OXIESEC PANEL

Name	Size	Modified	Perms
📁 ..	-	12/01/2022 06:13:58 PM	rwxr-xr-x
📄 addrselect.go	9.44 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 addrselect_test.go	6.22 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_aix.go	582 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_android.go	272 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_bsd.go	353 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_linux.go	642 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_netbsd.go	276 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_openbsd.go	276 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_resnew.go	590 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_resold.go	579 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_socknew.go	753 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_sockold.go	852 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_solaris.go	343 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_stub.go	1.03 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_unix.go	9.49 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_unix_test.go	1.84 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 cgo_windows.go	402 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 conf.go	9.65 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 conf_netcgo.go	370 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 conf_test.go	9.7 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 conn_test.go	1.73 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dial.go	22.73 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dial_test.go	26.1 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dial_unix_test.go	2.77 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsclient.go	5.57 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsclient_test.go	1.51 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsclient_unix.go	22.72 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsclient_unix_test.go	57.08 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsconfig.go	1.61 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsconfig_unix.go	4.01 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsconfig_unix_test.go	6.69 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsconfig_windows.go	1.42 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 dnsname_test.go	1.98 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_plan9.go	224 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_plan9_test.go	476 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_posix.go	542 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_posix_test.go	981 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_test.go	19.72 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_unix.go	372 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_unix_test.go	762 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_windows.go	355 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 error_windows_test.go	796 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 example_test.go	8.45 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 external_test.go	4.07 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 fcntl_libc_test.go	374 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 fcntl_syscall_test.go	496 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 fd_plan9.go	3.56 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 fd_posix.go	4.29 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 fd_unix.go	5.37 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 fd_windows.go	4.62 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 file.go	1.69 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 file_plan9.go	2.68 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 file_stub.go	489 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 file_test.go	6.38 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 file_unix.go	2.46 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 file_windows.go	521 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 hook.go	628 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 hook_plan9.go	283 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 hook_unix.go	690 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 hook_windows.go	875 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 hosts.go	3.02 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 hosts_test.go	4.58 KB	12/01/2022 06:12:59 PM	rw-r--r--
📁 http	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📄 interface.go	7.17 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_aix.go	4.4 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_bsd.go	2.76 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_bsd_test.go	1.44 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_bsdvar.go	718 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_darwin.go	1.29 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_freebsd.go	1.29 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_linux.go	6.9 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_linux_test.go	3.65 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_plan9.go	4.68 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_solaris.go	2.07 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_stub.go	812 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_test.go	9.67 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_unix_test.go	4.73 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 interface_windows.go	5.41 KB	12/01/2022 06:12:59 PM	rw-r--r--
📁 internal	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📄 ip.go	17.72 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 ip_test.go	25.33 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 iprawsock.go	7.08 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 iprawsock_plan9.go	874 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 iprawsock_posix.go	3.41 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 iprawsock_test.go	5.62 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 ipsock.go	8.97 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 ipsock_plan9.go	7.5 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 ipsock_plan9_test.go	645 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 ipsock_posix.go	7.66 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 ipsock_test.go	6.81 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 listen_test.go	20.51 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 lookup.go	27.82 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 lookup_fake.go	1.64 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 lookup_plan9.go	8.86 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 lookup_test.go	35.13 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 lookup_unix.go	4.46 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 lookup_windows.go	12.53 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 lookup_windows_test.go	8.5 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 mac.go	1.88 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 mac_test.go	3.26 KB	12/01/2022 06:12:59 PM	rw-r--r--
📁 mail	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📄 main_cloexec_test.go	693 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 main_conf_test.go	922 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 main_noconf_test.go	505 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 main_plan9_test.go	392 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 main_posix_test.go	1.38 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 main_test.go	7.08 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 main_unix_test.go	1.19 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 main_windows_test.go	1.08 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 mockserver_test.go	10.79 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 net.go	23.25 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 net_fake.go	6.59 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 net_test.go	13.88 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 net_windows_test.go	16.28 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 netgo.go	427 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 netgo_unix_test.go	656 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📁 netip	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📄 nss.go	3.64 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 nss_test.go	3.35 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 packetconn_test.go	3.03 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 parse.go	7.06 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 parse_test.go	1.46 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 pipe.go	5.43 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 pipe_test.go	1.2 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 platform_test.go	4.57 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 port.go	1.46 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 port_test.go	1.34 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 port_unix.go	1.24 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 protoconn_test.go	7.19 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 rawconn.go	1.89 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 rawconn_stub_test.go	631 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 rawconn_test.go	4.32 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 rawconn_unix_test.go	2.96 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 rawconn_windows_test.go	3.12 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 resolverdialfunc_test.go	8.29 KB	12/01/2022 06:12:59 PM	rw-r--r--
📁 rpc	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📄 sendfile_linux.go	1.1 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sendfile_stub.go	344 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sendfile_test.go	6.72 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sendfile_unix_alt.go	2.01 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sendfile_windows.go	1.02 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 server_test.go	11.01 KB	12/01/2022 06:12:59 PM	rw-r--r--
📁 smtp	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📄 sock_bsd.go	918 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sock_cloexec.go	741 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sock_linux.go	1.53 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sock_linux_test.go	545 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sock_plan9.go	262 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sock_posix.go	6.78 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sock_stub.go	390 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sock_windows.go	1.16 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockaddr_posix.go	914 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockopt_aix.go	1.43 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockopt_bsd.go	2.21 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockopt_linux.go	1.25 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockopt_plan9.go	406 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockopt_posix.go	2.62 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockopt_solaris.go	1.25 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockopt_stub.go	742 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockopt_windows.go	1.51 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockoptip_bsdvar.go	867 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockoptip_linux.go	735 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockoptip_posix.go	1.38 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockoptip_stub.go	767 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 sockoptip_windows.go	819 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 splice_linux.go	1.09 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 splice_stub.go	287 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 splice_test.go	10.05 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 sys_cloexec.go	962 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsock.go	10.61 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsock_plan9.go	2.21 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsock_posix.go	5.31 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsock_test.go	17.32 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsock_unix_test.go	2.35 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_darwin.go	770 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_dragonfly.go	698 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_openbsd.go	365 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_plan9.go	525 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_posix.go	442 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_solaris.go	1.15 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_stub.go	397 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_unix.go	722 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 tcpsockopt_windows.go	741 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📁 testdata	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📁 textproto	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📄 timeout_test.go	28.56 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 udpsock.go	11.83 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 udpsock_plan9.go	4.64 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 udpsock_plan9_test.go	1.31 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 udpsock_posix.go	6.78 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 udpsock_test.go	16.29 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock.go	10.17 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_linux_test.go	2.29 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_plan9.go	1.24 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_posix.go	5.87 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_readmsg_cloexec.go	654 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_readmsg_cmsg_cloexec.go	332 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_readmsg_other.go	275 bytes	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_readmsg_test.go	2.48 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_test.go	10.42 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 unixsock_windows_test.go	2.03 KB	12/01/2022 06:12:59 PM	rw-r--r--
📁 url	-	12/01/2022 06:13:56 PM	rwxr-xr-x
📄 write_unix_test.go	1.61 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 writev_test.go	4.97 KB	12/01/2022 06:12:59 PM	rw-r--r--
📄 writev_unix.go	733 bytes	12/01/2022 06:12:59 PM	rw-r--r--

