Adding upstream version 110.0.1.upstream/110.0.1upstream

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

4 files changed, 881 insertions, 0 deletions

diff --git a/third_party/rust/audioipc2-client/src/context.rs b/third_party/rust/audioipc2-client/src/context.rs
new file mode 100644
index 0000000000..c255815ac8
--- /dev/null
+++ b/third_party/rust/audioipc2-client/src/context.rs
@@ -0,0 +1,385 @@
+// 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::ipccore::EventLoopHandle;
+use audioipc::{ipccore, rpccore, sys, PlatformHandle};
+use audioipc::{
+    messages, messages::DeviceCollectionReq, messages::DeviceCollectionResp, ClientMessage,
+    ServerMessage,
+};
+use cubeb_backend::{
+    capi_new, ffi, Context, ContextOps, DeviceCollectionRef, DeviceId, DeviceType, Error, Ops,
+    Result, Stream, StreamParams, StreamParamsRef,
+};
+use std::ffi::{CStr, CString};
+use std::os::raw::c_void;
+use std::sync::{Arc, Mutex};
+use std::thread;
+use std::{fmt, mem, ptr};
+
+struct CubebClient;
+
+impl rpccore::Client for CubebClient {
+    type ServerMessage = ServerMessage;
+    type ClientMessage = ClientMessage;
+}
+
+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: rpccore::Proxy<ServerMessage, ClientMessage>,
+    rpc_thread: ipccore::EventLoopThread,
+    callback_thread: ipccore::EventLoopThread,
+    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 rpc_handle(&self) -> &EventLoopHandle {
+        self.rpc_thread.handle()
+    }
+
+    #[doc(hidden)]
+    pub fn rpc(&self) -> Result<rpccore::Proxy<ServerMessage, ClientMessage>> {
+        self.rpc.try_clone().map_err(|_| Error::default())
+    }
+
+    #[doc(hidden)]
+    pub fn callback_handle(&self) -> &EventLoopHandle {
+        self.callback_thread.handle()
+    }
+}
+
+#[cfg(target_os = "linux")]
+fn promote_thread(rpc: &rpccore::Proxy<ServerMessage, ClientMessage>) {
+    match get_current_thread_info() {
+        Ok(info) => {
+            let bytes = info.serialize();
+            let _ = rpc.call(ServerMessage::PromoteThreadToRealTime(bytes));
+        }
+        Err(_) => {
+            warn!("Could not remotely promote thread to RT.");
+        }
+    }
+}
+
+#[cfg(not(target_os = "linux"))]
+fn promote_thread(_rpc: &rpccore::Proxy<ServerMessage, ClientMessage>) {
+    match promote_current_thread_to_real_time(256, 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: &rpccore::Proxy<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>>,
+}
+
+impl rpccore::Server for DeviceCollectionServer {
+    type ServerMessage = DeviceCollectionReq;
+    type ClientMessage = DeviceCollectionResp;
+
+    fn process(&mut self, req: Self::ServerMessage) -> Self::ClientMessage {
+        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)
+                };
+
+                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)
+                        }
+                    }
+                });
+
+                DeviceCollectionResp::DeviceChange
+            }
+        }
+    }
+}
+
+impl ContextOps for ClientContext {
+    fn init(_context_name: Option<&CStr>) -> Result<Context> {
+        assert_not_in_callback();
+
+        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_connection =
+            unsafe { sys::Pipe::from_raw_handle(PlatformHandle::new(params.server_connection)) };
+
+        let rpc_thread = ipccore::EventLoopThread::new(
+            "AudioIPC Client RPC".to_string(),
+            None,
+            move || register_thread(thread_create_callback),
+            move || unregister_thread(thread_destroy_callback),
+        )
+        .map_err(|_| Error::default())?;
+        let rpc = rpc_thread
+            .handle()
+            .bind_client::<CubebClient>(server_connection)
+            .map_err(|_| Error::default())?;
+        let rpc2 = rpc.try_clone().map_err(|_| Error::default())?;
+
+        // 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");
+
+        // TODO: remove params.pool_size from init params.
