rust/src/test/bench/shootout-pfib.rs
2014-05-16 11:41:27 -07:00

126 lines
3.1 KiB
Rust

// Copyright 2012 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.
/*
A parallel version of fibonacci numbers.
This version is meant mostly as a way of stressing and benchmarking
the task system. It supports a lot of old command-line arguments to
control how it runs.
*/
extern crate getopts;
extern crate time;
use std::os;
use std::result::{Ok, Err};
use std::task;
use std::task::TaskBuilder;
use std::uint;
fn fib(n: int) -> int {
fn pfib(tx: &Sender<int>, n: int) {
if n == 0 {
tx.send(0);
} else if n <= 2 {
tx.send(1);
} else {
let (tx1, rx) = channel();
let tx2 = tx1.clone();
task::spawn(proc() pfib(&tx2, n - 1));
let tx2 = tx1.clone();
task::spawn(proc() pfib(&tx2, n - 2));
tx.send(rx.recv() + rx.recv());
}
}
let (tx, rx) = channel();
spawn(proc() pfib(&tx, n) );
rx.recv()
}
struct Config {
stress: bool
}
fn parse_opts(argv: Vec<StrBuf> ) -> Config {
let opts = vec!(getopts::optflag("", "stress", ""));
let argv = argv.iter().map(|x| x.to_strbuf()).collect::<Vec<_>>();
let opt_args = argv.slice(1, argv.len());
match getopts::getopts(opt_args, opts.as_slice()) {
Ok(ref m) => {
return Config {stress: m.opt_present("stress")}
}
Err(_) => { fail!(); }
}
}
fn stress_task(id: int) {
let mut i = 0;
loop {
let n = 15;
assert_eq!(fib(n), fib(n));
i += 1;
println!("{}: Completed {} iterations", id, i);
}
}
fn stress(num_tasks: int) {
let mut results = Vec::new();
for i in range(0, num_tasks) {
let mut builder = TaskBuilder::new();
results.push(builder.future_result());
builder.spawn(proc() {
stress_task(i);
});
}
for r in results.iter() {
r.recv();
}
}
fn main() {
let args = os::args();
let args = if os::getenv("RUST_BENCH").is_some() {
vec!("".to_strbuf(), "20".to_strbuf())
} else if args.len() <= 1u {
vec!("".to_strbuf(), "8".to_strbuf())
} else {
args.move_iter().map(|x| x.to_strbuf()).collect()
};
let opts = parse_opts(args.clone());
if opts.stress {
stress(2);
} else {
let max = uint::parse_bytes(args.get(1).as_bytes(), 10u).unwrap() as
int;
let num_trials = 10;
for n in range(1, max + 1) {
for _ in range(0, num_trials) {
let start = time::precise_time_ns();
let fibn = fib(n);
let stop = time::precise_time_ns();
let elapsed = stop - start;
println!("{}\t{}\t{}", n, fibn, elapsed.to_str());
}
}
}
}