Benchmark Mutex vs Channel

benchmark_mutex_and_channel_test.go

package main

import (
	"errors"
	"sync"
	"testing"
)

func BenchmarkChannel(b *testing.B) {
	ch := make(chan error, 1)
	for i := 0; i < b.N; i++ {
		wg := sync.WaitGroup{}
		wg.Add(16)

		err := errors.New("unknown error")

		for i := 0; i < 16; i++ {
			go func() {
				defer wg.Done()
				select {
				case ch <- err:
				default:
				}
			}()
		}

		wg.Wait()
	}
}

func BenchmarkMutex(b *testing.B) {
	var firstError error
	var mutex sync.Mutex
	for i := 0; i < b.N; i++ {
		wg := sync.WaitGroup{}
		wg.Add(16)

		err := errors.New("unknown error")

		for i := 0; i < 16; i++ {
			go func() {
				defer wg.Done()

				mutex.Lock()
				defer mutex.Unlock()
				if firstError == nil {
					firstError = err
				}

			}()
		}

		wg.Wait()
	}
}

$ go test -benchmem -bench .
goos: darwin
goarch: amd64
pkg: github.com/golang/playground
BenchmarkChannel-8   	  300000	      4525 ns/op	      32 B/op	       2 allocs/op
BenchmarkMutex-8     	  200000	      6342 ns/op	      32 B/op	       2 allocs/op
PASS
ok  	github.com/golang/playground	2.749s