47 lines
1.1 KiB
Rust
47 lines
1.1 KiB
Rust
// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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extern mod extra;
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use std::os;
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use std::uint;
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use std::rt::test::spawntask_later;
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use std::comm::oneshot;
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// A simple implementation of parfib. One subtree is found in a new
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// task and communicated over a oneshot pipe, the other is found
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// locally. There is no sequential-mode threshold.
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fn parfib(n: uint) -> uint {
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if(n == 0 || n == 1) {
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return 1;
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}
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let (port,chan) = oneshot::<uint>();
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do spawntask_later {
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chan.send(parfib(n-1));
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};
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let m2 = parfib(n-2);
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return (port.recv() + m2);
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}
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fn main() {
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let args = os::args();
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let n = if args.len() == 2 {
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from_str::<uint>(args[1]).unwrap()
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} else {
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10
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};
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parfib(n);
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}
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