select_close.go

// https://go.dev/play/p/RKU8IstAlhf
// Does close() signals select? Yes
// Is channel picked randomly? Yes
// If there is long buffered channel with many entries will cancel() / other channel be triggered? Yes
package main

import (
	"fmt"
	"time"
)

func main() {
	long := make(chan int, 100)
	for i := 0; i < 100; i++ {
		long <- i
	}

	stop := make(chan bool)
	go func() {
		t := time.NewTicker(time.Millisecond)
		for {
			select {
			case <-t.C:
				fmt.Println("tick")
			case <-stop:
				fmt.Println("stop")
				return
			case i := <-long:
				fmt.Printf("long %d\n", i)
				time.Sleep(time.Millisecond)
			}
		}
	}()

	fmt.Println("main: start")
	time.Sleep(time.Millisecond * 300)

	fmt.Println("main: close")
	close(stop)

	time.Sleep(time.Second)
	fmt.Println("main: exit")
}