//+build linux

package nnet

import (
	"github.com/valyala/tcplisten"
	"net"
	"syscall"
)

var cfg = tcplisten.Config{
	ReusePort: true, DeferAccept: true, FastOpen: true, Backlog: 0,
}

func Listen(addr string) (net.Listener, error) {
	err := setMaxConn()
	if err != nil {
		return nil, err
	}

	return cfg.NewListener("tcp4", addr)
}

func setMaxConn() error {
	var RLimit syscall.Rlimit
	err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &RLimit)
	if err != nil {
		return err
	}
	RLimit.Cur = 800000
	RLimit.Max = 800000
	err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &RLimit)
	if err != nil {
		return err
	}
	err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &RLimit)
	if err != nil {
		return err
	}
	return nil
}