Compare global lock to atomics

gistfile1.txt

import (
	"context"
	"sync"
	"sync/atomic"
	"testing"

	"golang.org/x/sync/errgroup"
)


func BenchmarkAtomicIncDec(b *testing.B) {
	var value uint32

	const increase = 1
	const decrease = 2

	actions := make(chan int, 10)

	rootCtx, cancel := context.WithCancel(context.Background())
	group, ctx := errgroup.WithContext(rootCtx)
	for i := 0; i < 10; i++ {
		group.Go(func() error {
			for {
				select {
				case action := <-actions:
					switch action {
					case increase:
						atomic.AddUint32(&value, 1)
					case decrease:
						atomic.AddUint32(&value, ^uint32(0))
					}
				case <-ctx.Done():
					return nil
				}
			}
			return nil
		})
	}

	for i := 0; i < b.N; i++ {
		actions <- increase
		actions <- decrease
	}

	cancel()
}

func BenchmarkLockIncDec(b *testing.B) {
	var value uint32

	globalLock := sync.RWMutex{}

	const increase = 1
	const decrease = 2

	actions := make(chan int, 10)

	rootCtx, cancel := context.WithCancel(context.Background())
	group, ctx := errgroup.WithContext(rootCtx)
	for i := 0; i < 10; i++ {
		group.Go(func() error {
			for {
				select {
				case action := <-actions:
					switch action {
					case increase:
						globalLock.Lock()
						value++
						globalLock.Unlock()
					case decrease:
						globalLock.Lock()
						value--
						globalLock.Unlock()
					}
				case <-ctx.Done():
					return nil
				}
			}
			return nil
		})
	}

	for i := 0; i < b.N; i++ {
		actions <- increase
		actions <- decrease
	}

	cancel()
}