How does Vim's autoread work?

Question

:h autoread says:

When a file has been detected to have been changed outside of Vim and it has not been changed inside of Vim, automatically

Answer 1

Outside of gvim, autoread doesn't work for me.

To get around this I use this rather ugly hack.

set autoread
augroup checktime
    au!
    if !has("gui_running")
        "silent! necessary otherwise throws errors when using command
        "line window.
        autocmd BufEnter        * silent! checktime
        autocmd CursorHold      * silent! checktime
        autocmd CursorHoldI     * silent! checktime
        "these two _may_ slow things down. Remove if they do.
        autocmd CursorMoved     * silent! checktime
        autocmd CursorMovedI    * silent! checktime
    endif
augroup END

This seems to be what the script irishjava linked to does, but that lets you toggle this for buffers. I just want it to work for everything.