golang互斥锁的两种实现

1.用Mutex实现

package main
import (
    "fmt"
    "sync"
)
var num int
var mtx sync.Mutex
var wg sync.WaitGroup
func add() {
    mtx.Lock()
    defer mtx.Unlock()
    defer wg.Done()
    num += 1
}
func main() {
    for i := 0; i < 100; i++ {
        wg.Add(1)
        go add()
    }
    wg.Wait()
    fmt.Println("num:", num)
}

2.使用chan实现

package main
import (
    "fmt"
    "sync"
)
var num int
func add(h chan int, wg *sync.WaitGroup) {
    defer wg.Done()
    h <- 1
    num += 1
    <-h
}
func main() {
    ch := make(chan int, 1)
    wg := &sync.WaitGroup{}
    for i := 0; i < 100; i++ {
        wg.Add(1)
        go add(ch, wg)
    }
    wg.Wait()
    fmt.Println("num:", num)
}