|
| 1 | +package go_22 |
| 2 | + |
| 3 | +import ( |
| 4 | + "fmt" |
| 5 | + "testing" |
| 6 | + "time" |
| 7 | +) |
| 8 | + |
| 9 | +/* |
| 10 | +CSP并发机制 当成java的异步操作理解就行了 |
| 11 | + |
| 12 | +## Channel |
| 13 | +- Channel是Go中的一个核心类型,你可以把它看成一个管道,通过它并发核心单元就可以发送或者接收数据进行通讯 |
| 14 | +- 容量(capacity)代表Channel容纳的最多的元素的数量,代表Channel的缓存的大小。 |
| 15 | +- 如果没有设置容量,或者容量设置为0, 说明Channel没有缓存,只有sender和receiver都准备好了后它们的通讯 |
| 16 | + |
| 17 | +##如图:普通Channel 与 设置容量了Buffered Channels的区别 |
| 18 | +https://github.com/java-aodeng/golang-examples/blob/master/go-22/channel.png |
| 19 | + |
| 20 | +*/ |
| 21 | + |
| 22 | +func service() string { |
| 23 | + time.Sleep(time.Millisecond * 50) |
| 24 | + return "Done" |
| 25 | +} |
| 26 | + |
| 27 | +func otherTask() { |
| 28 | + fmt.Println("working on something else") |
| 29 | + time.Sleep(time.Millisecond * 100) |
| 30 | + fmt.Println("Task is done.") |
| 31 | +} |
| 32 | + |
| 33 | +func TestService(t *testing.T) { |
| 34 | + fmt.Println(service()) |
| 35 | + otherTask() |
| 36 | +} |
| 37 | + |
| 38 | +//运行结果 可以看到结果是串行的,而且时间也等于两个函数总数相加 0.15s |
| 39 | +//=== RUN TestService |
| 40 | +//Done |
| 41 | +//working on something else |
| 42 | +//Task is done. |
| 43 | +//--- PASS: TestService (0.15s) |
| 44 | +//PASS |
| 45 | + |
| 46 | +func AsyncService() chan string { |
| 47 | + //使用make初始化普通Channel,不指定容量默认就是0 就是普通Channel |
| 48 | + retCh := make(chan string) |
| 49 | + go func() { |
| 50 | + ret := service() |
| 51 | + fmt.Println("returned result.") |
| 52 | + retCh <- ret |
| 53 | + fmt.Println("service exited.") |
| 54 | + }() |
| 55 | + return retCh |
| 56 | +} |
| 57 | + |
| 58 | +func AsyncService2() chan string { |
| 59 | + //使用make初始化Buffered Channels, 只要设置了容量,就是Buffered Channels |
| 60 | + retCh := make(chan string, 1) |
| 61 | + go func() { |
| 62 | + ret := service() |
| 63 | + fmt.Println("returned result.") |
| 64 | + retCh <- ret |
| 65 | + fmt.Println("service exited.") |
| 66 | + }() |
| 67 | + return retCh |
| 68 | +} |
| 69 | + |
| 70 | +//使用普通Channel |
| 71 | +func TestAsynService(t *testing.T) { |
| 72 | + retCh := AsyncService() |
| 73 | + otherTask() |
| 74 | + fmt.Println(<-retCh) |
| 75 | +} |
| 76 | + |
| 77 | +//运行结果 可以看到service exited.是最后返回结果的 |
| 78 | +//=== RUN TestAsynService |
| 79 | +//working on something else |
| 80 | +//returned result. |
| 81 | +//Task is done. |
| 82 | +//Done |
| 83 | +//service exited. |
| 84 | +//--- PASS: TestAsynService (0.10s) |
| 85 | +//PASS |
| 86 | + |
| 87 | +//使用指定容量的Buffered Channels |
| 88 | +func TestAsynService2(t *testing.T) { |
| 89 | + retCh := AsyncService2() |
| 90 | + otherTask() |
| 91 | + fmt.Println(<-retCh) |
| 92 | +} |
| 93 | + |
| 94 | +//运行结果 可以看到在等待的时候同时执行了,service exited.没有阻塞 |
| 95 | +//=== RUN TestAsynService |
| 96 | +//working on something else |
| 97 | +//returned result. |
| 98 | +//service exited. |
| 99 | +//Task is done. |
| 100 | +//Done |
| 101 | +//--- PASS: TestAsynService (0.10s) |
| 102 | +//PASS |
0 commit comments