https://golang.org/doc/effective_go.html#parallel

parallel.go

package main

import (
	"fmt"
	"runtime"
	"time"
)

var numCPU = runtime.NumCPU()

// Vector c
type Vector []float64

func (v Vector) doPart(i, n int, u Vector, done chan<- int) {
	for ; i < n; i++ {
		v[i] = v.op(u[i])
	}

	done <- 1
}

func (v Vector) doAll(u Vector) {
	c := make(chan int, numCPU)
	for i := 0; i < numCPU; i++ {
		go v.doPart(i*len(v)/numCPU, (i+1)*len(v)/numCPU, u, c)
	}

	for i := 0; i < numCPU; i++ {
		<-c
	}
}

func (v Vector) op(value float64) float64 {
	time.Sleep(time.Second)
	fmt.Println(value)

	return value
}

func main() {
	v := Vector(make([]float64, 100))
	u := Vector(make([]float64, 100))

	for i := 0; i < len(v); i++ {
		v[i] = float64(i)
		u[i] = float64(i)
	}

	v.doAll(u)
}