+        let callback_thread = ipccore::EventLoopThread::new(
+            "AudioIPC Client Callback".to_string(),
+            Some(params.stack_size),
+            move || promote_and_register_thread(&rpc2, thread_create_callback),
+            move || unregister_thread(thread_destroy_callback),
+        )
+        .map_err(|_| Error::default())?;
+
+        let ctx = Box::new(ClientContext {
+            _ops: &CLIENT_OPS as *const _,
+            rpc,
+            rpc_thread,
+            callback_thread,
+            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> = send_recv!(
+            self.rpc()?, ContextGetDeviceEnumeration(devtype.bits()) => ContextEnumeratedDevices())?
+        .into_iter()
+        .map(|i| i.into())
+        .collect();
+        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();
+
+        let stream_name = stream_name.map(|name| name.to_bytes_with_nul().to_vec());
+
+        let input_stream_params = input_stream_params.map(messages::StreamParams::from);
+        let output_stream_params = output_stream_params.map(messages::StreamParams::from);
+
+        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 mut fd = send_recv!(self.rpc()?,
+                                 ContextSetupDeviceCollectionCallback =>
+                                 ContextSetupDeviceCollectionCallback())?;
+
+            let stream = unsafe { sys::Pipe::from_raw_handle(fd.platform_handle.take_handle()) };
+
+            let server = DeviceCollectionServer {
+                input_device_callback: self.input_device_callback.clone(),
+                output_device_callback: self.output_device_callback.clone(),
+            };
+
+            self.rpc_handle()
+                .bind_server(server, stream)
+                .map_err(|_| Error::default())?;
+            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 _ = self
+            .rpc()
+            .and_then(|rpc| send_recv!(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.rpc_thread)
+            .field("cpu_pool", &"...")
+            .finish()
+    }
+}
diff --git a/third_party/rust/audioipc2-client/src/lib.rs b/third_party/rust/audioipc2-client/src/lib.rs
new file mode 100644
index 0000000000..51a68af709
--- /dev/null
+++ b/third_party/rust/audioipc2-client/src/lib.rs
@@ -0,0 +1,81 @@
+// 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 log;
+
+#[macro_use]
+mod send_recv;
+mod context;
+mod stream;
+
+use crate::context::ClientContext;
+use crate::stream::ClientStream;
+use audioipc::PlatformHandleType;
+use cubeb_backend::{capi, ffi};
+use std::os::raw::{c_char, c_int};
+
+thread_local!(static IN_CALLBACK: std::cell::RefCell<bool> = std::cell::RefCell::new(false));
+thread_local!(static AUDIOIPC_INIT_PARAMS: std::cell::RefCell<Option<AudioIpcInitParams>> = std::cell::RefCell::new(None));
+
+#[repr(C)]
+#[derive(Clone, Copy, Debug)]
+pub struct AudioIpcInitParams {
+    // Fields only need to be public for ipctest.
+    pub server_connection: PlatformHandleType,
+    pub pool_size: usize,
+    pub stack_size: usize,
+    pub thread_create_callback: Option<extern "C" fn(*const ::std::os::raw::c_char)>,
+    pub thread_destroy_callback: Option<extern "C" fn()>,
+}
+
+unsafe impl Send for AudioIpcInitParams {}
+
+fn set_in_callback(in_callback: bool) {
+    IN_CALLBACK.with(|b| {
+        assert_eq!(*b.borrow(), !in_callback);
+        *b.borrow_mut() = in_callback;
+    });
+}
+
+fn run_in_callback<F, R>(f: F) -> R
+where
+    F: FnOnce() -> R,
+{
+    set_in_callback(true);
+
+    let r = f();
+
+    set_in_callback(false);
+
+    r
+}
+
+fn assert_not_in_callback() {
+    IN_CALLBACK.with(|b| {
+        assert!(!*b.borrow());
+    });
+}
+
+#[allow(clippy::missing_safety_doc)]
+#[no_mangle]
+/// Entry point from C code.
