3 files changed, 226 insertions, 0 deletions
diff --git a/components/shared/canvas/webgl_channel/ipc.rs b/components/shared/canvas/webgl_channel/ipc.rs
new file mode 100644
index 00000000000..be320a69624
--- /dev/null
+++ b/components/shared/canvas/webgl_channel/ipc.rs
@@ -0,0 +1,15 @@
+/* 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()
+}
diff --git a/components/shared/canvas/webgl_channel/mod.rs b/components/shared/canvas/webgl_channel/mod.rs
new file mode 100644
index 00000000000..edfb90c8806
--- /dev/null
+++ b/components/shared/canvas/webgl_channel/mod.rs
@@ -0,0 +1,149 @@
+/* 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(|_| ()),
+            WebGLSender::Mpsc(ref sender) => sender.send(msg).map_err(|_| ()),
+        }
+    }
+}
+
+pub type WebGLSendResult = Result<(), ()>;
+
+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) -> Result<T, ()> {
+        match *self {
+            WebGLReceiver::Ipc(ref receiver) => receiver.recv().map_err(|_| ()),
+            WebGLReceiver::Mpsc(ref receiver) => receiver.recv().map_err(|_| ()),
+        }
+    }
+
+    pub fn try_recv(&self) -> Result<T, ()> {
+        match *self {
+            WebGLReceiver::Ipc(ref receiver) => receiver.try_recv().map_err(|_| ()),
+            WebGLReceiver::Mpsc(ref receiver) => receiver.try_recv().map_err(|_| ()),
+        }
+    }
+
+    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>() -> Result<(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)))
+            .map_err(|_| ())
+    } else {
+        mpsc::webgl_channel().map(|(tx, rx)| (WebGLSender::Mpsc(tx), WebGLReceiver::Mpsc(rx)))
+    }
+}
+
+#[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()
+    }
+}
diff --git a/components/shared/canvas/webgl_channel/mpsc.rs b/components/shared/canvas/webgl_channel/mpsc.rs
new file mode 100644
index 00000000000..b7d0bfcc3da
--- /dev/null
+++ b/components/shared/canvas/webgl_channel/mpsc.rs
@@ -0,0 +1,62 @@
+/* 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);