source: code/trunk/vendor/modernc.org/memory/mmap_windows.go@ 822

// Copyright 2017 The Memory Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package memory // import "modernc.org/memory"

import (
        "os"
        "syscall"
)

const (
        _MEM_COMMIT   = 0x1000
        _MEM_RESERVE  = 0x2000
        _MEM_DECOMMIT = 0x4000
        _MEM_RELEASE  = 0x8000

        _PAGE_READWRITE = 0x0004
        _PAGE_NOACCESS  = 0x0001
)

const pageSizeLog = 16

var (
        modkernel32      = syscall.NewLazyDLL("kernel32.dll")
        osPageMask       = osPageSize - 1
        osPageSize       = os.Getpagesize()
        procVirtualAlloc = modkernel32.NewProc("VirtualAlloc")
        procVirtualFree  = modkernel32.NewProc("VirtualFree")
)

// pageSize aligned.
func mmap(size int) (uintptr, int, error) {
        size = roundup(size, pageSize)
        addr, _, err := procVirtualAlloc.Call(0, uintptr(size), _MEM_COMMIT|_MEM_RESERVE, _PAGE_READWRITE)
        if err.(syscall.Errno) != 0 || addr == 0 {
                return addr, size, err
        }
        return addr, size, nil
}

func unmap(addr uintptr, size int) error {
        r, _, err := procVirtualFree.Call(addr, 0, _MEM_RELEASE)
        if r == 0 {
                return err
        }

        return nil
}