Editing: timeout_test.go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build !js

package net

import (
	"errors"
	"fmt"
	"internal/testenv"
	"io"
	"net/internal/socktest"
	"os"
	"runtime"
	"sync"
	"testing"
	"time"
)

var dialTimeoutTests = []struct {
	timeout time.Duration
	delta   time.Duration // for deadline

guard time.Duration
	max   time.Duration
}{
	// Tests that dial timeouts, deadlines in the past work.
	{-5 * time.Second, 0, -5 * time.Second, 100 * time.Millisecond},
	{0, -5 * time.Second, -5 * time.Second, 100 * time.Millisecond},
	{-5 * time.Second, 5 * time.Second, -5 * time.Second, 100 * time.Millisecond}, // timeout over deadline
	{-1 << 63, 0, time.Second, 100 * time.Millisecond},
	{0, -1 << 63, time.Second, 100 * time.Millisecond},

{50 * time.Millisecond, 0, 100 * time.Millisecond, time.Second},
	{0, 50 * time.Millisecond, 100 * time.Millisecond, time.Second},
	{50 * time.Millisecond, 5 * time.Second, 100 * time.Millisecond, time.Second}, // timeout over deadline
}

func TestDialTimeout(t *testing.T) {
	// Cannot use t.Parallel - modifies global hooks.
	origTestHookDialChannel := testHookDialChannel
	defer func() { testHookDialChannel = origTestHookDialChannel }()
	defer sw.Set(socktest.FilterConnect, nil)

for i, tt := range dialTimeoutTests {
		switch runtime.GOOS {
		case "plan9", "windows":
			testHookDialChannel = func() { time.Sleep(tt.guard) }
			if runtime.GOOS == "plan9" {
				break
			}
			fallthrough
		default:
			sw.Set(socktest.FilterConnect, func(so *socktest.Status) (socktest.AfterFilter, error) {
				time.Sleep(tt.guard)
				return nil, errTimedout
			})
		}

ch := make(chan error)
		d := Dialer{Timeout: tt.timeout}
		if tt.delta != 0 {
			d.Deadline = time.Now().Add(tt.delta)
		}
		max := time.NewTimer(tt.max)
		defer max.Stop()
		go func() {
			// This dial never starts to send any TCP SYN
			// segment because of above socket filter and
			// test hook.
			c, err := d.Dial("tcp", "127.0.0.1:0")
			if err == nil {
				err = fmt.Errorf("unexpectedly established: tcp:%s->%s", c.LocalAddr(), c.RemoteAddr())
				c.Close()
			}
			ch <- err
		}()

select {
		case <-max.C:
			t.Fatalf("#%d: Dial didn't return in an expected time", i)
		case err := <-ch:
			if perr := parseDialError(err); perr != nil {
				t.Errorf("#%d: %v", i, perr)
			}
			if nerr, ok := err.(Error); !ok || !nerr.Timeout() {
				t.Fatalf("#%d: %v", i, err)
			}
		}
	}
}

