Move webgl_channel into base crate (#32339)

* Move webgl_channel into a shared crate

* Add license header

* Rename channle types and simplify module

* Move module to base

Cargo.lock

@@ -341,6 +341,7 @@ dependencies = [
 name = "base"
 version = "0.0.1"
 dependencies = [
+ "crossbeam-channel",
  "ipc-channel",
  "lazy_static",
  "malloc_size_of",
@@ -661,6 +662,7 @@ dependencies = [
 name = "canvas_traits"
 version = "0.0.1"
 dependencies = [
+ "base",
  "crossbeam-channel",
  "euclid",
  "ipc-channel",

components/shared/base/Cargo.toml

@@ -13,6 +13,7 @@ test = false
 doctest = false
 
 [dependencies]
+crossbeam-channel = { workspace = true }
 ipc-channel = { workspace = true }
 lazy_static = { workspace = true }
 malloc_size_of = { workspace = true }

components/shared/base/generic_channel.rs

@@ -0,0 +1,128 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+//! Enum wrappers to be able to select different channel implementations at runtime.
+
+use std::fmt;
+
+use ipc_channel::router::ROUTER;
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+pub enum GenericSender<T: Serialize> {
+    Ipc(ipc_channel::ipc::IpcSender<T>),
+    Crossbeam(crossbeam_channel::Sender<T>),
+}
+
+impl<T: Serialize> Serialize for GenericSender<T> {
+    fn serialize<S: Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
+        match self {
+            GenericSender::Ipc(i) => i.serialize(s),
+            GenericSender::Crossbeam(_) => unreachable!(),
+        }
+    }
+}
+
+impl<'a, T: Serialize> Deserialize<'a> for GenericSender<T> {
+    fn deserialize<D>(d: D) -> Result<GenericSender<T>, D::Error>
+    where
+        D: Deserializer<'a>,
+    {
+        // Only ipc_channle will encounter deserialize scenario.
+        ipc_channel::ipc::IpcSender::<T>::deserialize(d).map(|s| GenericSender::Ipc(s))
+    }
+}
+
+impl<T> Clone for GenericSender<T>
+where
+    T: Serialize,
+{
+    fn clone(&self) -> Self {
+        match *self {
+            GenericSender::Ipc(ref chan) => GenericSender::Ipc(chan.clone()),
+            GenericSender::Crossbeam(ref chan) => GenericSender::Crossbeam(chan.clone()),
+        }
+    }
+}
+
+impl<T: Serialize> fmt::Debug for GenericSender<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Sender(..)")
+    }
+}
+
+impl<T: Serialize> GenericSender<T> {
+    #[inline]
+    pub fn send(&self, msg: T) -> SendResult {
+        match *self {
+            GenericSender::Ipc(ref sender) => sender.send(msg).map_err(|_| SendError),
+            GenericSender::Crossbeam(ref sender) => sender.send(msg).map_err(|_| SendError),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct SendError;
+pub type SendResult = Result<(), SendError>;
+
+#[derive(Debug)]
+pub struct ReceiveError;
+pub type ReceiveResult<T> = Result<T, ReceiveError>;
+
+pub enum GenericReceiver<T>
+where
+    T: for<'de> Deserialize<'de> + Serialize,
+{
+    Ipc(ipc_channel::ipc::IpcReceiver<T>),
+    Crossbeam(crossbeam_channel::Receiver<T>),
+}
+
+impl<T> GenericReceiver<T>
+where
+    T: for<'de> Deserialize<'de> + Serialize,
+{
+    pub fn recv(&self) -> ReceiveResult<T> {
+        match *self {
+            GenericReceiver::Ipc(ref receiver) => receiver.recv().map_err(|_| ReceiveError),
+            GenericReceiver::Crossbeam(ref receiver) => receiver.recv().map_err(|_| ReceiveError),
+        }
+    }
+
+    pub fn try_recv(&self) -> ReceiveResult<T> {
+        match *self {
+            GenericReceiver::Ipc(ref receiver) => receiver.try_recv().map_err(|_| ReceiveError),
+            GenericReceiver::Crossbeam(ref receiver) => {
+                receiver.try_recv().map_err(|_| ReceiveError)
+            },
+        }
+    }
+
+    pub fn into_inner(self) -> crossbeam_channel::Receiver<T>
+    where
+        T: Send + 'static,
+    {
+        match self {
+            GenericReceiver::Ipc(receiver) => {
+                ROUTER.route_ipc_receiver_to_new_crossbeam_receiver(receiver)
+            },
+            GenericReceiver::Crossbeam(receiver) => receiver,
+        }
+    }
+}
+
+/// Creates a Servo channel that can select different channel implementations based on multiprocess
+/// mode or not. If the scenario doesn't require message to pass process boundary, a simple
+/// crossbeam channel is preferred.
+pub fn channel<T>(multiprocess: bool) -> Option<(GenericSender<T>, GenericReceiver<T>)>
+where
+    T: for<'de> Deserialize<'de> + Serialize,
+{
+    if multiprocess {
+        ipc_channel::ipc::channel()
+            .map(|(tx, rx)| (GenericSender::Ipc(tx), GenericReceiver::Ipc(rx)))
+            .ok()
+    } else {
+        let (tx, rx) = crossbeam_channel::unbounded();
+        Some((GenericSender::Crossbeam(tx), GenericReceiver::Crossbeam(rx)))
+    }
+}

