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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:25:22 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:25:22 +0000
commitf6ad4dcef54c5ce997a4bad5a6d86de229015700 (patch)
tree7cfa4e31ace5c2bd95c72b154d15af494b2bcbef /src/os/pipe_test.go
parentInitial commit. (diff)
downloadgolang-1.22-f6ad4dcef54c5ce997a4bad5a6d86de229015700.tar.xz
golang-1.22-f6ad4dcef54c5ce997a4bad5a6d86de229015700.zip
Adding upstream version 1.22.1.upstream/1.22.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/os/pipe_test.go')
-rw-r--r--src/os/pipe_test.go478
1 files changed, 478 insertions, 0 deletions
diff --git a/src/os/pipe_test.go b/src/os/pipe_test.go
new file mode 100644
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+// Copyright 2015 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.
+
+// Test broken pipes on Unix systems.
+//
+//go:build !plan9 && !js && !wasip1
+
+package os_test
+
+import (
+ "bufio"
+ "bytes"
+ "fmt"
+ "internal/testenv"
+ "io"
+ "io/fs"
+ "os"
+ "os/exec"
+ "os/signal"
+ "runtime"
+ "strconv"
+ "strings"
+ "sync"
+ "syscall"
+ "testing"
+ "time"
+)
+
+func TestEPIPE(t *testing.T) {
+ // This test cannot be run in parallel because of a race similar
+ // to the one reported in https://go.dev/issue/22315.
+ //
+ // Even though the pipe is opened with O_CLOEXEC, if another test forks in
+ // between the call to os.Pipe and the call to r.Close, that child process can
+ // retain an open copy of r's file descriptor until it execs. If one of our
+ // Write calls occurs during that interval it can spuriously succeed,
+ // buffering the write to the child's copy of the pipe (even though the child
+ // will not actually read the buffered bytes).
+
+ r, w, err := os.Pipe()
+ if err != nil {
+ t.Fatal(err)
+ }
+ if err := r.Close(); err != nil {
+ t.Fatal(err)
+ }
+
+ expect := syscall.EPIPE
+ if runtime.GOOS == "windows" {
+ // 232 is Windows error code ERROR_NO_DATA, "The pipe is being closed".
+ expect = syscall.Errno(232)
+ }
+ // Every time we write to the pipe we should get an EPIPE.
+ for i := 0; i < 20; i++ {
+ _, err = w.Write([]byte("hi"))
+ if err == nil {
+ t.Fatal("unexpected success of Write to broken pipe")
+ }
+ if pe, ok := err.(*fs.PathError); ok {
+ err = pe.Err
+ }
+ if se, ok := err.(*os.SyscallError); ok {
+ err = se.Err
+ }
+ if err != expect {
+ t.Errorf("iteration %d: got %v, expected %v", i, err, expect)
+ }
+ }
+}
+
+func TestStdPipe(t *testing.T) {
+ switch runtime.GOOS {
+ case "windows":
+ t.Skip("Windows doesn't support SIGPIPE")
+ }
+
+ if os.Getenv("GO_TEST_STD_PIPE_HELPER") != "" {
+ if os.Getenv("GO_TEST_STD_PIPE_HELPER_SIGNAL") != "" {
+ signal.Notify(make(chan os.Signal, 1), syscall.SIGPIPE)
+ }
+ switch os.Getenv("GO_TEST_STD_PIPE_HELPER") {
+ case "1":
+ os.Stdout.Write([]byte("stdout"))
+ case "2":
+ os.Stderr.Write([]byte("stderr"))
+ case "3":
+ if _, err := os.NewFile(3, "3").Write([]byte("3")); err == nil {
+ os.Exit(3)
+ }
+ default:
+ panic("unrecognized value for GO_TEST_STD_PIPE_HELPER")
+ }
+ // For stdout/stderr, we should have crashed with a broken pipe error.
+ // The caller will be looking for that exit status,
+ // so just exit normally here to cause a failure in the caller.
+ // For descriptor 3, a normal exit is expected.
+ os.Exit(0)
+ }
+
+ testenv.MustHaveExec(t)
+ // This test cannot be run in parallel due to the same race as for TestEPIPE.
+ // (We expect a write to a closed pipe can fail, but a concurrent fork of a
+ // child process can cause the pipe to unexpectedly remain open.)
