chanVSatomic.go

/*
$ ./chanBench
Use Channel
Use Channel runs 1014856858 in 5 seconds, average 202971371 calls/s

Use Atomic
Use Channel runs 16146198617 in 5 seconds, average 3229239723 calls/s
*/
package main

import (
	"fmt"
	"sync/atomic"
	"time"
)

func main() {
	res := make(chan int)
	fmt.Println("Use Channel")
	m := &MyBench{end: make(chan struct{})}
	go m.useChan(res)
	<-time.After(time.Second * 5)
	m.CloseCh()
	resTimes := <-res
	fmt.Printf("Use Channel runs %d in %d seconds, average %v calls/s\n", resTimes, 5, (resTimes / 5.0))
	fmt.Println()

	fmt.Println("Use Atomic")
	go func() {
		<-time.After(time.Second * 5)
		m.CloseAtomic()
	}()
	resTimes = m.useAtomic()
	fmt.Printf("Use Channel runs %d in %d seconds, average %v calls/s\n", resTimes, 5, (resTimes / 5.0))
	fmt.Println()
}

type MyBench struct {
	stop uint64
	end  chan struct{}
}

func (m *MyBench) CloseCh() {
	close(m.end)
}

func (m *MyBench) CloseAtomic() {
	atomic.StoreUint64(&m.stop, 1)
}

func (m *MyBench) useChan(count chan<- int) {
	times := 0
	for {
		select {
		case <-m.end:
			count <- times
			return
		default:
			times++
		}
	}
}

func (m *MyBench) useAtomic() int {
	times := 0
	for atomic.LoadUint64(&m.stop) == 0 {
		times++
	}
	return times
}