// run // Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package main var counter uint var shift uint func GetValue() uint { counter++ return 1 << shift } func Send(a, b chan uint) int { var i int LOOP: for { select { case a <- GetValue(): i++ a = nil case b <- GetValue(): i++ b = nil default: break LOOP } shift++ } return i } func main() { a := make(chan uint, 1) b := make(chan uint, 1) if v := Send(a, b); v != 2 { println("Send returned", v, "!= 2") panic("fail") } if av, bv := <-a, <-b; av|bv != 3 { println("bad values", av, bv) panic("fail") } if v := Send(a, nil); v != 1 { println("Send returned", v, "!= 1") panic("fail") } if counter != 10 { println("counter is", counter, "!= 10") panic("fail") } }