Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 1079 insertions, 0 deletions

diff --git a/media/audioipc/server/Cargo.toml b/media/audioipc/server/Cargo.toml
new file mode 100644
index 0000000000..6ae2877030
--- /dev/null
+++ b/media/audioipc/server/Cargo.toml
@@ -0,0 +1,23 @@
+[package]
+name = "audioipc-server"
+version = "0.2.3"
+authors = [
+        "Matthew Gregan <kinetik@flim.org>",
+        "Dan Glastonbury <dan.glastonbury@gmail.com>"
+        ]
+description = "Remote cubeb server"
+edition = "2018"
+
+[dependencies]
+audio_thread_priority = "0.23.4"
+audioipc = { path = "../audioipc" }
+cubeb-core = "0.8.0"
+futures = "0.1.29"
+once_cell = "1.2.0"
+log = "0.4"
+slab = "0.4"
+tokio = "0.1"
+
+[dependencies.error-chain]
+version = "0.11.0"
+default-features = false
diff --git a/media/audioipc/server/cbindgen.toml b/media/audioipc/server/cbindgen.toml
new file mode 100644
index 0000000000..9a7c204fe4
--- /dev/null
+++ b/media/audioipc/server/cbindgen.toml
@@ -0,0 +1,28 @@
+header = """/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */"""
+autogen_warning = """/* DO NOT MODIFY THIS MANUALLY! This file was generated using cbindgen. */"""
+include_version = true
+braces = "SameLine"
+line_length = 100
+tab_width = 2
+language = "C++"
+namespaces = ["mozilla", "audioipc"]
+
+[export]
+item_types = ["globals", "enums", "structs", "unions", "typedefs", "opaque", "functions", "constants"]
+
+[parse]
+parse_deps = true
+include = ['audioipc']
+
+[fn]
+args = "Vertical"
+rename_args = "GeckoCase"
+
+[struct]
+rename_fields = "GeckoCase"
+
+[defines]
+"windows" = "XP_WIN"
+"unix" = "XP_UNIX"
diff --git a/media/audioipc/server/src/lib.rs b/media/audioipc/server/src/lib.rs
new file mode 100644
index 0000000000..4d49c8fc08
--- /dev/null
+++ b/media/audioipc/server/src/lib.rs
@@ -0,0 +1,166 @@
+// Copyright © 2017 Mozilla Foundation
+//
+// This program is made available under an ISC-style license.  See the
+// accompanying file LICENSE for details
+#![warn(unused_extern_crates)]
+
+#[macro_use]
+extern crate error_chain;
+#[macro_use]
+extern crate log;
+
+use audio_thread_priority::promote_current_thread_to_real_time;
+use audioipc::core;
+use audioipc::platformhandle_passing::framed_with_platformhandles;
+use audioipc::rpc;
+use audioipc::{MessageStream, PlatformHandle, PlatformHandleType};
+use futures::sync::oneshot;
+use futures::Future;
+use once_cell::sync::Lazy;
+use std::ffi::{CStr, CString};
+use std::os::raw::c_void;
+use std::ptr;
+use std::sync::Mutex;
+use tokio::reactor;
+
+mod server;
+
+struct CubebContextParams {
+    context_name: CString,
+    backend_name: Option<CString>,
+}
+
+static G_CUBEB_CONTEXT_PARAMS: Lazy<Mutex<CubebContextParams>> = Lazy::new(|| {
+    Mutex::new(CubebContextParams {
+        context_name: CString::new("AudioIPC Server").unwrap(),
+        backend_name: None,
+    })
+});
+
+#[allow(deprecated)]
+pub mod errors {
+    error_chain! {
+        links {
+            AudioIPC(::audioipc::errors::Error, ::audioipc::errors::ErrorKind);
+        }
+        foreign_links {
+            Cubeb(cubeb_core::Error);
+            Io(::std::io::Error);
+            Canceled(::futures::sync::oneshot::Canceled);
+        }
+    }
+}
+
+use crate::errors::*;
+
+struct ServerWrapper {
+    core_thread: core::CoreThread,
+    callback_thread: core::CoreThread,
+}
+
+fn run() -> Result<ServerWrapper> {
+    trace!("Starting up cubeb audio server event loop thread...");
+
+    let callback_thread = core::spawn_thread(
+        "AudioIPC Callback RPC",
+        || {
+            match promote_current_thread_to_real_time(0, 48000) {
+                Ok(_) => {}
+                Err(_) => {
+                    debug!("Failed to promote audio callback thread to real-time.");
+                }
+            }
+            trace!("Starting up cubeb audio callback event loop thread...");
+            Ok(())
+        },
+        || {},
+    )
+    .or_else(|e| {
+        debug!(
+            "Failed to start cubeb audio callback event loop thread: {:?}",
+            e
+        );
+        Err(e)
+    })?;
+
+    let core_thread = core::spawn_thread(
+        "AudioIPC Server RPC",
+        move || {
+            audioipc::server_platform_init();
+            Ok(())
+        },
+        || {},
+    )
+    .or_else(|e| {
+        debug!("Failed to cubeb audio core event loop thread: {:?}", e);
+        Err(e)
+    })?;
+
+    Ok(ServerWrapper {
+        core_thread,
+        callback_thread,
+    })
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn audioipc_server_start(
+    context_name: *const std::os::raw::c_char,
+    backend_name: *const std::os::raw::c_char,
+) -> *mut c_void {
+    let mut params = G_CUBEB_CONTEXT_PARAMS.lock().unwrap();
+    if !context_name.is_null() {
+        params.context_name = CStr::from_ptr(context_name).to_owned();
+    }
+    if !backend_name.is_null() {
+        let backend_string = CStr::from_ptr(backend_name).to_owned();
+        params.backend_name = Some(backend_string);
+    }
+    match run() {
+        Ok(server) => Box::into_raw(Box::new(server)) as *mut _,
+        Err(_) => ptr::null_mut() as *mut _,
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn audioipc_server_new_client(p: *mut c_void) -> PlatformHandleType {
+    let (wait_tx, wait_rx) = oneshot::channel();
+    let wrapper: &ServerWrapper = unsafe { &*(p as *mut _) };
+
+    let core_handle = wrapper.callback_thread.handle();
+
+    // We create a connected pair of anonymous IPC endpoints. One side
+    // is registered with the reactor core, the other side is returned
+    // to the caller.
