maolan_engine/plugins/
ipc.rs

1use crate::audio::io::AudioIO;
2use crate::mutex::UnsafeMutex;
3use maolan_plugin_protocol::events::EventPair;
4use maolan_plugin_protocol::protocol::*;
5use maolan_plugin_protocol::shm::ShmMapping;
6use std::path::{Path, PathBuf};
7use std::process::{Child, ChildStderr, Command, Stdio};
8use std::sync::Arc;
9use std::sync::atomic::{AtomicU64, Ordering};
10use std::time::{Duration, Instant};
11
12static NEXT_INSTANCE_ID: AtomicU64 = AtomicU64::new(0);
13
14pub fn unique_instance_id(format: &str) -> String {
15    let n = NEXT_INSTANCE_ID.fetch_add(1, Ordering::Relaxed);
16    format!("{}-{}-{}", format, std::process::id(), n)
17}
18
19pub struct HostSpawnArgs<'a> {
20    pub host_binary: &'a Path,
21    pub format: &'a str,
22    pub plugin_spec: &'a str,
23    pub instance_id: &'a str,
24    pub extra_args: &'a [&'a str],
25}
26
27pub fn spawn_host(
28    args: HostSpawnArgs,
29) -> Result<(Child, ShmMapping, EventPair, String, Option<ChildStderr>), String> {
30    let pid = std::process::id();
31    let shm_name = format!("/maolan-{pid}-{}", args.instance_id);
32
33    let mapping = ShmMapping::create(&shm_name, SHM_SIZE)
34        .map_err(|e| format!("failed to create shared memory: {e}"))?;
35    unsafe {
36        init_shm_layout(mapping.as_ptr(), mapping.size());
37    }
38
39    let mut events = EventPair::new().map_err(|e| format!("failed to create event pipes: {e}"))?;
40
41    let mut cmd = Command::new(args.host_binary);
42    cmd.arg(args.format)
43        .arg(args.plugin_spec)
44        .arg(&shm_name)
45        .arg(args.instance_id)
46        .stdin(Stdio::null())
47        .stdout(Stdio::null())
48        .stderr(Stdio::piped());
49
50    #[cfg(unix)]
51    {
52        cmd.arg(events.host_read_fd().to_string())
53            .arg(events.host_write_fd().to_string());
54    }
55
56    for arg in args.extra_args {
57        cmd.arg(arg);
58    }
59    #[cfg(windows)]
60    {
61        cmd.arg(events.daw_to_host_name())
62            .arg(events.host_to_daw_name());
63    }
64
65    append_parent_log_level(&mut cmd);
66
67    let mut child = cmd
68        .spawn()
69        .map_err(|e| format!("failed to spawn {} host: {e}", args.format))?;
70    let stderr = child.stderr.take();
71
72    events.close_daw_unused();
73
74    Ok((child, mapping, events, shm_name, stderr))
75}
76
77pub fn append_parent_log_level(cmd: &mut Command) {
78    let parent_args: Vec<String> = std::env::args().collect();
79    if let Some(pos) = parent_args.iter().position(|a| a == "--log-level")
80        && pos + 1 < parent_args.len()
81    {
82        cmd.arg("--log-level").arg(&parent_args[pos + 1]);
83    }
84}
85
86pub fn wait_for_ready(header: &ShmHeader, timeout: Duration) -> bool {
87    let start = Instant::now();
88    while start.elapsed() < timeout {
89        if header.ready.load(Ordering::Acquire) != 0 {
90            return true;
91        }
92        std::thread::sleep(Duration::from_millis(5));
93    }
94    false
95}
96
97pub fn bypass_copy_inputs_to_outputs(inputs: &[Arc<AudioIO>], outputs: &[Arc<AudioIO>]) {
98    for (input, output) in inputs.iter().zip(outputs.iter()) {
99        let src = input.buffer.lock();
100        let dst = output.buffer.lock();
101        dst.fill(0.0);
102        for (d, s) in dst.iter_mut().zip(src.iter()) {
103            *d = *s;
104        }
105        *output.finished.lock() = true;
106    }
107    for output in outputs.iter().skip(inputs.len()) {
108        let dst = output.buffer.lock();
109        dst.fill(0.0);
110        *output.finished.lock() = true;
111    }
112}
113
114pub fn drop_host(
115    mapping: &Option<ShmMapping>,
116    events: &Option<EventPair>,
117    child: &UnsafeMutex<Option<Child>>,
118    shm_name: &str,
119) {
120    if let Some(mapping) = mapping