func TestDialTimeoutMaxDuration(t *testing.T) {
	ln := newLocalListener(t, "tcp")
	defer func() {
		if err := ln.Close(); err != nil {
			t.Error(err)
		}
	}()

for _, tt := range []struct {
		timeout time.Duration
		delta   time.Duration // for deadline
	}{
		// Large timeouts that will overflow an int64 unix nanos.
		{1<<63 - 1, 0},
		{0, 1<<63 - 1},
	} {
		t.Run(fmt.Sprintf("timeout=%s/delta=%s", tt.timeout, tt.delta), func(t *testing.T) {
			d := Dialer{Timeout: tt.timeout}
			if tt.delta != 0 {
				d.Deadline = time.Now().Add(tt.delta)
			}
			c, err := d.Dial(ln.Addr().Network(), ln.Addr().String())
			if err != nil {
				t.Fatal(err)
			}
			if err := c.Close(); err != nil {
				t.Error(err)
			}
		})
	}
}

var acceptTimeoutTests = []struct {
	timeout time.Duration
	xerrs   [2]error // expected errors in transition
}{
	// Tests that accept deadlines in the past work, even if
	// there's incoming connections available.
	{-5 * time.Second, [2]error{os.ErrDeadlineExceeded, os.ErrDeadlineExceeded}},

{50 * time.Millisecond, [2]error{nil, os.ErrDeadlineExceeded}},
}

func TestAcceptTimeout(t *testing.T) {
	testenv.SkipFlaky(t, 17948)
	t.Parallel()

switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}

ln := newLocalListener(t, "tcp")
	defer ln.Close()

var wg sync.WaitGroup
	for i, tt := range acceptTimeoutTests {
		if tt.timeout < 0 {
			wg.Add(1)
			go func() {
				defer wg.Done()
				d := Dialer{Timeout: 100 * time.Millisecond}
				c, err := d.Dial(ln.Addr().Network(), ln.Addr().String())
				if err != nil {
					t.Error(err)
					return
				}
				c.Close()
			}()
		}

if err := ln.(*TCPListener).SetDeadline(time.Now().Add(tt.timeout)); err != nil {
			t.Fatalf("$%d: %v", i, err)
		}
		for j, xerr := range tt.xerrs {
			for {
				c, err := ln.Accept()
				if xerr != nil {
					if perr := parseAcceptError(err); perr != nil {
						t.Errorf("#%d/%d: %v", i, j, perr)
					}
					if !isDeadlineExceeded(err) {
						t.Fatalf("#%d/%d: %v", i, j, err)
					}
				}
				if err == nil {
					c.Close()
					time.Sleep(10 * time.Millisecond)
					continue
				}
				break
			}
		}
	}
	wg.Wait()
}

func TestAcceptTimeoutMustReturn(t *testing.T) {
	t.Parallel()

switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}

ln := newLocalListener(t, "tcp")
	defer ln.Close()

max := time.NewTimer(time.Second)
	defer max.Stop()
	ch := make(chan error)
	go func() {
		if err := ln.(*TCPListener).SetDeadline(noDeadline); err != nil {
			t.Error(err)
		}
		if err := ln.(*TCPListener).SetDeadline(time.Now().Add(10 * time.Millisecond)); err != nil {
			t.Error(err)
		}
		c, err := ln.Accept()
		if err == nil {
			c.Close()
		}
		ch <- err
	}()

select {
	case <-max.C:
		ln.Close()
		<-ch // wait for tester goroutine to stop
		t.Fatal("Accept didn't return in an expected time")
	case err := <-ch:
		if perr := parseAcceptError(err); perr != nil {
			t.Error(perr)
		}
		if !isDeadlineExceeded(err) {
			t.Fatal(err)
		}
	}
}

func TestAcceptTimeoutMustNotReturn(t *testing.T) {
	t.Parallel()

switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}

ln := newLocalListener(t, "tcp")
	defer ln.Close()

maxch := make(chan *time.Timer)
	ch := make(chan error)
	go func() {
		if err := ln.(*TCPListener).SetDeadline(time.Now().Add(-5 * time.Second)); err != nil {
			t.Error(err)
		}
		if err := ln.(*TCPListener).SetDeadline(noDeadline); err != nil {
			t.Error(err)
		}
		maxch <- time.NewTimer(100 * time.Millisecond)
		_, err := ln.Accept()
		ch <- err
	}()

max := <-maxch
	defer max.Stop()

select {
	case err := <-ch:
		if perr := parseAcceptError(err); perr != nil {
			t.Error(perr)
		}
		t.Fatalf("expected Accept to not return, but it returned with %v", err)
	case <-max.C:
		ln.Close()
		<-ch // wait for tester goroutine to stop
	}
}

var readTimeoutTests = []struct {
	timeout time.Duration
	xerrs   [2]error // expected errors in transition
}{
	// Tests that read deadlines work, even if there's data ready
	// to be read.
	{-5 * time.Second, [2]error{os.ErrDeadlineExceeded, os.ErrDeadlineExceeded}},

