Adapter and Instance as_hal functions (#2663)

These functions are added to allow lower level access to adapter and instance from backends.

wgpu-core/src/hub.rs

@@ -907,6 +907,17 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         }
     }
 
+    /// # Safety
+    ///
+    /// - The raw handle obtained from the hal Instance must not be manually destroyed
+    pub unsafe fn instance_as_hal<A: HalApi, F: FnOnce(Option<&A::Instance>) -> R, R>(
+        &self,
+        hal_instance_callback: F,
+    ) -> R {
+        let hal_instance = A::instance_as_hal(&self.instance);
+        hal_instance_callback(hal_instance)
+    }
+
     pub fn clear_backend<A: HalApi>(&self, _dummy: ()) {
         let mut surface_guard = self.surfaces.data.write();
         let hub = A::hub(self);
@@ -991,6 +1002,7 @@ impl<G: GlobalIdentityHandlerFactory> Drop for Global<G> {
 pub trait HalApi: hal::Api {
     const VARIANT: Backend;
     fn create_instance_from_hal(name: &str, hal_instance: Self::Instance) -> Instance;
+    fn instance_as_hal(instance: &Instance) -> Option<&Self::Instance>;
     fn hub<G: GlobalIdentityHandlerFactory>(global: &Global<G>) -> &Hub<Self, G>;
     fn get_surface(surface: &Surface) -> &HalSurface<Self>;
     fn get_surface_mut(surface: &mut Surface) -> &mut HalSurface<Self>;
@@ -1006,6 +1018,9 @@ impl HalApi for hal::api::Vulkan {
             ..Default::default()
         }
     }
+    fn instance_as_hal(instance: &Instance) -> Option<&Self::Instance> {
+        instance.vulkan.as_ref()
+    }
     fn hub<G: GlobalIdentityHandlerFactory>(global: &Global<G>) -> &Hub<Self, G> {
         &global.hubs.vulkan
     }
@@ -1027,6 +1042,9 @@ impl HalApi for hal::api::Metal {
             ..Default::default()
         }
     }
+    fn instance_as_hal(instance: &Instance) -> Option<&Self::Instance> {
+        instance.metal.as_ref()
+    }
     fn hub<G: GlobalIdentityHandlerFactory>(global: &Global<G>) -> &Hub<Self, G> {
         &global.hubs.metal
     }
@@ -1048,6 +1066,9 @@ impl HalApi for hal::api::Dx12 {
             ..Default::default()
         }
     }
+    fn instance_as_hal(instance: &Instance) -> Option<&Self::Instance> {
+        instance.dx12.as_ref()
+    }
     fn hub<G: GlobalIdentityHandlerFactory>(global: &Global<G>) -> &Hub<Self, G> {
         &global.hubs.dx12
     }
@@ -1069,6 +1090,9 @@ impl HalApi for hal::api::Dx11 {
             ..Default::default()
         }
     }
+    fn instance_as_hal(instance: &Instance) -> Option<&Self::Instance> {
+        instance.dx11.as_ref()
+    }
     fn hub<G: GlobalIdentityHandlerFactory>(global: &Global<G>) -> &Hub<Self, G> {
         &global.hubs.dx11
     }
@@ -1091,6 +1115,9 @@ impl HalApi for hal::api::Gles {
             ..Default::default()
         }
     }
+    fn instance_as_hal(instance: &Instance) -> Option<&Self::Instance> {
+        instance.gl.as_ref()
+    }
     fn hub<G: GlobalIdentityHandlerFactory>(global: &Global<G>) -> &Hub<Self, G> {
         &global.hubs.gl
     }

wgpu-core/src/resource.rs

@@ -1,7 +1,7 @@
 use crate::{
     device::{DeviceError, HostMap, MissingFeatures},
     hub::{Global, GlobalIdentityHandlerFactory, HalApi, Resource, Token},
-    id::{DeviceId, SurfaceId, TextureId, Valid},
+    id::{AdapterId, DeviceId, SurfaceId, TextureId, Valid},
     init_tracker::{BufferInitTracker, TextureInitTracker},
     track::{TextureSelector, DUMMY_SELECTOR},
     validation::MissingBufferUsageError,
@@ -250,6 +250,26 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         hal_texture_callback(hal_texture);
     }
 