121        && let Some(events) = events
122    {
123        let header = unsafe { header_mut(mapping.as_ptr()) };
124        header.shutdown_request.store(1, Ordering::Release);
125        let _ = events.signal_host();
126    }
127    let mut child_opt = child.lock().take();
128    if let Some(mut child) = child_opt.take() {
129        let start = Instant::now();
130        while start.elapsed() < Duration::from_secs(2) {
131            if child.try_wait().map(|s| s.is_some()).unwrap_or(true) {
132                break;
133            }
134            std::thread::sleep(Duration::from_millis(10));
135        }
136        if child.try_wait().map(|s| s.is_none()).unwrap_or(false) {
137            let _ = child.kill();
138        }
139    }
140    let _ = ShmMapping::unlink(shm_name);
141}
142
143pub fn find_plugin_host_binary() -> Option<PathBuf> {
144    let host_name = if cfg!(windows) {
145        "maolan-plugin-host.exe"
146    } else {
147        "maolan-plugin-host"
148    };
149
150    if let Ok(override_path) = std::env::var("MAOLAN_PLUGIN_HOST") {
151        let candidate = PathBuf::from(override_path);
152        if candidate.exists() {
153            tracing::info!(path = %candidate.display(), "Using plugin-host from MAOLAN_PLUGIN_HOST");
154            return Some(candidate);
155        }
156        tracing::warn!(path = %candidate.display(), "MAOLAN_PLUGIN_HOST points to a missing file");
157    }
158
159    let exe_dir = std::env::current_exe()
160        .ok()
161        .and_then(|p| p.parent().map(PathBuf::from));
162
163    if let Some(ref dir) = exe_dir {
164        let candidate = dir.join(host_name);
165        if candidate.exists() {
166            tracing::info!(path = %candidate.display(), "Using plugin-host from exe directory");
167            return Some(candidate);
168        }
169    }
170
171    if let Ok(manifest) = std::env::var("CARGO_MANIFEST_DIR") {
172        let engine_root = Path::new(&manifest);
173        for profile in ["debug", "release"] {
174            let candidate = engine_root
175                .parent()
176                .unwrap_or(Path::new(""))
177                .join("daw")
178                .join("target")
179                .join(profile)
180                .join(host_name);
181            if candidate.exists() {
182                tracing::info!(path = %candidate.display(), "Using plugin-host from daw workspace target");
183                return Some(candidate);
184            }
185
186            let candidate = engine_root
187                .parent()
188                .unwrap_or(Path::new(""))
189                .join("daw")
190                .join("plugin-host")
191                .join("target")
192                .join(profile)
193                .join(host_name);
194            if candidate.exists() {
195                tracing::info!(path = %candidate.display(), "Using plugin-host from plugin-host crate target");
196                return Some(candidate);
197            }
198        }
199    }
200
201    if let Ok(path_var) = std::env::var("PATH") {
202        #[cfg(windows)]
203        let path_sep = ';';
204        #[cfg(not(windows))]
205        let path_sep = ':';
206        for dir in path_var.split(path_sep) {
207            let candidate = Path::new(dir).join(host_name);
208            if candidate.exists() {
209                tracing::info!(path = %candidate.display(), "Using plugin-host from PATH");
210                return Some(candidate);
211            }
212        }
213    }
214
215    tracing::error!("maolan-plugin-host binary not found");
216    None
217}
218
219/// # Safety
220///
221/// `ptr` must point to a valid, initialized shared-memory layout with enough
222/// space for the configured number of input channels and `frames` samples.
