passby_test.go

package main

import (
	"fmt"
	"os"
	"runtime/trace"
	"testing"
)

func BenchmarkMemoryStack(b *testing.B) {
	var s S

	f, err := os.Create("stack.out")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	err = trace.Start(f)
	if err != nil {
		panic(err)
	}

	for i := 0; i < b.N; i++ {
		s = byCopy()
	}

	trace.Stop()

	b.StopTimer()

	_ = fmt.Sprintf("%v", s.a)
}

func BenchmarkMemoryStackArg(b *testing.B) {
	var s S

	f, err := os.Create("stack_arg.out")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	err = trace.Start(f)
	if err != nil {
		panic(err)
	}

	for i := 0; i < b.N; i++ {
		s = byCopy()
		byCopyArg(s)
	}

	trace.Stop()

	b.StopTimer()

	_ = fmt.Sprintf("%v", s.a)
}

func BenchmarkMemoryStackArgReturns(b *testing.B) {
	var s S

	f, err := os.Create("stack_arg_returns.out")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	err = trace.Start(f)
	if err != nil {
		panic(err)
	}

	for i := 0; i < b.N; i++ {
		s = byCopy()
		s = byCopyArgReturns(s)
	}

	trace.Stop()

	b.StopTimer()

	_ = fmt.Sprintf("%v", s.a)
}

func BenchmarkMemoryHeap(b *testing.B) {
	var s *S

	f, err := os.Create("heap.out")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	err = trace.Start(f)
	if err != nil {
		panic(err)
	}

	for i := 0; i < b.N; i++ {
		s = byPointer()
	}

	trace.Stop()

	b.StopTimer()

	_ = fmt.Sprintf("%v", s.a)
}

func BenchmarkMemoryHeapArg(b *testing.B) {
	var s *S

	f, err := os.Create("heap_arg.out")
	if err != nil {
		panic(err)
	}
	defer f.Close()

	err = trace.Start(f)
	if err != nil {
		panic(err)
	}

	for i := 0; i < b.N; i++ {
		s = byPointer()
		byPointerArg(s)
	}

	trace.Stop()

	b.StopTimer()

	_ = fmt.Sprintf("%v", s.a)
}

func TestS(t *testing.T) {
	// verify the array is allocated
	s := byCopy()
	fmt.Printf("%v\n", s)
}