure_rt_thread(B::WORKER_THREAD_NAME, RT_PRIORITY_WORKER) {
245            error!("{} worker realtime priority not enabled: {}", B::LABEL, e);
246        }
247        #[cfg(target_os = "macos")]
248        unsafe {
249            libc::pthread_set_qos_class_self_np(libc::qos_class_t::QOS_CLASS_USER_INTERACTIVE, 0);
250        }
251        let assist_state = Arc::new((Mutex::new(AssistState::default()), Condvar::new()));
252        let assist_handle = Self::start_assist_thread(self.driver.clone(), assist_state.clone());
253        loop {
254            match self.rx.recv().await {
255                Some(msg) => match msg {
256                    Message::Request(crate::message::Action::Quit) => {
257                        if !self.pending_midi_out_events.is_empty() {
258                            if !self.pending_midi_out_sorted {
259                                self.pending_midi_out_events.sort_by(|a, b| {
260                                    a.event
261                                        .frame
262                                        .cmp(&b.event.frame)
263                                        .then_with(|| a.device.cmp(&b.device))
264                                });
265                                self.pending_midi_out_sorted = true;
266                            }
267                            let midi_hub = self.midi_hub.lock();
268                            midi_hub.write_events(&self.pending_midi_out_events);
269                            self.pending_midi_out_events.clear();
270                        }
271                        Self::stop_assist_thread(&assist_state, assist_handle);
272                        return;
273                    }
274                    Message::TracksFinished => {
275                        {
276                            let midi_hub = self.midi_hub.lock();
277                            midi_hub.read_events_into(&mut self.midi_in_events);
278                        }
279                        spread_hw_event_frames(&mut self.midi_in_events, self.cycle_frames);
280                        if !self.midi_in_events.is_empty() {
281                            let cap = self.midi_in_events.capacity();
282                            let out = std::mem::replace(
283                                &mut self.midi_in_events,
284                                Vec::with_capacity(cap.max(64)),
285                            );
286                            if let Err(e) = self.tx.send(Message::HWMidiEvents(out)).await {
287                                error!(
288                                    "{} worker failed to send HWMidiEvents to engine: {}",
289                                    B::LABEL,
290                                    e
291                                );
292                            }
293                        }
294                        {
295                            if !self.pending_midi_out_events.is_empty() {
296                                if !self.pending_midi_out_sorted {
297                                    self.pending_midi_out_events.sort_by(|a, b| {
298                                        a.event
299                                            .frame
300                                            .cmp(&b.event.frame)
301                                            .then_with(|| a.device.cmp(&b.device))
302                                    });
303                                    self.pending_midi_out_sorted = true;
304                                }
305                                let midi_hub = self.midi_hub.lock();
306                                midi_hub.write_events(&self.pending_midi_out_events);
307                                self.pending_midi_out_events.clear();
308                            }
309                        }
310                        if let Err(e) = Self::run_assist_cycle(&assist_state) {
311                            error!("{} assist cycle error: {}", B::LABEL, e);
312                        }
313                        if let Err(e) = self.tx.send(Message::HWFinished).await {
314                            error!(
315                                "{} worker failed to send HWFinished to engine: {}",
316                                B::LABEL,
317                                e
318                            );
319                        }
320                    }
321                    Message::HWMidiOutEvents(mut events) => {
322                        self.pending_midi_out_events.append(&mut events);
323                        self.pending_midi_out_sorted = false;
324                    }
325                    Message::ClearHWMidiOutEvents => {
326                        self.pending_midi_out_events.clear();
327                        self.pending_midi_out_sorted = true;
328                    }
329                    _ => {}
330                },
331                None => {
332                    Self::stop_assist_thread(&assist_state, assist_handle);
333                    return;
334                }
335            }
336        }
337    }
338
339    fn start_assist_thread(
340        driver: Arc<UnsafeMutex<B::Driver>>,
341        assist_state: Arc<(Mutex<AssistState>, Condvar)>,
342    ) -> JoinHandle<()> {
343        let profile = Self::profile_enabled();
344        let autonomous = Self::assist_autonomous_enabled();
345        std::thread::spawn(move || {
346            if let Err(e) = Self::configure_rt_thread(B::ASSIST_THREAD_NAME, RT_PRIORITY_ASSIST) {
347                error!("{} assist realtime priority not enabled: {}", B::LABEL, e);
348            }
349            #[cfg(target_os = "macos")]
350            unsafe {
351                libc::pthread_set_qos_class_self_np(libc::qos_class_t::QOS_CLASS_USER_INITIATED, 0);
352            }
353            let mut profiler = if profile {
354                let (cycle_samples, sample_rate) = {
355                    let d = driver.lock();
356                    (d.cycle_samples(), d.sample_rate())
357                };
358                error!(
359                    "{} profile enabled: cycle_samples={} sample_rate={} expected_cps={:.1}",
360                    B::LABEL,
361                    cycle_samples,
362                    sample_rate,
363                    if cycle_samples > 0 {
364                        sample_rate as f64 / cycle_samples as f64
365                    } else {
366                        0.0
367                    }
368                );
369                Some(AssistProfiler::new())
370            } else {
371                None
372            };
