| /* |
| 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. |
| */ |
| |
| /* The Computer Language Benchmarks Game |
| * http://shootout.alioth.debian.org/ |
| * |
| * contributed by The Go Authors. |
| */ |
| |
| package main |
| |
| import ( |
| "flag" |
| "fmt" |
| "os" |
| ) |
| |
| var n = flag.Int("n", 1000, "how many passes") |
| |
| const Nthread = 503 |
| |
| func f(i int, in <-chan int, out chan<- int) { |
| for { |
| n := <-in |
| if n == 0 { |
| fmt.Printf("%d\n", i) |
| os.Exit(0) |
| } |
| out <- n - 1 |
| } |
| } |
| |
| func main() { |
| flag.Parse() |
| |
| one := make(chan int) // will be input to thread 1 |
| var in, out chan int = nil, one |
| for i := 1; i <= Nthread-1; i++ { |
| in, out = out, make(chan int) |
| go f(i, in, out) |
| } |
| go f(Nthread, out, one) |
| one <- *n |
| <-make(chan int) // hang until ring completes |
| } |