{50 * time.Millisecond, [2]error{nil, os.ErrDeadlineExceeded}},
}

// There is a very similar copy of this in os/timeout_test.go.
func TestReadTimeout(t *testing.T) {
	handler := func(ls *localServer, ln Listener) {
		c, err := ln.Accept()
		if err != nil {
			t.Error(err)
			return
		}
		c.Write([]byte("READ TIMEOUT TEST"))
		defer c.Close()
	}
	ls := newLocalServer(t, "tcp")
	defer ls.teardown()
	if err := ls.buildup(handler); err != nil {
		t.Fatal(err)
	}

c, err := Dial(ls.Listener.Addr().Network(), ls.Listener.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

for i, tt := range readTimeoutTests {
		if err := c.SetReadDeadline(time.Now().Add(tt.timeout)); err != nil {
			t.Fatalf("#%d: %v", i, err)
		}
		var b [1]byte
		for j, xerr := range tt.xerrs {
			for {
				n, err := c.Read(b[:])
				if xerr != nil {
					if perr := parseReadError(err); perr != nil {
						t.Errorf("#%d/%d: %v", i, j, perr)
					}
					if !isDeadlineExceeded(err) {
						t.Fatalf("#%d/%d: %v", i, j, err)
					}
				}
				if err == nil {
					time.Sleep(tt.timeout / 3)
					continue
				}
				if n != 0 {
					t.Fatalf("#%d/%d: read %d; want 0", i, j, n)
				}
				break
			}
		}
	}
}

// There is a very similar copy of this in os/timeout_test.go.
func TestReadTimeoutMustNotReturn(t *testing.T) {
	t.Parallel()

switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}

ln := newLocalListener(t, "tcp")
	defer ln.Close()

c, err := Dial(ln.Addr().Network(), ln.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

maxch := make(chan *time.Timer)
	ch := make(chan error)
	go func() {
		if err := c.SetDeadline(time.Now().Add(-5 * time.Second)); err != nil {
			t.Error(err)
		}
		if err := c.SetWriteDeadline(time.Now().Add(-5 * time.Second)); err != nil {
			t.Error(err)
		}
		if err := c.SetReadDeadline(noDeadline); err != nil {
			t.Error(err)
		}
		maxch <- time.NewTimer(100 * time.Millisecond)
		var b [1]byte
		_, err := c.Read(b[:])
		ch <- err
	}()

max := <-maxch
	defer max.Stop()

select {
	case err := <-ch:
		if perr := parseReadError(err); perr != nil {
			t.Error(perr)
		}
		t.Fatalf("expected Read to not return, but it returned with %v", err)
	case <-max.C:
		c.Close()
		err := <-ch // wait for tester goroutine to stop
		if perr := parseReadError(err); perr != nil {
			t.Error(perr)
		}
		if nerr, ok := err.(Error); !ok || nerr.Timeout() || nerr.Temporary() {
			t.Fatal(err)
		}
	}
}

var readFromTimeoutTests = []struct {
	timeout time.Duration
	xerrs   [2]error // expected errors in transition
}{
	// Tests that read deadlines work, even if there's data ready
	// to be read.
	{-5 * time.Second, [2]error{os.ErrDeadlineExceeded, os.ErrDeadlineExceeded}},

{50 * time.Millisecond, [2]error{nil, os.ErrDeadlineExceeded}},
}

func TestReadFromTimeout(t *testing.T) {
	ch := make(chan Addr)
	defer close(ch)
	handler := func(ls *localPacketServer, c PacketConn) {
		if dst, ok := <-ch; ok {
			c.WriteTo([]byte("READFROM TIMEOUT TEST"), dst)
		}
	}
	ls := newLocalPacketServer(t, "udp")
	defer ls.teardown()
	if err := ls.buildup(handler); err != nil {
		t.Fatal(err)
	}

host, _, err := SplitHostPort(ls.PacketConn.LocalAddr().String())
	if err != nil {
		t.Fatal(err)
	}
	c, err := ListenPacket(ls.PacketConn.LocalAddr().Network(), JoinHostPort(host, "0"))
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()
	ch <- c.LocalAddr()

for i, tt := range readFromTimeoutTests {
		if err := c.SetReadDeadline(time.Now().Add(tt.timeout)); err != nil {
			t.Fatalf("#%d: %v", i, err)
		}
		var b [1]byte
		for j, xerr := range tt.xerrs {
			for {
				n, _, err := c.ReadFrom(b[:])
				if xerr != nil {
					if perr := parseReadError(err); perr != nil {
						t.Errorf("#%d/%d: %v", i, j, perr)
					}
					if !isDeadlineExceeded(err) {
						t.Fatalf("#%d/%d: %v", i, j, err)
					}
				}
				if err == nil {
					time.Sleep(tt.timeout / 3)
					continue
				}
				if nerr, ok := err.(Error); ok && nerr.Timeout() && n != 0 {
					t.Fatalf("#%d/%d: read %d; want 0", i, j, n)
				}
				break
			}
		}
	}
}

var writeTimeoutTests = []struct {
	timeout time.Duration
	xerrs   [2]error // expected errors in transition
}{
	// Tests that write deadlines work, even if there's buffer
	// space available to write.
	{-5 * time.Second, [2]error{os.ErrDeadlineExceeded, os.ErrDeadlineExceeded}},