+
+ r, w, err := os.Pipe()
+ if err != nil {
+ t.Fatal(err)
+ }
+ if err := r.Close(); err != nil {
+ t.Fatal(err)
+ }
+ // Invoke the test program to run the test and write to a closed pipe.
+ // If sig is false:
+ // writing to stdout or stderr should cause an immediate SIGPIPE;
+ // writing to descriptor 3 should fail with EPIPE and then exit 0.
+ // If sig is true:
+ // all writes should fail with EPIPE and then exit 0.
+ for _, sig := range []bool{false, true} {
+ for dest := 1; dest < 4; dest++ {
+ cmd := testenv.Command(t, os.Args[0], "-test.run", "TestStdPipe")
+ cmd.Stdout = w
+ cmd.Stderr = w
+ cmd.ExtraFiles = []*os.File{w}
+ cmd.Env = append(os.Environ(), fmt.Sprintf("GO_TEST_STD_PIPE_HELPER=%d", dest))
+ if sig {
+ cmd.Env = append(cmd.Env, "GO_TEST_STD_PIPE_HELPER_SIGNAL=1")
+ }
+ if err := cmd.Run(); err == nil {
+ if !sig && dest < 3 {
+ t.Errorf("unexpected success of write to closed pipe %d sig %t in child", dest, sig)
+ }
+ } else if ee, ok := err.(*exec.ExitError); !ok {
+ t.Errorf("unexpected exec error type %T: %v", err, err)
+ } else if ws, ok := ee.Sys().(syscall.WaitStatus); !ok {
+ t.Errorf("unexpected wait status type %T: %v", ee.Sys(), ee.Sys())
+ } else if ws.Signaled() && ws.Signal() == syscall.SIGPIPE {
+ if sig || dest > 2 {
+ t.Errorf("unexpected SIGPIPE signal for descriptor %d sig %t", dest, sig)
+ }
+ } else {
+ t.Errorf("unexpected exit status %v for descriptor %d sig %t", err, dest, sig)
+ }
+ }
+ }
+
+ // Test redirecting stdout but not stderr. Issue 40076.
+ cmd := testenv.Command(t, os.Args[0], "-test.run", "TestStdPipe")
+ cmd.Stdout = w
+ var stderr bytes.Buffer
+ cmd.Stderr = &stderr
+ cmd.Env = append(cmd.Environ(), "GO_TEST_STD_PIPE_HELPER=1")
+ if err := cmd.Run(); err == nil {
+ t.Errorf("unexpected success of write to closed stdout")
+ } else if ee, ok := err.(*exec.ExitError); !ok {
+ t.Errorf("unexpected exec error type %T: %v", err, err)
+ } else if ws, ok := ee.Sys().(syscall.WaitStatus); !ok {
+ t.Errorf("unexpected wait status type %T: %v", ee.Sys(), ee.Sys())
+ } else if !ws.Signaled() || ws.Signal() != syscall.SIGPIPE {
+ t.Errorf("unexpected exit status %v for write to closed stdout", err)
+ }
+ if output := stderr.Bytes(); len(output) > 0 {
+ t.Errorf("unexpected output on stderr: %s", output)
+ }
+}
+
+func testClosedPipeRace(t *testing.T, read bool) {
+ // This test cannot be run in parallel due to the same race as for TestEPIPE.
+ // (We expect a write to a closed pipe can fail, but a concurrent fork of a
+ // child process can cause the pipe to unexpectedly remain open.)
+
+ limit := 1
+ if !read {
+ // Get the amount we have to write to overload a pipe
+ // with no reader.
+ limit = 131073
+ if b, err := os.ReadFile("/proc/sys/fs/pipe-max-size"); err == nil {
+ if i, err := strconv.Atoi(strings.TrimSpace(string(b))); err == nil {
+ limit = i + 1
+ }
+ }
+ t.Logf("using pipe write limit of %d", limit)
+ }
+
+ r, w, err := os.Pipe()
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer r.Close()
+ defer w.Close()
+
+ // Close the read end of the pipe in a goroutine while we are
+ // writing to the write end, or vice-versa.
+ go func() {
+ // Give the main goroutine a chance to enter the Read or
+ // Write call. This is sloppy but the test will pass even
+ // if we close before the read/write.
