#![feature(test)]
extern crate test;
extern crate lwkt;
use lwkt::{Context, Stack};

static mut ctx_slot: *mut Context<SliceStack<'static>> = 0 as *mut Context<_>;
static mut stack_buf: [u8; 1024] = [0; 1024];

#[bench]
fn context_new(b: &mut test::Bencher) {
  b.iter(|| unsafe {
    let stack = SliceStack(&mut stack_buf);

    let mut ctx = Context::new(stack, move || {
      let ctx_ptr = ctx_slot;
      loop {
        (*ctx_ptr).swap()
      }
    });

    ctx_slot = &mut ctx;

    ctx.swap();
  })
}

struct SliceStack<'a>(&'a mut [u8]);
impl<'a> lwkt::Stack for SliceStack<'a> {
  fn top(&mut self) -> *mut u8 {
    unsafe {
      self.0.as_mut_ptr().offset(self.0.len() as isize)
    }
  }

  fn limit(&self) -> *const u8 {
    self.0.as_ptr()
  }
}