githaven/vendor/github.com/edsrzf/mmap-go/mmap_unix.go
2018-05-19 20:49:46 +08:00

68 lines
1.4 KiB
Go

// 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 (
"syscall"
)
func mmap(len int, inprot, inflags, fd uintptr, off int64) ([]byte, error) {
flags := syscall.MAP_SHARED
prot := syscall.PROT_READ
switch {
case inprot&COPY != 0:
prot |= syscall.PROT_WRITE
flags = syscall.MAP_PRIVATE
case inprot&RDWR != 0:
prot |= syscall.PROT_WRITE
}
if inprot&EXEC != 0 {
prot |= syscall.PROT_EXEC
}
if inflags&ANON != 0 {
flags |= syscall.MAP_ANON
}
b, err := syscall.Mmap(int(fd), off, len, prot, flags)
if err != nil {
return nil, err
}
return b, nil
}
func flush(addr, len uintptr) error {
_, _, errno := syscall.Syscall(_SYS_MSYNC, addr, len, _MS_SYNC)
if errno != 0 {
return syscall.Errno(errno)
}
return nil
}
func lock(addr, len uintptr) error {
_, _, errno := syscall.Syscall(syscall.SYS_MLOCK, addr, len, 0)
if errno != 0 {
return syscall.Errno(errno)
}
return nil
}
func unlock(addr, len uintptr) error {
_, _, errno := syscall.Syscall(syscall.SYS_MUNLOCK, addr, len, 0)
if errno != 0 {
return syscall.Errno(errno)
}
return nil
}
func unmap(addr, len uintptr) error {
_, _, errno := syscall.Syscall(syscall.SYS_MUNMAP, addr, len, 0)
if errno != 0 {
return syscall.Errno(errno)
}
return nil
}