+ time.Sleep(20 * time.Millisecond)
+
+ var err error
+ if read {
+ err = r.Close()
+ } else {
+ err = w.Close()
+ }
+ if err != nil {
+ t.Error(err)
+ }
+ }()
+
+ b := make([]byte, limit)
+ if read {
+ _, err = r.Read(b[:])
+ } else {
+ _, err = w.Write(b[:])
+ }
+ if err == nil {
+ t.Error("I/O on closed pipe unexpectedly succeeded")
+ } else if pe, ok := err.(*fs.PathError); !ok {
+ t.Errorf("I/O on closed pipe returned unexpected error type %T; expected fs.PathError", pe)
+ } else if pe.Err != fs.ErrClosed {
+ t.Errorf("got error %q but expected %q", pe.Err, fs.ErrClosed)
+ } else {
+ t.Logf("I/O returned expected error %q", err)
+ }
+}
+
+func TestClosedPipeRaceRead(t *testing.T) {
+ testClosedPipeRace(t, true)
+}
+
+func TestClosedPipeRaceWrite(t *testing.T) {
+ testClosedPipeRace(t, false)
+}
+
+// Issue 20915: Reading on nonblocking fd should not return "waiting
+// for unsupported file type." Currently it returns EAGAIN; it is
+// possible that in the future it will simply wait for data.
+func TestReadNonblockingFd(t *testing.T) {
+ switch runtime.GOOS {
+ case "windows":
+ t.Skip("Windows doesn't support SetNonblock")
+ }
+ if os.Getenv("GO_WANT_READ_NONBLOCKING_FD") == "1" {
+ fd := syscallDescriptor(os.Stdin.Fd())
+ syscall.SetNonblock(fd, true)
+ defer syscall.SetNonblock(fd, false)
+ _, err := os.Stdin.Read(make([]byte, 1))
+ if err != nil {
+ if perr, ok := err.(*fs.PathError); !ok || perr.Err != syscall.EAGAIN {
+ t.Fatalf("read on nonblocking stdin got %q, should have gotten EAGAIN", err)
+ }
+ }
+ os.Exit(0)
+ }
+
+ testenv.MustHaveExec(t)
+ t.Parallel()
+
+ r, w, err := os.Pipe()
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer r.Close()
+ defer w.Close()
+ cmd := testenv.Command(t, os.Args[0], "-test.run=^"+t.Name()+"$")
+ cmd.Env = append(cmd.Environ(), "GO_WANT_READ_NONBLOCKING_FD=1")
+ cmd.Stdin = r
+ output, err := cmd.CombinedOutput()
+ t.Logf("%s", output)
+ if err != nil {
+ t.Errorf("child process failed: %v", err)
+ }
+}
+
+func TestCloseWithBlockingReadByNewFile(t *testing.T) {
+ t.Parallel()
+
+ var p [2]syscallDescriptor
+ err := syscall.Pipe(p[:])
+ if err != nil {
+ t.Fatal(err)
+ }
+ // os.NewFile returns a blocking mode file.
+ testCloseWithBlockingRead(t, os.NewFile(uintptr(p[0]), "reader"), os.NewFile(uintptr(p[1]), "writer"))
+}
+
+func TestCloseWithBlockingReadByFd(t *testing.T) {
+ t.Parallel()
+
+ r, w, err := os.Pipe()
+ if err != nil {
+ t.Fatal(err)
+ }
+ // Calling Fd will put the file into blocking mode.
+ _ = r.Fd()
+ testCloseWithBlockingRead(t, r, w)
+}
+
+// Test that we don't let a blocking read prevent a close.
+func testCloseWithBlockingRead(t *testing.T, r, w *os.File) {
+ var (
+ enteringRead = make(chan struct{})
+ done = make(chan struct{})
+ )
+ go func() {
+ var b [1]byte
+ close(enteringRead)
+ _, err := r.Read(b[:])
+ if err == nil {
+ t.Error("I/O on closed pipe unexpectedly succeeded")
+ }
+
+ if pe, ok := err.(*fs.PathError); ok {
+ err = pe.Err
+ }
+ if err != io.EOF && err != fs.ErrClosed {
+ t.Errorf("got %v, expected EOF or closed", err)
+ }
+ close(done)
+ }()
+
+ // Give the goroutine a chance to enter the Read
+ // or Write call. This is sloppy but the test will
+ // pass even if we close before the read/write.
