golang WaitGroup 并发使用

题目原地址

package main

import (
    "fmt"
    "sync"
    "time"
    "sync/atomic"
)

const THREE_MINUTES = 3 * 60 * 1

type BanTable struct {
    VisTable map[string]int64
    Lock     *sync.Mutex
}

func NewBanTable() *BanTable {
    return &BanTable{
        VisTable: make(map[string]int64, 0),
        Lock:     new(sync.Mutex),
    }
}

func (self *BanTable) IsVisited(ip string) bool {
    self.Lock.Lock()
    defer self.Lock.Unlock()
    ts, ok := self.VisTable[ip]
    ret := false
    if ok && ts > 0 && time.Now().Unix()-ts < THREE_MINUTES {
        ret = true
    }
    if !ret {
        self.VisTable[ip] = time.Now().Unix()
    }
    return ret
}

func main() {
    var succ int64 = 0
    ban := NewBanTable()
    wg := new(sync.WaitGroup)
    for i := 0; i < 1000; i++ {
        for j := 0; j < 100; j++ {
            wg.Add(1)
            ip := fmt.Sprintf("192.168.1.%d", j)
            // 注意，若不注明参数类型，这里取外层的引用地址
            go func(ip string, wg *sync.WaitGroup, succ *int64) {
                defer wg.Done()
                if !ban.IsVisited(ip) {
                    atomic.AddInt64(succ, 1)
                }
            }(ip, wg, &succ)
        }
    }
    wg.Wait()
    fmt.Println("success:", succ)
}