From c19fc4625a651f049fc13c110b6878df9cebdaf1 Mon Sep 17 00:00:00 2001
From: edef <edef@edef.eu>
Date: Wed, 15 Apr 2015 22:01:08 -0400
Subject: [PATCH] use a statically-allocated stack for Context::new
 benchmarking

Now it's an actual context creation benchmark, instead of benchmarking
our stack creation, which is swappable anyway.
---
 benches/context_new.rs | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/benches/context_new.rs b/benches/context_new.rs
index 6ac9f51..eb170b9 100644
--- a/benches/context_new.rs
+++ b/benches/context_new.rs
@@ -1,14 +1,15 @@
 #![feature(test)]
 extern crate test;
 extern crate lwkt;
-use lwkt::{Context, StackSource};
+use lwkt::{Context, Stack};
 
-static mut ctx_slot: *mut Context<lwkt::os::Stack> = 0 as *mut Context<_>;
+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 = lwkt::os::StackSource::get_stack(4 << 20);
+    let stack = SliceStack(&mut stack_buf);
 
     let mut ctx = Context::new(stack, move || {
       let ctx_ptr = ctx_slot;
@@ -22,3 +23,16 @@ fn context_new(b: &mut test::Bencher) {
     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()
+  }
+}