{10 * time.Millisecond, [2]error{nil, os.ErrDeadlineExceeded}},
}

// There is a very similar copy of this in os/timeout_test.go.
func TestWriteTimeout(t *testing.T) {
	t.Parallel()

ln := newLocalListener(t, "tcp")
	defer ln.Close()

for i, tt := range writeTimeoutTests {
		c, err := Dial(ln.Addr().Network(), ln.Addr().String())
		if err != nil {
			t.Fatal(err)
		}
		defer c.Close()

if err := c.SetWriteDeadline(time.Now().Add(tt.timeout)); err != nil {
			t.Fatalf("#%d: %v", i, err)
		}
		for j, xerr := range tt.xerrs {
			for {
				n, err := c.Write([]byte("WRITE TIMEOUT TEST"))
				if xerr != nil {
					if perr := parseWriteError(err); perr != nil {
						t.Errorf("#%d/%d: %v", i, j, perr)
					}
					if !isDeadlineExceeded(err) {
						t.Fatalf("#%d/%d: %v", i, j, err)
					}
				}
				if err == nil {
					time.Sleep(tt.timeout / 3)
					continue
				}
				if n != 0 {
					t.Fatalf("#%d/%d: wrote %d; want 0", i, j, n)
				}
				break
			}
		}
	}
}

// There is a very similar copy of this in os/timeout_test.go.
func TestWriteTimeoutMustNotReturn(t *testing.T) {
	t.Parallel()

switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}

ln := newLocalListener(t, "tcp")
	defer ln.Close()

c, err := Dial(ln.Addr().Network(), ln.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

maxch := make(chan *time.Timer)
	ch := make(chan error)
	go func() {
		if err := c.SetDeadline(time.Now().Add(-5 * time.Second)); err != nil {
			t.Error(err)
		}
		if err := c.SetReadDeadline(time.Now().Add(-5 * time.Second)); err != nil {
			t.Error(err)
		}
		if err := c.SetWriteDeadline(noDeadline); err != nil {
			t.Error(err)
		}
		maxch <- time.NewTimer(100 * time.Millisecond)
		var b [1]byte
		for {
			if _, err := c.Write(b[:]); err != nil {
				ch <- err
				break
			}
		}
	}()

max := <-maxch
	defer max.Stop()

select {
	case err := <-ch:
		if perr := parseWriteError(err); perr != nil {
			t.Error(perr)
		}
		t.Fatalf("expected Write to not return, but it returned with %v", err)
	case <-max.C:
		c.Close()
		err := <-ch // wait for tester goroutine to stop
		if perr := parseWriteError(err); perr != nil {
			t.Error(perr)
		}
		if nerr, ok := err.(Error); !ok || nerr.Timeout() || nerr.Temporary() {
			t.Fatal(err)
		}
	}
}

func TestWriteToTimeout(t *testing.T) {
	t.Parallel()

c1 := newLocalPacketListener(t, "udp")
	defer c1.Close()

host, _, err := SplitHostPort(c1.LocalAddr().String())
	if err != nil {
		t.Fatal(err)
	}

timeouts := []time.Duration{
		-5 * time.Second,
		10 * time.Millisecond,
	}

for _, timeout := range timeouts {
		t.Run(fmt.Sprint(timeout), func(t *testing.T) {
			c2, err := ListenPacket(c1.LocalAddr().Network(), JoinHostPort(host, "0"))
			if err != nil {
				t.Fatal(err)
			}
			defer c2.Close()

if err := c2.SetWriteDeadline(time.Now().Add(timeout)); err != nil {
				t.Fatalf("SetWriteDeadline: %v", err)
			}
			backoff := 1 * time.Millisecond
			nDeadlineExceeded := 0
			for j := 0; nDeadlineExceeded < 2; j++ {
				n, err := c2.WriteTo([]byte("WRITETO TIMEOUT TEST"), c1.LocalAddr())
				t.Logf("#%d: WriteTo: %d, %v", j, n, err)
				if err == nil && timeout >= 0 && nDeadlineExceeded == 0 {
					// If the timeout is nonnegative, some number of WriteTo calls may
					// succeed before the timeout takes effect.
					t.Logf("WriteTo succeeded; sleeping %v", timeout/3)
					time.Sleep(timeout / 3)
					continue
				}
				if isENOBUFS(err) {
					t.Logf("WriteTo: %v", err)
					// We're looking for a deadline exceeded error, but if the kernel's
					// network buffers are saturated we may see ENOBUFS instead (see
					// https://go.dev/issue/49930). Give it some time to unsaturate.
					time.Sleep(backoff)
					backoff *= 2
					continue
				}
				if perr := parseWriteError(err); perr != nil {
					t.Errorf("failed to parse error: %v", perr)
				}
				if !isDeadlineExceeded(err) {
					t.Errorf("error is not 'deadline exceeded'")
				}
				if n != 0 {
					t.Errorf("unexpectedly wrote %d bytes", n)
				}
				if !t.Failed() {
					t.Logf("WriteTo timed out as expected")
				}
				nDeadlineExceeded++
			}
		})
	}
}

const (
	// minDynamicTimeout is the minimum timeout to attempt for
	// tests that automatically increase timeouts until success.
	//
	// Lower values may allow tests to succeed more quickly if the value is close
	// to the true minimum, but may require more iterations (and waste more time
	// and CPU power on failed attempts) if the timeout is too low.
	minDynamicTimeout = 1 * time.Millisecond

