# ants
A goroutine pool for Go
[![Build Status][1]][2] [![codecov][3]][4] [![goreportcard for panjf2000/ants][5]][6] [![godoc for panjf2000/ants][7]][8] [![MIT Licence][9]][10] [英文](README.md) | [项目介绍文章传送门](http://blog.taohuawu.club/article/goroutine-pool) `ants`是一个高性能的协程池,实现了对大规模goroutine的调度管理、goroutine复用,允许使用者在开发并发程序的时候限制协程数量,复用资源,达到更高效执行任务的效果。 ## 功能: - 实现了自动调度并发的goroutine,复用goroutine - 定时清理过期的goroutine,进一步节省资源 - 提供了友好的接口:任务提交、获取运行中的协程数量、动态调整协程池大小 - 优雅处理panic,防止程序崩溃 - 资源复用,极大节省内存使用量;在大规模批量并发任务场景下比原生goroutine并发具有更高的性能 ## 目前测试通过的Golang版本: - 1.8.x - 1.9.x - 1.10.x - 1.11.x - master ## 安装 ``` sh go get -u github.com/panjf2000/ants ``` 使用包管理工具 glide 安装: ``` sh glide get github.com/panjf2000/ants ``` ## 使用 写 go 并发程序的时候如果程序会启动大量的 goroutine ,势必会消耗大量的系统资源(内存,CPU),通过使用 `ants`,可以实例化一个协程池,复用 goroutine ,节省资源,提升性能: ``` go package main import ( "fmt" "sync" "sync/atomic" "time" "github.com/panjf2000/ants" ) var sum int32 func myFunc(i interface{}) { n := i.(int32) atomic.AddInt32(&sum, n) fmt.Printf("run with %d\n", n) } func demoFunc() { time.Sleep(10 * time.Millisecond) fmt.Println("Hello World!") } func main() { defer ants.Release() runTimes := 1000 // Use the common pool var wg sync.WaitGroup for i := 0; i < runTimes; i++ { wg.Add(1) ants.Submit(func() { demoFunc() wg.Done() }) } wg.Wait() fmt.Printf("running goroutines: %d\n", ants.Running()) fmt.Printf("finish all tasks.\n") // Use the pool with a function, // set 10 to the size of goroutine pool and 1 second for expired duration p, _ := ants.NewPoolWithFunc(10, func(i interface{}) { myFunc(i) wg.Done() }) defer p.Release() // Submit tasks for i := 0; i < runTimes; i++ { wg.Add(1) p.Serve(int32(i)) } wg.Wait() fmt.Printf("running goroutines: %d\n", p.Running()) fmt.Printf("finish all tasks, result is %d\n", sum) } ``` ## 与http server集成 ```go package main import ( "io/ioutil" "net/http" "github.com/panjf2000/ants" ) type Request struct { Param []byte Result chan []byte } func main() { pool, _ := ants.NewPoolWithFunc(100, func(payload interface{}) { request, ok := payload.(*Request) if !ok { return } reverseParam := func(s []byte) []byte { for i, j := 0, len(s)-1; i < j; i, j = i+1, j-1 { s[i], s[j] = s[j], s[i] } return s }(request.Param) request.Result <- reverseParam }) defer pool.Release() http.HandleFunc("/reverse", func(w http.ResponseWriter, r *http.Request) { param, err := ioutil.ReadAll(r.Body) if err != nil { http.Error(w, "request error", http.StatusInternalServerError) } defer r.Body.Close() request := &Request{Param: param, Result: make(chan []byte)} // Throttle the requests traffic with ants pool. This process is asynchronous and // you can receive a result from the channel defined outside. if err := pool.Serve(request); err != nil { http.Error(w, "throttle limit error", http.StatusInternalServerError) } w.Write(<-request.Result) }) http.ListenAndServe(":8080", nil) } ``` ## 任务提交 提交任务通过调用 `ants.Submit(func())`方法: ```go ants.Submit(func(){}) ``` ## 自定义池 `ants`支持实例化使用者自己的一个 Pool ,指定具体的池容量;通过调用 `NewPool` 方法可以实例化一个新的带有指定容量的 Pool ,如下: ``` go // Set 10000 the size of goroutine pool p, _ := ants.NewPool(10000) // Submit a task p.Submit(func(){}) ``` ## 动态调整协程池容量 需要动态调整协程池容量可以通过调用`Tune(int)`: ``` go pool.Tune(1000) // Tune its capacity to 1000 pool.Tune(100000) // Tune its capacity to 100000 ``` 该方法是线程安全的。 ## 销毁协程池 ```go pool.Release() ``` ## Benchmarks 系统参数: ``` OS: macOS High Sierra Processor: 2.7 GHz Intel Core i5 Memory: 8 GB 1867 MHz DDR3 Go Version: 1.9 ```