[wgpu-hal] replace Instance.destroy_surface() with Drop impls on Surfaces

Only the metal and vulkan backends require
destruction code and it can go in a `Drop` impl since
the `Instance` is unused in those implementations.

wgpu-core/src/global.rs

@@ -1,5 +1,3 @@
-use std::sync::Arc;
-
 use wgt::Backend;
 
 use crate::{
@@ -8,7 +6,6 @@ use crate::{
     instance::{Instance, Surface},
     registry::{Registry, RegistryReport},
     resource_log,
-    storage::Element,
 };
 
 #[derive(Debug, PartialEq, Eq)]
@@ -152,14 +149,7 @@ impl Drop for Global {
             self.hubs.gl.clear(&surfaces_locked, true);
         }
 
-        // destroy surfaces
-        for element in surfaces_locked.map.drain(..) {
-            if let Element::Occupied(arc_surface, _) = element {
-                let surface = Arc::into_inner(arc_surface)
-                    .expect("Surface cannot be destroyed because is still in use");
-                self.instance.destroy_surface(surface);
-            }
-        }
+        surfaces_locked.map.clear();
     }
 }
 

wgpu-core/src/hub.rs

@@ -248,7 +248,6 @@ impl<A: HalApi> Hub<A> {
                         let suf = A::surface_as_hal(surface);
                         unsafe {
                             suf.unwrap().unconfigure(device.raw());
-                            //TODO: we could destroy the surface here
                         }
                     }
                 }

wgpu-core/src/instance.rs

@@ -112,24 +112,6 @@ impl Instance {
             flags: instance_desc.flags,
         }
     }
-
-    pub(crate) fn destroy_surface(&self, surface: Surface) {
-        fn destroy<A: HalApi>(instance: &Option<A::Instance>, mut surface: Option<HalSurface<A>>) {
-            if let Some(surface) = surface.take() {
-                unsafe {
-                    instance.as_ref().unwrap().destroy_surface(surface);
-                }
-            }
-        }
-        #[cfg(vulkan)]
-        destroy::<hal::api::Vulkan>(&self.vulkan, surface.vulkan);
-        #[cfg(metal)]
-        destroy::<hal::api::Metal>(&self.metal, surface.metal);
-        #[cfg(dx12)]
-        destroy::<hal::api::Dx12>(&self.dx12, surface.dx12);
-        #[cfg(gles)]
-        destroy::<hal::api::Gles>(&self.gl, surface.gl);
-    }
 }
 
 pub struct Surface {
@@ -707,7 +689,7 @@ impl Global {
             #[cfg(gles)]
             unconfigure::<hal::api::Gles>(self, &surface.gl, &present);
         }
-        self.instance.destroy_surface(surface);
+        drop(surface)
     }
 
     fn enumerate<A: HalApi>(

wgpu-hal/examples/halmark/main.rs

@@ -578,7 +578,7 @@ impl<A: hal::Api> Example<A> {
 
             self.surface.unconfigure(&self.device);
             self.device.exit(self.queue);
-            self.instance.destroy_surface(self.surface);
+            drop(self.surface);
             drop(self.adapter);
         }
     }

wgpu-hal/examples/ray-traced-triangle/main.rs

@@ -1039,7 +1039,7 @@ impl<A: hal::Api> Example<A> {
 
             self.surface.unconfigure(&self.device);
             self.device.exit(self.queue);
-            self.instance.destroy_surface(self.surface);
+            drop(self.surface);
             drop(self.adapter);
         }
     }

wgpu-hal/src/dx12/instance.rs

@@ -143,9 +143,6 @@ impl crate::Instance for super::Instance {
             ))),
         }
     }
-    unsafe fn destroy_surface(&self, _surface: super::Surface) {
-        // just drop
-    }
 
     unsafe fn enumerate_adapters(
         &self,

wgpu-hal/src/empty.rs

@@ -53,7 +53,6 @@ impl crate::Instance for Context {
     ) -> Result<Context, crate::InstanceError> {
         Ok(Context)
     }
-    unsafe fn destroy_surface(&self, surface: Context) {}
     unsafe fn enumerate_adapters(
         &self,
         _surface_hint: Option<&Context>,

wgpu-hal/src/gles/egl.rs

@@ -1002,8 +1002,6 @@ impl crate::Instance for Instance {
         })
     }
 
-    unsafe fn destroy_surface(&self, _surface: Surface) {}
-
     unsafe fn enumerate_adapters(
         &self,
         _surface_hint: Option<&Surface>,

wgpu-hal/src/gles/web.rs

@@ -171,8 +171,6 @@ impl crate::Instance for Instance {
 
         self.create_surface_from_canvas(canvas)
     }
-
-    unsafe fn destroy_surface(&self, _surface: Surface) {}
 }
 
 #[derive(Debug)]

wgpu-hal/src/gles/wgl.rs

@@ -535,7 +535,6 @@ impl crate::Instance for Instance {
             srgb_capable: self.srgb_capable,
         })
     }
-    unsafe fn destroy_surface(&self, _surface: Surface) {}
 
     unsafe fn enumerate_adapters(
         &self,

wgpu-hal/src/lib.rs

@@ -443,7 +443,6 @@ pub trait Instance: Sized + WasmNotSendSync {
         display_handle: raw_window_handle::RawDisplayHandle,
         window_handle: raw_window_handle::RawWindowHandle,
     ) -> Result<<Self::A as Api>::Surface, InstanceError>;
-    unsafe fn destroy_surface(&self, surface: <Self::A as Api>::Surface);
     /// `surface_hint` is only used by the GLES backend targeting WebGL2
     unsafe fn enumerate_adapters(
         &self,

wgpu-hal/src/metal/mod.rs

@@ -117,10 +117,6 @@ impl crate::Instance for Instance {
         }
     }
 
-    unsafe fn destroy_surface(&self, surface: Surface) {
-        unsafe { surface.dispose() };
-    }
-
     unsafe fn enumerate_adapters(
         &self,
         _surface_hint: Option<&Surface>,

wgpu-hal/src/metal/surface.rs

@@ -70,12 +70,6 @@ impl super::Surface {
         }
     }
 
-    pub unsafe fn dispose(self) {
-        if let Some(view) = self.view {
-            let () = msg_send![view.as_ptr(), release];
-        }
-    }
-
     /// If not called on the main thread, this will panic.
     #[allow(clippy::transmute_ptr_to_ref)]
     pub unsafe fn from_view(
@@ -178,6 +172,16 @@ impl super::Surface {
     }
 }
 
+impl Drop for super::Surface {
+    fn drop(&mut self) {
+        if let Some(view) = self.view {
+            unsafe {
+                let () = msg_send![view.as_ptr(), release];
+            }
+        }
+    }
+}
+
 impl crate::Surface for super::Surface {
     type A = super::Api;
 

wgpu-hal/src/vulkan/instance.rs

@@ -880,10 +880,6 @@ impl crate::Instance for super::Instance {
         }
     }
 
-    unsafe fn destroy_surface(&self, surface: super::Surface) {
-        unsafe { surface.functor.destroy_surface(surface.raw, None) };
-    }
-
     unsafe fn enumerate_adapters(
         &self,
         _surface_hint: Option<&super::Surface>,
@@ -942,6 +938,12 @@ impl crate::Instance for super::Instance {
     }
 }
 
+impl Drop for super::Surface {
+    fn drop(&mut self) {
+        unsafe { self.functor.destroy_surface(self.raw, None) };
+    }
+}
+
 impl crate::Surface for super::Surface {
     type A = super::Api;