+    MessageStream::anonymous_ipc_pair()
+        .and_then(|(ipc_server, ipc_client)| {
+            // Spawn closure to run on same thread as reactor::Core
+            // via remote handle.
+            wrapper
+                .core_thread
+                .handle()
+                .spawn(futures::future::lazy(|| {
+                    trace!("Incoming connection");
+                    let handle = reactor::Handle::default();
+                    ipc_server.into_tokio_ipc(&handle)
+                    .and_then(|sock| {
+                        let transport = framed_with_platformhandles(sock, Default::default());
+                        rpc::bind_server(transport, server::CubebServer::new(core_handle));
+                        Ok(())
+                    }).map_err(|_| ())
+                    // Notify waiting thread that server has been registered.
+                    .and_then(|_| wait_tx.send(()))
+                }))
+                .expect("Failed to spawn CubebServer");
+            // Wait for notification that server has been registered
+            // with reactor::Core.
+            let _ = wait_rx.wait();
+            Ok(unsafe { PlatformHandle::from(ipc_client).into_raw() })
+        })
+        .unwrap_or(audioipc::INVALID_HANDLE_VALUE)
+}
+
+#[no_mangle]
+pub extern "C" fn audioipc_server_stop(p: *mut c_void) {
+    let wrapper = unsafe { Box::<ServerWrapper>::from_raw(p as *mut _) };
+    drop(wrapper);
+}
diff --git a/media/audioipc/server/src/server.rs b/media/audioipc/server/src/server.rs
new file mode 100644
index 0000000000..c2d4f31a02
--- /dev/null
+++ b/media/audioipc/server/src/server.rs
@@ -0,0 +1,862 @@
+// Copyright © 2017 Mozilla Foundation
+//
+// This program is made available under an ISC-style license.  See the
+// accompanying file LICENSE for details
+
+#[cfg(target_os = "linux")]
+use audio_thread_priority::{promote_thread_to_real_time, RtPriorityThreadInfo};
+use audioipc;
+use audioipc::codec::LengthDelimitedCodec;
+use audioipc::frame::{framed, Framed};
+use audioipc::messages::{
+    CallbackReq, CallbackResp, ClientMessage, Device, DeviceCollectionReq, DeviceCollectionResp,
+    DeviceInfo, RegisterDeviceCollectionChanged, ServerMessage, StreamCreate, StreamCreateParams,
+    StreamInitParams, StreamParams,
+};
+use audioipc::platformhandle_passing::FramedWithPlatformHandles;
+use audioipc::rpc;
+use audioipc::shm::{SharedMemReader, SharedMemWriter};
+use audioipc::{MessageStream, PlatformHandle};
+use cubeb_core as cubeb;
+use cubeb_core::ffi;
+use futures::future::{self, FutureResult};
+use futures::sync::oneshot;
+use futures::Future;
+use slab;
+use std::convert::From;
+use std::ffi::CStr;
+use std::mem::size_of;
+use std::os::raw::{c_long, c_void};
+use std::rc::Rc;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::{cell::RefCell, sync::Mutex};
+use std::{panic, slice};
+use tokio::reactor;
+use tokio::runtime::current_thread;
+
+use crate::errors::*;
+
+fn error(error: cubeb::Error) -> ClientMessage {
+    ClientMessage::Error(error.raw_code())
+}
+
+struct CubebDeviceCollectionManager {
+    servers: Mutex<Vec<Rc<RefCell<CubebServerCallbacks>>>>,
+}
+
+impl CubebDeviceCollectionManager {
+    fn new() -> CubebDeviceCollectionManager {
+        CubebDeviceCollectionManager {
+            servers: Mutex::new(Vec::new()),
+        }
+    }
+
+    fn register(
+        &mut self,
+        context: &cubeb::Context,
+        server: &Rc<RefCell<CubebServerCallbacks>>,
+        devtype: cubeb::DeviceType,
+    ) -> cubeb::Result<()> {
+        let mut servers = self.servers.lock().unwrap();
+        if servers.is_empty() {
+            self.internal_register(context, true)?;
+        }
+        server.borrow_mut().devtype.insert(devtype);
+        if servers.iter().find(|s| Rc::ptr_eq(s, server)).is_none() {
+            servers.push(server.clone());
+        }
+        Ok(())
+    }
+
+    fn unregister(
+        &mut self,
+        context: &cubeb::Context,
+        server: &Rc<RefCell<CubebServerCallbacks>>,
+        devtype: cubeb::DeviceType,
+    ) -> cubeb::Result<()> {
+        let mut servers = self.servers.lock().unwrap();
+        server.borrow_mut().devtype.remove(devtype);
+        if server.borrow().devtype.is_empty() {
