"cgo benchmark"

gist title

benchmark output

cpu: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
BenchmarkGoToGoCall-12    	1000000000	         0.2525 ns/op
BenchmarkGoToCCall-12     	22471992	        53.89 ns/op
BenchmarkCToGoCall-12     	 8209108	       148.8 ns/op

helper.c

#include <stdint.h>

void call() {
}

void goCallback();

void callCallback() {
  goCallback();
}

helper.go

package helper

// #include <stdint.h>
// void call();
// void callCallback();
import "C"

import (
	"runtime"
)

func GoCall(v interface{}) {
	runtime.KeepAlive(v)
}

func CCall() {
	C.call()
}

//export goCallback
func goCallback() {
}

func GoCallback() {
	C.callCallback()
}

helper_test.go

package helper

import (
	"testing"
)

func BenchmarkGoToGoCall(b *testing.B) {
	for i := 0; i < b.N; i++ {
		GoCall(i)
	}
}

func BenchmarkGoToCCall(b *testing.B) {
	for i := 0; i < b.N; i++ {
		CCall()
	}
}

func BenchmarkCToGoCall(b *testing.B) {
	for i := 0; i < b.N; i++ {
		GoCallback()
	}
}