1 files changed, 451 insertions, 0 deletions
diff --git a/media/audioipc/client/src/context.rs b/media/audioipc/client/src/context.rs
new file mode 100644
index 0000000000..7441d0c0e0
--- /dev/null
+++ b/media/audioipc/client/src/context.rs
@@ -0,0 +1,451 @@
+// Copyright © 2017 Mozilla Foundation
+//
+// This program is made available under an ISC-style license.  See the
+// accompanying file LICENSE for details
+
+use crate::stream;
+use crate::{assert_not_in_callback, run_in_callback};
+use crate::{ClientStream, AUDIOIPC_INIT_PARAMS};
+#[cfg(target_os = "linux")]
+use audio_thread_priority::get_current_thread_info;
+#[cfg(not(target_os = "linux"))]
+use audio_thread_priority::promote_current_thread_to_real_time;
+use audioipc::codec::LengthDelimitedCodec;
+use audioipc::frame::{framed, Framed};
+use audioipc::platformhandle_passing::{framed_with_platformhandles, FramedWithPlatformHandles};
+use audioipc::{core, rpc};
+use audioipc::{
+    messages, messages::DeviceCollectionReq, messages::DeviceCollectionResp, ClientMessage,
+    ServerMessage,
+};
+use cubeb_backend::{
+    ffi, Context, ContextOps, DeviceCollectionRef, DeviceId, DeviceType, Error, Ops, Result,
+    Stream, StreamParams, StreamParamsRef,
+};
+use futures::Future;
+use futures_cpupool::{CpuFuture, CpuPool};
+use std::ffi::{CStr, CString};
+use std::os::raw::c_void;
+use std::sync::mpsc;
+use std::sync::{Arc, Mutex};
+use std::thread;
+use std::{fmt, io, mem, ptr};
+use tokio::reactor;
+use tokio::runtime::current_thread;
+
+struct CubebClient;
+
+impl rpc::Client for CubebClient {
+    type Request = ServerMessage;
+    type Response = ClientMessage;
+    type Transport = FramedWithPlatformHandles<
+        audioipc::AsyncMessageStream,
+        LengthDelimitedCodec<Self::Request, Self::Response>,
+    >;
+}
+
+pub const CLIENT_OPS: Ops = capi_new!(ClientContext, ClientStream);
+
+// ClientContext's layout *must* match cubeb.c's `struct cubeb` for the
+// common fields.
+#[repr(C)]
+pub struct ClientContext {
+    _ops: *const Ops,
+    rpc: rpc::ClientProxy<ServerMessage, ClientMessage>,
+    core: core::CoreThread,
+    cpu_pool: CpuPool,
+    backend_id: CString,
+    device_collection_rpc: bool,
+    input_device_callback: Arc<Mutex<DeviceCollectionCallback>>,
+    output_device_callback: Arc<Mutex<DeviceCollectionCallback>>,
+}
+
+impl ClientContext {
+    #[doc(hidden)]
+    pub fn handle(&self) -> current_thread::Handle {
+        self.core.handle()
+    }
+
+    #[doc(hidden)]
+    pub fn rpc(&self) -> rpc::ClientProxy<ServerMessage, ClientMessage> {
+        self.rpc.clone()
+    }
+
+    #[doc(hidden)]
+    pub fn cpu_pool(&self) -> CpuPool {
+        self.cpu_pool.clone()
+    }
+}
+
+#[cfg(target_os = "linux")]
+fn promote_thread(rpc: &rpc::ClientProxy<ServerMessage, ClientMessage>) {
+    match get_current_thread_info() {
+        Ok(info) => {
+            let bytes = info.serialize();
+            // Don't wait for the response, this is on the callback thread, which must not block.
