From dbb97f0534b40a77e9d9883774aed209c9e49257 Mon Sep 17 00:00:00 2001
From: Robbert van der Helm <mail@robbertvanderhelm.nl>
Date: Sun, 23 Oct 2022 15:52:14 +0200
Subject: [PATCH] Use channels for Windows event loop

Instead of an `ArrayQueue`. Since this doesn't need to both send and
receive on the same object.
---
 src/event_loop/linux.rs   | 18 ++++++++----------
 src/event_loop/windows.rs | 14 ++++++--------
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/src/event_loop/linux.rs b/src/event_loop/linux.rs
index d5e0c713..d5288b3d 100644
--- a/src/event_loop/linux.rs
+++ b/src/event_loop/linux.rs
@@ -31,7 +31,7 @@ pub(crate) struct LinuxEventLoop<T, E> {
     worker_thread: Option<JoinHandle<()>>,
     /// A channel for waking up the worker thread and having it perform one of the tasks from
     /// [`Message`].
-    worker_thread_channel: channel::Sender<Message<T>>,
+    tasks_sender: channel::Sender<Message<T>>,
 }
 
 /// A message for communicating with the worker thread.
@@ -48,7 +48,7 @@ where
     E: MainThreadExecutor<T> + 'static,
 {
     fn new_and_spawn(executor: Arc<E>) -> Self {
-        let (sender, receiver) = channel::bounded(super::TASK_QUEUE_CAPACITY);
+        let (tasks_sender, tasks_receiver) = channel::bounded(super::TASK_QUEUE_CAPACITY);
 
         Self {
             executor: executor.clone(),
@@ -57,10 +57,10 @@ where
             worker_thread: Some(
                 thread::Builder::new()
                     .name(String::from("worker"))
-                    .spawn(move || worker_thread(receiver, Arc::downgrade(&executor)))
+                    .spawn(move || worker_thread(tasks_receiver, Arc::downgrade(&executor)))
                     .expect("Could not spawn worker thread"),
             ),
-            worker_thread_channel: sender,
+            tasks_sender,
         }
     }
 
@@ -69,9 +69,7 @@ where
             self.executor.execute(task, true);
             true
         } else {
-            self.worker_thread_channel
-                .try_send(Message::Task(task))
-                .is_ok()
+            self.tasks_sender.try_send(Message::Task(task)).is_ok()
         }
     }
 
@@ -84,7 +82,7 @@ where
 
 impl<T, E> Drop for LinuxEventLoop<T, E> {
     fn drop(&mut self) {
-        self.worker_thread_channel
+        self.tasks_sender
             .send(Message::Shutdown)
             .expect("Failed while sending worker thread shutdown request");
         if let Some(join_handle) = self.worker_thread.take() {
@@ -95,13 +93,13 @@ impl<T, E> Drop for LinuxEventLoop<T, E> {
 
 /// The worker thread used in [`EventLoop`] that executes incoming tasks on the event loop's
 /// executor.
-fn worker_thread<T, E>(receiver: channel::Receiver<Message<T>>, executor: Weak<E>)
+fn worker_thread<T, E>(tasks_receiver: channel::Receiver<Message<T>>, executor: Weak<E>)
 where
     T: Send,
     E: MainThreadExecutor<T>,
 {
     loop {
-        match receiver.recv() {
+        match tasks_receiver.recv() {
             Ok(Message::Task(task)) => match executor.upgrade() {
                 Some(e) => e.execute(task, true),
                 None => {
diff --git a/src/event_loop/windows.rs b/src/event_loop/windows.rs
index 55a136ac..4f024813 100644
--- a/src/event_loop/windows.rs
+++ b/src/event_loop/windows.rs
@@ -1,7 +1,7 @@
 //! An event loop for windows, using an invisible window to hook into the host's message loop. This
 //! has only been tested under Wine with [yabridge](https://github.com/robbert-vdh/yabridge).
 
-use crossbeam::queue::ArrayQueue;
+use crossbeam::channel;
 use std::ffi::{c_void, CString};
 use std::mem;
 use std::ptr;
@@ -51,7 +51,7 @@ pub(crate) struct WindowsEventLoop<T, E> {
     /// A queue of tasks that still need to be performed. When something gets added to this queue
     /// we'll wake up the window, which then continues to pop tasks off this queue until it is
     /// empty.
-    tasks: Arc<ArrayQueue<T>>,
+    tasks_sender: channel::Sender<T>,
 }
 
 impl<T, E> EventLoop<T, E> for WindowsEventLoop<T, E>
@@ -60,8 +60,7 @@ where
     E: MainThreadExecutor<T> + 'static,
 {
     fn new_and_spawn(executor: Arc<E>) -> Self {
-        // We'll pass one copy of the this to the window, and we'll keep the other copy here
-        let tasks = Arc::new(ArrayQueue::new(super::TASK_QUEUE_CAPACITY));
+        let (tasks_sender, tasks_receiver) = channel::bounded(super::TASK_QUEUE_CAPACITY);
 
         // Window classes need to have unique names or else multiple plugins loaded into the same
         // process will end up calling the other plugin's callbacks
@@ -85,7 +84,6 @@ where
         // erased version of the polling loop.
         let callback: PollCallback = {
             let executor = Arc::downgrade(&executor);
-            let tasks = tasks.clone();
 
             Box::new(move || {
                 let executor = match executor.upgrade() {
@@ -96,7 +94,7 @@ where
                     }
                 };
 
-                while let Some(task) = tasks.pop() {
+                while let Ok(task) = tasks_receiver.try_recv() {
                     executor.execute(task, true);
                 }
             })
@@ -128,7 +126,7 @@ where
             main_thread_id: thread::current().id(),
             message_window: window,
             message_window_class_name: class_name,
-            tasks,
+            tasks_sender,
         }
     }
 
@@ -137,7 +135,7 @@ where
             self.executor.execute(task, true);
             true
         } else {
-            let success = self.tasks.push(task).is_ok();
+            let success = self.tasks_sender.try_send(task).is_ok();
             if success {
                 // Instead of polling on a timer, we can just wake up the window whenever there's a
                 // new message.