Files
gio/app/gl_macos.go
Elias Naur 8d8aeef66b app,gpu,internal/egl: lock OS thread when making OpenGL context current
OpenGL stores the current context in thread-local memory, but commit
4f5baa9a51 removed a runtime.LockOSThread from app.Window that ensured
the goroutine that drives the context stays on the operating thread that
has the context current. This change restores the thread lock.

As a bonus, this change makes the OpenGL contexts responsible for locking
the thread at MakeCurrent, thereby removing LockOSThread calls from GPU
backend-agnostic code.

Fixes: https://todo.sr.ht/~eliasnaur/gio/334
Signed-off-by: Elias Naur <mail@eliasnaur.com>
2022-01-05 11:49:29 +01:00

122 lines
2.8 KiB
Go

// SPDX-License-Identifier: Unlicense OR MIT
//go:build darwin && !ios && nometal
// +build darwin,!ios,nometal
package app
import (
"errors"
"runtime"
"unsafe"
"gioui.org/gpu"
"gioui.org/internal/gl"
)
/*
#include <CoreFoundation/CoreFoundation.h>
#include <CoreGraphics/CoreGraphics.h>
#include <AppKit/AppKit.h>
#include <dlfcn.h>
__attribute__ ((visibility ("hidden"))) CFTypeRef gio_createGLContext(void);
__attribute__ ((visibility ("hidden"))) void gio_setContextView(CFTypeRef ctx, CFTypeRef view);
__attribute__ ((visibility ("hidden"))) void gio_makeCurrentContext(CFTypeRef ctx);
__attribute__ ((visibility ("hidden"))) void gio_updateContext(CFTypeRef ctx);
__attribute__ ((visibility ("hidden"))) void gio_flushContextBuffer(CFTypeRef ctx);
__attribute__ ((visibility ("hidden"))) void gio_clearCurrentContext(void);
__attribute__ ((visibility ("hidden"))) void gio_lockContext(CFTypeRef ctxRef);
__attribute__ ((visibility ("hidden"))) void gio_unlockContext(CFTypeRef ctxRef);
typedef void (*PFN_glFlush)(void);
static void glFlush(PFN_glFlush f) {
f();
}
*/
import "C"
type glContext struct {
c *gl.Functions
ctx C.CFTypeRef
view C.CFTypeRef
glFlush C.PFN_glFlush
}
func newContext(w *window) (*glContext, error) {
clib := C.CString("/System/Library/Frameworks/OpenGL.framework/OpenGL")
defer C.free(unsafe.Pointer(clib))
lib, err := C.dlopen(clib, C.RTLD_NOW|C.RTLD_LOCAL)
if err != nil {
return nil, err
}
csym := C.CString("glFlush")
defer C.free(unsafe.Pointer(csym))
glFlush := C.PFN_glFlush(C.dlsym(lib, csym))
if glFlush == nil {
return nil, errors.New("gl: missing symbol glFlush in the OpenGL framework")
}
view := w.contextView()
ctx := C.gio_createGLContext()
if ctx == 0 {
return nil, errors.New("gl: failed to create NSOpenGLContext")
}
C.gio_setContextView(ctx, view)
c := &glContext{
ctx: ctx,
view: view,
glFlush: glFlush,
}
return c, nil
}
func (c *glContext) RenderTarget() (gpu.RenderTarget, error) {
return gpu.OpenGLRenderTarget{}, nil
}
func (c *glContext) API() gpu.API {
return gpu.OpenGL{}
}
func (c *glContext) Release() {
if c.ctx != 0 {
C.gio_clearCurrentContext()
C.CFRelease(c.ctx)
c.ctx = 0
}
}
func (c *glContext) Present() error {
// Assume the caller already locked the context.
C.glFlush(c.glFlush)
return nil
}
func (c *glContext) Lock() error {
// OpenGL contexts are implicit and thread-local. Lock the OS thread.
runtime.LockOSThread()
C.gio_lockContext(c.ctx)
C.gio_makeCurrentContext(c.ctx)
return nil
}
func (c *glContext) Unlock() {
C.gio_clearCurrentContext()
C.gio_unlockContext(c.ctx)
}
func (c *glContext) Refresh() error {
c.Lock()
defer c.Unlock()
C.gio_updateContext(c.ctx)
return nil
}
func (w *window) NewContext() (context, error) {
return newContext(w)
}