+            servers.retain(|s| !Rc::ptr_eq(&s, server));
+        }
+        if servers.is_empty() {
+            self.internal_register(context, false)?;
+        }
+        Ok(())
+    }
+
+    fn internal_register(&self, context: &cubeb::Context, enable: bool) -> cubeb::Result<()> {
+        let user_ptr = if enable {
+            self as *const CubebDeviceCollectionManager as *mut c_void
+        } else {
+            std::ptr::null_mut()
+        };
+        for &(dir, cb) in &[
+            (
+                cubeb::DeviceType::INPUT,
+                device_collection_changed_input_cb_c as _,
+            ),
+            (
+                cubeb::DeviceType::OUTPUT,
+                device_collection_changed_output_cb_c as _,
+            ),
+        ] {
+            unsafe {
+                context.register_device_collection_changed(
+                    dir,
+                    if enable { Some(cb) } else { None },
+                    user_ptr,
+                )?;
+            }
+        }
+        Ok(())
+    }
+
+    // Warning: this is called from an internal cubeb thread, so we must not mutate unprotected shared state.
+    unsafe fn device_collection_changed_callback(&self, device_type: ffi::cubeb_device_type) {
+        let servers = self.servers.lock().unwrap();
+        servers.iter().for_each(|server| {
+            if server
+                .borrow()
+                .devtype
+                .contains(cubeb::DeviceType::from_bits_truncate(device_type))
+            {
+                server
+                    .borrow_mut()
+                    .device_collection_changed_callback(device_type)
+            }
+        });
+    }
+}
+
+struct DevIdMap {
+    devices: Vec<usize>,
+}
+
+// A cubeb_devid is an opaque type which may be implemented with a stable
+// pointer in a cubeb backend.  cubeb_devids received remotely must be
+// validated before use, so DevIdMap provides a simple 1:1 mapping between a
+// cubeb_devid and an IPC-transportable value suitable for use as a unique
+// handle.
+impl DevIdMap {
+    fn new() -> DevIdMap {
+        let mut d = DevIdMap {
+            devices: Vec::with_capacity(32),
+        };
+        // A null cubeb_devid is used for selecting the default device.
+        // Pre-populate the mapping with 0 -> 0 to handle nulls.
+        d.devices.push(0);
+        d
+    }
+
+    // Given a cubeb_devid, return a unique stable value suitable for use
+    // over IPC.
+    fn to_handle(&mut self, devid: usize) -> usize {
+        if let Some(i) = self.devices.iter().position(|&d| d == devid) {
+            return i;
+        }
+        self.devices.push(devid);
+        self.devices.len() - 1
+    }
+
+    // Given a handle produced by `to_handle`, return the associated
+    // cubeb_devid.  Invalid handles result in a panic.
+    fn from_handle(&self, handle: usize) -> usize {
+        self.devices[handle]
+    }
+}
+
+struct CubebContextState {
+    context: cubeb::Result<cubeb::Context>,
+    manager: CubebDeviceCollectionManager,
+}
+
+thread_local!(static CONTEXT_KEY: RefCell<Option<CubebContextState>> = RefCell::new(None));
+
+fn cubeb_init_from_context_params() -> cubeb::Result<cubeb::Context> {
+    let params = super::G_CUBEB_CONTEXT_PARAMS.lock().unwrap();
+    let context_name = Some(params.context_name.as_c_str());
+    let backend_name = if let Some(ref name) = params.backend_name {
+        Some(name.as_c_str())
+    } else {
+        None
+    };
+    let r = cubeb::Context::init(context_name, backend_name);
+    r.map_err(|e| {
+        info!("cubeb::Context::init failed r={:?}", e);
+        e
+    })
+}
+
+fn with_local_context<T, F>(f: F) -> T
+where
+    F: FnOnce(&cubeb::Result<cubeb::Context>, &mut CubebDeviceCollectionManager) -> T,
+{
+    CONTEXT_KEY.with(|k| {
+        let mut state = k.borrow_mut();
+        if state.is_none() {
+            *state = Some(CubebContextState {
+                context: cubeb_init_from_context_params(),
+                manager: CubebDeviceCollectionManager::new(),
+            });
+        }
+        let CubebContextState { context, manager } = state.as_mut().unwrap();
+        // Always reattempt to initialize cubeb, OS config may have changed.