+            rpc.call(ServerMessage::PromoteThreadToRealTime(bytes));
+        }
+        Err(_) => {
+            warn!("Could not remotely promote thread to RT.");
+        }
+    }
+}
+
+#[cfg(not(target_os = "linux"))]
+fn promote_thread(_rpc: &rpc::ClientProxy<ServerMessage, ClientMessage>) {
+    match promote_current_thread_to_real_time(0, 48000) {
+        Ok(_) => {
+            info!("Audio thread promoted to real-time.");
+        }
+        Err(_) => {
+            warn!("Could not promote thread to real-time.");
+        }
+    }
+}
+
+fn register_thread(callback: Option<extern "C" fn(*const ::std::os::raw::c_char)>) {
+    if let Some(func) = callback {
+        let thr = thread::current();
+        let name = CString::new(thr.name().unwrap()).unwrap();
+        func(name.as_ptr());
+    }
+}
+
+fn unregister_thread(callback: Option<extern "C" fn()>) {
+    if let Some(func) = callback {
+        func();
+    }
+}
+
+fn promote_and_register_thread(
+    rpc: &rpc::ClientProxy<ServerMessage, ClientMessage>,
+    callback: Option<extern "C" fn(*const ::std::os::raw::c_char)>,
+) {
+    promote_thread(rpc);
+    register_thread(callback);
+}
+
+#[derive(Default)]
+struct DeviceCollectionCallback {
+    cb: ffi::cubeb_device_collection_changed_callback,
+    user_ptr: usize,
+}
+
+struct DeviceCollectionServer {
+    input_device_callback: Arc<Mutex<DeviceCollectionCallback>>,
+    output_device_callback: Arc<Mutex<DeviceCollectionCallback>>,
+    cpu_pool: CpuPool,
+}
+
+impl rpc::Server for DeviceCollectionServer {
+    type Request = DeviceCollectionReq;
+    type Response = DeviceCollectionResp;
+    type Future = CpuFuture<Self::Response, ()>;
+    type Transport =
+        Framed<audioipc::AsyncMessageStream, LengthDelimitedCodec<Self::Response, Self::Request>>;
+
+    fn process(&mut self, req: Self::Request) -> Self::Future {
+        match req {
+            DeviceCollectionReq::DeviceChange(device_type) => {
+                trace!(
+                    "ctx_thread: DeviceChange Callback: device_type={}",
+                    device_type
+                );
+
+                let devtype = cubeb_backend::DeviceType::from_bits_truncate(device_type);
+
+                let (input_cb, input_user_ptr) = {
+                    let dcb = self.input_device_callback.lock().unwrap();
+                    (dcb.cb, dcb.user_ptr)
+                };
+                let (output_cb, output_user_ptr) = {
+                    let dcb = self.output_device_callback.lock().unwrap();
+                    (dcb.cb, dcb.user_ptr)
+                };
+
+                self.cpu_pool.spawn_fn(move || {
+                    run_in_callback(|| {
+                        if devtype.contains(cubeb_backend::DeviceType::INPUT) {
+                            unsafe {
+                                input_cb.unwrap()(ptr::null_mut(), input_user_ptr as *mut c_void)
+                            }
+                        }
+                        if devtype.contains(cubeb_backend::DeviceType::OUTPUT) {
+                            unsafe {
+                                output_cb.unwrap()(ptr::null_mut(), output_user_ptr as *mut c_void)
+                            }
+                        }
+                    });
+
+                    Ok(DeviceCollectionResp::DeviceChange)
+                })
+            }
+        }
+    }
+}
+
+impl ContextOps for ClientContext {
+    fn init(_context_name: Option<&CStr>) -> Result<Context> {
+        fn bind_and_send_client(
+            stream: audioipc::AsyncMessageStream,
+            tx_rpc: &mpsc::Sender<rpc::ClientProxy<ServerMessage, ClientMessage>>,
+        ) -> io::Result<()> {
+            let transport = framed_with_platformhandles(stream, Default::default());
+            let rpc = rpc::bind_client::<CubebClient>(transport);
+            // If send fails then the rx end has closed
+            // which is unlikely here.
+            let _ = tx_rpc.send(rpc);
+            Ok(())
+        }
+
+        assert_not_in_callback();
+
+        let (tx_rpc, rx_rpc) = mpsc::channel();
+
+        let params = AUDIOIPC_INIT_PARAMS.with(|p| p.replace(None).unwrap());
+        let thread_create_callback = params.thread_create_callback;
+        let thread_destroy_callback = params.thread_destroy_callback;
+
+        let server_stream =
+            unsafe { audioipc::MessageStream::from_raw_fd(params.server_connection) };
+
+        let core = core::spawn_thread(
+            "AudioIPC Client RPC",
+            move || {
+                let handle = reactor::Handle::default();
+
+                register_thread(thread_create_callback);
+
+                server_stream
+                    .into_tokio_ipc(&handle)
+                    .and_then(|stream| bind_and_send_client(stream, &tx_rpc))
+            },
+            move || unregister_thread(thread_destroy_callback),
+        )
+        .map_err(|_| Error::default())?;
+
+        let rpc = rx_rpc.recv().map_err(|_| Error::default())?;
+        let rpc2 = rpc.clone();
+
+        // Don't let errors bubble from here.  Later calls against this context
+        // will return errors the caller expects to handle.