+pub unsafe extern "C" fn audioipc2_client_init(
+    c: *mut *mut ffi::cubeb,
+    context_name: *const c_char,
+    init_params: *const AudioIpcInitParams,
+) -> c_int {
+    if init_params.is_null() {
+        return cubeb_backend::ffi::CUBEB_ERROR;
+    }
+
+    let init_params = &*init_params;
+
+    AUDIOIPC_INIT_PARAMS.with(|p| {
+        *p.borrow_mut() = Some(*init_params);
+    });
+    capi::capi_init::<ClientContext>(c, context_name)
+}
diff --git a/third_party/rust/audioipc2-client/src/send_recv.rs b/third_party/rust/audioipc2-client/src/send_recv.rs
new file mode 100644
index 0000000000..1134c99a49
--- /dev/null
+++ b/third_party/rust/audioipc2-client/src/send_recv.rs
@@ -0,0 +1,73 @@
+// Copyright © 2017 Mozilla Foundation
+//
+// This program is made available under an ISC-style license.  See the
+// accompanying file LICENSE for details.
+
+use cubeb_backend::Error;
+use std::os::raw::c_int;
+
+#[doc(hidden)]
+pub fn _err<E>(e: E) -> Error
+where
+    E: Into<Option<c_int>>,
+{
+    match e.into() {
+        Some(e) => Error::from_raw(e),
+        None => Error::error(),
+    }
+}
+
+#[macro_export]
+macro_rules! send_recv {
+    ($rpc:expr, $smsg:ident => $rmsg:ident) => {{
+        let resp = send_recv!(__send $rpc, $smsg);
+        send_recv!(__recv resp, $rmsg)
+    }};
+    ($rpc:expr, $smsg:ident => $rmsg:ident()) => {{
+        let resp = send_recv!(__send $rpc, $smsg);
+        send_recv!(__recv resp, $rmsg __result)
+    }};
+    ($rpc:expr, $smsg:ident($($a:expr),*) => $rmsg:ident) => {{
+        let resp = send_recv!(__send $rpc, $smsg, $($a),*);
+        send_recv!(__recv resp, $rmsg)
+    }};
+    ($rpc:expr, $smsg:ident($($a:expr),*) => $rmsg:ident()) => {{
+        let resp = send_recv!(__send $rpc, $smsg, $($a),*);
+        send_recv!(__recv resp, $rmsg __result)
+    }};
+    //
+    (__send $rpc:expr, $smsg:ident) => ({
+        $rpc.call(ServerMessage::$smsg)
+    });
+    (__send $rpc:expr, $smsg:ident, $($a:expr),*) => ({
+        $rpc.call(ServerMessage::$smsg($($a),*))
+    });
+    (__recv $resp:expr, $rmsg:ident) => ({
+        match $resp {
+            Ok(ClientMessage::$rmsg) => Ok(()),
+            Ok(ClientMessage::Error(e)) => Err($crate::send_recv::_err(e)),
+            Ok(m) => {
+                debug!("received wrong message - got={:?}", m);
+                Err($crate::send_recv::_err(None))
+            },
+            Err(e) => {
+                debug!("received error from rpc - got={:?}", e);
+                Err($crate::send_recv::_err(None))
+            },
+        }
+    });
+    (__recv $resp:expr, $rmsg:ident __result) => ({
+        match $resp {
+            Ok(ClientMessage::$rmsg(v)) => Ok(v),
+            Ok(ClientMessage::Error(e)) => Err($crate::send_recv::_err(e)),
+            Ok(m) => {
+                debug!("received wrong message - got={:?}", m);
+                Err($crate::send_recv::_err(None))
+            },
+            Err(e) => {
+                debug!("received error - got={:?}", e);
+                Err($crate::send_recv::_err(None))
+            },
+        }
+    })
+}
diff --git a/third_party/rust/audioipc2-client/src/stream.rs b/third_party/rust/audioipc2-client/src/stream.rs
