channel_test.go

package main

import (
	"sync"
	"testing"
)

// probably not necessary, but whatever
type message struct {
	arbitrary []byte
	result    chan error
}

func runBench(b *testing.B, c chan message, f func()) {
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()
		for completion := range c {
			completion.result <- nil
		}
	}()

	b.RunParallel(func(pb *testing.PB) {
		for pb.Next() {
			f()
		}
	})
	close(c)
	wg.Wait()
}

func BenchmarkChanThrowaway(b *testing.B) {
	dest := make(chan message, 1000)
	runBench(b, dest, func() {
		completion := make(chan error, 1)
		dest <- message{result: completion}
		<-completion
	})
}

func BenchmarkChanPool(b *testing.B) {
	dest := make(chan message, 1000)
	pool := sync.Pool{New: func() interface{} { return make(chan error, 1) }}
	runBench(b, dest, func() {
		completion := pool.Get().(chan error)
		dest <- message{result: completion}
		<-completion
		pool.Put(completion)
	})
}

results.txt

$ go test -parallel 8 -bench .
testing: warning: no tests to run
PASS
BenchmarkChanThrowaway-4	 2000000	       818 ns/op
BenchmarkChanPool-4     	 2000000	       691 ns/op
ok  	producer	4.582s
$ go test -parallel 24 -bench .
testing: warning: no tests to run
PASS
BenchmarkChanThrowaway-4	 2000000	       774 ns/op
BenchmarkChanPool-4     	 2000000	       701 ns/op
ok  	producer	4.442s