ants

  • 自动调度海量的 goroutines,复用 goroutines
  • 定期清理过期的 goroutines,进一步节省资源
  • 提供了大量有用的接口:任务提交、获取运行中的 goroutine 数量、动态调整 Pool 大小、释放 Pool、重启 Pool
  • 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
  • 非阻塞机制

Img

安装

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go get -u github.com/panjf2000/ants/v2
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package main

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

"github.com/panjf2000/ants/v2"
)

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
syncCalculateSum := func() {
demoFunc()
wg.Done()
}
for i := 0; i < runTimes; i++ {
wg.Add(1)
_ = ants.Submit(syncCalculateSum)
}
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 capacity 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 one by one.
for i := 0; i < runTimes; i++ {
wg.Add(1)
_ = p.Invoke(int32(i))
}
wg.Wait()
fmt.Printf("running goroutines: %d\n", p.Running())
fmt.Printf("finish all tasks, result is %d\n", sum)
}

Pool 配置

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// Option represents the optional function.
type Option func(opts *Options)

// Options contains all options which will be applied when instantiating a ants pool.
type Options struct {
// 方法的持续时间,超过该时间,会被清理掉
ExpiryDuration time.Duration

// 是否进行内存预分配
PreAlloc bool

// 最大阻塞任务数量。即池中 goroutine 数量已到池容量,且所有 goroutine 都处理繁忙状态,这时到来的任务会在阻塞列表等待。
// 这个选项设置的是列表的最大长度。
// 阻塞的任务数量达到这个值后,后续任务提交直接返回失败
MaxBlockingTasks int

// 池是否阻塞,默认阻塞。
// 提交任务时,如果ants池中 goroutine 已到上限且全部繁忙,阻塞的池会将任务添加的阻塞列表等待(当然受限于阻塞列表长度,见上一个选项)。
// 非阻塞的池直接返回失败
Nonblocking bool

// panic 处理。遇到 panic 会调用这里设置的处理函数
PanicHandler func(interface{})

// 指定日志记录器
Logger Logger
}

// WithOptions accepts the whole options config.
func WithOptions(options Options) Option {
return func(opts *Options) {
*opts = options
}
}

// WithExpiryDuration sets up the interval time of cleaning up goroutines.
func WithExpiryDuration(expiryDuration time.Duration) Option {
return func(opts *Options) {
opts.ExpiryDuration = expiryDuration
}
}

// WithPreAlloc indicates whether it should malloc for workers.
func WithPreAlloc(preAlloc bool) Option {
return func(opts *Options) {
opts.PreAlloc = preAlloc
}
}

// WithMaxBlockingTasks sets up the maximum number of goroutines that are blocked when it reaches the capacity of pool.
func WithMaxBlockingTasks(maxBlockingTasks int) Option {
return func(opts *Options) {
opts.MaxBlockingTasks = maxBlockingTasks
}
}

// WithNonblocking indicates that pool will return nil when there is no available workers.
func WithNonblocking(nonblocking bool) Option {
return func(opts *Options) {
opts.Nonblocking = nonblocking
}
}

// WithPanicHandler sets up panic handler.
func WithPanicHandler(panicHandler func(interface{})) Option {
return func(opts *Options) {
opts.PanicHandler = panicHandler
}
}

// WithLogger sets up a customized logger.
func WithLogger(logger Logger) Option {
return func(opts *Options) {
opts.Logger = logger
}
}

动态调整 goroutine 池容量

需要动态调整 goroutine 池容量可以通过调用Tune(int):

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pool.Tune(1000) // Tune its capacity to 1000
pool.Tune(100000) // Tune its capacity to 100000

释放 Pool

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pool.Release()

重启 Pool

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// 只要调用 Reboot() 方法,就可以重新激活一个之前已经被销毁掉的池,并且投入使用。
pool.Reboot()