需求

统计 1-8000之间的素数。

思路分析

代码

// goroutine + channel 求素数
package main
import (
    "fmt"
)
func putNum(intChan chan int) {
    for i := 1; i <= 800; i++ {
        intChan <- i
    }
    close(intChan)
}
func primeNum(intChan chan int, primeChan chan int, exitChan chan bool) {
    var flag bool
    for {
        // time.Sleep(time.Millisecond * 10)
        num, ok := <-intChan
        if !ok {
            break
        }
        flag = true
        for i := 2; i < num; i++ {
            if num%i == 0 {
                // 不是素数
                flag = false
                break
            }
        }
        if flag {
            primeChan <- num
        }
    }
    exitChan <- true
    fmt.Println("该协程退出 primeNum")
}
func main() {
    intChan := make(chan int, 1000)
    primeChan := make(chan int, 2000)
    exitChan := make(chan bool, 4)
    go putNum(intChan)
    for i := 0; i < 4; i++ {
        go primeNum(intChan, primeChan, exitChan)
    }
    go func() {
        for i := 0; i < 4; i++ {
            <-exitChan
        }
        close(primeChan)
    }()
    for v := range primeChan {
        fmt.Println("素数： ", v)
    }
    fmt.Println("主线程退出")
}