223/// `frames` must not exceed the block size reserved in that layout.
224pub unsafe fn copy_inputs_to_shm(inputs: &[Arc<AudioIO>], ptr: *mut u8, frames: usize) {
225    for (ch, input) in inputs.iter().enumerate() {
226        let src = input.buffer.lock();
227        let dst = unsafe { audio_channel_ptr(ptr, ch, 0) };
228        let len = frames.min(src.len());
229        unsafe {
230            std::ptr::copy_nonoverlapping(src.as_ptr(), dst, len);
231        }
232    }
233}
234
235/// # Safety
236///
237/// `ptr` must point to a valid, initialized shared-memory layout with enough
238/// space for the configured number of output channels and `frames` samples.
239/// Each output buffer must be writable and at least `frames` elements long.
240pub unsafe fn copy_outputs_from_shm(outputs: &[Arc<AudioIO>], ptr: *mut u8, frames: usize) {
241    for (ch, output) in outputs.iter().enumerate() {
242        let dst = output.buffer.lock();
243        let src = unsafe { audio_channel_ptr(ptr, ch, 1) };
244        let len = frames.min(dst.len());
245        unsafe {
246            std::ptr::copy_nonoverlapping(src, dst.as_mut_ptr(), len);
247        }
248        *output.finished.lock() = true;
249    }
250}
251
252/// # Safety
253///
254/// `ptr` must point to a valid, initialized shared-memory layout whose header
255/// can safely be written to.
256pub unsafe fn configure_shm_header(
257    ptr: *mut u8,
258    frames: usize,
259    num_in: usize,
260    num_out: usize,
261    midi_in: usize,
262    midi_out: usize,
263) {
264    unsafe {
265        let h = header_mut(ptr);
266        h.block_size.store(frames as u32, Ordering::Release);
267        h.num_input_channels.store(num_in as u32, Ordering::Release);
268        h.num_output_channels
269            .store(num_out as u32, Ordering::Release);
270        h.midi_in_port_count
271            .store(midi_in as u32, Ordering::Release);
272        h.midi_out_port_count
273            .store(midi_out as u32, Ordering::Release);
274    }
275}
276
277#[macro_export]
278macro_rules! impl_ipc_processor_wrapper {
279    ($processor:ty) => {
280        impl $crate::mutex::UnsafeMutex<$processor> {
281            pub fn setup_audio_ports(&self) {
282                self.lock().setup_audio_ports();
283            }
284
285            pub fn audio_inputs(&self) -> &[std::sync::Arc<$crate::audio::io::AudioIO>] {
286                self.lock().audio_inputs()
287            }
288
289            pub fn audio_outputs(&self) -> &[std::sync::Arc<$crate::audio::io::AudioIO>] {
290                self.lock().audio_outputs()
291            }
292
293            pub fn main_audio_input_count(&self) -> usize {
294                self.lock().main_audio_input_count()
295            }
296
297            pub fn main_audio_output_count(&self) -> usize {
298                self.lock().main_audio_output_count()
299            }
300
301            pub fn midi_input_count(&self) -> usize {
302                self.lock().midi_input_count()
303            }
304
305            pub fn midi_output_count(&self) -> usize {
306                self.lock().midi_output_count()
307            }
308
309            pub fn set_bypassed(&self, bypassed: bool) {
310                self.lock().set_bypassed(bypassed);
311            }
312
313            pub fn name(&self) -> String {
314                self.lock().name().to_string()
315            }
316
317            pub fn run_host_callbacks_main_thread(&self) {
318                self.lock().run_host_callbacks_main_thread();
319            }
320
321            pub fn reconfigure_ports_if_needed(&self) -> Result<bool, String> {
322                self.lock().reconfigure_ports_if_needed()
323            }
324        }
325    };
326}
maolan_engine/plugins/ipc.rs

maolan_engine/plugins/
ipc.rs