components/shared/base/lib.rs

@@ -11,6 +11,7 @@
 
 use serde::{Deserialize, Serialize};
 
+pub mod generic_channel;
 pub mod id;
 pub mod print_tree;
 use webrender_api::Epoch as WebRenderEpoch;

components/shared/canvas/Cargo.toml

@@ -15,6 +15,7 @@ webgl_backtrace = []
 xr-profile = ["webxr-api/profile", "time"]
 
 [dependencies]
+base = { workspace = true }
 crossbeam-channel = { workspace = true }
 euclid = { workspace = true }
 ipc-channel = { workspace = true }

components/shared/canvas/lib.rs

@@ -14,7 +14,6 @@ use crate::canvas::CanvasId;
 pub mod canvas;
 #[macro_use]
 pub mod webgl;
-mod webgl_channel;
 
 pub enum ConstellationCanvasMsg {
     Create {

components/shared/canvas/webgl.rs

@@ -7,6 +7,12 @@ use std::fmt;
 use std::num::{NonZeroU32, NonZeroU64};
 use std::ops::Deref;
 
+/// Receiver type used in WebGLCommands.
+pub use base::generic_channel::GenericReceiver as WebGLReceiver;
+/// Sender type used in WebGLCommands.
+pub use base::generic_channel::GenericSender as WebGLSender;
+/// Result type for send()/recv() calls in in WebGLCommands.
+pub use base::generic_channel::SendResult as WebGLSendResult;
 use euclid::default::{Rect, Size2D};
 use ipc_channel::ipc::{IpcBytesReceiver, IpcBytesSender, IpcSharedMemory};
 use malloc_size_of_derive::MallocSizeOf;
@@ -20,17 +26,33 @@ use webxr_api::{
 };
 
 /// Helper function that creates a WebGL channel (WebGLSender, WebGLReceiver) to be used in WebGLCommands.
-pub use crate::webgl_channel::webgl_channel;
+pub fn webgl_channel<T>() -> Option<(WebGLSender<T>, WebGLReceiver<T>)>
+where
+    T: for<'de> Deserialize<'de> + Serialize,
+{
+    base::generic_channel::channel(servo_config::opts::multiprocess())
+}
+
 /// Entry point channel type used for sending WebGLMsg messages to the WebGL renderer.
-pub use crate::webgl_channel::WebGLChan;
+#[derive(Clone, Debug, Deserialize, Serialize)]
+pub struct WebGLChan(pub WebGLSender<WebGLMsg>);
+
+impl WebGLChan {
+    #[inline]
+    pub fn send(&self, msg: WebGLMsg) -> WebGLSendResult {
+        self.0.send(msg)
+    }
+}
+
 /// Entry point type used in a Script Pipeline to get the WebGLChan to be used in that thread.
-pub use crate::webgl_channel::WebGLPipeline;
+#[derive(Clone, Debug, Deserialize, Serialize)]
-/// Receiver type used in WebGLCommands.
+pub struct WebGLPipeline(pub WebGLChan);
-pub use crate::webgl_channel::WebGLReceiver;
+
-/// Result type for send()/recv() calls in in WebGLCommands.
+impl WebGLPipeline {
-pub use crate::webgl_channel::WebGLSendResult;
+    pub fn channel(&self) -> WebGLChan {
-/// Sender type used in WebGLCommands.
+        self.0.clone()
-pub use crate::webgl_channel::WebGLSender;
+    }
+}
 
