1// Copyright 2018 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package poll
6
7import (
8	"syscall"
9	_ "unsafe" // for go:linkname
10)
11
12// OpenDir returns a pointer to a DIR structure suitable for
13// ReadDir. In case of an error, the name of the failed
14// syscall is returned along with a syscall.Errno.
15func (fd *FD) OpenDir() (uintptr, string, error) {
16	// fdopendir(3) takes control of the file descriptor,
17	// so use a dup.
18	fd2, call, err := fd.Dup()
19	if err != nil {
20		return 0, call, err
21	}
22	var dir uintptr
23	for {
24		dir, err = fdopendir(fd2)
25		if err != syscall.EINTR {
26			break
27		}
28	}
29	if err != nil {
30		syscall.Close(fd2)
31		return 0, "fdopendir", err
32	}
33	return dir, "", nil
34}
35
36// Implemented in syscall/syscall_darwin.go.
37//
38//go:linkname fdopendir syscall.fdopendir
39func fdopendir(fd int) (dir uintptr, err error)
40