new file mode 100644
index 0000000000..315efd7906
--- /dev/null
+++ b/third_party/rust/audioipc2-client/src/stream.rs
@@ -0,0 +1,342 @@
+// Copyright © 2017 Mozilla Foundation
+//
+// This program is made available under an ISC-style license.  See the
+// accompanying file LICENSE for details
+
+use crate::ClientContext;
+use crate::{assert_not_in_callback, run_in_callback};
+use audioipc::messages::StreamCreateParams;
+use audioipc::messages::{self, CallbackReq, CallbackResp, ClientMessage, ServerMessage};
+use audioipc::shm::SharedMem;
+use audioipc::{rpccore, sys};
+use cubeb_backend::{ffi, DeviceRef, Error, Result, Stream, StreamOps};
+use std::ffi::{CStr, CString};
+use std::os::raw::c_void;
+use std::ptr;
+use std::sync::mpsc;
+use std::sync::{Arc, Mutex};
+
+pub struct Device(ffi::cubeb_device);
+
+impl Drop for Device {
+    fn drop(&mut self) {
+        unsafe {
+            if !self.0.input_name.is_null() {
+                let _ = CString::from_raw(self.0.input_name as *mut _);
+            }
+            if !self.0.output_name.is_null() {
+                let _ = CString::from_raw(self.0.output_name as *mut _);
+            }
+        }
+    }
+}
+
+// ClientStream's layout *must* match cubeb.c's `struct cubeb_stream` for the
+// common fields.
+#[repr(C)]
+#[derive(Debug)]
+pub struct ClientStream<'ctx> {
+    // This must be a reference to Context for cubeb, cubeb accesses
+    // stream methods via stream->context->ops
+    context: &'ctx ClientContext,
+    user_ptr: *mut c_void,
+    token: usize,
+    device_change_cb: Arc<Mutex<ffi::cubeb_device_changed_callback>>,
+    // Signals ClientStream that CallbackServer has dropped.
+    shutdown_rx: mpsc::Receiver<()>,
+}
+
+struct CallbackServer {
+    shm: SharedMem,
+    duplex_input: Option<Vec<u8>>,
+    data_cb: ffi::cubeb_data_callback,
+    state_cb: ffi::cubeb_state_callback,
+    user_ptr: usize,
+    device_change_cb: Arc<Mutex<ffi::cubeb_device_changed_callback>>,
+    // Signals ClientStream that CallbackServer has dropped.
+    _shutdown_tx: mpsc::Sender<()>,
+}
+
+impl rpccore::Server for CallbackServer {
+    type ServerMessage = CallbackReq;
+    type ClientMessage = CallbackResp;
+
+    fn process(&mut self, req: Self::ServerMessage) -> Self::ClientMessage {
+        match req {
+            CallbackReq::Data {
+                nframes,
+                input_frame_size,
+                output_frame_size,
+            } => {
+                trace!(
+                    "stream_thread: Data Callback: nframes={} input_fs={} output_fs={}",
+                    nframes,
+                    input_frame_size,
+                    output_frame_size,
+                );
+
+                let input_nbytes = nframes as usize * input_frame_size;
+                let output_nbytes = nframes as usize * output_frame_size;
+
+                // Input and output reuse the same shmem backing.  Unfortunately, cubeb's data_callback isn't
+                // specified in such a way that would require the callee to consume all of the input before
+                // writing to the output (i.e., it is passed as two pointers that aren't expected to alias).
+                // That means we need to copy the input here.
