Use lazy gl context on linux

Signed-off-by: sagudev <[email protected]>

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "rust-analyzer.cargo.features": "all"
+}

src/platform/egl/context.rs

@@ -47,6 +47,7 @@ pub struct Context {
     pub(crate) egl_context: EGLContext,
     pub(crate) id: ContextID,
     pub(crate) pbuffer: EGLSurface,
+    pub(crate) gl: LazyCell<Gl>,
     framebuffer: Framebuffer<Surface, ExternalEGLSurfaces>,
     context_is_owned: bool,
 }

src/platform/generic/egl/context.rs

@@ -14,6 +14,7 @@ use crate::surface::Framebuffer;
 use crate::{ContextAttributeFlags, ContextAttributes, ContextID, Error, GLApi, GLVersion};
 use crate::{Gl, SurfaceInfo};
 
+use std::cell::LazyCell;
 use std::ffi::CString;
 use std::mem;
 use std::os::raw::c_void;
@@ -211,7 +212,7 @@ impl EGLBackedContext {
 
     pub(crate) unsafe fn unbind_surface(
         &mut self,
-        gl: &Gl,
+        gl: &LazyCell<Gl>,
         egl_display: EGLDisplay,
     ) -> Result<Option<EGLBackedSurface>, Error> {
         match self.framebuffer {

src/platform/generic/egl/surface.rs

@@ -21,6 +21,7 @@ use crate::{ContextAttributes, ContextID, Error, SurfaceID, SurfaceInfo};
 
 use euclid::default::Size2D;
 use glow::{Framebuffer, HasContext, PixelUnpackData, Texture};
+use std::cell::LazyCell;
 use std::fmt::{self, Debug, Formatter};
 use std::marker::PhantomData;
 use std::mem;
@@ -207,7 +208,7 @@ impl EGLBackedSurface {
 
     pub(crate) fn destroy(
         &mut self,
-        gl: &Gl,
+        gl: &LazyCell<Gl>,
         egl_display: EGLDisplay,
         context_id: ContextID,
     ) -> Result<Option<*const c_void>, Error> {
@@ -315,14 +316,22 @@ impl EGLBackedSurface {
         }
     }
 
-    pub(crate) fn unbind(&self, gl: &Gl, egl_display: EGLDisplay, egl_context: EGLContext) {
+    pub(crate) fn unbind(
+        &self,
+        gl: &LazyCell<Gl>,
+        egl_display: EGLDisplay,
+        egl_context: EGLContext,
+    ) {
         // If we're current, we stay current, but with no surface attached.
         unsafe {
             EGL_FUNCTIONS.with(|egl| {
                 if egl.GetCurrentContext() != egl_context {
                     return;
                 }
 
+                // Flush to avoid races on Mesa/Intel and possibly other GPUs.
+                gl.flush();
+
                 egl.MakeCurrent(egl_display, egl::NO_SURFACE, egl::NO_SURFACE, egl_context);
 
                 match self.objects {

src/platform/unix/generic/context.rs

@@ -10,15 +10,11 @@ use crate::egl::types::EGLint;
 use crate::platform::generic::egl::context::{self, CurrentContextGuard, EGLBackedContext};
 use crate::{ContextAttributes, Error, Gl, SurfaceInfo};
 
+use std::cell::LazyCell;
 use std::os::raw::c_void;
 
 pub use crate::platform::generic::egl::context::{ContextDescriptor, NativeContext};
 
-thread_local! {
-    #[doc(hidden)]
-    pub static GL_FUNCTIONS: Gl = unsafe {Gl::from_loader_function(context::get_proc_address)};
-}
-
 /// Represents an OpenGL rendering context.
 ///
 /// A context allows you to issue rendering commands to a surface. When initially created, a
@@ -35,7 +31,7 @@ thread_local! {
 /// allow for sharing of texture data. Contexts are local to a single thread and device.
 ///
 /// A context must be explicitly destroyed with `destroy_context()`, or a panic will occur.
-pub struct Context(pub(crate) EGLBackedContext);
+pub struct Context(pub(crate) EGLBackedContext, pub(crate) LazyCell<Gl>);
 
