src/test/bench/rt-parfib.rs


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

// 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.

extern mod extra;

use std::os;
use std::uint;

// A simple implementation of parfib. One subtree is found in a new
// task and communicated over a oneshot pipe, the other is found
// locally. There is no sequential-mode threshold.

fn parfib(n: uint) -> uint {
    if(n == 0 || n == 1) {
        return 1;
    }

    let (port,chan) = Chan::new();
    do spawn {
        chan.send(parfib(n-1));
    };
    let m2 = parfib(n-2);
    return (port.recv() + m2);
}

fn main() {

    let args = os::args();
    let n = if args.len() == 2 {
        from_str::<uint>(args[1]).unwrap()
    } else {
        10
    };

    parfib(n);

}