// maxDynamicTimeout is the maximum timeout to attempt for
	// tests that automatically increase timeouts until succeess.
	//
	// This should be a strict upper bound on the latency required to hit a
	// timeout accurately, even on a slow or heavily-loaded machine. If a test
	// would increase the timeout beyond this value, the test fails.
	maxDynamicTimeout = 4 * time.Second
)

// timeoutUpperBound returns the maximum time that we expect a timeout of
// duration d to take to return the caller.
func timeoutUpperBound(d time.Duration) time.Duration {
	switch runtime.GOOS {
	case "openbsd", "netbsd":
		// NetBSD and OpenBSD seem to be unable to reliably hit deadlines even when
		// the absolute durations are long.
		// In https://build.golang.org/log/c34f8685d020b98377dd4988cd38f0c5bd72267e,
		// we observed that an openbsd-amd64-68 builder took 4.090948779s for a
		// 2.983020682s timeout (37.1% overhead).
		// (See https://go.dev/issue/50189 for further detail.)
		// Give them lots of slop to compensate.
		return d * 3 / 2
	}
	// Other platforms seem to hit their deadlines more reliably,
	// at least when they are long enough to cover scheduling jitter.
	return d * 11 / 10
}

// nextTimeout returns the next timeout to try after an operation took the given
// actual duration with a timeout shorter than that duration.
func nextTimeout(actual time.Duration) (next time.Duration, ok bool) {
	if actual >= maxDynamicTimeout {
		return maxDynamicTimeout, false
	}
	// Since the previous attempt took actual, we can't expect to beat that
	// duration by any significant margin. Try the next attempt with an arbitrary
	// factor above that, so that our growth curve is at least exponential.
	next = actual * 5 / 4
	if next > maxDynamicTimeout {
		return maxDynamicTimeout, true
	}
	return next, true
}

// There is a very similar copy of this in os/timeout_test.go.
func TestReadTimeoutFluctuation(t *testing.T) {
	ln := newLocalListener(t, "tcp")
	defer ln.Close()

c, err := Dial(ln.Addr().Network(), ln.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

d := minDynamicTimeout
	b := make([]byte, 256)
	for {
		t.Logf("SetReadDeadline(+%v)", d)
		t0 := time.Now()
		deadline := t0.Add(d)
		if err = c.SetReadDeadline(deadline); err != nil {
			t.Fatalf("SetReadDeadline(%v): %v", deadline, err)
		}
		var n int
		n, err = c.Read(b)
		t1 := time.Now()

if n != 0 || err == nil || !err.(Error).Timeout() {
			t.Errorf("Read did not return (0, timeout): (%d, %v)", n, err)
		}
		if perr := parseReadError(err); perr != nil {
			t.Error(perr)
		}
		if !isDeadlineExceeded(err) {
			t.Errorf("Read error is not DeadlineExceeded: %v", err)
		}

actual := t1.Sub(t0)
		if t1.Before(deadline) {
			t.Errorf("Read took %s; expected at least %s", actual, d)
		}
		if t.Failed() {
			return
		}
		if want := timeoutUpperBound(d); actual > want {
			next, ok := nextTimeout(actual)
			if !ok {
				t.Fatalf("Read took %s; expected at most %v", actual, want)
			}
			// Maybe this machine is too slow to reliably schedule goroutines within
			// the requested duration. Increase the timeout and try again.
			t.Logf("Read took %s (expected %s); trying with longer timeout", actual, d)
			d = next
			continue
		}

break
	}
}

// There is a very similar copy of this in os/timeout_test.go.
func TestReadFromTimeoutFluctuation(t *testing.T) {
	c1 := newLocalPacketListener(t, "udp")
	defer c1.Close()

c2, err := Dial(c1.LocalAddr().Network(), c1.LocalAddr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c2.Close()

d := minDynamicTimeout
	b := make([]byte, 256)
	for {
		t.Logf("SetReadDeadline(+%v)", d)
		t0 := time.Now()
		deadline := t0.Add(d)
		if err = c2.SetReadDeadline(deadline); err != nil {
			t.Fatalf("SetReadDeadline(%v): %v", deadline, err)
		}
		var n int
		n, _, err = c2.(PacketConn).ReadFrom(b)
		t1 := time.Now()

if n != 0 || err == nil || !err.(Error).Timeout() {
			t.Errorf("ReadFrom did not return (0, timeout): (%d, %v)", n, err)
		}
		if perr := parseReadError(err); perr != nil {
			t.Error(perr)
		}
		if !isDeadlineExceeded(err) {
			t.Errorf("ReadFrom error is not DeadlineExceeded: %v", err)
		}

actual := t1.Sub(t0)
		if t1.Before(deadline) {
			t.Errorf("ReadFrom took %s; expected at least %s", actual, d)
		}
		if t.Failed() {
			return
		}
		if want := timeoutUpperBound(d); actual > want {
			next, ok := nextTimeout(actual)
			if !ok {
				t.Fatalf("ReadFrom took %s; expected at most %s", actual, want)
			}
			// Maybe this machine is too slow to reliably schedule goroutines within
			// the requested duration. Increase the timeout and try again.
			t.Logf("ReadFrom took %s (expected %s); trying with longer timeout", actual, d)
			d = next
			continue
		}

