examples/winit_multithread: Make thread persistent again

examples/winit_multithread.rs

@@ -19,17 +19,16 @@ mod ex {
 
  fn render_thread(
  window: Arc<Window>,
- surface: Arc<Mutex<Surface>>,
- do_render: mpsc::Receiver<()>,
+ do_render: mpsc::Receiver<Arc<Mutex<Surface>>>,
  done: mpsc::Sender<()>,
  ) {
  loop {
  println!("waiting for render...");
- if do_render.recv().is_err() {
- println!("Main thread destroyed");
+ let Ok(surface) = do_render.recv() else {
+ println!("main thread destroyed");
  // The surface state returned from init_surface below is destroyed.
  break;
- }
+ };
 
  // Perform the rendering.
  let mut surface = surface.lock().unwrap();
@@ -74,15 +73,6 @@ mod ex {
 
  let context = softbuffer::Context::new(window.clone()).unwrap();
 
- (window, context)
- },
- |_elwt, (window, context)| {
- let surface = {
- println!("making surface...");
- let surface = softbuffer::Surface::new(context, window.clone()).unwrap();
- Arc::new(Mutex::new(surface))
- };
-
  // Spawn a thread to handle rendering for this specific surface. The channels will
  // be closed and the thread will be stopped whenever this surface (the returned
  // context below) is dropped, so that it can all be recreated again (on Android)
@@ -92,28 +82,33 @@ mod ex {
  println!("starting thread...");
  std::thread::spawn({
  let window = window.clone();
- let surface = surface.clone();
- move || render_thread(window, surface, do_render, render_done)
+ move || render_thread(window, do_render, render_done)
  });
 
- (surface, start_render, finish_render)
+ (window, context, start_render, finish_render)
+ },
+ |_elwt, (window, context, start_render, finish_render)| {
+ println!("making surface...");
+ Arc::new(Mutex::new(
+ softbuffer::Surface::new(context, window.clone()).unwrap(),
+ ))
  },
  )
  .with_event_handler(|state, surface, event, elwt| {
- let (window, _context) = state;
+ let (window, _context, start_render, finish_render) = state;
  elwt.set_control_flow(ControlFlow::Wait);
 
  match event {
  Event::WindowEvent {
  window_id,
  event: WindowEvent::RedrawRequested,
  } if window_id == window.id() => {
- let Some((_surface, start_render, finish_render)) = surface else {
+ let Some(surface) = surface else {
  eprintln!("RedrawRequested fired before Resumed or after Suspended");
  return;
  };
  // Start the render and then finish it.
- start_render.send(()).unwrap();
+ start_render.send(surface.clone()).unwrap();
  finish_render.recv().unwrap();
  }
  Event::WindowEvent {