main.go

package main

import (
  "fmt"
  "jiechen"
)

var (
  intChan chan int
  resMap  map[int]float64 = make(map[int]float64)
)

func main() {
  for i := 1; i <= 10; i++ {
    jiechen.WG.Add(1)
    go jiechen.Calc2(i)
  }
  jiechen.WG.Wait()
}

func test2() {
  for i := 1; i <= 100; i++ {
    res := jiechen.Calc(i)
    fmt.Println(res)
    resMap[i] = res
  }
  fmt.Println("====================")
  fmt.Println(resMap)
}

func test1() {
  intChan = make(chan int, 3)
  intChan <- 11
  intChan <- 22
  intChan <- 33
  fmt.Println(<-intChan)
}

jiechen.go

package jiechen

import (
  "fmt"
  "sync"
)

var (
  WG   sync.WaitGroup
  Lock sync.Mutex
)

func Calc2(i int) {
  defer WG.Done()
  Lock.Lock()
  var res float64 = 1
  resmap := make(map[int]float64)
  for j := 1; j <= i; j++ {
    res *= float64(j)
  }
  resmap[i] = res
  fmt.Println(resmap)
  Lock.Unlock()
}

func Calc(i int) float64 {
  var res float64 = 1
  for idx := 1; idx <= i; idx++ {
    res *= float64(idx)
  }
  return res
}

go.mod

module channel

go 1.16

require jiechen v1.1.1

replace jiechen => ./jiechen

日志输出

go代码sync.Mutex同步加锁示例：并行求阶乘_i++