+        if context.is_err() {
+            *context = cubeb_init_from_context_params();
+        }
+        f(context, manager)
+    })
+}
+
+struct DeviceCollectionClient;
+
+impl rpc::Client for DeviceCollectionClient {
+    type Request = DeviceCollectionReq;
+    type Response = DeviceCollectionResp;
+    type Transport =
+        Framed<audioipc::AsyncMessageStream, LengthDelimitedCodec<Self::Request, Self::Response>>;
+}
+
+struct CallbackClient;
+
+impl rpc::Client for CallbackClient {
+    type Request = CallbackReq;
+    type Response = CallbackResp;
+    type Transport =
+        Framed<audioipc::AsyncMessageStream, LengthDelimitedCodec<Self::Request, Self::Response>>;
+}
+
+struct ServerStreamCallbacks {
+    /// Size of input frame in bytes
+    input_frame_size: u16,
+    /// Size of output frame in bytes
+    output_frame_size: u16,
+    /// Shared memory buffer for sending input data to client
+    input_shm: SharedMemWriter,
+    /// Shared memory buffer for receiving output data from client
+    output_shm: SharedMemReader,
+    /// RPC interface to callback server running in client
+    rpc: rpc::ClientProxy<CallbackReq, CallbackResp>,
+}
+
+impl ServerStreamCallbacks {
+    fn data_callback(&mut self, input: &[u8], output: &mut [u8], nframes: isize) -> isize {
+        trace!(
+            "Stream data callback: {} {} {}",
+            nframes,
+            input.len(),
+            output.len()
+        );
+
+        self.input_shm.write(input).unwrap();
+
+        let r = self
+            .rpc
+            .call(CallbackReq::Data {
+                nframes,
+                input_frame_size: self.input_frame_size as usize,
+                output_frame_size: self.output_frame_size as usize,
+            })
+            .wait();
+
+        match r {
+            Ok(CallbackResp::Data(frames)) => {
+                if frames >= 0 {
+                    let nbytes = frames as usize * self.output_frame_size as usize;
+                    trace!("Reslice output to {}", nbytes);
+                    self.output_shm.read(&mut output[..nbytes]).unwrap();
+                }
+                frames
+            }
+            _ => {
+                debug!("Unexpected message {:?} during data_callback", r);
+                // TODO: Return a CUBEB_ERROR result here once
+                // https://github.com/kinetiknz/cubeb/issues/553 is
+                // fixed.
+                0
+            }
+        }
+    }
+
+    fn state_callback(&mut self, state: cubeb::State) {
+        trace!("Stream state callback: {:?}", state);
+        let r = self.rpc.call(CallbackReq::State(state.into())).wait();
+        match r {
+            Ok(CallbackResp::State) => {}
+            _ => {
+                debug!("Unexpected message {:?} during state callback", r);
+            }
+        }
+    }
+
+    fn device_change_callback(&mut self) {
+        trace!("Stream device change callback");
+        let r = self.rpc.call(CallbackReq::DeviceChange).wait();
+        match r {
+            Ok(CallbackResp::DeviceChange) => {}
+            _ => {
+                debug!("Unexpected message {:?} during device change callback", r);
+            }
+        }
+    }
+}
+
+static SHM_ID: AtomicUsize = AtomicUsize::new(0);
+
+// Generate a temporary shm_id fragment that is unique to the process.  This
+// path is used temporarily to create a shm segment, which is then
+// immediately deleted from the filesystem while retaining handles to the
+// shm to be shared between the server and client.
+fn get_shm_id() -> String {
+    format!(
+        "cubeb-shm-{}-{}",
+        std::process::id(),
+        SHM_ID.fetch_add(1, Ordering::SeqCst)
+    )
+}
+
+struct ServerStream {
+    stream: Option<cubeb::Stream>,
+    cbs: Box<ServerStreamCallbacks>,
+}
+
+impl Drop for ServerStream {
+    fn drop(&mut self) {
+        // `stream` *must* be dropped before `cbs`.
+        drop(self.stream.take());
+    }
+}
+
+type StreamSlab = slab::Slab<ServerStream>;
+
+struct CubebServerCallbacks {
+    rpc: rpc::ClientProxy<DeviceCollectionReq, DeviceCollectionResp>,
+    devtype: cubeb::DeviceType,
+}
+
+impl CubebServerCallbacks {
+    fn device_collection_changed_callback(&mut self, device_type: ffi::cubeb_device_type) {
+        // TODO: Assert device_type is in devtype.
