Make sure to unset current context in wgl Surface::configure/present (#5087)

CHANGELOG.md

@@ -61,6 +61,12 @@ Bottom level categories:
         - `tan`
         - `tanh`
 
+### Bug Fixes
+
+#### WGL
+
+- In Surface::configure and Surface::present, fix the current GL context not being unset when releasing the lock that guards access to making the context current. This was causing other threads to panic when trying to make the context current. By @Imberflur in [#5087](https://github.com/gfx-rs/wgpu/pull/5087).
+
 ## v0.19.0 (2024-01-17)
 
 This release includes:

wgpu-hal/src/gles/egl.rs

@@ -1092,6 +1092,7 @@ impl Surface {
             .map_err(|e| {
                 log::error!("swap_buffers failed: {}", e);
                 crate::SurfaceError::Lost
+                // TODO: should we unset the current context here?
             })?;
         self.egl
             .instance

wgpu-hal/src/gles/wgl.rs

@@ -77,6 +77,24 @@ impl AdapterContext {
 
         AdapterContextLock { inner }
     }
+
+    /// Obtain a lock to the WGL context and get handle to the [`glow::Context`] that can be used to
+    /// do rendering.
+    ///
+    /// Unlike [`lock`](Self::lock), this accepts a device to pass to `make_current` and exposes the error
+    /// when `make_current` fails.
+    #[track_caller]
+    fn lock_with_dc(&self, device: HDC) -> Result<AdapterContextLock<'_>, Error> {
+        let inner = self
+            .inner
+            .try_lock_for(Duration::from_secs(CONTEXT_LOCK_TIMEOUT_SECS))
+            .expect("Could not lock adapter context. This is most-likely a deadlock.");
+
+        inner
+            .context
+            .make_current(device)
+            .map(|()| AdapterContextLock { inner })
+    }
 }
 
 /// A guard containing a lock to an [`AdapterContext`]
@@ -603,16 +621,10 @@ impl Surface {
             window: self.window,
         };
 
-        let inner = context.inner.lock();
-
-        if let Err(e) = inner.context.make_current(dc.device) {
+        let gl = context.lock_with_dc(dc.device).map_err(|e| {
             log::error!("unable to make the OpenGL context current for surface: {e}",);
-            return Err(crate::SurfaceError::Other(
-                "unable to make the OpenGL context current for surface",
-            ));
-        }
-
-        let gl = &inner.gl;
+            crate::SurfaceError::Other("unable to make the OpenGL context current for surface")
+        })?;
 
         unsafe { gl.bind_framebuffer(glow::DRAW_FRAMEBUFFER, None) };
         unsafe { gl.bind_framebuffer(glow::READ_FRAMEBUFFER, Some(sc.framebuffer)) };
@@ -693,16 +705,11 @@ impl crate::Surface<super::Api> for Surface {
         }
 
         let format_desc = device.shared.describe_texture_format(config.format);
-        let inner = &device.shared.context.inner.lock();
-
-        if let Err(e) = inner.context.make_current(dc.device) {
+        let gl = &device.shared.context.lock_with_dc(dc.device).map_err(|e| {
             log::error!("unable to make the OpenGL context current for surface: {e}",);
-            return Err(crate::SurfaceError::Other(
-                "unable to make the OpenGL context current for surface",
-            ));
-        }
+            crate::SurfaceError::Other("unable to make the OpenGL context current for surface")
+        })?;
 
-        let gl = &inner.gl;
         let renderbuffer = unsafe { gl.create_renderbuffer() }.map_err(|error| {
             log::error!("Internal swapchain renderbuffer creation failed: {error}");
             crate::DeviceError::OutOfMemory