Golang程序
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// Copyright 2017 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.
// +build !nacl
// +build !js
// +build !plan9
// +build !windows
package os_test
import (
"fmt"
"internal/poll"
"io"
"io/ioutil"
"math/rand"
"os"
"os/signal"
"runtime"
"sync"
"syscall"
"testing"
"time"
)
func TestNonpollableDeadline(t *testing.T) {
// On BSD systems regular files seem to be pollable,
// so just run this test on Linux.
if runtime.GOOS != "linux" {
t.Skipf("skipping on %s", runtime.GOOS)
}
f, err := ioutil.TempFile("", "ostest")
if err != nil {
t.Fatal(err)
}
defer os.Remove(f.Name())
defer f.Close()
deadline := time.Now().Add(10 * time.Second)
if err := f.SetDeadline(deadline); err != os.ErrNoDeadline {
t.Errorf("SetDeadline on file returned %v, wanted %v", err, os.ErrNoDeadline)
}
if err := f.SetReadDeadline(deadline); err != os.ErrNoDeadline {
t.Errorf("SetReadDeadline on file returned %v, wanted %v", err, os.ErrNoDeadline)
}
if err := f.SetWriteDeadline(deadline); err != os.ErrNoDeadline {
t.Errorf("SetWriteDeadline on file returned %v, wanted %v", err, os.ErrNoDeadline)
}
}
// noDeadline is a zero time.Time value, which cancels a deadline.
var noDeadline time.Time
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{poll.ErrTimeout, poll.ErrTimeout}},
{50 * time.Millisecond, [2]error{nil, poll.ErrTimeout}},
}
func TestReadTimeout(t *testing.T) {
t.Parallel()
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
if _, err := w.Write([]byte("READ TIMEOUT TEST")); err != nil {
t.Fatal(err)
}
for i, tt := range readTimeoutTests {
if err := r.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 := r.Read(b[:])
if xerr != nil {
if !os.IsTimeout(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
}
}
}
}
func TestReadTimeoutMustNotReturn(t *testing.T) {
t.Parallel()
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
max := time.NewTimer(100 * time.Millisecond)
defer max.Stop()
ch := make(chan error)
go func() {
if err := r.SetDeadline(time.Now().Add(-5 * time.Second)); err != nil {
t.Error(err)
}
if err := r.SetWriteDeadline(time.Now().Add(-5 * time.Second)); err != nil {
t.Error(err)
}
if err := r.SetReadDeadline(noDeadline); err != nil {
t.Error(err)
}
var b [1]byte
_, err := r.Read(b[:])
ch <- err
}()
select {
case err := <-ch:
t.Fatalf("expected Read to not return, but it returned with %v", err)
case <-max.C:
w.Close()
err := <-ch // wait for tester goroutine to stop
if os.IsTimeout(err) {
t.Fatal(err)
}
}
}
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{poll.ErrTimeout, poll.ErrTimeout}},
{10 * time.Millisecond, [2]error{nil, poll.ErrTimeout}},
}
func TestWriteTimeout(t *testing.T) {
t.Parallel()
for i, tt := range writeTimeoutTests {
t.Run(fmt.Sprintf("#%d", i), func(t *testing.T) {
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
if err := w.SetWriteDeadline(time.Now().Add(tt.timeout)); err != nil {
t.Fatalf("%v", err)
}
for j, xerr := range tt.xerrs {
for {
n, err := w.Write([]byte("WRITE TIMEOUT TEST"))
if xerr != nil {
if !os.IsTimeout(err) {
t.Fatalf("%d: %v", j, err)
}
}
if err == nil {
time.Sleep(tt.timeout / 3)