+        debug!(
+            "Sending device collection ({:?}) changed event",
+            device_type
+        );
+        let _ = self
+            .rpc
+            .call(DeviceCollectionReq::DeviceChange(device_type))
+            .wait();
+    }
+}
+
+pub struct CubebServer {
+    handle: current_thread::Handle,
+    streams: StreamSlab,
+    remote_pid: Option<u32>,
+    cbs: Option<Rc<RefCell<CubebServerCallbacks>>>,
+    devidmap: DevIdMap,
+}
+
+impl rpc::Server for CubebServer {
+    type Request = ServerMessage;
+    type Response = ClientMessage;
+    type Future = FutureResult<Self::Response, ()>;
+    type Transport = FramedWithPlatformHandles<
+        audioipc::AsyncMessageStream,
+        LengthDelimitedCodec<Self::Response, Self::Request>,
+    >;
+
+    fn process(&mut self, req: Self::Request) -> Self::Future {
+        if let ServerMessage::ClientConnect(pid) = req {
+            self.remote_pid = Some(pid);
+        }
+        let resp = with_local_context(|context, manager| match *context {
+            Err(_) => error(cubeb::Error::error()),
+            Ok(ref context) => self.process_msg(context, manager, &req),
+        });
+        future::ok(resp)
+    }
+}
+
+// Debugging for BMO 1594216/1612044.
+macro_rules! try_stream {
+    ($self:expr, $stm_tok:expr) => {
+        if $self.streams.contains($stm_tok) {
+            $self.streams[$stm_tok]
+                .stream
+                .as_mut()
+                .expect("uninitialized stream")
+        } else {
+            error!(
+                "{}:{}:{} - Stream({}): invalid token",
+                file!(),
+                line!(),
+                column!(),
+                $stm_tok
+            );
+            return error(cubeb::Error::invalid_parameter());
+        }
+    };
+}
+
+impl CubebServer {
+    pub fn new(handle: current_thread::Handle) -> Self {
+        CubebServer {
+            handle,
+            streams: StreamSlab::new(),
+            remote_pid: None,
+            cbs: None,
+            devidmap: DevIdMap::new(),
+        }
+    }
+
+    // Process a request coming from the client.
+    fn process_msg(
+        &mut self,
+        context: &cubeb::Context,
+        manager: &mut CubebDeviceCollectionManager,
+        msg: &ServerMessage,
+    ) -> ClientMessage {
+        let resp: ClientMessage = match *msg {
+            ServerMessage::ClientConnect(_) => {
+                // remote_pid is set before cubeb initialization, just verify here.
+                assert!(self.remote_pid.is_some());
+                ClientMessage::ClientConnected
+            }
+
+            ServerMessage::ClientDisconnect => {
+                // TODO:
+                //self.connection.client_disconnect();
+                ClientMessage::ClientDisconnected
+            }
+
+            ServerMessage::ContextGetBackendId => {
+                ClientMessage::ContextBackendId(context.backend_id().to_string())
+            }
+
+            ServerMessage::ContextGetMaxChannelCount => context
+                .max_channel_count()
+                .map(ClientMessage::ContextMaxChannelCount)
+                .unwrap_or_else(error),
+
+            ServerMessage::ContextGetMinLatency(ref params) => {
+                let format = cubeb::SampleFormat::from(params.format);
+                let layout = cubeb::ChannelLayout::from(params.layout);
+
+                let params = cubeb::StreamParamsBuilder::new()
+                    .format(format)
+                    .rate(params.rate)
+                    .channels(params.channels)
+                    .layout(layout)
+                    .take();
+
+                context
+                    .min_latency(&params)
+                    .map(ClientMessage::ContextMinLatency)
+                    .unwrap_or_else(error)
+            }
+
+            ServerMessage::ContextGetPreferredSampleRate => context
+                .preferred_sample_rate()
+                .map(ClientMessage::ContextPreferredSampleRate)
+                .unwrap_or_else(error),
+
+            ServerMessage::ContextGetDeviceEnumeration(device_type) => context
+                .enumerate_devices(cubeb::DeviceType::from_bits_truncate(device_type))
+                .map(|devices| {
+                    let v: Vec<DeviceInfo> = devices
+                        .iter()
+                        .map(|i| {
+                            let mut tmp: DeviceInfo = i.as_ref().into();
+                            // Replace each cubeb_devid with a unique handle suitable for IPC.
