mmap go

package main

import (
    "fmt"
    "os"
    "syscall"
    "unsafe"
    )

func main() {
    n := 1000
    t := int(unsafe.Sizeof(0)) * n

    map_file, _ := os.Create("/tmp/test.dat")
    _, _ = map_file.Seek(int64(t - 1), 0)
    map_file.Write([]byte(" "))

    mmap, _ := syscall.Mmap(map_file.Fd(), 0, int(t), syscall.PROT_READ | syscall.PROT_WRITE, syscall.MAP_SHARED)
    map_array := (*[1000]int)(unsafe.Pointer(&mmap))

    for i:=0; i < n; i++ {
        map_array[i] = i*i
    }

    fmt.Println(*map_array)
}