| // run |
| |
| // 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) |
| } |
| |
| } |