+                            tmp.devid = self.devidmap.to_handle(tmp.devid);
+                            tmp
+                        })
+                        .collect();
+                    ClientMessage::ContextEnumeratedDevices(v)
+                })
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamCreate(ref params) => self
+                .process_stream_create(params)
+                .unwrap_or_else(|_| error(cubeb::Error::error())),
+
+            ServerMessage::StreamInit(stm_tok, ref params) => self
+                .process_stream_init(context, stm_tok, params)
+                .unwrap_or_else(|_| error(cubeb::Error::error())),
+
+            ServerMessage::StreamDestroy(stm_tok) => {
+                if self.streams.contains(stm_tok) {
+                    debug!("Unregistering stream {:?}", stm_tok);
+                    self.streams.remove(stm_tok);
+                } else {
+                    // Debugging for BMO 1594216/1612044.
+                    error!("StreamDestroy({}): invalid token", stm_tok);
+                    return error(cubeb::Error::invalid_parameter());
+                }
+                ClientMessage::StreamDestroyed
+            }
+
+            ServerMessage::StreamStart(stm_tok) => try_stream!(self, stm_tok)
+                .start()
+                .map(|_| ClientMessage::StreamStarted)
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamStop(stm_tok) => try_stream!(self, stm_tok)
+                .stop()
+                .map(|_| ClientMessage::StreamStopped)
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamResetDefaultDevice(stm_tok) => try_stream!(self, stm_tok)
+                .reset_default_device()
+                .map(|_| ClientMessage::StreamDefaultDeviceReset)
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamGetPosition(stm_tok) => try_stream!(self, stm_tok)
+                .position()
+                .map(ClientMessage::StreamPosition)
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamGetLatency(stm_tok) => try_stream!(self, stm_tok)
+                .latency()
+                .map(ClientMessage::StreamLatency)
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamGetInputLatency(stm_tok) => try_stream!(self, stm_tok)
+                .input_latency()
+                .map(ClientMessage::StreamInputLatency)
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamSetVolume(stm_tok, volume) => try_stream!(self, stm_tok)
+                .set_volume(volume)
+                .map(|_| ClientMessage::StreamVolumeSet)
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamSetName(stm_tok, ref name) => try_stream!(self, stm_tok)
+                .set_name(name)
+                .map(|_| ClientMessage::StreamNameSet)
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamGetCurrentDevice(stm_tok) => try_stream!(self, stm_tok)
+                .current_device()
+                .map(|device| ClientMessage::StreamCurrentDevice(Device::from(device)))
+                .unwrap_or_else(error),
+
+            ServerMessage::StreamRegisterDeviceChangeCallback(stm_tok, enable) => {
+                try_stream!(self, stm_tok)
+                    .register_device_changed_callback(if enable {
+                        Some(device_change_cb_c)
+                    } else {
+                        None
+                    })
+                    .map(|_| ClientMessage::StreamRegisterDeviceChangeCallback)
+                    .unwrap_or_else(error)
+            }
+
+            ServerMessage::ContextSetupDeviceCollectionCallback => {
+                if let Ok((ipc_server, ipc_client)) = MessageStream::anonymous_ipc_pair() {
+                    debug!(
+                        "Created device collection RPC pair: {:?}-{:?}",
+                        ipc_server, ipc_client
+                    );
+
+                    // This code is currently running on the Client/Server RPC
+                    // handling thread.  We need to move the registration of the
+                    // bind_client to the callback RPC handling thread.  This is
+                    // done by spawning a future on `handle`.
+                    let (tx, rx) = oneshot::channel();
+                    self.handle
+                        .spawn(futures::future::lazy(move || {
+                            let handle = reactor::Handle::default();
+                            let stream = ipc_server.into_tokio_ipc(&handle).unwrap();
+                            let transport = framed(stream, Default::default());
+                            let rpc = rpc::bind_client::<DeviceCollectionClient>(transport);
+                            drop(tx.send(rpc));
+                            Ok(())
+                        }))
+                        .expect("Failed to spawn DeviceCollectionClient");
+
+                    // TODO: The lowest comms layer expects exactly 3 PlatformHandles, but we only
+                    // need one here.  Send some dummy handles over for the other side to discard.