+ <-enteringRead
+ time.Sleep(20 * time.Millisecond)
+
+ if err := r.Close(); err != nil {
+ t.Error(err)
+ }
+ // r.Close has completed, but since we assume r is in blocking mode that
+ // probably didn't unblock the call to r.Read. Close w to unblock it.
+ w.Close()
+ <-done
+}
+
+func TestPipeEOF(t *testing.T) {
+ t.Parallel()
+
+ r, w, err := os.Pipe()
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ testPipeEOF(t, r, w)
+}
+
+// testPipeEOF tests that when the write side of a pipe or FIFO is closed,
+// a blocked Read call on the reader side returns io.EOF.
+//
+// This scenario previously failed to unblock the Read call on darwin.
+// (See https://go.dev/issue/24164.)
+func testPipeEOF(t *testing.T, r io.ReadCloser, w io.WriteCloser) {
+ // parkDelay is an arbitrary delay we wait for a pipe-reader goroutine to park
+ // before issuing the corresponding write. The test should pass no matter what
+ // delay we use, but with a longer delay is has a higher chance of detecting
+ // poller bugs.
+ parkDelay := 10 * time.Millisecond
+ if testing.Short() {
+ parkDelay = 100 * time.Microsecond
+ }
+ writerDone := make(chan struct{})
+ defer func() {
+ if err := r.Close(); err != nil {
+ t.Errorf("error closing reader: %v", err)
+ }
+ <-writerDone
+ }()
+
+ write := make(chan int, 1)
+ go func() {
+ defer close(writerDone)
+
+ for i := range write {
+ time.Sleep(parkDelay)
+ _, err := fmt.Fprintf(w, "line %d\n", i)
+ if err != nil {
+ t.Errorf("error writing to fifo: %v", err)
+ return
+ }
+ }
+
+ time.Sleep(parkDelay)
+ if err := w.Close(); err != nil {
+ t.Errorf("error closing writer: %v", err)
+ }
+ }()
+
+ rbuf := bufio.NewReader(r)
+ for i := 0; i < 3; i++ {
+ write <- i
+ b, err := rbuf.ReadBytes('\n')
+ if err != nil {
+ t.Fatal(err)
+ }
+ t.Logf("%s\n", bytes.TrimSpace(b))
+ }
+
+ close(write)
+ b, err := rbuf.ReadBytes('\n')
+ if err != io.EOF || len(b) != 0 {
+ t.Errorf(`ReadBytes: %q, %v; want "", io.EOF`, b, err)
+ }
+}
+
+// Issue 24481.
+func TestFdRace(t *testing.T) {
+ // This test starts 100 simultaneous goroutines, which could bury a more
+ // interesting stack if this or some other test happens to panic. It is also
+ // nearly instantaneous, so any latency benefit from running it in parallel
+ // would be minimal.
+
+ r, w, err := os.Pipe()
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer r.Close()
+ defer w.Close()
+
+ var wg sync.WaitGroup
+ call := func() {
+ defer wg.Done()
+ w.Fd()
+ }
+
+ const tries = 100
+ for i := 0; i < tries; i++ {
+ wg.Add(1)
+ go call()
+ }
+ wg.Wait()
+}
+
+func TestFdReadRace(t *testing.T) {
+ t.Parallel()
+
+ r, w, err := os.Pipe()
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer r.Close()
+ defer w.Close()
+
+ const count = 10
+
+ c := make(chan bool, 1)
+ var wg sync.WaitGroup
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ var buf [count]byte
+ r.SetReadDeadline(time.Now().Add(time.Minute))
+ c <- true
+ if _, err := r.Read(buf[:]); os.IsTimeout(err) {
+ t.Error("read timed out")
+ }
+ }()
+
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ <-c
+ // Give the other goroutine a chance to enter the Read.
+ // It doesn't matter if this occasionally fails, the test
+ // will still pass, it just won't test anything.
+ time.Sleep(10 * time.Millisecond)
+ r.Fd()
+
+ // The bug was that Fd would hang until Read timed out.
+ // If the bug is fixed, then writing to w and closing r here
+ // will cause the Read to exit before the timeout expires.
+ w.Write(make([]byte, count))
+ r.Close()
+ }()
+
+ wg.Wait()
+}