package main

import (
        "fmt"
        "time"
        "sync"
)

var p sync.Pool
const reqs = 200000
const bufsz = 256

func syncpool() {
        var buf []byte
        v := p.Get()
        if v == nil {
                buf = make([]byte, bufsz)
        } else {
                buf = v.([]byte)
        }
        buf[0] = 12
        p.Put(buf)
}

func alloc() {
        buf := make([]byte, bufsz)
        buf[0] = 12
}

func bench(f func()) time.Duration {
        var wg sync.WaitGroup
        t := time.Now()
        wg.Add(reqs)
        for i := 0; i < reqs; i++ {
                go func() {
                        f()
                        wg.Done()
                }()
        }
        wg.Wait()
        return time.Since(t) / reqs
}

func benchSerial(f func()) time.Duration {
        t := time.Now()
        for i := 0; i < reqs; i++ {
                f()
        }
        return time.Since(t) / reqs
}

func main() {
        fmt.Println("avg-sp:", bench(syncpool))
        fmt.Println("avg-alloc:", bench(alloc))

        fmt.Println("avg-serial-sp:", benchSerial(syncpool))
        fmt.Println("avg-serial-alloc:", benchSerial(alloc))

}