+                    let (dummy1, dummy2) =
+                        MessageStream::anonymous_ipc_pair().expect("need dummy IPC pair");
+                    if let Ok(rpc) = rx.wait() {
+                        self.cbs = Some(Rc::new(RefCell::new(CubebServerCallbacks {
+                            rpc,
+                            devtype: cubeb::DeviceType::empty(),
+                        })));
+                        let fds = RegisterDeviceCollectionChanged {
+                            platform_handles: [
+                                PlatformHandle::from(ipc_client),
+                                PlatformHandle::from(dummy1),
+                                PlatformHandle::from(dummy2),
+                            ],
+                            target_pid: self.remote_pid.unwrap(),
+                        };
+
+                        ClientMessage::ContextSetupDeviceCollectionCallback(fds)
+                    } else {
+                        warn!("Failed to setup RPC client");
+                        error(cubeb::Error::error())
+                    }
+                } else {
+                    warn!("Failed to create RPC pair");
+                    error(cubeb::Error::error())
+                }
+            }
+
+            ServerMessage::ContextRegisterDeviceCollectionChanged(device_type, enable) => self
+                .process_register_device_collection_changed(
+                    context,
+                    manager,
+                    cubeb::DeviceType::from_bits_truncate(device_type),
+                    enable,
+                )
+                .unwrap_or_else(error),
+
+            #[cfg(target_os = "linux")]
+            ServerMessage::PromoteThreadToRealTime(thread_info) => {
+                let info = RtPriorityThreadInfo::deserialize(thread_info);
+                match promote_thread_to_real_time(info, 0, 48000) {
+                    Ok(_) => {
+                        info!("Promotion of content process thread to real-time OK");
+                    }
+                    Err(_) => {
+                        warn!("Promotion of content process thread to real-time error");
+                    }
+                }
+                ClientMessage::ThreadPromoted
+            }
+        };
+
+        trace!("process_msg: req={:?}, resp={:?}", msg, resp);
+
+        resp
+    }
+
+    fn process_register_device_collection_changed(
+        &mut self,
+        context: &cubeb::Context,
+        manager: &mut CubebDeviceCollectionManager,
+        devtype: cubeb::DeviceType,
+        enable: bool,
+    ) -> cubeb::Result<ClientMessage> {
+        if devtype == cubeb::DeviceType::UNKNOWN {
+            return Err(cubeb::Error::invalid_parameter());
+        }
+
+        assert!(self.cbs.is_some());
+        let cbs = self.cbs.as_ref().unwrap();
+
+        if enable {
+            manager.register(context, cbs, devtype)
+        } else {
+            manager.unregister(context, cbs, devtype)
+        }
+        .map(|_| ClientMessage::ContextRegisteredDeviceCollectionChanged)
+    }
+
+    // Stream create is special, so it's been separated from process_msg.
+    fn process_stream_create(&mut self, params: &StreamCreateParams) -> Result<ClientMessage> {
+        fn frame_size_in_bytes(params: Option<&StreamParams>) -> u16 {
+            params
+                .map(|p| {
+                    let format = p.format.into();
+                    let sample_size = match format {
+                        cubeb::SampleFormat::S16LE
+                        | cubeb::SampleFormat::S16BE
+                        | cubeb::SampleFormat::S16NE => 2,
+                        cubeb::SampleFormat::Float32LE
+                        | cubeb::SampleFormat::Float32BE
+                        | cubeb::SampleFormat::Float32NE => 4,
+                    };
+                    let channel_count = p.channels as u16;
+                    sample_size * channel_count
+                })
+                .unwrap_or(0u16)
+        }
+
+        // Create the callback handling struct which is attached the cubeb stream.
+        let input_frame_size = frame_size_in_bytes(params.input_stream_params.as_ref());
+        let output_frame_size = frame_size_in_bytes(params.output_stream_params.as_ref());
+
+        let (ipc_server, ipc_client) = MessageStream::anonymous_ipc_pair()?;
+        debug!("Created callback pair: {:?}-{:?}", ipc_server, ipc_client);
+        let shm_id = get_shm_id();
+        let (input_shm, input_file) =
+            SharedMemWriter::new(&format!("{}-input", shm_id), audioipc::SHM_AREA_SIZE)?;
+        let (output_shm, output_file) =
+            SharedMemReader::new(&format!("{}-output", shm_id), audioipc::SHM_AREA_SIZE)?;
+
+        // This code is currently running on the Client/Server RPC
+        // handling thread.  We need to move the registration of the
+        // bind_client to the callback RPC handling thread.  This is
+        // done by spawning a future on `handle`.
+        let (tx, rx) = oneshot::channel();
+        self.handle
+            .spawn(futures::future::lazy(move || {
+                let handle = reactor::Handle::default();
+                let stream = ipc_server.into_tokio_ipc(&handle).unwrap();
+                let transport = framed(stream, Default::default());
+                let rpc = rpc::bind_client::<CallbackClient>(transport);
+                drop(tx.send(rpc));
+                Ok(())
+            }))
+            .expect("Failed to spawn CallbackClient");
+
+        let rpc: rpc::ClientProxy<CallbackReq, CallbackResp> = match rx.wait() {
+            Ok(rpc) => rpc,
+            Err(_) => bail!("Failed to create callback rpc."),
+        };
+
+        let cbs = Box::new(ServerStreamCallbacks {
+            input_frame_size,
+            output_frame_size,
+            input_shm,
+            output_shm,
+            rpc,
+        });
+
+        let entry = self.streams.vacant_entry();
+        let key = entry.key();
+        debug!("Registering stream {:?}", key);
+
+        entry.insert(ServerStream { stream: None, cbs });
+
+        Ok(ClientMessage::StreamCreated(StreamCreate {
+            token: key,
+            platform_handles: [
+                PlatformHandle::from(ipc_client),
+                PlatformHandle::from(input_file),
+                PlatformHandle::from(output_file),
+            ],
+            target_pid: self.remote_pid.unwrap(),
+        }))
+    }
+
+    // Stream init is special, so it's been separated from process_msg.
