go并发编程系列七：开学季抢票返程

背景：学校开学，3位同学要买票回校上课了，就有了这样一个购票程序，当然，实际情况复杂的多，本文仅供参考。

package main

import (
    "fmt"
    "sync"
)

type Train struct {
    station map[string]int
    mu sync.Mutex
}

func NewTrain() *Train {
    return &Train{station: map[string]int{}}
}

func (train *Train) Add(name string, ticket int) {
    train.mu.Lock()
    defer train.mu.Unlock()

    train.station[name] = ticket
}

func (train *Train) Buy(name string, ticket int) bool {
    train.mu.Lock()
    defer train.mu.Unlock()

    if train.station[name] == 0 || train.station[name] - ticket < 0 {
        return false
    }

    train.station[name] = train.station[name] - ticket

    return true
}

func main() {
    train := NewTrain()
    train.Add("郑州", 100)
    train.Add("许昌", 50)
    train.Add("漯河", 20)
    train.Add("驻马店", 50)
    train.Add("信阳", 30)

    var wg sync.WaitGroup
    wg.Add(3)

    go func() {
        defer wg.Done()

        ticket := 15
        own := train.Buy("信阳", ticket)
        fmt.Printf("张三购票：%d，状态：%t\n", ticket, own)
    }()

    go func() {
        defer wg.Done()

        ticket := 20
        own := train.Buy("信阳", ticket)
        fmt.Printf("李四购票：%d，状态：%t\n", ticket, own)
    }()

    go func() {
        defer wg.Done()

        ticket := 10
        own := train.Buy("信阳", ticket)
        fmt.Printf("王五购票：%d，状态：%t\n", ticket, own)
    }()

    wg.Wait()

    fmt.Println(train.station)
}

 

运行效果：

 

posted @ 2023-09-04 20:48  jamstack  阅读(27)  评论(0)  编辑  收藏  举报