From 7a050f09b237a2dff1ca303df288a14c8cfede48 Mon Sep 17 00:00:00 2001
From: xiaopengli89 <x.friday@outlook.com>
Date: Thu, 5 May 2022 14:58:22 +0800
Subject: [PATCH] Return `queue_empty` for Device::poll

---
 deno_webgpu/src/buffer.rs   | 2 +-
 wgpu-core/src/device/mod.rs | 8 +++++---
 wgpu/src/backend/direct.rs  | 6 +++---
 wgpu/src/backend/web.rs     | 3 ++-
 wgpu/src/lib.rs             | 8 +++++---
 5 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/deno_webgpu/src/buffer.rs b/deno_webgpu/src/buffer.rs
index 845f218372f..45eab483d15 100644
--- a/deno_webgpu/src/buffer.rs
+++ b/deno_webgpu/src/buffer.rs
@@ -128,7 +128,7 @@ pub async fn op_webgpu_buffer_get_map_async(
             {
                 let state = state.borrow();
                 let instance = state.borrow::<super::Instance>();
-                gfx_select!(device => instance.device_poll(device, false)).unwrap()
+                gfx_select!(device => instance.device_poll(device, false)).unwrap();
             }
             tokio::time::sleep(Duration::from_millis(10)).await;
         }
diff --git a/wgpu-core/src/device/mod.rs b/wgpu-core/src/device/mod.rs
index 760de1195c6..9d014c39c9d 100644
--- a/wgpu-core/src/device/mod.rs
+++ b/wgpu-core/src/device/mod.rs
@@ -4949,12 +4949,14 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
     }
 
     /// Check `device_id` for freeable resources and completed buffer mappings.
+    ///
+    /// Return `queue_empty` indicating whether there are more queue submissions still in flight.
     pub fn device_poll<A: HalApi>(
         &self,
         device_id: id::DeviceId,
         force_wait: bool,
-    ) -> Result<(), WaitIdleError> {
-        let (closures, _) = {
+    ) -> Result<bool, WaitIdleError> {
+        let (closures, queue_empty) = {
             let hub = A::hub(self);
             let mut token = Token::root();
             let (device_guard, mut token) = hub.devices.read(&mut token);
@@ -4966,7 +4968,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         unsafe {
             closures.fire();
         }
-        Ok(())
+        Ok(queue_empty)
     }
 
     /// Poll all devices belonging to the backend `A`.
diff --git a/wgpu/src/backend/direct.rs b/wgpu/src/backend/direct.rs
index 753b08d9424..62014032f1c 100644
--- a/wgpu/src/backend/direct.rs
+++ b/wgpu/src/backend/direct.rs
@@ -1554,7 +1554,7 @@ impl crate::Context for Context {
         #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
         {
             match wgc::gfx_select!(device.id => global.device_poll(device.id, true)) {
-                Ok(()) => (),
+                Ok(_) => (),
                 Err(err) => self.handle_error_fatal(err, "Device::drop"),
             }
         }
@@ -1562,7 +1562,7 @@ impl crate::Context for Context {
         wgc::gfx_select!(device.id => global.device_drop(device.id));
     }
 
-    fn device_poll(&self, device: &Self::DeviceId, maintain: crate::Maintain) {
+    fn device_poll(&self, device: &Self::DeviceId, maintain: crate::Maintain) -> bool {
         let global = &self.0;
         match wgc::gfx_select!(device.id => global.device_poll(
             device.id,
@@ -1571,7 +1571,7 @@ impl crate::Context for Context {
                 crate::Maintain::Wait => true,
             }
         )) {
-            Ok(()) => (),
+            Ok(queue_empty) => queue_empty,
             Err(err) => self.handle_error_fatal(err, "Device::poll"),
         }
     }
diff --git a/wgpu/src/backend/web.rs b/wgpu/src/backend/web.rs
index d45d491f411..6e766b06a79 100644
--- a/wgpu/src/backend/web.rs
+++ b/wgpu/src/backend/web.rs
@@ -1691,8 +1691,9 @@ impl crate::Context for Context {
         // Device is dropped automatically
     }
 
-    fn device_poll(&self, _device: &Self::DeviceId, _maintain: crate::Maintain) {
+    fn device_poll(&self, _device: &Self::DeviceId, _maintain: crate::Maintain) -> bool {
         // Device is polled automatically
+        true
     }
 
     fn device_on_uncaptured_error(
diff --git a/wgpu/src/lib.rs b/wgpu/src/lib.rs
index afe3e7ac8ab..1463e179611 100644
--- a/wgpu/src/lib.rs
+++ b/wgpu/src/lib.rs
@@ -322,7 +322,7 @@ trait Context: Debug + Send + Sized + Sync {
         desc: &RenderBundleEncoderDescriptor,
     ) -> Self::RenderBundleEncoderId;
     fn device_drop(&self, device: &Self::DeviceId);
-    fn device_poll(&self, device: &Self::DeviceId, maintain: Maintain);
+    fn device_poll(&self, device: &Self::DeviceId, maintain: Maintain) -> bool;
     fn device_on_uncaptured_error(
         &self,
         device: &Self::DeviceId,
@@ -1687,9 +1687,11 @@ impl Adapter {
 impl Device {
     /// Check for resource cleanups and mapping callbacks.
     ///
+    /// Return `queue_empty` indicating whether there are more queue submissions still in flight.
+    ///
     /// no-op on the web, device is automatically polled.
-    pub fn poll(&self, maintain: Maintain) {
-        Context::device_poll(&*self.context, &self.id, maintain);
+    pub fn poll(&self, maintain: Maintain) -> bool {
+        Context::device_poll(&*self.context, &self.id, maintain)
     }
 
     /// List all features that may be used with this device.