Golangchannelselect并发控制解析

ch1 := make(chan string)
ch2 := make(chan string)
go func() { time.Sleep(2  time.Second); ch1 <- "result from source 1" }()
go func() { time.Sleep(1  time.Second); ch2 <- "result from source 2" }()
select {
case res := <-ch1:
fmt.Println(res)
case res := <-ch2:
fmt.Println(res)
}
// 输出: result from source 2（更快）

select {
case data := 

done := make(chan struct{})
go func() {
time.Sleep(5 * time.Second)
close(done) // 模拟任务完成
}()
go func() {
for {
select {
case <-done:
fmt.Println("task stopped")
return
default:
fmt.Print(".")
time.Sleep(500 * time.Millisecond)
}
}
}()
time.Sleep(3 * time.Second)
fmt.Println("\nmain exits")

stage1 := make(chan int)
stage2 := make(chan int)
finish := make(chan bool)
go func() {
stage1 <- 100
}()
go func() {
val := <-stage1
stage2 <- val * 2
}()
go func() {
val := <-stage2
fmt.Println("final result:", val)
finish <- true
}()
select {
case <-finish:
fmt.Println("pipeline completed")
case <-time.After(2 * time.Second):
fmt.Println("pipeline timeout")
}