| // The Computer Language Benchmarks Game |
| // http://benchmarksgame.alioth.debian.org/ |
| // |
| // contributed by the Rust Project Developers |
| |
| // Copyright (c) 2012-2014 The Rust Project Developers |
| // |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions |
| // are met: |
| // |
| // - Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // |
| // - Redistributions in binary form must reproduce the above copyright |
| // notice, this list of conditions and the following disclaimer in |
| // the documentation and/or other materials provided with the |
| // distribution. |
| // |
| // - Neither the name of "The Computer Language Benchmarks Game" nor |
| // the name of "The Computer Language Shootout Benchmarks" nor the |
| // names of its contributors may be used to endorse or promote |
| // products derived from this software without specific prior |
| // written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| // COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| // OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| use std::sync::mpsc::{channel, Sender, Receiver}; |
| use std::thread; |
| |
| fn start(n_tasks: i32, token: i32) { |
| let (tx, mut rx) = channel(); |
| tx.send(token).unwrap(); |
| let mut guards = Vec::with_capacity(n_tasks as usize); |
| for i in 2 .. n_tasks + 1 { |
| let (tx, next_rx) = channel(); |
| let cur_rx = std::mem::replace(&mut rx, next_rx); |
| guards.push(thread::spawn(move|| roundtrip(i, tx, cur_rx))); |
| } |
| let guard = thread::spawn(move|| roundtrip(1, tx, rx)); |
| } |
| |
| fn roundtrip(id: i32, tx: Sender<i32>, rx: Receiver<i32>) { |
| for token in rx.iter() { |
| if token == 1 { |
| println!("{}", id); |
| break; |
| } |
| tx.send(token - 1).unwrap(); |
| } |
| } |
| |
| fn main() { |
| let mut args = std::env::args(); |
| let token = if std::env::var_os("RUST_BENCH").is_some() { |
| 2000000 |
| } else { |
| args.nth(1).and_then(|arg| arg.parse().ok()).unwrap_or(1000) |
| }; |
| let n_tasks = args.next() |
| .and_then(|arg| arg.parse().ok()) |
| .unwrap_or(503); |
| |
| start(n_tasks, token); |
| } |