rust/src/libstd/rt/stack.rs
Daniel Micay ef870d37a5 implement pointer arithmetic with GEP
Closes #8118, #7136

~~~rust
extern mod extra;

use std::vec;
use std::ptr;

fn bench_from_elem(b: &mut extra::test::BenchHarness) {
    do b.iter {
        let v: ~[u8] = vec::from_elem(1024, 0u8);
    }
}

fn bench_set_memory(b: &mut extra::test::BenchHarness) {
    do b.iter {
        let mut v: ~[u8] = vec::with_capacity(1024);
        unsafe {
            let vp = vec::raw::to_mut_ptr(v);
            ptr::set_memory(vp, 0, 1024);
            vec::raw::set_len(&mut v, 1024);
        }
    }
}

fn bench_vec_repeat(b: &mut extra::test::BenchHarness) {
    do b.iter {
        let v: ~[u8] = ~[0u8, ..1024];
    }
}
~~~

Before:

    test bench_from_elem ... bench: 415 ns/iter (+/- 17)
    test bench_set_memory ... bench: 85 ns/iter (+/- 4)
    test bench_vec_repeat ... bench: 83 ns/iter (+/- 3)

After:

    test bench_from_elem ... bench: 84 ns/iter (+/- 2)
    test bench_set_memory ... bench: 84 ns/iter (+/- 5)
    test bench_vec_repeat ... bench: 84 ns/iter (+/- 3)
2013-07-30 02:50:31 -04:00

77 lines
2.1 KiB
Rust

// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use container::Container;
use ptr::RawPtr;
use vec;
use ops::Drop;
use libc::{c_uint, uintptr_t};
pub struct StackSegment {
buf: ~[u8],
valgrind_id: c_uint
}
impl StackSegment {
pub fn new(size: uint) -> StackSegment {
unsafe {
// Crate a block of uninitialized values
let mut stack = vec::with_capacity(size);
vec::raw::set_len(&mut stack, size);
let mut stk = StackSegment {
buf: stack,
valgrind_id: 0
};
// XXX: Using the FFI to call a C macro. Slow
stk.valgrind_id = rust_valgrind_stack_register(stk.start(), stk.end());
return stk;
}
}
/// Point to the low end of the allocated stack
pub fn start(&self) -> *uint {
vec::raw::to_ptr(self.buf) as *uint
}
/// Point one word beyond the high end of the allocated stack
pub fn end(&self) -> *uint {
vec::raw::to_ptr(self.buf).offset(self.buf.len() as int) as *uint
}
}
impl Drop for StackSegment {
fn drop(&self) {
unsafe {
// XXX: Using the FFI to call a C macro. Slow
rust_valgrind_stack_deregister(self.valgrind_id);
}
}
}
pub struct StackPool(());
impl StackPool {
pub fn new() -> StackPool { StackPool(()) }
fn take_segment(&self, min_size: uint) -> StackSegment {
StackSegment::new(min_size)
}
fn give_segment(&self, _stack: StackSegment) {
}
}
extern {
fn rust_valgrind_stack_register(start: *uintptr_t, end: *uintptr_t) -> c_uint;
fn rust_valgrind_stack_deregister(id: c_uint);
}