+                if let Some(buf) = &mut self.duplex_input {
+                    assert!(input_nbytes > 0);
+                    assert!(buf.capacity() >= input_nbytes);
+                    unsafe {
+                        let input = self.shm.get_slice(input_nbytes).unwrap();
+                        ptr::copy_nonoverlapping(input.as_ptr(), buf.as_mut_ptr(), input.len());
+                    }
+                }
+
+                run_in_callback(|| {
+                    let nframes = unsafe {
+                        let input_ptr = if input_frame_size > 0 {
+                            if let Some(buf) = &mut self.duplex_input {
+                                buf.as_ptr()
+                            } else {
+                                self.shm.get_slice(input_nbytes).unwrap().as_ptr()
+                            }
+                        } else {
+                            ptr::null()
+                        };
+                        let output_ptr = if output_frame_size > 0 {
+                            self.shm.get_mut_slice(output_nbytes).unwrap().as_mut_ptr()
+                        } else {
+                            ptr::null_mut()
+                        };
+
+                        self.data_cb.unwrap()(
+                            ptr::null_mut(), // https://github.com/kinetiknz/cubeb/issues/518
+                            self.user_ptr as *mut c_void,
+                            input_ptr as *const _,
+                            output_ptr as *mut _,
+                            nframes as _,
+                        )
+                    };
+
+                    CallbackResp::Data(nframes as isize)
+                })
+            }
+            CallbackReq::State(state) => {
+                trace!("stream_thread: State Callback: {:?}", state);
+                run_in_callback(|| unsafe {
+                    self.state_cb.unwrap()(ptr::null_mut(), self.user_ptr as *mut _, state);
+                });
+
+                CallbackResp::State
+            }
+            CallbackReq::DeviceChange => {
+                run_in_callback(|| {
+                    let cb = *self.device_change_cb.lock().unwrap();
+                    if let Some(cb) = cb {
+                        unsafe {
+                            cb(self.user_ptr as *mut _);
+                        }
+                    } else {
+                        warn!("DeviceChange received with null callback");
+                    }
+                });
+
+                CallbackResp::DeviceChange
+            }
+        }
+    }
+}
+
+impl<'ctx> ClientStream<'ctx> {
+    fn init(
+        ctx: &'ctx ClientContext,
+        init_params: messages::StreamInitParams,
+        data_callback: ffi::cubeb_data_callback,
+        state_callback: ffi::cubeb_state_callback,
+        user_ptr: *mut c_void,
+    ) -> Result<Stream> {
+        assert_not_in_callback();
+
+        let rpc = ctx.rpc()?;
+        let create_params = StreamCreateParams {
+            input_stream_params: init_params.input_stream_params,
+            output_stream_params: init_params.output_stream_params,
+        };
+        let mut data = send_recv!(rpc, StreamCreate(create_params) => StreamCreated())?;
+
+        debug!(
+            "token = {}, handle = {:?} area_size = {:?}",
+            data.token, data.shm_handle, data.shm_area_size
+        );
+
+        let shm =
+            match unsafe { SharedMem::from(data.shm_handle.take_handle(), data.shm_area_size) } {
+                Ok(shm) => shm,
+                Err(e) => {
+                    warn!(
+                        "SharedMem client mapping failed (size={}, err={:?})",
+                        data.shm_area_size, e
+                    );
+                    return Err(Error::default());
+                }
+            };
+
+        let duplex_input = if let (Some(_), Some(_)) = (
+            init_params.input_stream_params,
+            init_params.output_stream_params,
+        ) {
+            let mut duplex_input = Vec::new();
+            match duplex_input.try_reserve_exact(data.shm_area_size) {
+                Ok(()) => Some(duplex_input),
+                Err(e) => {
+                    warn!(
+                        "duplex_input allocation failed (size={}, err={:?})",
+                        data.shm_area_size, e
+                    );
+                    return Err(Error::default());
+                }
+            }
+        } else {
+            None
+        };
+
+        let mut stream =
+            send_recv!(rpc, StreamInit(data.token, init_params) => StreamInitialized())?;
+        let stream = unsafe { sys::Pipe::from_raw_handle(stream.take_handle()) };
+
+        let user_data = user_ptr as usize;
+
+        let null_cb: ffi::cubeb_device_changed_callback = None;
+        let device_change_cb = Arc::new(Mutex::new(null_cb));
+
+        let (_shutdown_tx, shutdown_rx) = mpsc::channel();
+
+        let server = CallbackServer {
+            shm,
+            duplex_input,
+            data_cb: data_callback,
+            state_cb: state_callback,
+            user_ptr: user_data,
+            device_change_cb: device_change_cb.clone(),
+            _shutdown_tx,
+        };
+
+        ctx.callback_handle()
+            .bind_server(server, stream)
+            .map_err(|_| Error::default())?;
+
+        let stream = Box::into_raw(Box::new(ClientStream {
+            context: ctx,
+            user_ptr,
+            token: data.token,
+            device_change_cb,
+            shutdown_rx,
+        }));
+        Ok(unsafe { Stream::from_ptr(stream as *mut _) })
+    }
+}
+
+impl Drop for ClientStream<'_> {
+    fn drop(&mut self) {
+        debug!("ClientStream drop");
+        let _ = self
+            .context
+            .rpc()
+            .and_then(|rpc| send_recv!(rpc, StreamDestroy(self.token) => StreamDestroyed));
+        debug!("ClientStream drop - stream destroyed");
+        // Wait for CallbackServer to shutdown.  The remote server drops the RPC
+        // connection during StreamDestroy, which will cause CallbackServer to drop
+        // once the connection close is detected.  Dropping CallbackServer will
+        // cause the shutdown channel to error on recv, which we rely on to
+        // synchronize with CallbackServer dropping.