373            let (lock, cvar) = &*assist_state;
374            loop {
375                let (shutdown, has_request, target, init_complete) = {
376                    let st = lock.lock().expect("assist mutex poisoned");
377                    (
378                        st.shutdown,
379                        st.request_seq > st.done_seq,
380                        st.request_seq,
381                        st.init_complete,
382                    )
383                };
384                if shutdown {
385                    break;
386                }
387                if has_request {
388                    let started = Instant::now();
389                    let run_error = {
390                        let d = driver.lock();
391                        d.run_cycle_for_worker().err().map(|e| e.to_string())
392                    };
393                    if let Some(p) = profiler.as_mut() {
394                        p.cycle_count += 1;
395                        if run_error.is_some() {
396                            p.cycle_err_count += 1;
397                        }
398                        p.cycle_time_ns += started.elapsed().as_nanos();
399                        let (cycle_samples, sample_rate) = {
400                            let d = driver.lock();
401                            (d.cycle_samples(), d.sample_rate())
402                        };
403                        p.maybe_report(cycle_samples, sample_rate, B::LABEL);
404                    }
405                    let mut st = lock.lock().expect("assist mutex poisoned");
406                    st.done_seq = st.done_seq.max(target);
407                    if run_error.is_none() {
408                        st.init_complete = true;
409                    }
410                    st.last_error = run_error;
411                    cvar.notify_all();
412                    continue;
413                }
414
415                if B::ASSIST_STEP_REQUIRES_REQUEST_CYCLE && !init_complete {
416                    let st = lock.lock().expect("assist mutex poisoned");
417                    if st.shutdown {
418                        break;
419                    }
420                    let wait_started = Instant::now();
421                    let _guard = cvar.wait(st).expect("assist condvar failed");
422                    if let Some(p) = profiler.as_mut() {
423                        p.wait_count += 1;
424                        p.wait_time_ns += wait_started.elapsed().as_nanos();
425                    }
426                    continue;
427                }
428
429                if !autonomous {
430                    let st = lock.lock().expect("assist mutex poisoned");
431                    if st.shutdown {
432                        break;
433                    }
434                    let wait_started = Instant::now();
435                    let _guard = cvar.wait(st).expect("assist condvar failed");
436                    if let Some(p) = profiler.as_mut() {
437                        p.wait_count += 1;
438                        p.wait_time_ns += wait_started.elapsed().as_nanos();
439                    }
440                    continue;
441                }
442
443                let started = Instant::now();
444                let did_work = {
445                    let d = driver.lock();
446                    match d.run_assist_step_for_worker() {
447                        Ok(v) => v,
448                        Err(e) => {
449                            if let Some(p) = profiler.as_mut() {
450                                p.step_err_count += 1;
451                            }
452                            let mut st = lock.lock().expect("assist mutex poisoned");
453                            st.last_error = Some(e.to_string());
454                            cvar.notify_all();
455                            false
456                        }
457                    }
458                };
459                if let Some(p) = profiler.as_mut() {
460                    p.step_count += 1;
461                    if did_work {
462                        p.step_work_count += 1;
463                    }
464                    p.step_time_ns += started.elapsed().as_nanos();
465                    let (cycle_samples, sample_rate) = {
466                        let d = driver.lock();
467                        (d.cycle_samples(), d.sample_rate())
468                    };
469                    p.maybe_report(cycle_samples, sample_rate, B::LABEL);
470                }
471                if !did_work {
472                    let st = lock.lock().expect("assist mutex poisoned");
473                    if st.shutdown {
474                        break;
475                    }
476                    let wait_started = Instant::now();
477                    let _guard = cvar.wait(st).expect("assist condvar failed");
478                    if let Some(p) = profiler.as_mut() {
479                        p.wait_count += 1;
480                        p.wait_time_ns += wait_started.elapsed().as_nanos();
481                    }
482                }
483            }
484        })
485    }
486
487    fn run_assist_cycle(assist_state: &Arc<(Mutex<AssistState>, Condvar)>) -> Result<(), String> {
488        let (lock, cvar) = &**assist_state;
489        let mut st = lock
490            .lock()
491            .map_err(|_| "assist mutex poisoned".to_string())?;
492        st.request_seq = st.request_seq.saturating_add(1);
493        let target = st.request_seq;
494        cvar.notify_one();
495        while st.done_seq < target && !st.shutdown {
496            st = cvar
497                .wait(st)
498                .map_err(|_| "assist condvar wait failed".to_string())?;
499        }
500        if let Some(err) = st.last_error.take() {
501            return Err(err);
502        }
503        Ok(())
504    }
505
506    fn stop_assist_thread(
507        assist_state: &Arc<(Mutex<AssistState>, Condvar)>,
508        assist_handle: JoinHandle<()>,
509    ) {
510        let (lock, cvar) = &**assist_state;
511        if let Ok(mut st) = lock.lock() {
512            st.shutdown = true;
513            cvar.notify_all();
514        }
515        let _ = assist_handle.join();
516    }
517}
518
519fn spread_hw_event_frames(events: &mut [HwMidiEvent], frames: u32) {
520    if events.len() <= 1 || frames <= 1 {
521        return;
522    }
523    let n = events.len() as u32;
524    for (idx, event) in events.iter_mut().enumerate() {
525        let pos = idx as u32;
526        event.event.frame = ((pos as u64 * (frames - 1) as u64) / n as u64) as u32;
527    }
528}