1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
// Copyright 2023 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 unix || (js && wasm)
package poll
import "syscall"
type SysFile struct {
// Writev cache.
iovecs *[]syscall.Iovec
}
func (s *SysFile) init() {}
func (s *SysFile) destroy(fd int) error {
// We don't use ignoringEINTR here because POSIX does not define
// whether the descriptor is closed if close returns EINTR.
// If the descriptor is indeed closed, using a loop would race
// with some other goroutine opening a new descriptor.
// (The Linux kernel guarantees that it is closed on an EINTR error.)
return CloseFunc(fd)
}
// dupCloseOnExecOld is the traditional way to dup an fd and
// set its O_CLOEXEC bit, using two system calls.
func dupCloseOnExecOld(fd int) (int, string, error) {
syscall.ForkLock.RLock()
defer syscall.ForkLock.RUnlock()
newfd, err := syscall.Dup(fd)
if err != nil {
return -1, "dup", err
}
syscall.CloseOnExec(newfd)
return newfd, "", nil
}
// Fchdir wraps syscall.Fchdir.
func (fd *FD) Fchdir() error {
if err := fd.incref(); err != nil {
return err
}
defer fd.decref()
return syscall.Fchdir(fd.Sysfd)
}
// ReadDirent wraps syscall.ReadDirent.
// We treat this like an ordinary system call rather than a call
// that tries to fill the buffer.
func (fd *FD) ReadDirent(buf []byte) (int, error) {
if err := fd.incref(); err != nil {
return 0, err
}
defer fd.decref()
for {
n, err := ignoringEINTRIO(syscall.ReadDirent, fd.Sysfd, buf)
if err != nil {
n = 0
if err == syscall.EAGAIN && fd.pd.pollable() {
if err = fd.pd.waitRead(fd.isFile); err == nil {
continue
}
}
}
// Do not call eofError; caller does not expect to see io.EOF.
return n, err
}
}
// Seek wraps syscall.Seek.
func (fd *FD) Seek(offset int64, whence int) (int64, error) {
if err := fd.incref(); err != nil {
return 0, err
}
defer fd.decref()
return syscall.Seek(fd.Sysfd, offset, whence)
}
|
