You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: system_listener.go
    path of file: ./repos/Xray-core/transport/internet
    
    the code of the file until where you have to start completion: package internet

import (
	"context"
	"os"
	"runtime"
	"strconv"
	"strings"
	"syscall"
	"time"

	"github.com/pires/go-proxyproto"
	"github.com/sagernet/sing/common/control"
	"github.com/xtls/xray-core/common/net"
	"github.com/xtls/xray-core/common/session"
)

var effectiveListener = DefaultListener{}

type DefaultListener struct {
	controllers []control.Func
}

type combinedListener struct {
	net.Listener
	locker *FileLocker // for unix domain socket
}

func (cl *combinedListener) Close() error {
	if cl.locker != nil {
		cl.locker.Release()
		cl.locker = nil
	}
	r
    
func getControlFunc(ctx context.Context, sockopt *SocketConfig, controllers []control.Func) func(network, address string, c syscall.RawConn) error {
	return func(network, address string, c syscall.RawConn) error {
		return c.Control(func(fd uintptr) {
			for _, controller := range controllers {
				if err := controller(network, address, c); err != nil {
					newError("failed to apply external controller").Base(err).WriteToLog(session.ExportIDToError(ctx))
				}
			}

			if sockopt != nil {
				if err := applyInboundSocketOptions(network, fd, sockopt); err != nil {
					newError("failed to apply socket options to incoming connection").Base(err).WriteToLog(session.ExportIDToError(ctx))
				}
			}

			setReusePort(fd)
		})
	}
}