+    fn process_stream_init(
+        &mut self,
+        context: &cubeb::Context,
+        stm_tok: usize,
+        params: &StreamInitParams,
+    ) -> Result<ClientMessage> {
+        // Create cubeb stream from params
+        let stream_name = params
+            .stream_name
+            .as_ref()
+            .and_then(|name| CStr::from_bytes_with_nul(name).ok());
+
+        // Map IPC handle back to cubeb_devid.
+        let input_device = self.devidmap.from_handle(params.input_device) as *const _;
+        let input_stream_params = params.input_stream_params.as_ref().map(|isp| unsafe {
+            cubeb::StreamParamsRef::from_ptr(isp as *const StreamParams as *mut _)
+        });
+
+        // Map IPC handle back to cubeb_devid.
+        let output_device = self.devidmap.from_handle(params.output_device) as *const _;
+        let output_stream_params = params.output_stream_params.as_ref().map(|osp| unsafe {
+            cubeb::StreamParamsRef::from_ptr(osp as *const StreamParams as *mut _)
+        });
+
+        let latency = params.latency_frames;
+
+        let server_stream = &mut self.streams[stm_tok];
+        assert!(size_of::<Box<ServerStreamCallbacks>>() == size_of::<usize>());
+        let user_ptr = server_stream.cbs.as_ref() as *const ServerStreamCallbacks as *mut c_void;
+
+        let stream = unsafe {
+            let stream = context.stream_init(
+                stream_name,
+                input_device,
+                input_stream_params,
+                output_device,
+                output_stream_params,
+                latency,
+                Some(data_cb_c),
+                Some(state_cb_c),
+                user_ptr,
+            );
+            match stream {
+                Ok(stream) => stream,
+                Err(e) => return Err(e.into()), // XXX full teardown of ServerStream?
+            }
+        };
+
+        server_stream.stream = Some(stream);
+
+        Ok(ClientMessage::StreamInitialized)
+    }
+}
+
+// C callable callbacks
+unsafe extern "C" fn data_cb_c(
+    _: *mut ffi::cubeb_stream,
+    user_ptr: *mut c_void,
+    input_buffer: *const c_void,
+    output_buffer: *mut c_void,
+    nframes: c_long,
+) -> c_long {
+    let ok = panic::catch_unwind(|| {
+        let cbs = &mut *(user_ptr as *mut ServerStreamCallbacks);
+        let input = if input_buffer.is_null() {
+            &[]
+        } else {
+            let nbytes = nframes * c_long::from(cbs.input_frame_size);
+            slice::from_raw_parts(input_buffer as *const u8, nbytes as usize)
+        };
+        let output: &mut [u8] = if output_buffer.is_null() {
+            &mut []
+        } else {
+            let nbytes = nframes * c_long::from(cbs.output_frame_size);
+            slice::from_raw_parts_mut(output_buffer as *mut u8, nbytes as usize)
+        };
+        cbs.data_callback(input, output, nframes as isize) as c_long
+    });
+    // TODO: Return a CUBEB_ERROR result here once
+    // https://github.com/kinetiknz/cubeb/issues/553 is fixed.
+    ok.unwrap_or(0)
+}
+
+unsafe extern "C" fn state_cb_c(
+    _: *mut ffi::cubeb_stream,
+    user_ptr: *mut c_void,
+    state: ffi::cubeb_state,
+) {
+    let ok = panic::catch_unwind(|| {
+        let state = cubeb::State::from(state);
+        let cbs = &mut *(user_ptr as *mut ServerStreamCallbacks);
+        cbs.state_callback(state);
+    });
+    ok.expect("State callback panicked");
+}
+
+unsafe extern "C" fn device_change_cb_c(user_ptr: *mut c_void) {
+    let ok = panic::catch_unwind(|| {
+        let cbs = &mut *(user_ptr as *mut ServerStreamCallbacks);
+        cbs.device_change_callback();
+    });
+    ok.expect("Device change callback panicked");
+}
+
+unsafe extern "C" fn device_collection_changed_input_cb_c(
+    _: *mut ffi::cubeb,
+    user_ptr: *mut c_void,
+) {
+    let ok = panic::catch_unwind(|| {
+        let manager = &mut *(user_ptr as *mut CubebDeviceCollectionManager);
+        manager.device_collection_changed_callback(ffi::CUBEB_DEVICE_TYPE_INPUT);
+    });
+    ok.expect("Collection changed (input) callback panicked");
+}
+
+unsafe extern "C" fn device_collection_changed_output_cb_c(
+    _: *mut ffi::cubeb,
+    user_ptr: *mut c_void,
+) {
+    let ok = panic::catch_unwind(|| {
+        let manager = &mut *(user_ptr as *mut CubebDeviceCollectionManager);
+        manager.device_collection_changed_callback(ffi::CUBEB_DEVICE_TYPE_OUTPUT);
+    });
+    ok.expect("Collection changed (output) callback panicked");
+}