Long polling with golang... only 282 clients?

log

% 8g -V                 
8g version weekly.2011-06-16 8787+

% make && ./long_polling
8g  -o _go_.8 long_polling.go
8l  -o long_polling _go_.8

(On a second shell: % ab -c 1000 -n 1000 http://localhost:8000/)

New client: 1
New client: 2
New client: 3
New client: 4
[...]
New client: 281
New client: 282

% ps aux
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
nono     23835  0.6  0.4 3119508 9008 pts/2    Sl+  11:19   0:00 ./long_polling

long_polling.go

package main

import (
	"container/vector"
	"fmt"
	"http"
	"io"
	"io/ioutil"
	"log"
	"os"
	"os/signal"
	"time"
)


func ChannelsKeeper(clients chan chan string, signals chan bool) {
	channels := new(vector.Vector)
	counter  := 0
	go func() {
		for {
			select {
			case <-signals:
				msg := fmt.Sprintf("%d\n", counter)
				for channels.Len() > 0 {
					channel := channels.Pop().(chan string)
					channel <- msg
					close(channel)
				}
				counter++
			case c := <-clients:
				channels.Push(c)
				fmt.Printf("New client: %d\n", channels.Len())
			}
		}
	}()
}


func InstallSignalHandlers(signals chan bool) {
	go func() {
		for s := range signal.Incoming {
			if s == os.SIGINT {
				fmt.Printf("\nCtrl-C signalled\n")
				os.Exit(0)
			} else if s == os.SIGUSR1 {
				signals <- true
			}
		}
	}()
}


func CreatePidfile() {
	pid := []byte(fmt.Sprintf("%d", os.Getpid()))
	ioutil.WriteFile("long_polling.pid", pid, 0755)
}


func MakeLPHandler(clients chan chan string) func(w http.ResponseWriter, r *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		timeout := make(chan bool, 1)
		message := make(chan string, 1)

		clients <- message

		go func () {
			time.Sleep(60e9)
			timeout <- true
			close(timeout)
		}()

		select {
		case <-timeout:
			io.WriteString(w, "Timeout!\n")
		case msg := <-message:
			io.WriteString(w, msg)
		}
	}
}


func CreateHttpServer(clients chan chan string) {
	http.HandleFunc("/", MakeLPHandler(clients))
	err := http.ListenAndServe(":8000", nil)
	if err != nil {
		log.Fatal("ListenAndServe: ", err.String())
	}
}


func main() {
	clients := make(chan chan string, 1)
	signals := make(chan bool, 1)

	CreatePidfile()
	ChannelsKeeper(clients, signals)
	InstallSignalHandlers(signals)
	CreateHttpServer(clients)
}

Makefile

include $(GOROOT)/src/Make.inc

TARG=long_polling
GOFILES=long_polling.go

include $(GOROOT)/src/Make.cmd