Go 并发控制利器 ants 使用方法与实践

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

package main

import (
	"fmt"
	"time"

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

func main() {
	// 创建一个容量为 10 的 goroutine 池
	pool, _ := ants.NewPool(10)
	defer pool.Release() // 程序结束释放资源

	// 提交任务
	for i := 0; i < 20; i++ {
		n := i
		_ = pool.Submit(func() {
			fmt.Printf("Task %d running\n", n)
			time.Sleep(time.Second)
		})
	}

	fmt.Println("All tasks submitted")
	time.Sleep(3 * time.Second) // 等待任务执行完
}

ants.WithPreAlloc(true)           // 预先分配内存，减少运行时分配
ants.WithNonblocking(true)        // worker 不够时立即返回错误，而不是等待
ants.WithMaxBlockingTasks(1000)   // 最大等待任务数
ants.WithPanicHandler(func(err interface{}) {
	fmt.Println("panic:", err)     // 捕获任务中的 panic
})
ants.WithExpiryDuration(time.Second * 10) // 空闲 worker 过期时间

package main

import (
	"fmt"
	"github.com/panjf2000/ants/v2"
	"time"
)

func main() {
	// 定义处理函数
	handler := func(data interface{}) {
		fmt.Printf("Processing: %v\n", data)
		time.Sleep(time.Millisecond * 500)
	}

	// 创建绑定函数的池
	pool, _ := ants.NewPoolWithFunc(5, handler)
	defer pool.Release()

	for i := 0; i < 10; i++ {
		_ = pool.Invoke(i) // 直接传参数
	}
}

package main

import (
	"fmt"
	"sync"
	"time"

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

func processTask(id int) {
	fmt.Printf("Task %d start\n", id)
	time.Sleep(time.Second)
	fmt.Printf("Task %d done\n", id)
}

func main() {
	var wg sync.WaitGroup
	pool, _ := ants.NewPool(50) // 控制并发为 50
	defer pool.Release()

	for i := 0; i < 10000; i++ {
		wg.Add(1)
		taskID := i
		_ = pool.Submit(func() {
			defer wg.Done()
			processTask(taskID)
		})
	}
	wg.Wait()
}

package main

import (
	"fmt"
	"net/http"
	"sync"

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

func fetch(url string) {
	resp, err := http.Get(url)
	if err != nil {
		fmt.Println(err)
		return
	}
	defer resp.Body.Close()
	fmt.Println(url, resp.StatusCode)
}

func main() {
	urls := []string{
		"https://golang.org",
		"https://github.com",
		"https://google.com",
	}

	var wg sync.WaitGroup
	pool, _ := ants.NewPool(5)
	defer pool.Release()

	for _, url := range urls {
		wg.Add(1)
		u := url
		_ = pool.Submit(func() {
			defer wg.Done()
			fetch(u)
		})
	}

	wg.Wait()
}