goroutine_chan_send_obj_test.go

package main

import "testing"
import "sync"

type obj struct {
	test string
}

type obj2 struct {
	dummy int
	test  string
}

var testString = "Test String"

func BenchmarkSendFunc(b *testing.B) {
	wg := sync.WaitGroup{}
	defer wg.Wait()

	send := make(chan func() int, 1)
	result := make(chan int)

	wg.Add(1)
	go func(wg *sync.WaitGroup, receive chan func() int) {
		defer wg.Done()

		total := 0
		defer func() {
			result <- total
		}()

		for c := range send {
			total += c()
		}
	}(&wg, send)

	b.ReportAllocs()
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		if i%2 == 0 {
			newObj := obj{test: testString}

			send <- func() int {
				return len(newObj.test)
			}
		} else {
			newObj := obj2{dummy: 1, test: testString}

			send <- func() int {
				return len(newObj.test)
			}
		}
	}

	close(send)

	expectedLen := b.N * len(testString)

	if expectedLen != <-result {
		b.Error("Result mismatched")
	}
}

func BenchmarkSendObj(b *testing.B) {
	wg := sync.WaitGroup{}
	defer wg.Wait()

	send := make(chan obj, 1)
	result := make(chan int)

	wg.Add(1)
	go func(wg *sync.WaitGroup, receive chan obj) {
		defer wg.Done()

		total := 0
		defer func() {
			result <- total
		}()

		for c := range send {
			total += len(c.test)
		}
	}(&wg, send)

	b.ReportAllocs()
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		send <- obj{test: testString}
	}

	close(send)

	expectedLen := b.N * len(testString)

	if expectedLen != <-result {
		b.Error("Result mismatched")
	}
}

func BenchmarkSendObjTypeAssert(b *testing.B) {
	wg := sync.WaitGroup{}
	defer wg.Wait()

	send := make(chan interface{}, 1)
	result := make(chan int)

	wg.Add(1)
	go func(wg *sync.WaitGroup, receive chan interface{}) {
		defer wg.Done()

		total := 0
		defer func() {
			result <- total
		}()

		for c := range send {
			switch cc := c.(type) {
			case obj:
				total += len(cc.test)
			case obj2:
				total += len(cc.test)
			default:
				panic("Unsupported type")
			}
		}
	}(&wg, send)

	b.ReportAllocs()
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		if i%2 == 0 {
			send <- obj{test: testString}
		} else {
			send <- obj2{dummy: 1, test: testString}
		}
	}

	close(send)

	expectedLen := b.N * len(testString)

	if expectedLen != <-result {
		b.Error("Result mismatched")
	}
}

$ go test -bench . -benchtime 20s
goos: linux
goarch: amd64
BenchmarkSendFunc-2            	39275546	       627 ns/op	      32 B/op	       1 allocs/op
BenchmarkSendObj-2             	48919554	       452 ns/op	       0 B/op	       0 allocs/op
BenchmarkSendObjTypeAssert-2   	38451140	       624 ns/op	      24 B/op	       1 allocs/op
PASS