1//go:build windows
 2// +build windows
 3
 4package osfs
 5
 6import (
 7	"os"
 8	"runtime"
 9	"unsafe"
10
11	"golang.org/x/sys/windows"
12)
13
14var (
15	kernel32DLL    = windows.NewLazySystemDLL("kernel32.dll")
16	lockFileExProc = kernel32DLL.NewProc("LockFileEx")
17	unlockFileProc = kernel32DLL.NewProc("UnlockFile")
18)
19
20const (
21	lockfileExclusiveLock = 0x2
22)
23
24func (f *file) Lock() error {
25	f.m.Lock()
26	defer f.m.Unlock()
27
28	var overlapped windows.Overlapped
29	// err is always non-nil as per sys/windows semantics.
30	ret, _, err := lockFileExProc.Call(f.File.Fd(), lockfileExclusiveLock, 0, 0xFFFFFFFF, 0,
31		uintptr(unsafe.Pointer(&overlapped)))
32	runtime.KeepAlive(&overlapped)
33	if ret == 0 {
34		return err
35	}
36	return nil
37}
38
39func (f *file) Unlock() error {
40	f.m.Lock()
41	defer f.m.Unlock()
42
43	// err is always non-nil as per sys/windows semantics.
44	ret, _, err := unlockFileProc.Call(f.File.Fd(), 0, 0, 0xFFFFFFFF, 0)
45	if ret == 0 {
46		return err
47	}
48	return nil
49}
50
51func rename(from, to string) error {
52	return os.Rename(from, to)
53}
54
55func umask(new int) func() {
56	return func() {
57	}
58}