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct WebGLCommandBacktrace {

components/shared/canvas/webgl_channel/ipc.rs

@@ -1,15 +0,0 @@
-/* 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 https://mozilla.org/MPL/2.0/. */
-
-use std::io;
-
-use serde::{Deserialize, Serialize};
-
-pub type WebGLSender<T> = ipc_channel::ipc::IpcSender<T>;
-pub type WebGLReceiver<T> = ipc_channel::ipc::IpcReceiver<T>;
-
-pub fn webgl_channel<T: Serialize + for<'de> Deserialize<'de>>(
-) -> Result<(WebGLSender<T>, WebGLReceiver<T>), io::Error> {
-    ipc_channel::ipc::channel()
-}

components/shared/canvas/webgl_channel/mod.rs

@@ -1,157 +0,0 @@
-/* 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 https://mozilla.org/MPL/2.0/. */
-
-//! Enum wrappers to be able to select different channel implementations at runtime.
-
-mod ipc;
-mod mpsc;
-
-use std::fmt;
-
-use ipc_channel::ipc::IpcSender;
-use ipc_channel::router::ROUTER;
-use lazy_static::lazy_static;
-use serde::{Deserialize, Serialize};
-use servo_config::opts;
-
-use crate::webgl::WebGLMsg;
-
-lazy_static! {
-    static ref IS_MULTIPROCESS: bool = opts::multiprocess();
-}
-
-#[derive(Deserialize, Serialize)]
-pub enum WebGLSender<T: Serialize> {
-    Ipc(ipc::WebGLSender<T>),
-    Mpsc(mpsc::WebGLSender<T>),
-}
-
-impl<T> Clone for WebGLSender<T>
-where
-    T: Serialize,
-{
-    fn clone(&self) -> Self {
-        match *self {
-            WebGLSender::Ipc(ref chan) => WebGLSender::Ipc(chan.clone()),
-            WebGLSender::Mpsc(ref chan) => WebGLSender::Mpsc(chan.clone()),
-        }
-    }
-}
-
-impl<T: Serialize> fmt::Debug for WebGLSender<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "WebGLSender(..)")
-    }
-}
-
-impl<T: Serialize> WebGLSender<T> {
-    #[inline]
-    pub fn send(&self, msg: T) -> WebGLSendResult {
-        match *self {
-            WebGLSender::Ipc(ref sender) => sender.send(msg).map_err(|_| WebGLSendError),
-            WebGLSender::Mpsc(ref sender) => sender.send(msg).map_err(|_| WebGLSendError),
-        }
-    }
-}
-
-#[derive(Debug)]
-pub struct WebGLSendError;
-pub type WebGLSendResult = Result<(), WebGLSendError>;
-
-#[derive(Debug)]
-pub struct WebGLReceiveError;
-pub type WebGLReceiveResult<T> = Result<T, WebGLReceiveError>;
-
-pub enum WebGLReceiver<T>
-where
-    T: for<'de> Deserialize<'de> + Serialize,
-{
-    Ipc(ipc::WebGLReceiver<T>),
-    Mpsc(mpsc::WebGLReceiver<T>),
-}
-
-impl<T> WebGLReceiver<T>
-where
-    T: for<'de> Deserialize<'de> + Serialize,
-{
-    pub fn recv(&self) -> WebGLReceiveResult<T> {
-        match *self {
-            WebGLReceiver::Ipc(ref receiver) => receiver.recv().map_err(|_| WebGLReceiveError),
-            WebGLReceiver::Mpsc(ref receiver) => receiver.recv().map_err(|_| WebGLReceiveError),
-        }
-    }
-
-    pub fn try_recv(&self) -> WebGLReceiveResult<T> {
-        match *self {
-            WebGLReceiver::Ipc(ref receiver) => receiver.try_recv().map_err(|_| WebGLReceiveError),
-            WebGLReceiver::Mpsc(ref receiver) => receiver.try_recv().map_err(|_| WebGLReceiveError),
-        }
-    }
-
-    pub fn into_inner(self) -> crossbeam_channel::Receiver<T>
-    where
-        T: Send + 'static,
-    {
-        match self {
-            WebGLReceiver::Ipc(receiver) => {
-                ROUTER.route_ipc_receiver_to_new_crossbeam_receiver(receiver)
-            },
-            WebGLReceiver::Mpsc(receiver) => receiver.into_inner(),
-        }
-    }
-}
-
-pub fn webgl_channel<T>() -> Option<(WebGLSender<T>, WebGLReceiver<T>)>
-where
-    T: for<'de> Deserialize<'de> + Serialize,
-{
-    if *IS_MULTIPROCESS {
-        ipc::webgl_channel()
-            .map(|(tx, rx)| (WebGLSender::Ipc(tx), WebGLReceiver::Ipc(rx)))
-            .ok()
-    } else {
-        mpsc::webgl_channel()
-            .map(|(tx, rx)| (WebGLSender::Mpsc(tx), WebGLReceiver::Mpsc(rx)))
-            .ok()
-    }
-}
-
-#[derive(Clone, Debug, Deserialize, Serialize)]
-pub struct WebGLChan(pub WebGLSender<WebGLMsg>);
-
-impl WebGLChan {
-    #[inline]
-    pub fn send(&self, msg: WebGLMsg) -> WebGLSendResult {
-        self.0.send(msg)
-    }
-
-    pub fn to_ipc(&self) -> IpcSender<WebGLMsg> {
-        match self.0 {
-            WebGLSender::Ipc(ref sender) => sender.clone(),
-            WebGLSender::Mpsc(ref mpsc_sender) => {
-                let (sender, receiver) =
-                    ipc_channel::ipc::channel().expect("IPC Channel creation failed");
-                let mpsc_sender = mpsc_sender.clone();
-                ipc_channel::router::ROUTER.add_route(
-                    receiver.to_opaque(),
-                    Box::new(move |message| {
-                        if let Ok(message) = message.to() {
-                            let _ = mpsc_sender.send(message);
-                        }
-                    }),
-                );
-                sender
-            },
-        }
-    }
-}
-
-#[derive(Clone, Debug, Deserialize, Serialize)]
-pub struct WebGLPipeline(pub WebGLChan);
-
-impl WebGLPipeline {
-    pub fn channel(&self) -> WebGLChan {
-        self.0.clone()
-    }
-}