+        let _ = send_recv!(rpc, ClientConnect(std::process::id()) => ClientConnected);
+
+        let backend_id = send_recv!(rpc, ContextGetBackendId => ContextBackendId())
+            .unwrap_or_else(|_| "(remote error)".to_string());
+        let backend_id = CString::new(backend_id).expect("backend_id query failed");
+
+        let cpu_pool = futures_cpupool::Builder::new()
+            .name_prefix("AudioIPC")
+            .after_start(move || promote_and_register_thread(&rpc2, thread_create_callback))
+            .before_stop(move || unregister_thread(thread_destroy_callback))
+            .pool_size(params.pool_size)
+            .stack_size(params.stack_size)
+            .create();
+
+        let ctx = Box::new(ClientContext {
+            _ops: &CLIENT_OPS as *const _,
+            rpc,
+            core,
+            cpu_pool,
+            backend_id,
+            device_collection_rpc: false,
+            input_device_callback: Arc::new(Mutex::new(Default::default())),
+            output_device_callback: Arc::new(Mutex::new(Default::default())),
+        });
+        Ok(unsafe { Context::from_ptr(Box::into_raw(ctx) as *mut _) })
+    }
+
+    fn backend_id(&mut self) -> &CStr {
+        assert_not_in_callback();
+        self.backend_id.as_c_str()
+    }
+
+    fn max_channel_count(&mut self) -> Result<u32> {
+        assert_not_in_callback();
+        send_recv!(self.rpc(), ContextGetMaxChannelCount => ContextMaxChannelCount())
+    }
+
+    fn min_latency(&mut self, params: StreamParams) -> Result<u32> {
+        assert_not_in_callback();
+        let params = messages::StreamParams::from(params.as_ref());
+        send_recv!(self.rpc(), ContextGetMinLatency(params) => ContextMinLatency())
+    }
+
+    fn preferred_sample_rate(&mut self) -> Result<u32> {
+        assert_not_in_callback();
+        send_recv!(self.rpc(), ContextGetPreferredSampleRate => ContextPreferredSampleRate())
+    }
+
+    fn enumerate_devices(
+        &mut self,
+        devtype: DeviceType,
+        collection: &DeviceCollectionRef,
+    ) -> Result<()> {
+        assert_not_in_callback();
+        let v: Vec<ffi::cubeb_device_info> = match send_recv!(self.rpc(),
+                             ContextGetDeviceEnumeration(devtype.bits()) =>
+                             ContextEnumeratedDevices())
+        {
+            Ok(mut v) => v.drain(..).map(|i| i.into()).collect(),
+            Err(e) => return Err(e),
+        };
+        let mut vs = v.into_boxed_slice();
+        let coll = unsafe { &mut *collection.as_ptr() };
+        coll.device = vs.as_mut_ptr();
+        coll.count = vs.len();
+        // Giving away the memory owned by vs.  Don't free it!
+        // Reclaimed in `device_collection_destroy`.