 impl Device {
     /// Creates a context descriptor with the given attributes.
@@ -75,15 +71,17 @@ impl Device {
         descriptor: &ContextDescriptor,
         share_with: Option<&Context>,
     ) -> Result<Context, Error> {
-        unsafe {
-            EGLBackedContext::new(
-                self.native_connection.egl_display,
-                descriptor,
-                share_with.map(|ctx| &ctx.0),
-                self.gl_api(),
-            )
-            .map(Context)
-        }
+        Ok(Context(
+            unsafe {
+                EGLBackedContext::new(
+                    self.native_connection.egl_display,
+                    descriptor,
+                    share_with.map(|ctx| &ctx.0),
+                    self.gl_api(),
+                )?
+            },
+            LazyCell::new(|| unsafe { Gl::from_loader_function(context::get_proc_address) }),
+        ))
     }
 
     /// Wraps an `EGLContext` in a native context and returns it.
@@ -96,9 +94,10 @@ impl Device {
         &self,
         native_context: NativeContext,
     ) -> Result<Context, Error> {
-        Ok(Context(EGLBackedContext::from_native_context(
-            native_context,
-        )))
+        Ok(Context(
+            EGLBackedContext::from_native_context(native_context),
+            LazyCell::new(|| unsafe { Gl::from_loader_function(context::get_proc_address) }),
+        ))
     }
 
     /// Destroys a context.
@@ -213,12 +212,12 @@ impl Device {
         &self,
         context: &mut Context,
     ) -> Result<Option<Surface>, Error> {
-        GL_FUNCTIONS.with(|gl| unsafe {
+        unsafe {
             context
                 .0
-                .unbind_surface(gl, self.native_connection.egl_display)
+                .unbind_surface(&context.1, self.native_connection.egl_display)
                 .map(|maybe_surface| maybe_surface.map(Surface))
-        })
+        }
     }
 
     /// Returns a unique ID representing a context.

src/platform/unix/generic/surface.rs

@@ -2,7 +2,7 @@
 //!
 //! Wrapper for EGL surfaces on Mesa.
 
-use super::context::{Context, GL_FUNCTIONS};
+use super::context::Context;
 use super::device::Device;
 use crate::gl;
 use crate::platform::generic::egl::surface::{EGLBackedSurface, EGLSurfaceTexture};
@@ -77,16 +77,15 @@ impl Device {
         let _guard = self.temporarily_make_context_current(context)?;
         let context_descriptor = self.context_descriptor(context);
         let context_attributes = self.context_descriptor_attributes(&context_descriptor);
-        GL_FUNCTIONS.with(|gl| {
-            Ok(Surface(EGLBackedSurface::new_generic(
-                gl,
-                self.native_connection.egl_display,
-                context.0.egl_context,
-                context.0.id,
-                &context_attributes,
-                size,
-            )))
-        })
+
+        Ok(Surface(EGLBackedSurface::new_generic(
+            &context.1,
+            self.native_connection.egl_display,
+            context.0.egl_context,
+            context.0.id,
+            &context_attributes,
+            size,
+        )))
     }
 
     /// Creates a surface texture from an existing generic surface for use with the given context.
@@ -109,10 +108,10 @@ impl Device {
             Err(err) => return Err((err, surface)),
         };
 
-        GL_FUNCTIONS.with(|gl| match surface.0.to_surface_texture(gl) {
+        match surface.0.to_surface_texture(&context.1) {
             Ok(surface_texture) => Ok(SurfaceTexture(surface_texture)),
             Err((err, surface)) => Err((err, Surface(surface))),
-        })
+        }
     }
 
     /// Destroys a surface.
@@ -127,12 +126,10 @@ impl Device {
         context: &mut Context,
         surface: &mut Surface,
     ) -> Result<(), Error> {
-        GL_FUNCTIONS.with(|gl| {
-            let egl_display = self.native_connection.egl_display;
-            let window = surface.0.destroy(gl, egl_display, context.0.id)?;
-            debug_assert!(window.is_none());
-            Ok(())
-        })
+        let egl_display = self.native_connection.egl_display;
+        let window = surface.0.destroy(&context.1, egl_display, context.0.id)?;
+        debug_assert!(window.is_none());
+        Ok(())
     }
 
