defer_bench.go

package locktest

import (
       	"sync"
       	"testing"
)

var l sync.Mutex

func dLock() {
       	l.Lock()
       	defer l.Unlock()
}

func lock() {
       	l.Lock()
       	l.Unlock()
}

func BenchmarkLock(b *testing.B) {
       	for n := 0; n < b.N; n++ {
       		lock()
       	}
}

func BenchmarkDeferLock(b *testing.B) {
       	for n := 0; n < b.N; n++ {
       		dLock()
       	}
}

result.txt

PASS
BenchmarkLock-4        	100000000      	        20.7 ns/op
BenchmarkDeferLock-4   	20000000       	        93.2 ns/op
ok     	_/Users/ryanuber/Desktop       	4.055s