通信顺序过程 （Communicating sequential processes, CSP） 是一种用于描述并发系统中交互模式的形式语言。讲究的是”通过 通信 来共享内存, 而非通过共享内存来通信”

    1. package testa
    3. import (
    4.     "fmt"
    5.     "testing"
    6.     "time"
    7. )
    9. func service() string {
    10.     time.Sleep(time.Millisecond * 50)
    11.     return "done"
    12. }
    14. func otherTask() {
    15.     fmt.Println("working on something else")
    16.     time.Sleep(time.Millisecond * 100)
    17.     fmt.Println("task is done")
    18. }
    20. func Test1(t *testing.T) {
    21.     start := time.Now()
    22.     ret := service()
    23.     fmt.Println(ret)
    24.     otherTask()
    25.     t.Log("Test1 cost:", time.Since(start)) // Test1 cost: 157.401782ms
    26. }
    28. func AsyncService() chan string {
    29.     retCh := make(chan string)
    30.     go func() {
    31.         ret := service()
    32.         retCh <- ret
    33.     }()
    34.     return retCh
    35. }
    37. func Test2(t *testing.T) {
    38.     start := time.Now()
    39.     retCh := AsyncService()
    40.     otherTask()
    41.     fmt.Println(<-retCh)
    42.     t.Log("Test2 cost:", time.Since(start)) // Test2 cost: 104.309487ms
    43. }