continue
}
if n != 0 {
t.Fatalf("%d: wrote %d; want 0", j, n)
}
break
}
}
})
}
}
func TestWriteTimeoutMustNotReturn(t *testing.T) {
t.Parallel()
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
max := time.NewTimer(100 * time.Millisecond)
defer max.Stop()
ch := make(chan error)
go func() {
if err := w.SetDeadline(time.Now().Add(-5 * time.Second)); err != nil {
t.Error(err)
}
if err := w.SetReadDeadline(time.Now().Add(-5 * time.Second)); err != nil {
t.Error(err)
}
if err := w.SetWriteDeadline(noDeadline); err != nil {
t.Error(err)
}
var b [1]byte
for {
if _, err := w.Write(b[:]); err != nil {
ch <- err
break
}
}
}()
select {
case err := <-ch:
t.Fatalf("expected Write to not return, but it returned with %v", err)
case <-max.C:
r.Close()
err := <-ch // wait for tester goroutine to stop
if os.IsTimeout(err) {
t.Fatal(err)
}
}
}
func timeoutReader(r *os.File, d, min, max time.Duration, ch chan<- error) {
var err error
defer func() { ch <- err }()
t0 := time.Now()
if err = r.SetReadDeadline(time.Now().Add(d)); err != nil {
return
}
b := make([]byte, 256)
var n int
n, err = r.Read(b)
t1 := time.Now()
if n != 0 || err == nil || !os.IsTimeout(err) {
err = fmt.Errorf("Read did not return (0, timeout): (%d, %v)", n, err)
return
}
if dt := t1.Sub(t0); min > dt || dt > max && !testing.Short() {
err = fmt.Errorf("Read took %s; expected %s", dt, d)
return
}
}
func TestReadTimeoutFluctuation(t *testing.T) {
t.Parallel()
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
max := time.NewTimer(time.Second)
defer max.Stop()
ch := make(chan error)
go timeoutReader(r, 100*time.Millisecond, 50*time.Millisecond, 250*time.Millisecond, ch)
select {
case <-max.C:
t.Fatal("Read took over 1s; expected 0.1s")
case err := <-ch:
if !os.IsTimeout(err) {
t.Fatal(err)
}
}
}
func timeoutWriter(w *os.File, d, min, max time.Duration, ch chan<- error) {
var err error
defer func() { ch <- err }()
t0 := time.Now()
if err = w.SetWriteDeadline(time.Now().Add(d)); err != nil {
return
}
var n int
for {
n, err = w.Write([]byte("TIMEOUT WRITER"))
if err != nil {
break
}
}
t1 := time.Now()
if err == nil || !os.IsTimeout(err) {
err = fmt.Errorf("Write did not return (any, timeout): (%d, %v)", n, err)
return
}
if dt := t1.Sub(t0); min > dt || dt > max && !testing.Short() {
err = fmt.Errorf("Write took %s; expected %s", dt, d)
return
}
}
func TestWriteTimeoutFluctuation(t *testing.T) {
t.Parallel()
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
d := time.Second
max := time.NewTimer(d)
defer max.Stop()
ch := make(chan error)
go timeoutWriter(w, 100*time.Millisecond, 50*time.Millisecond, 250*time.Millisecond, ch)
select {
case <-max.C:
t.Fatalf("Write took over %v; expected 0.1s", d)
case err := <-ch:
if !os.IsTimeout(err) {
t.Fatal(err)
}
}
}
func TestVariousDeadlines(t *testing.T) {
t.Parallel()
testVariousDeadlines(t)
}
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)
}
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) {
type result struct {
n int64
err error
d time.Duration
}
handler := func(w *os.File, pasvch chan result) {
// The writer, with no timeouts of its own,
// sending bytes to clients as fast as it can.
