Adding upstream version 1.19.8.upstream/1.19.8upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 706 insertions, 0 deletions

diff --git a/src/os/timeout_test.go b/src/os/timeout_test.go
new file mode 100644
index 0000000..ff0d77a
--- /dev/null
+++ b/src/os/timeout_test.go
@@ -0,0 +1,706 @@
+// 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.
+
+//go:build !js && !plan9 && !windows
+
+package os_test
+
+import (
+	"fmt"
+	"io"
+	"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 := os.CreateTemp("", "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{os.ErrDeadlineExceeded, os.ErrDeadlineExceeded}},
+
+	{50 * time.Millisecond, [2]error{nil, os.ErrDeadlineExceeded}},
+}
+
+// There is a very similar copy of this in net/timeout_test.go.
+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 !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 net/timeout_test.go.
+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{os.ErrDeadlineExceeded, os.ErrDeadlineExceeded}},
+
+	{10 * time.Millisecond, [2]error{nil, os.ErrDeadlineExceeded}},
+}
+
+// There is a very similar copy of this in net/timeout_test.go.
+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 !isDeadlineExceeded(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
+				}
+			}
+		})
+	}
+}
+
+// There is a very similar copy of this in net/timeout_test.go.
+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)
+		}
+	}
+}
+
+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 net/timeout_test.go.
+func TestReadTimeoutFluctuation(t *testing.T) {
+	t.Parallel()
+
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer r.Close()
+	defer w.Close()
+
+	d := minDynamicTimeout
+	b := make([]byte, 256)
+	for {
+		t.Logf("SetReadDeadline(+%v)", d)
+		t0 := time.Now()
+		deadline := t0.Add(d)
+		if err = r.SetReadDeadline(deadline); err != nil {
+			t.Fatalf("SetReadDeadline(%v): %v", deadline, err)
+		}
+		var n int
+		n, err = r.Read(b)
+		t1 := time.Now()
+
+		if n != 0 || err == nil || !isDeadlineExceeded(err) {
+			t.Errorf("Read did not return (0, timeout): (%d, %v)", n, 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 net/timeout_test.go.
+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 := minDynamicTimeout
+	for {
+		t.Logf("SetWriteDeadline(+%v)", d)
+		t0 := time.Now()
+		deadline := t0.Add(d)
+		if err = w.SetWriteDeadline(deadline); err != nil {
+			t.Fatalf("SetWriteDeadline(%v): %v", deadline, err)
+		}
+		var n int64
+		for {
+			var dn int
+			dn, err = w.Write([]byte("TIMEOUT TRANSMITTER"))
+			n += int64(dn)
+			if err != nil {
+				break
+			}
+		}
+		t1 := time.Now()
+
+		if err == nil || !isDeadlineExceeded(err) {
+			t.Fatalf("Write did not return (any, timeout): (%d, %v)", n, 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 net/timeout_test.go.
+func TestVariousDeadlines(t *testing.T) {
+	t.Parallel()
+	testVariousDeadlines(t)
+}
+
+// There is a very similar copy of this in net/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 net/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) {
+	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(io.Discard, r)
+					dt := time.Since(t0)
+					r.Close()
+					actvch <- result{n, err, dt}
+				}()
+
+				select {
+				case res := <-actvch:
+					if !isDeadlineExceeded(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")
+				}
+			})
+		}
+	}
+}
+
+// There is a very similar copy of this in net/timeout_test.go.
+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 && !isDeadlineExceeded(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 && !isDeadlineExceeded(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 cancellation 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 !isDeadlineExceeded(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 cancellation 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(io.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 !isDeadlineExceeded(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.
+}