From f777726ff073f8066c017649b572bd8c40940a42 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <iant@golang.org>
Date: Mon, 15 May 2023 21:50:51 -0700
Subject: [PATCH] os: if descriptor is non-blocking, retain that in Fd method
For #58408
Fixes #60211
Change-Id: I30f5678b46e15121865b19d1c0f82698493fad4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/495079
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
---
src/internal/syscall/unix/nonblocking.go | 4 ++
src/internal/syscall/unix/nonblocking_js.go | 4 ++
src/internal/syscall/unix/nonblocking_libc.go | 4 ++
.../syscall/unix/nonblocking_wasip1.go | 4 ++
src/os/fifo_test.go | 50 +++++++++++++++++++
src/os/file_unix.go | 17 +++++--
6 files changed, 78 insertions(+), 5 deletions(-)
diff --git a/src/internal/syscall/unix/nonblocking.go b/src/internal/syscall/unix/nonblocking.go
index a0becd1e01e..6c6f0674d66 100644
--- a/src/internal/syscall/unix/nonblocking.go
+++ b/src/internal/syscall/unix/nonblocking.go
@@ -19,3 +19,7 @@ func IsNonblock(fd int) (nonblocking bool, err error) {
}
return flag&syscall.O_NONBLOCK != 0, nil
}
+
+func HasNonblockFlag(flag int) bool {
+ return flag&syscall.O_NONBLOCK != 0
+}
diff --git a/src/internal/syscall/unix/nonblocking_js.go b/src/internal/syscall/unix/nonblocking_js.go
index 8ed40f3f910..cfe78c58d8d 100644
--- a/src/internal/syscall/unix/nonblocking_js.go
+++ b/src/internal/syscall/unix/nonblocking_js.go
@@ -9,3 +9,7 @@ package unix
func IsNonblock(fd int) (nonblocking bool, err error) {
return false, nil
}
+
+func HasNonblockFlag(flag int) bool {
+ return false
+}
diff --git a/src/internal/syscall/unix/nonblocking_libc.go b/src/internal/syscall/unix/nonblocking_libc.go
index bff66849623..1310dbf8ce5 100644
--- a/src/internal/syscall/unix/nonblocking_libc.go
+++ b/src/internal/syscall/unix/nonblocking_libc.go
@@ -19,6 +19,10 @@ func IsNonblock(fd int) (nonblocking bool, err error) {
return flag&syscall.O_NONBLOCK != 0, nil
}
+func HasNonblockFlag(flag int) bool {
+ return flag&syscall.O_NONBLOCK != 0
+}
+
// Implemented in the syscall package.
//
//go:linkname fcntl syscall.fcntl
diff --git a/src/internal/syscall/unix/nonblocking_wasip1.go b/src/internal/syscall/unix/nonblocking_wasip1.go
index 208db28c3ef..5b2b53bf5c3 100644
--- a/src/internal/syscall/unix/nonblocking_wasip1.go
+++ b/src/internal/syscall/unix/nonblocking_wasip1.go
@@ -19,6 +19,10 @@ func IsNonblock(fd int) (nonblocking bool, err error) {
return flags&syscall.FDFLAG_NONBLOCK != 0, nil
}
+func HasNonblockFlag(flag int) bool {
+ return flag&syscall.FDFLAG_NONBLOCK != 0
+}
+
// This helper is implemented in the syscall package. It means we don't have
// to redefine the fd_fdstat_get host import or the fdstat struct it
// populates.
diff --git a/src/os/fifo_test.go b/src/os/fifo_test.go
index 867c294f5ec..df4b2ee757c 100644
--- a/src/os/fifo_test.go
+++ b/src/os/fifo_test.go
@@ -8,6 +8,7 @@ package os_test
import (
"errors"
+ "internal/syscall/unix"
"internal/testenv"
"io/fs"
"os"
@@ -155,3 +156,52 @@ func TestNonPollable(t *testing.T) {
}
}
}
+
+// Issue 60211.
+func TestOpenFileNonBlocking(t *testing.T) {
+ exe, err := os.Executable()
+ if err != nil {
+ t.Skipf("can't find executable: %v", err)
+ }
+ f, err := os.OpenFile(exe, os.O_RDONLY|syscall.O_NONBLOCK, 0666)
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer f.Close()
+ nonblock, err := unix.IsNonblock(int(f.Fd()))
+ if err != nil {
+ t.Fatal(err)
+ }
+ if !nonblock {
+ t.Errorf("file opened with O_NONBLOCK but in blocking mode")
+ }
+}
+
+func TestNewFileNonBlocking(t *testing.T) {
+ var p [2]int
+ if err := syscall.Pipe(p[:]); err != nil {
+ t.Fatal(err)
+ }
+ if err := syscall.SetNonblock(p[0], true); err != nil {
+ t.Fatal(err)
+ }
+ f := os.NewFile(uintptr(p[0]), "pipe")
+ nonblock, err := unix.IsNonblock(p[0])
+ if err != nil {
+ t.Fatal(err)
+ }
+ if !nonblock {
+ t.Error("pipe blocking after NewFile")
+ }
+ fd := f.Fd()
+ if fd != uintptr(p[0]) {
+ t.Errorf("Fd returned %d, want %d", fd, p[0])
+ }
+ nonblock, err = unix.IsNonblock(p[0])
+ if err != nil {
+ t.Fatal(err)
+ }
+ if !nonblock {
+ t.Error("pipe blocking after Fd")
+ }
+}
diff --git a/src/os/file_unix.go b/src/os/file_unix.go
index f7f942f5f52..3d3a8b2056b 100644
--- a/src/os/file_unix.go
+++ b/src/os/file_unix.go
@@ -116,12 +116,12 @@ const (
// kindNewFile means that the descriptor was passed to us via NewFile.
kindNewFile newFileKind = iota
// kindOpenFile means that the descriptor was opened using
- // Open, Create, or OpenFile.
+ // Open, Create, or OpenFile (without O_NONBLOCK).
kindOpenFile
// kindPipe means that the descriptor was opened using Pipe.
kindPipe
- // kindNonBlock means that the descriptor was passed to us via NewFile,
- // and the descriptor is already in non-blocking mode.
+ // kindNonBlock means that the descriptor is already in
+ // non-blocking mode.
kindNonBlock
// kindNoPoll means that we should not put the descriptor into
// non-blocking mode, because we know it is not a pipe or FIFO.
@@ -184,7 +184,9 @@ func newFile(fd uintptr, name string, kind newFileKind) *File {
clearNonBlock := false
if pollable {
if kind == kindNonBlock {
- f.nonblock = true
+ // The descriptor is already in non-blocking mode.
+ // We only set f.nonblock if we put the file into
+ // non-blocking mode.
} else if err := syscall.SetNonblock(fdi, true); err == nil {
f.nonblock = true
clearNonBlock = true
@@ -263,7 +265,12 @@ func openFileNolog(name string, flag int, perm FileMode) (*File, error) {
syscall.CloseOnExec(r)
}
- f := newFile(uintptr(r), name, kindOpenFile)
+ kind := kindOpenFile
+ if unix.HasNonblockFlag(flag) {
+ kind = kindNonBlock
+ }
+
+ f := newFile(uintptr(r), name, kind)
f.pfd.SysFile = s
return f, nil
}
--
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