break
	}
}

func TestWriteTimeoutFluctuation(t *testing.T) {
	switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}

ln := newLocalListener(t, "tcp")
	defer ln.Close()

c, err := Dial(ln.Addr().Network(), ln.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

d := minDynamicTimeout
	for {
		t.Logf("SetWriteDeadline(+%v)", d)
		t0 := time.Now()
		deadline := t0.Add(d)
		if err = c.SetWriteDeadline(deadline); err != nil {
			t.Fatalf("SetWriteDeadline(%v): %v", deadline, err)
		}
		var n int64
		for {
			var dn int
			dn, err = c.Write([]byte("TIMEOUT TRANSMITTER"))
			n += int64(dn)
			if err != nil {
				break
			}
		}
		t1 := time.Now()

if err == nil || !err.(Error).Timeout() {
			t.Fatalf("Write did not return (any, timeout): (%d, %v)", n, err)
		}
		if perr := parseWriteError(err); perr != nil {
			t.Error(perr)
		}
		if !isDeadlineExceeded(err) {
			t.Errorf("Write error is not DeadlineExceeded: %v", err)
		}

actual := t1.Sub(t0)
		if t1.Before(deadline) {
			t.Errorf("Write took %s; expected at least %s", actual, d)
		}
		if t.Failed() {
			return
		}
		if want := timeoutUpperBound(d); actual > want {
			if n > 0 {
				// SetWriteDeadline specifies a time “after which I/O operations fail
				// instead of blocking”. However, the kernel's send buffer is not yet
				// full, we may be able to write some arbitrary (but finite) number of
				// bytes to it without blocking.
				t.Logf("Wrote %d bytes into send buffer; retrying until buffer is full", n)
				if d <= maxDynamicTimeout/2 {
					// We don't know how long the actual write loop would have taken if
					// the buffer were full, so just guess and double the duration so that
					// the next attempt can make twice as much progress toward filling it.
					d *= 2
				}
			} else if next, ok := nextTimeout(actual); !ok {
				t.Fatalf("Write took %s; expected at most %s", actual, want)
			} else {
				// Maybe this machine is too slow to reliably schedule goroutines within
				// the requested duration. Increase the timeout and try again.
				t.Logf("Write took %s (expected %s); trying with longer timeout", actual, d)
				d = next
			}
			continue
		}

break
	}
}

// There is a very similar copy of this in os/timeout_test.go.
func TestVariousDeadlines(t *testing.T) {
	t.Parallel()
	testVariousDeadlines(t)
}

// There is a very similar copy of this in os/timeout_test.go.
func TestVariousDeadlines1Proc(t *testing.T) {
	// Cannot use t.Parallel - modifies global GOMAXPROCS.
	if testing.Short() {
		t.Skip("skipping in short mode")
	}
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
	testVariousDeadlines(t)
}

// There is a very similar copy of this in os/timeout_test.go.
func TestVariousDeadlines4Proc(t *testing.T) {
	// Cannot use t.Parallel - modifies global GOMAXPROCS.
	if testing.Short() {
		t.Skip("skipping in short mode")
	}
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(4))
	testVariousDeadlines(t)
}

type neverEnding byte

func (b neverEnding) Read(p []byte) (int, error) {
	for i := range p {
		p[i] = byte(b)
	}
	return len(p), nil
}

func testVariousDeadlines(t *testing.T) {
	if runtime.GOOS == "plan9" {
		t.Skip("skipping test on plan9; see golang.org/issue/26945")
	}
	type result struct {
		n   int64
		err error
		d   time.Duration
	}

handler := func(ls *localServer, ln Listener) {
		for {
			c, err := ln.Accept()
			if err != nil {
				break
			}
			c.Read(make([]byte, 1)) // wait for client to close connection
			c.Close()
		}
	}
	ls := newLocalServer(t, "tcp")
	defer ls.teardown()
	if err := ls.buildup(handler); err != nil {
		t.Fatal(err)
	}

for _, timeout := range []time.Duration{
		1 * time.Nanosecond,
		2 * time.Nanosecond,
		5 * time.Nanosecond,
		50 * time.Nanosecond,
		100 * time.Nanosecond,
		200 * time.Nanosecond,
		500 * time.Nanosecond,
		750 * time.Nanosecond,
		1 * time.Microsecond,
		5 * time.Microsecond,
		25 * time.Microsecond,
		250 * time.Microsecond,
		500 * time.Microsecond,
		1 * time.Millisecond,
		5 * time.Millisecond,
		100 * time.Millisecond,
		250 * time.Millisecond,
		500 * time.Millisecond,
		1 * time.Second,
	} {
		numRuns := 3
		if testing.Short() {
			numRuns = 1
			if timeout > 500*time.Microsecond {
				continue
			}
		}
		for run := 0; run < numRuns; run++ {
			name := fmt.Sprintf("%v %d/%d", timeout, run, numRuns)
			t.Log(name)

c, err := Dial(ls.Listener.Addr().Network(), ls.Listener.Addr().String())
			if err != nil {
				t.Fatal(err)
			}

t0 := time.Now()
			if err := c.SetDeadline(t0.Add(timeout)); err != nil {
				t.Error(err)
			}
			n, err := io.Copy(io.Discard, c)
			dt := time.Since(t0)
			c.Close()

if nerr, ok := err.(Error); ok && nerr.Timeout() {
				t.Logf("%v: good timeout after %v; %d bytes", name, dt, n)
			} else {
				t.Fatalf("%v: Copy = %d, %v; want timeout", name, n, err)
			}
		}
	}
}