t0 := time.Now()
n, err := io.Copy(w, neverEnding('a'))
dt := time.Since(t0)
pasvch <- result{n, err, dt}
}
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++ {
t.Run(fmt.Sprintf("%v-%d", timeout, run+1), func(t *testing.T) {
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
pasvch := make(chan result)
go handler(w, pasvch)
tooLong := 5 * time.Second
max := time.NewTimer(tooLong)
defer max.Stop()
actvch := make(chan result)
go func() {
t0 := time.Now()
if err := r.SetDeadline(t0.Add(timeout)); err != nil {
t.Error(err)
}
n, err := io.Copy(ioutil.Discard, r)
dt := time.Since(t0)
r.Close()
actvch <- result{n, err, dt}
}()
select {
case res := <-actvch:
if os.IsTimeout(res.err) {
t.Logf("good client timeout after %v, reading %d bytes", res.d, res.n)
} else {
t.Fatalf("client Copy = %d, %v; want timeout", res.n, res.err)
}
case <-max.C:
t.Fatalf("timeout (%v) waiting for client to timeout (%v) reading", tooLong, timeout)
}
select {
case res := <-pasvch:
t.Logf("writer in %v wrote %d: %v", res.d, res.n, res.err)
case <-max.C:
t.Fatalf("timeout waiting for writer to finish writing")
}
})
}
}
}
func TestReadWriteDeadlineRace(t *testing.T) {
t.Parallel()
N := 1000
if testing.Short() {
N = 50
}
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.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 := r.SetReadDeadline(time.Now().Add(2 * time.Microsecond)); err != nil {
break
}
if err := w.SetWriteDeadline(time.Now().Add(2 * time.Microsecond)); err != nil {
break
}
<-tic.C
}
}()
go func() {
defer wg.Done()
var b [1]byte
for i := 0; i < N; i++ {
_, err := r.Read(b[:])
if err != nil && !os.IsTimeout(err) {
t.Error("Read returned non-timeout error", err)
}
}
}()
go func() {
defer wg.Done()
var b [1]byte
for i := 0; i < N; i++ {
_, err := w.Write(b[:])
if err != nil && !os.IsTimeout(err) {
t.Error("Write returned non-timeout error", err)
}
}
}()
wg.Wait() // wait for tester goroutine to stop
}
// TestRacyRead tests that it is safe to mutate the input Read buffer
// immediately after cancelation has occurred.
func TestRacyRead(t *testing.T) {
t.Parallel()
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
var wg sync.WaitGroup
defer wg.Wait()
go io.Copy(w, rand.New(rand.NewSource(0)))
r.SetReadDeadline(time.Now().Add(time.Millisecond))
for i := 0; i < 10; i++ {
wg.Add(1)
go func() {
defer wg.Done()
b1 := make([]byte, 1024)
b2 := make([]byte, 1024)
for j := 0; j < 100; j++ {
_, err := r.Read(b1)
copy(b1, b2) // Mutate b1 to trigger potential race
if err != nil {
if !os.IsTimeout(err) {
t.Error(err)
}
r.SetReadDeadline(time.Now().Add(time.Millisecond))
}
}
}()
}
}
// TestRacyWrite tests that it is safe to mutate the input Write buffer
// immediately after cancelation has occurred.
func TestRacyWrite(t *testing.T) {
t.Parallel()
r, w, err := os.Pipe()
if err != nil {
t.Fatal(err)
}
defer r.Close()
defer w.Close()
var wg sync.WaitGroup
defer wg.Wait()
go io.Copy(ioutil.Discard, r)
w.SetWriteDeadline(time.Now().Add(time.Millisecond))
for i := 0; i < 10; i++ {
wg.Add(1)
go func() {
defer wg.Done()
b1 := make([]byte, 1024)
b2 := make([]byte, 1024)
for j := 0; j < 100; j++ {
_, err := w.Write(b1)
copy(b1, b2) // Mutate b1 to trigger potential race
if err != nil {
if !os.IsTimeout(err) {
t.Error(err)
}
w.SetWriteDeadline(time.Now().Add(time.Millisecond))
}
}
}()
}
}
// Closing a TTY while reading from it should not hang. Issue 23943.
func TestTTYClose(t *testing.T) {
// Ignore SIGTTIN in case we are running in the background.
signal.Ignore(syscall.SIGTTIN)
defer signal.Reset(syscall.SIGTTIN)
f, err := os.Open("/dev/tty")
if err != nil {
t.Skipf("skipping because opening /dev/tty failed: %v", err)
}
go func() {
var buf [1]byte
f.Read(buf[:])
}()
// Give the goroutine a chance to enter the read.
// It doesn't matter much if it occasionally fails to do so,
// we won't be testing what we want to test but the test will pass.
time.Sleep(time.Millisecond)
c := make(chan bool)
go func() {
defer close(c)
f.Close()
}()
select {
case <-c:
case <-time.After(time.Second):
t.Error("timed out waiting for close")
}
// On some systems the goroutines may now be hanging.
// There's not much we can do about that.
}