+        let _ = self.shutdown_rx.recv();
+        debug!("ClientStream dropped");
+    }
+}
+
+impl StreamOps for ClientStream<'_> {
+    fn start(&mut self) -> Result<()> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        send_recv!(rpc, StreamStart(self.token) => StreamStarted)
+    }
+
+    fn stop(&mut self) -> Result<()> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        send_recv!(rpc, StreamStop(self.token) => StreamStopped)
+    }
+
+    fn position(&mut self) -> Result<u64> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        send_recv!(rpc, StreamGetPosition(self.token) => StreamPosition())
+    }
+
+    fn latency(&mut self) -> Result<u32> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        send_recv!(rpc, StreamGetLatency(self.token) => StreamLatency())
+    }
+
+    fn input_latency(&mut self) -> Result<u32> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        send_recv!(rpc, StreamGetInputLatency(self.token) => StreamInputLatency())
+    }
+
+    fn set_volume(&mut self, volume: f32) -> Result<()> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        send_recv!(rpc, StreamSetVolume(self.token, volume) => StreamVolumeSet)
+    }
+
+    fn set_name(&mut self, name: &CStr) -> Result<()> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        send_recv!(rpc, StreamSetName(self.token, name.to_owned()) => StreamNameSet)
+    }
+
+    fn current_device(&mut self) -> Result<&DeviceRef> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        match send_recv!(rpc, StreamGetCurrentDevice(self.token) => StreamCurrentDevice()) {
+            Ok(d) => Ok(unsafe { DeviceRef::from_ptr(Box::into_raw(Box::new(d.into()))) }),
+            Err(e) => Err(e),
+        }
+    }
+
+    fn device_destroy(&mut self, device: &DeviceRef) -> Result<()> {
+        assert_not_in_callback();
+        if device.as_ptr().is_null() {
+            Err(Error::error())
+        } else {
+            unsafe {
+                let _: Box<Device> = Box::from_raw(device.as_ptr() as *mut _);
+            }
+            Ok(())
+        }
+    }
+
+    fn register_device_changed_callback(
+        &mut self,
+        device_changed_callback: ffi::cubeb_device_changed_callback,
+    ) -> Result<()> {
+        assert_not_in_callback();
+        let rpc = self.context.rpc()?;
+        let enable = device_changed_callback.is_some();
+        *self.device_change_cb.lock().unwrap() = device_changed_callback;
+        send_recv!(rpc, StreamRegisterDeviceChangeCallback(self.token, enable) => StreamRegisterDeviceChangeCallback)
+    }
+}
+
+pub fn init(
+    ctx: &ClientContext,
+    init_params: messages::StreamInitParams,
+    data_callback: ffi::cubeb_data_callback,
+    state_callback: ffi::cubeb_state_callback,
+    user_ptr: *mut c_void,
+) -> Result<Stream> {
+    let stm = ClientStream::init(ctx, init_params, data_callback, state_callback, user_ptr)?;
+    debug_assert_eq!(stm.user_ptr(), user_ptr);
+    Ok(stm)
+}