// TestReadWriteProlongedTimeout tests concurrent deadline
// modification. Known to cause data races in the past.
func TestReadWriteProlongedTimeout(t *testing.T) {
	t.Parallel()

switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}

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

var wg sync.WaitGroup
		wg.Add(2)
		go func() {
			defer wg.Done()
			var b [1]byte
			for {
				if err := c.SetReadDeadline(time.Now().Add(time.Hour)); err != nil {
					if perr := parseCommonError(err); perr != nil {
						t.Error(perr)
					}
					t.Error(err)
					return
				}
				if _, err := c.Read(b[:]); err != nil {
					if perr := parseReadError(err); perr != nil {
						t.Error(perr)
					}
					return
				}
			}
		}()
		go func() {
			defer wg.Done()
			var b [1]byte
			for {
				if err := c.SetWriteDeadline(time.Now().Add(time.Hour)); err != nil {
					if perr := parseCommonError(err); perr != nil {
						t.Error(perr)
					}
					t.Error(err)
					return
				}
				if _, err := c.Write(b[:]); err != nil {
					if perr := parseWriteError(err); perr != nil {
						t.Error(perr)
					}
					return
				}
			}
		}()
		wg.Wait()
	}
	ls := newLocalServer(t, "tcp")
	defer ls.teardown()
	if err := ls.buildup(handler); err != nil {
		t.Fatal(err)
	}

c, err := Dial(ls.Listener.Addr().Network(), ls.Listener.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

var b [1]byte
	for i := 0; i < 1000; i++ {
		c.Write(b[:])
		c.Read(b[:])
	}
}

// There is a very similar copy of this in os/timeout_test.go.
func TestReadWriteDeadlineRace(t *testing.T) {
	t.Parallel()

N := 1000
	if testing.Short() {
		N = 50
	}

ln := newLocalListener(t, "tcp")
	defer ln.Close()

c, err := Dial(ln.Addr().Network(), ln.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()

var wg sync.WaitGroup
	wg.Add(3)
	go func() {
		defer wg.Done()
		tic := time.NewTicker(2 * time.Microsecond)
		defer tic.Stop()
		for i := 0; i < N; i++ {
			if err := c.SetReadDeadline(time.Now().Add(2 * time.Microsecond)); err != nil {
				if perr := parseCommonError(err); perr != nil {
					t.Error(perr)
				}
				break
			}
			if err := c.SetWriteDeadline(time.Now().Add(2 * time.Microsecond)); err != nil {
				if perr := parseCommonError(err); perr != nil {
					t.Error(perr)
				}
				break
			}
			<-tic.C
		}
	}()
	go func() {
		defer wg.Done()
		var b [1]byte
		for i := 0; i < N; i++ {
			c.Read(b[:]) // ignore possible timeout errors
		}
	}()
	go func() {
		defer wg.Done()
		var b [1]byte
		for i := 0; i < N; i++ {
			c.Write(b[:]) // ignore possible timeout errors
		}
	}()
	wg.Wait() // wait for tester goroutine to stop
}

// Issue 35367.
func TestConcurrentSetDeadline(t *testing.T) {
	ln := newLocalListener(t, "tcp")
	defer ln.Close()

const goroutines = 8
	const conns = 10
	const tries = 100

var c [conns]Conn
	for i := 0; i < conns; i++ {
		var err error
		c[i], err = Dial(ln.Addr().Network(), ln.Addr().String())
		if err != nil {
			t.Fatal(err)
		}
		defer c[i].Close()
	}

var wg sync.WaitGroup
	wg.Add(goroutines)
	now := time.Now()
	for i := 0; i < goroutines; i++ {
		go func(i int) {
			defer wg.Done()
			// Make the deadlines steadily earlier,
			// to trigger runtime adjusttimers calls.
			for j := tries; j > 0; j-- {
				for k := 0; k < conns; k++ {
					c[k].SetReadDeadline(now.Add(2*time.Hour + time.Duration(i*j*k)*time.Second))
					c[k].SetWriteDeadline(now.Add(1*time.Hour + time.Duration(i*j*k)*time.Second))
				}
			}
		}(i)
	}
	wg.Wait()
}

// isDeadlineExceeded reports whether err is or wraps os.ErrDeadlineExceeded.
// We also check that the error implements net.Error, and that the
// Timeout method returns true.
func isDeadlineExceeded(err error) bool {
	nerr, ok := err.(Error)
	if !ok {
		return false
	}
	if !nerr.Timeout() {
		return false
	}
	if !errors.Is(err, os.ErrDeadlineExceeded) {
		return false
	}
	return true
}