Worker is used by display driver code to execute OpenGL calls.

Typically display driver code creates a gl.Context for an application, and along with it establishes a locked OS thread to execute the cgo calls:

go func() {
	// ... platform-specific cgo call to bind a C OpenGL context
	// into thread-local storage.

	glctx, worker := gl.NewContext()
	workAvailable := worker.WorkAvailable()
	go userAppCode(glctx)
	for {
		select {
		case <-workAvailable:
		case <-drawEvent:
			// ... platform-specific cgo call to draw screen

This interface is an internal implementation detail and should only be used by the package responsible for managing the screen, such as

Worker is referenced in 6 repositories