t.Cleanup(func() {
		testPreHookSetKeepAlive = func(*netFD) {}
	})
	var (
		errHook error
		oldCfg  KeepAliveConfig
	)
	testPreHookSetKeepAlive = func(nfd *netFD) {
		oldCfg, errHook = getCurrentKeepAliveSettings(fdType(nfd.pfd.Sysfd))
	}

	handler := func(ls *localServer, ln Listener) {
		for {
			c, err := ln.Accept()
			if err != nil {
				return
			}
			c.Close()
		}
	}

// license that can be found in the LICENSE file.

//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || windows

package net

import (
	"syscall"
	"testing"
	"time"
)

func getCurrentKeepAliveSettings(fd fdType) (cfg KeepAliveConfig, err error) {
	tcpKeepAlive, err := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_KEEPALIVE)
	if err != nil {
		return
	}

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build illumos

package net

import (
	"syscall"
	"testing"
	"time"
)

func getCurrentKeepAliveSettings(fd fdType) (cfg KeepAliveConfig, err error) {
	tcpKeepAlive, err := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_KEEPALIVE)
	if err != nil {
		return
	}

// license that can be found in the LICENSE file.

//go:build solaris && !illumos

package net

import (
	"internal/syscall/unix"
	"syscall"
	"testing"
	"time"
)

func getCurrentKeepAliveSettings(fd fdType) (cfg KeepAliveConfig, err error) {
	tcpKeepAlive, err := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_KEEPALIVE)
	if err != nil {
		return
	}

	var (
		tcpKeepAliveIdle         int