android - SceneRenderer中的Kotlin内联函数

Question

如果在渲染循环中使用内联函数，会不会有性能优势？

class SceneRenderer(val f: () -> Unit): GLSurfaceView.Renderer {
  override fun onSurfaceCreated(glUnused: GL10, config: EGLConfig) { ... }

  override fun onSurfaceChanged(glUnused: GL10, width: Int, height: Int) { ... }

  override fun onDrawFrame(glUnused: GL10) {
    ...
    inlineFun(f)
    ...
  }

  private inline fun inlineFun(f: () -> Unit) {
    f.invoke()
  }
}

还是使用直接函数调用就足够了？

override fun onDrawFrame(glUnused: GL10) {
  ...
  f.invoke()
  ...
}

提前致谢!

Answer 1

TL; DR

Or is it enough to use a direct function call?

是的。

排队

Kotlinlang:

Using higher-order functions imposes certain runtime penalties: each function is an object, and it captures a closure, i.e. those variables that are accessed in the body of the function. Memory allocations (both for function objects and classes) and virtual calls introduce runtime overhead.

您的函数不是高阶函数，因为它位于SceneRenderer类内部，并且使其成为inline不会产生任何合理影响。

Inlining may cause the generated code to grow; however, if we do it in a reasonable way (i.e. avoiding inlining large functions), it will pay off in performance, especially at "megamorphic" call-sites inside loops.