components/shared/canvas/webgl_channel/mpsc.rs

@@ -1,62 +0,0 @@
-/* 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 https://mozilla.org/MPL/2.0/. */
-
-use serde::{Deserialize, Deserializer, Serialize, Serializer};
-
-macro_rules! unreachable_serializable {
-    ($name:ident) => {
-        impl<T> Serialize for $name<T> {
-            fn serialize<S: Serializer>(&self, _: S) -> Result<S::Ok, S::Error> {
-                unreachable!();
-            }
-        }
-
-        impl<'a, T> Deserialize<'a> for $name<T> {
-            fn deserialize<D>(_: D) -> Result<$name<T>, D::Error>
-            where
-                D: Deserializer<'a>,
-            {
-                unreachable!();
-            }
-        }
-    };
-}
-
-pub struct WebGLSender<T>(crossbeam_channel::Sender<T>);
-pub struct WebGLReceiver<T>(crossbeam_channel::Receiver<T>);
-
-impl<T> Clone for WebGLSender<T> {
-    fn clone(&self) -> Self {
-        WebGLSender(self.0.clone())
-    }
-}
-
-impl<T> WebGLSender<T> {
-    #[inline]
-    pub fn send(&self, data: T) -> Result<(), crossbeam_channel::SendError<T>> {
-        self.0.send(data)
-    }
-}
-
-impl<T> WebGLReceiver<T> {
-    #[inline]
-    pub fn recv(&self) -> Result<T, crossbeam_channel::RecvError> {
-        self.0.recv()
-    }
-    #[inline]
-    pub fn try_recv(&self) -> Result<T, crossbeam_channel::TryRecvError> {
-        self.0.try_recv()
-    }
-    pub fn into_inner(self) -> crossbeam_channel::Receiver<T> {
-        self.0
-    }
-}
-
-pub fn webgl_channel<T>() -> Result<(WebGLSender<T>, WebGLReceiver<T>), ()> {
-    let (sender, receiver) = crossbeam_channel::unbounded();
-    Ok((WebGLSender(sender), WebGLReceiver(receiver)))
-}
-
-unreachable_serializable!(WebGLReceiver);
-unreachable_serializable!(WebGLSender);