blob: 09adb9bdca4cd7319ab0dedf058a050775f19adc [file] [log] [blame]
// 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.
package net
import (
"context"
"errors"
"fmt"
"io"
"os"
"runtime"
"sync"
"testing"
"time"
)
func init() {
// Install a hook to ensure that a 1ns timeout will always
// be exceeded by the time Dial gets to the relevant system call.
//
// Without this, systems with a very large timer granularity — such as
// Windows — may be able to accept connections without measurably exceeding
// even an implausibly short deadline.
testHookStepTime = func() {
now := time.Now()
for time.Since(now) == 0 {
time.Sleep(1 * time.Nanosecond)
}
}
}
var dialTimeoutTests = []struct {
initialTimeout time.Duration
initialDelta time.Duration // for deadline
}{
// Tests that dial timeouts, deadlines in the past work.
{-5 * time.Second, 0},
{0, -5 * time.Second},
{-5 * time.Second, 5 * time.Second}, // timeout over deadline
{-1 << 63, 0},
{0, -1 << 63},
{1 * time.Millisecond, 0},
{0, 1 * time.Millisecond},
{1 * time.Millisecond, 5 * time.Second}, // timeout over deadline
}
func TestDialTimeout(t *testing.T) {
switch runtime.GOOS {
case "plan9":
t.Skipf("not supported on %s", runtime.GOOS)
}
t.Parallel()
ln := newLocalListener(t, "tcp")
defer func() {
if err := ln.Close(); err != nil {
t.Error(err)
}
}()
for _, tt := range dialTimeoutTests {
t.Run(fmt.Sprintf("%v/%v", tt.initialTimeout, tt.initialDelta), func(t *testing.T) {
// We don't run these subtests in parallel because we don't know how big
// the kernel's accept queue is, and we don't want to accidentally saturate
// it with concurrent calls. (That could cause the Dial to fail with
// ECONNREFUSED or ECONNRESET instead of a timeout error.)
d := Dialer{Timeout: tt.initialTimeout}
delta := tt.initialDelta
var (
beforeDial time.Time
afterDial time.Time
err error
)
for {
if delta != 0 {
d.Deadline = time.Now().Add(delta)
}
beforeDial = time.Now()
var c Conn
c, err = d.Dial(ln.Addr().Network(), ln.Addr().String())
afterDial = time.Now()
if err != nil {
break
}
// Even though we're not calling Accept on the Listener, the kernel may
// spuriously accept connections on its behalf. If that happens, we will
// close the connection (to try to get it out of the kernel's accept
// queue) and try a shorter timeout.
//
// We assume that we will reach a point where the call actually does
// time out, although in theory (since this socket is on a loopback
// address) a sufficiently clever kernel could notice that no Accept
// call is pending and bypass both the queue and the timeout to return
// another error immediately.
t.Logf("closing spurious connection from Dial")
c.Close()
if delta <= 1 && d.Timeout <= 1 {
t.Fatalf("can't reduce Timeout or Deadline")
}
if delta > 1 {
delta /= 2
t.Logf("reducing Deadline delta to %v", delta)
}
if d.Timeout > 1 {
d.Timeout /= 2
t.Logf("reducing Timeout to %v", d.Timeout)
}
}
if d.Deadline.IsZero() || afterDial.Before(d.Deadline) {
delay := afterDial.Sub(beforeDial)
if delay < d.Timeout {
t.Errorf("Dial returned after %v; want ≥%v", delay, d.Timeout)
}
}
if perr := parseDialError(err); perr != nil {
t.Errorf("unexpected error from Dial: %v", perr)
}
if nerr, ok := err.(Error); !ok || !nerr.Timeout() {
t.Errorf("Dial: %v, want timeout", 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)
}
})
}
}
func TestAcceptTimeout(t *testing.T) {
t.Parallel()
switch runtime.GOOS {
case "plan9":
t.Skipf("not supported on %s", runtime.GOOS)
}
timeouts := []time.Duration{
-5 * time.Second,
10 * time.Millisecond,
}
for _, timeout := range timeouts {
timeout := timeout
t.Run(fmt.Sprintf("%v", timeout), func(t *testing.T) {
t.Parallel()
ln := newLocalListener(t, "tcp")
defer ln.Close()
if timeout >= 0 {
// Don't dial the listener at all, so that Accept will hang.
} else {
// A deadline in the past should cause Accept to fail even if there are
// incoming connections available. Try to make one available before the
// call to Accept happens. (It's ok if the timing doesn't always work
// out that way, though: the test should pass regardless.)
ctx, cancel := context.WithCancel(context.Background())
dialDone := make(chan struct{})
// Ensure that our background Dial returns before we close the listener.
// Otherwise, the listener's port could be reused immediately and we
// might spuriously Dial some completely unrelated socket, causing some
// other test to see an unexpected extra connection.
defer func() {
cancel()
<-dialDone
}()
go func() {
defer close(dialDone)
d := Dialer{}
c, err := d.DialContext(ctx, ln.Addr().Network(), ln.Addr().String())
if err != nil {
// If the timing didn't work out, it is possible for this Dial
// to return an error (depending on the kernel's buffering behavior).
// In https://go.dev/issue/65240 we saw failures with ECONNREFUSED
// and ECONNRESET.
//
// What this test really cares about is the behavior of Accept, not
// Dial, so just log the error and ignore it.
t.Logf("DialContext: %v", err)
return
}
t.Logf("Dialed %v -> %v", c.LocalAddr(), c.RemoteAddr())
c.Close()
}()
time.Sleep(10 * time.Millisecond)
}
if err := ln.(*TCPListener).SetDeadline(time.Now().Add(timeout)); err != nil {
t.Fatal(err)
}
t.Logf("ln.SetDeadline(time.Now().Add(%v))", timeout)
c, err := ln.Accept()
if err == nil {
c.Close()
}
t.Logf("ln.Accept: %v", err)
if perr := parseAcceptError(err); perr != nil {
t.Error(perr)
}
if !isDeadlineExceeded(err) {
t.Error("wanted deadline exceeded")
}
})
}
}
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()
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()
}
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 [1024]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 success.
//
// 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
var err error
for {
var dn int
dn, err = c.Write([]byte("TIMEOUT TRANSMITTER"))
n += int64(dn)
if err != nil {
break
}
}
t1 := time.Now()
// Inv: err != nil
if !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)
}
func testVariousDeadlines(t *testing.T) {
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
}