41 lines
567 B
Go
41 lines
567 B
Go
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package main
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import (
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"fmt"
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"math/rand"
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"sync"
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"time"
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)
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//waitGroup
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func f() {
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//生成随机数
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rand.New(rand.NewSource(time.Now().UnixNano()))
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for i := 0; i < 5; i++ {
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r1 := rand.Int()
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r2 := rand.Intn(10)
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fmt.Println(r1, r2)
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}
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}
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func f1(i int) {
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defer wg.Done() //任务结束后计数器-1
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time.Sleep(time.Second * time.Duration(rand.Intn(3)))
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fmt.Println(i)
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}
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var wg sync.WaitGroup
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func main() {
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for i := 0; i < 10; i++ {
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wg.Add(1)
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go f1(i)
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}
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//如何知道这10个goroutine都结束了
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wg.Wait() //等待wg的计数器减为0
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}
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