+    /// # Safety
+    ///
+    /// - The raw adapter handle must not be manually destroyed
+    pub unsafe fn adapter_as_hal<A: HalApi, F: FnOnce(Option<&A::Adapter>) -> R, R>(
+        &self,
+        id: AdapterId,
+        hal_adapter_callback: F,
+    ) -> R {
+        profiling::scope!("as_hal", "Adapter");
+
+        let hub = A::hub(self);
+        let mut token = Token::root();
+
+        let (guard, _) = hub.adapters.read(&mut token);
+        let adapter = guard.get(id).ok();
+        let hal_adapter = adapter.map(|adapter| &adapter.raw.adapter);
+
+        hal_adapter_callback(hal_adapter)
+    }
+
     /// # Safety
     ///
     /// - The raw device handle must not be manually destroyed

wgpu/src/backend/direct.rs

@@ -47,6 +47,14 @@ impl Context {
         ))
     }
 
+    #[cfg(any(not(target_arch = "wasm32"), feature = "webgl2"))]
+    pub unsafe fn instance_as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Instance>) -> R, R>(
+        &self,
+        hal_instance_callback: F,
+    ) -> R {
+        self.0.instance_as_hal::<A, F, R>(hal_instance_callback)
+    }
+
     pub(crate) fn global(&self) -> &wgc::hub::Global<wgc::hub::IdentityManagerFactory> {
         &self.0
     }
@@ -67,6 +75,16 @@ impl Context {
         self.0.create_adapter_from_hal(hal_adapter, PhantomData)
     }
 
+    #[cfg(any(not(target_arch = "wasm32"), feature = "webgl2"))]
+    pub unsafe fn adapter_as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Adapter>) -> R, R>(
+        &self,
+        adapter: wgc::id::AdapterId,
+        hal_adapter_callback: F,
+    ) -> R {
+        self.0
+            .adapter_as_hal::<A, F, R>(adapter, hal_adapter_callback)
+    }
+
     #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
     pub unsafe fn create_device_from_hal<A: wgc::hub::HalApi>(
         &self,

wgpu/src/lib.rs

@@ -1632,6 +1632,21 @@ impl Instance {
         }
     }
 
+    /// Returns the inner hal Instance using a callback. The hal instance will be `None` if the
+    /// backend type argument does not match with this wgpu Instance
+    ///
+    /// # Safety
+    ///
+    /// - The raw handle obtained from the hal Instance must not be manually destroyed
+    #[cfg(any(not(target_arch = "wasm32"), feature = "webgl2"))]
+    pub unsafe fn as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Instance>) -> R, R>(
+        &self,
+        hal_instance_callback: F,
+    ) -> R {
+        self.context
+            .instance_as_hal::<A, F, R>(hal_instance_callback)
+    }
+
     /// Retrieves all available [`Adapter`]s that match the given [`Backends`].
     ///
     /// # Arguments
@@ -1848,6 +1863,21 @@ impl Adapter {
             })
     }
 
+    /// Returns the inner hal Adapter using a callback. The hal adapter will be `None` if the
+    /// backend type argument does not match with this wgpu Adapter
+    ///
+    /// # Safety
+    ///
+    /// - The raw handle obtained from the hal Adapter must not be manually destroyed
+    #[cfg(any(not(target_arch = "wasm32"), feature = "webgl2"))]
+    pub unsafe fn as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Adapter>) -> R, R>(
+        &self,
+        hal_adapter_callback: F,
+    ) -> R {
+        self.context
+            .adapter_as_hal::<A, F, R>(self.id, hal_adapter_callback)
+    }
+
     /// Returns whether this adapter may present to the passed surface.
     pub fn is_surface_supported(&self, surface: &Surface) -> bool {
         Context::adapter_is_surface_supported(&*self.context, &self.id, &surface.id)