Diff btw chan size 0 and 1

main.go

package main

import (
	"fmt"
	"time"
)

func main() {
	// c := make(chan struct{}, 1)
	c := make(chan struct{})
	go func() {
		time.Sleep(2 * time.Second)
		<-c
	}()
	start := time.Now()
	c <- struct{}{}
	elapsed := time.Since(start)
	fmt.Printf("Elapsed: %v\n", elapsed)
}