| // Copyright 2015 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 std::thread; |
| use std::sync::Mutex; |
| |
| fn par_for<I, F>(iter: I, f: F) |
| where I: Iterator, |
| I::Item: Send, |
| F: Fn(I::Item) + Sync |
| { |
| for item in iter { |
| f(item) |
| } |
| } |
| |
| fn sum(x: &[i32]) { |
| let sum_lengths = Mutex::new(0); |
| par_for(x.windows(4), |x| { |
| *sum_lengths.lock().unwrap() += x.len() |
| }); |
| |
| assert_eq!(*sum_lengths.lock().unwrap(), (x.len() - 3) * 4); |
| } |
| |
| fn main() { |
| let mut elements = [0; 20]; |
| |
| // iterators over references into this stack frame |
| par_for(elements.iter_mut().enumerate(), |(i, x)| { |
| *x = i as i32 |
| }); |
| |
| sum(&elements) |
| } |