| // skip | |
| // Copyright 2019 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" | |
| "time" | |
| ) | |
| func main() { | |
| // Make a big map. | |
| m := map[int]int{} | |
| for i := 0; i < 100000; i++ { | |
| m[i] = i | |
| } | |
| c := make(chan string) | |
| go func() { | |
| // Print the map. | |
| s := fmt.Sprintln(m) | |
| c <- s | |
| }() | |
| go func() { | |
| time.Sleep(1 * time.Millisecond) | |
| // Add an extra item to the map while iterating. | |
| m[-1] = -1 | |
| c <- "" | |
| }() | |
| <-c | |
| <-c | |
| } |