golang basic multi client run queue

go_clients.go

/* -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.

* File Name : main.go

* Purpose :

* Creation Date : 02-26-2014

* Last Modified : Wed 26 Feb 2014 01:30:21 AM UTC

* Created By : Kiyor

_._._._._._._._._._._._._._._._._._._._._.*/

package main

import (
	"fmt"
	"math/rand"
	"runtime"
	"sync"
	"time"
)

type client struct {
	conn interface{}
	loc  *bool
}

func (c *client) lock() {
	*c.loc = true
}

func (c *client) unlock() {
	*c.loc = false
}

type worker struct {
	sync.WaitGroup
	counter *int
}

func (w *worker) add(n int) {
	w.Add(n)
	*w.counter += n
}

func (w *worker) done() {
	*w.counter--
	w.Done()
}

func initClient() client {
	var conn interface{}
	return client{conn, new(bool)}
}

func (c *client) doSomething(id, index int, w worker) {
	r := random(5)
	for i := 0; i < random(5); i++ {
		time.Sleep(1 * time.Second)
	}
	fmt.Printf("I'm doing process[%d] in client[%d] and finish it using %d seconds, running %d\n", index, id, r, *w.counter-1)
	c.unlock()
}

func random(rg int) int {
	return rand.Intn(rg) + 1
}

func getClient(clients []client) int {
	for {
		for k, c := range clients {
			if !*c.loc {
				c.lock()
				return k
			}
		}
		time.Sleep(1 * time.Millisecond)
	}
}

var (
	clients []client
	size    = 10
	process = 100
)

func init() {
	runtime.GOMAXPROCS(runtime.NumCPU())
	for i := 0; i < size; i++ {
		clients = append(clients, initClient())
	}
}

func main() {
	var w worker
	w.counter = new(int)
	for i := 0; i < process; i++ {
		w.add(1)
		id := getClient(clients)
		go func(id, i int, w *worker) {
			clients[id].doSomething(id, i, *w)
			w.done()
		}(id, i, &w)
	}
	w.Wait()
}