     /// Destroys a surface texture and returns the underlying surface.
@@ -148,7 +145,7 @@ impl Device {
         surface_texture: SurfaceTexture,
     ) -> Result<Surface, (Error, SurfaceTexture)> {
         match self.temporarily_make_context_current(context) {
-            Ok(_guard) => GL_FUNCTIONS.with(|gl| Ok(Surface(surface_texture.0.destroy(gl)))),
+            Ok(_guard) => Ok(Surface(surface_texture.0.destroy(&context.1))),
             Err(err) => Err((err, surface_texture)),
         }
     }

src/platform/unix/wayland/context.rs

@@ -12,15 +12,11 @@ use crate::egl::types::EGLint;
 use crate::platform::generic::egl::context::{self, CurrentContextGuard, EGLBackedContext};
 use crate::{ContextAttributes, Error, Gl, SurfaceInfo};
 
+use std::cell::LazyCell;
 use std::os::raw::c_void;
 
 pub use crate::platform::generic::egl::context::{ContextDescriptor, NativeContext};
 
-thread_local! {
-    #[doc(hidden)]
-    pub static GL_FUNCTIONS: Gl = unsafe {Gl::from_loader_function(context::get_proc_address)};
-}
-
 /// Represents an OpenGL rendering context.
 ///
 /// A context allows you to issue rendering commands to a surface. When initially created, a
@@ -37,7 +33,7 @@ thread_local! {
 /// allow for sharing of texture data. Contexts are local to a single thread and device.
 ///
 /// A context must be explicitly destroyed with `destroy_context()`, or a panic will occur.
-pub struct Context(pub(crate) EGLBackedContext);
+pub struct Context(pub(crate) EGLBackedContext, pub(crate) LazyCell<Gl>);
 
 impl Device {
     /// Creates a context descriptor with the given attributes.
@@ -75,15 +71,17 @@ impl Device {
         descriptor: &ContextDescriptor,
         share_with: Option<&Context>,
     ) -> Result<Context, Error> {
-        unsafe {
-            EGLBackedContext::new(
-                self.native_connection.egl_display,
-                descriptor,
-                share_with.map(|ctx| &ctx.0),
-                self.gl_api(),
-            )
-            .map(Context)
-        }
+        Ok(Context(
+            unsafe {
+                EGLBackedContext::new(
+                    self.native_connection.egl_display,
+                    descriptor,
+                    share_with.map(|ctx| &ctx.0),
+                    self.gl_api(),
+                )?
+            },
+            LazyCell::new(|| unsafe { Gl::from_loader_function(context::get_proc_address) }),
+        ))
     }
 
     /// Wraps an `EGLContext` in a native context and returns it.
@@ -96,9 +94,10 @@ impl Device {
         &self,
         native_context: NativeContext,
     ) -> Result<Context, Error> {
-        Ok(Context(EGLBackedContext::from_native_context(
-            native_context,
-        )))
+        Ok(Context(
+            EGLBackedContext::from_native_context(native_context),
+            LazyCell::new(|| unsafe { Gl::from_loader_function(context::get_proc_address) }),
+        ))
     }
 
     /// Destroys a context.
@@ -213,17 +212,12 @@ impl Device {
         &self,
         context: &mut Context,
     ) -> Result<Option<Surface>, Error> {
-        GL_FUNCTIONS.with(|gl| {
-            unsafe {
-                // Flush to avoid races on Mesa/Intel and possibly other GPUs.
-                gl.flush();
-
-                context
-                    .0
-                    .unbind_surface(gl, self.native_connection.egl_display)
-                    .map(|maybe_surface| maybe_surface.map(Surface))
-            }
-        })
+        unsafe {
+            context
+                .0
+                .unbind_surface(&context.1, self.native_connection.egl_display)
+                .map(|maybe_surface| maybe_surface.map(Surface))
+        }
     }
 
     /// Returns a unique ID representing a context.