1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47
48. 48
49. 49
50. 50
51. 51

// Copyright 2011 Evan Shaw. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// +build darwin dragonfly freebsd linux openbsd solaris netbsd

package mmap

import (
	"golang.org/x/sys/unix"
)

func mmap(len int, inprot, inflags, fd uintptr, off int64) ([]byte, error) {
	flags := unix.MAP_SHARED
	prot := unix.PROT_READ
	switch {
	case inprot&COPY != 0:
		prot |= unix.PROT_WRITE
		flags = unix.MAP_PRIVATE
	case inprot&RDWR != 0:
		prot |= unix.PROT_WRITE
	}
	if inprot&EXEC != 0 {
		prot |= unix.PROT_EXEC
	}
	if inflags&ANON != 0 {
		flags |= unix.MAP_ANON
	}

	b, err := unix.Mmap(int(fd), off, len, prot, flags)
	if err != nil {
		return nil, err
	}
	return b, nil
}

func (m MMap) flush() error {
	return unix.Msync([]byte(m), unix.MS_SYNC)
}

func (m MMap) lock() error {
	return unix.Mlock([]byte(m))
}

func (m MMap) unlock() error {
	return unix.Munlock([]byte(m))
}

func (m MMap) unmap() error {
	return unix.Munmap([]byte(m))
}