panos 已修改 . 還原成這個修訂版本
1 file changed, 81 insertions
main.go(檔案已創建)
| @@ -0,0 +1,81 @@ | |||
| 1 | + | package main | |
| 2 | + | ||
| 3 | + | import ( | |
| 4 | + | "fmt" | |
| 5 | + | "log" | |
| 6 | + | "math/rand" | |
| 7 | + | "sync" | |
| 8 | + | ||
| 9 | + | "github.com/hashicorp/go-multierror" | |
| 10 | + | ) | |
| 11 | + | ||
| 12 | + | func main() { | |
| 13 | + | if err := runConcurrently(); err != nil { | |
| 14 | + | log.Fatalf("errors occured: %v", err) | |
| 15 | + | } | |
| 16 | + | log.Printf("all done, no errors") | |
| 17 | + | } | |
| 18 | + | ||
| 19 | + | func runConcurrently() error { | |
| 20 | + | intChan := make(chan int) | |
| 21 | + | wg := sync.WaitGroup{} | |
| 22 | + | workers := 5 | |
| 23 | + | errC := make(chan error) | |
| 24 | + | ||
| 25 | + | // producer | |
| 26 | + | wg.Add(1) | |
| 27 | + | go func() { | |
| 28 | + | defer wg.Done() | |
| 29 | + | defer close(intChan) | |
| 30 | + | // insert random numbers into the channel | |
| 31 | + | for i := 0; i < 30; i++ { | |
| 32 | + | intChan <- rand.Intn(100) | |
| 33 | + | } | |
| 34 | + | }() | |
| 35 | + | ||
| 36 | + | // consumer | |
| 37 | + | for i := 0; i < workers; i++ { | |
| 38 | + | wg.Add(1) | |
| 39 | + | go func() { | |
| 40 | + | defer wg.Done() | |
| 41 | + | for { | |
| 42 | + | select { | |
| 43 | + | case number, ok := <-intChan: | |
| 44 | + | if !ok { | |
| 45 | + | return | |
| 46 | + | } | |
| 47 | + | if err := doSomething(number); err != nil { | |
| 48 | + | errC <- err | |
| 49 | + | } | |
| 50 | + | } | |
| 51 | + | } | |
| 52 | + | }() | |
| 53 | + | } | |
| 54 | + | ||
| 55 | + | go func() { | |
| 56 | + | wg.Wait() | |
| 57 | + | close(errC) | |
| 58 | + | }() | |
| 59 | + | ||
| 60 | + | var errs *multierror.Error | |
| 61 | + | ||
| 62 | + | for { | |
| 63 | + | select { | |
| 64 | + | case err, ok := <-errC: | |
| 65 | + | if !ok { | |
| 66 | + | return errs.ErrorOrNil() | |
| 67 | + | } | |
| 68 | + | if err != nil { | |
| 69 | + | errs = multierror.Append(errs, err) | |
| 70 | + | } | |
| 71 | + | } | |
| 72 | + | } | |
| 73 | + | } | |
| 74 | + | ||
| 75 | + | func doSomething(i int) error { | |
| 76 | + | if i%15 == 0 { | |
| 77 | + | return fmt.Errorf("random error: %v", i) | |
| 78 | + | } | |
| 79 | + | log.Printf("doing something with %d", i) | |
| 80 | + | return nil | |
| 81 | + | } | |
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