+        mem::forget(vs);
+        Ok(())
+    }
+
+    fn device_collection_destroy(&mut self, collection: &mut DeviceCollectionRef) -> Result<()> {
+        assert_not_in_callback();
+        unsafe {
+            let coll = &mut *collection.as_ptr();
+            let mut devices = Vec::from_raw_parts(
+                coll.device as *mut ffi::cubeb_device_info,
+                coll.count,
+                coll.count,
+            );
+            for dev in &mut devices {
+                if !dev.device_id.is_null() {
+                    let _ = CString::from_raw(dev.device_id as *mut _);
+                }
+                if !dev.group_id.is_null() {
+                    let _ = CString::from_raw(dev.group_id as *mut _);
+                }
+                if !dev.vendor_name.is_null() {
+                    let _ = CString::from_raw(dev.vendor_name as *mut _);
+                }
+                if !dev.friendly_name.is_null() {
+                    let _ = CString::from_raw(dev.friendly_name as *mut _);
+                }
+            }
+            coll.device = ptr::null_mut();
+            coll.count = 0;
+            Ok(())
+        }
+    }
+
+    fn stream_init(
+        &mut self,
+        stream_name: Option<&CStr>,
+        input_device: DeviceId,
+        input_stream_params: Option<&StreamParamsRef>,
+        output_device: DeviceId,
+        output_stream_params: Option<&StreamParamsRef>,
+        latency_frames: u32,
+        // These params aren't sent to the server
+        data_callback: ffi::cubeb_data_callback,
+        state_callback: ffi::cubeb_state_callback,
+        user_ptr: *mut c_void,
+    ) -> Result<Stream> {
+        assert_not_in_callback();
+
+        fn opt_stream_params(p: Option<&StreamParamsRef>) -> Option<messages::StreamParams> {
+            match p {
+                Some(p) => Some(messages::StreamParams::from(p)),
+                None => None,
+            }
+        }
+
+        let stream_name = match stream_name {
+            Some(s) => Some(s.to_bytes_with_nul().to_vec()),
+            None => None,
+        };
+
+        let input_stream_params = opt_stream_params(input_stream_params);
+        let output_stream_params = opt_stream_params(output_stream_params);
+
+        let init_params = messages::StreamInitParams {
+            stream_name,
+            input_device: input_device as usize,
+            input_stream_params,
+            output_device: output_device as usize,
+            output_stream_params,
+            latency_frames,
+        };
+        stream::init(self, init_params, data_callback, state_callback, user_ptr)
+    }
+
+    fn register_device_collection_changed(
+        &mut self,
+        devtype: DeviceType,
+        collection_changed_callback: ffi::cubeb_device_collection_changed_callback,
+        user_ptr: *mut c_void,
+    ) -> Result<()> {
+        assert_not_in_callback();
+
+        if !self.device_collection_rpc {
+            let fds = send_recv!(self.rpc(),
+                                 ContextSetupDeviceCollectionCallback =>
+                                 ContextSetupDeviceCollectionCallback())?;
+
+            let stream =
+                unsafe { audioipc::MessageStream::from_raw_fd(fds.platform_handles[0].into_raw()) };
+
+            // TODO: The lowest comms layer expects exactly 3 PlatformHandles, but we only
+            // need one here.  Drop the dummy handles the other side sent us to discard.
+            unsafe {
+                fds.platform_handles[1].into_file();
+                fds.platform_handles[2].into_file();
+            }
+
+            let server = DeviceCollectionServer {
+                input_device_callback: self.input_device_callback.clone(),
+                output_device_callback: self.output_device_callback.clone(),
+                cpu_pool: self.cpu_pool(),
+            };
+
+            let (wait_tx, wait_rx) = mpsc::channel();
+            self.handle()
+                .spawn(futures::future::lazy(move || {
+                    let handle = reactor::Handle::default();
+                    let stream = stream.into_tokio_ipc(&handle).unwrap();
+                    let transport = framed(stream, Default::default());
+                    rpc::bind_server(transport, server);
+                    wait_tx.send(()).unwrap();
+                    Ok(())
+                }))
+                .expect("Failed to spawn DeviceCollectionServer");
+            wait_rx.recv().unwrap();
+            self.device_collection_rpc = true;
+        }
+
+        if devtype.contains(cubeb_backend::DeviceType::INPUT) {
+            let mut cb = self.input_device_callback.lock().unwrap();
+            cb.cb = collection_changed_callback;
+            cb.user_ptr = user_ptr as usize;
+        }
+        if devtype.contains(cubeb_backend::DeviceType::OUTPUT) {
+            let mut cb = self.output_device_callback.lock().unwrap();
+            cb.cb = collection_changed_callback;
+            cb.user_ptr = user_ptr as usize;
+        }
+
+        let enable = collection_changed_callback.is_some();
+        send_recv!(self.rpc(),
+                   ContextRegisterDeviceCollectionChanged(devtype.bits(), enable) =>
+                   ContextRegisteredDeviceCollectionChanged)
+    }
+}
+
+impl Drop for ClientContext {
+    fn drop(&mut self) {
+        debug!("ClientContext dropped...");
+        let _ = send_recv!(self.rpc(), ClientDisconnect => ClientDisconnected);
+    }
+}
+
+impl fmt::Debug for ClientContext {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("ClientContext")
+            .field("_ops", &self._ops)
+            .field("rpc", &self.rpc)
+            .field("core", &self.core)
+            .field("cpu_pool", &"...")
+            .finish()
+    }
+}