| // run | |
| // +build !js | |
| // Copyright 2017 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 | |
| import ( | |
| "fmt" | |
| "runtime" | |
| "sync/atomic" | |
| "time" | |
| ) | |
| var a uint64 = 0 | |
| func main() { | |
| runtime.GOMAXPROCS(2) // With just 1, infinite loop never yields | |
| go func() { | |
| for { | |
| atomic.AddUint64(&a, uint64(1)) | |
| } | |
| }() | |
| time.Sleep(10 * time.Millisecond) // Short sleep is enough in passing case | |
| i, val := 0, atomic.LoadUint64(&a) | |
| for ; val == 0 && i < 100; val, i = atomic.LoadUint64(&a), i+1 { | |
| time.Sleep(100 * time.Millisecond) | |
| } | |
| if val == 0 { | |
| fmt.Printf("Failed to observe atomic increment after %d tries\n", i) | |
| } | |
| } |