pingpong_benchmark.go

// Explain the following benchmark results:
//
// Benchmark____SingleThread	      10	 155639126 ns/op
// Benchmark_MultipleThreads	       5	 885528027 ns/op
//
// Run on a Core i7 processor (4 cores).

package benchmarks

import (
	"runtime"
	"testing"
)

const (
	PING int = iota
	PONG
)

func pingPong(b *testing.B) {
	for j := 0; j < 100000; j++ {
		pingCh := make(chan int, 1)
		pongCh := make(chan int, 1)

		go func() {
			for i := 0; i < b.N; i++ {
				pingCh <- PING
				<-pongCh
			}   
			close(pingCh)
		}() 

		go func() {
			for i := 0; i < b.N; i++ {
				pongCh <- PONG
				<-pingCh
			}   
			close(pongCh)
		}() 

		// Wait for the goroutines to return.
		<-pingCh
		<-pongCh
	}   
}

func Benchmark____SingleThread(b *testing.B) {
	pingPong(b)
}

func Benchmark_MultipleThreads(b *testing.B) {
	// Let Go use 2 OS threads.
	runtime.GOMAXPROCS(2)
	defer runtime.GOMAXPROCS(1)

	pingPong(b)
}