Go 并发模式 2 Worker Pool模式

Worker Pool模式

import (
	"fmt"
	"sync"
	"time"
)

func worker(id int, jobs <-chan int, results chan<- int, wg *sync.WaitGroup) {
	defer wg.Done()
	for job := range jobs {
		fmt.Printf("worker %d starting job %d\n", id, job)
		time.Sleep(time.Second)
		results <- job * 2
	}
}

func main() {
	const numJobs = 10
	const numWorkers = 5
	jobs := make(chan int, numJobs)
	results := make(chan int, numJobs)
	var wg sync.WaitGroup

	//启动固定的worker
	for i := 0; i < numWorkers; i++ {
		wg.Add(1)
		go worker(i, jobs, results, &wg)
	}

	//发送任务
	for i := 1; i < numJobs; i++ {
		jobs <- i
	}
	close(jobs) // 有始有终，避免阻塞

	go func() {
		wg.Wait()
		close(results) // 等待所有worker完成后关闭结果通道
	}()

	for result := range results {
		fmt.Println("result:", result)
	}

}