1func main() {
2    userCount := math.MaxInt64
3    for i := 0; i < userCount; i++ {
4        go func(i int) {
5            fmt.Printf("go func: %d\n", i)
6            time.Sleep(time.Second)
7        }(i)
8    }
9}

 1package main
 2
 3import (
 4	"fmt"
 5	"sync"
 6	"time"
 7)
 8
 9func main() {
10	const maxGoroutines = 5 // 最大协程数
11	const totalTasks = 20   // 总任务数
12
13	sem := make(chan struct{}, maxGoroutines) // 信号量通道
14	var wg sync.WaitGroup
15
16	for i := 0; i < totalTasks; i++ {
17		wg.Add(1)
18		sem <- struct{}{} // 获取信号量，如果已满则阻塞
19
20		go func(taskID int) {
21			defer func() {
22				<-sem // 释放信号量
23				wg.Done()
24			}()
25
26			// 模拟任务处理
27			fmt.Printf("任务 %d 开始执行\n", taskID)
28			time.Sleep(time.Second)
29			fmt.Printf("任务 %d 完成\n", taskID)
30		}(i)
31	}
32
33	wg.Wait()
34	fmt.Println("所有任务完成")
35}

 1func Example_workerPool() {
 2	ctx := context.TODO()
 3
 4	var (
 5		maxWorkers = runtime.GOMAXPROCS(0)
 6		sem        = semaphore.NewWeighted(int64(maxWorkers))
 7		out        = make([]int, 32)
 8	)
 9
10	for i := range out {
11		if err := sem.Acquire(ctx, 1); err != nil {
12			log.Printf("Failed to acquire semaphore: %v", err)
13			break
14		}
15
16		go func(i int) {
17			defer sem.Release(1)
18			out[i] = collatzSteps(i + 1)
19		}(i)
20	}
21
22	if err := sem.Acquire(ctx, int64(maxWorkers)); err != nil {
23		log.Printf("Failed to acquire semaphore: %v", err)
24	}
25
26	fmt.Println(out)
27}

 1package main
 2
 3import (
 4	"fmt"
 5	"sync"
 6	"time"
 7)
 8
 9func worker(id int, jobs <-chan int, results chan<- int) {
10	for job := range jobs {
11		fmt.Printf("Worker %d 处理任务 %d\n", id, job)
12		time.Sleep(time.Second) // 模拟工作
13		results <- job * 2      // 返回结果
14	}
15}
16
17func main() {
18	const numJobs = 20
19	const numWorkers = 5 // 工作协程数量
20
21	jobs := make(chan int, numJobs)
22	results := make(chan int, numJobs)
23
24	// 创建工作池
25	for w := 1; w <= numWorkers; w++ {
26		go worker(w, jobs, results)
27	}
28
29	// 发送任务
30	for j := 1; j <= numJobs; j++ {
31		jobs <- j
32	}
33	close(jobs)
34
35	// 收集结果
36	for r := 1; r <= numJobs; r++ {
37		fmt.Printf("任务结果: %d\n", <-results)
38	}
39}

 1package main
 2
 3import (
 4	"fmt"
 5	"time"
 6
 7	"github.com/panjf2000/ants/v2"
 8)
 9
10func task(i interface{}) {
11	n := i.(int)
12	fmt.Printf("任务 %d 开始执行\n", n)
13	time.Sleep(time.Second)
14	fmt.Printf("任务 %d 完成\n", n)
15}
16
17func main() {
18	defer ants.Release()
19
20	pool, _ := ants.NewPool(5) // 创建容量为5的协程池
21
22	for i := 0; i < 20; i++ {
23		_ = pool.Submit(func() {
24			task(i)
25		})
26	}
27
28	// 等待所有任务完成
29	time.Sleep(3 * time.Second)
30	fmt.Println("所有任务完成")
31}