Re: [PATCH v2 4/5] Cygwin: pty: Prevent pty from changing code page of parent console.

[Corinna Vinschen <corinna-cygwin@cygwin.com>]

On Jan 18 21:57, Takashi Yano via Cygwin-patches wrote:
> On Mon, 18 Jan 2021 13:39:01 +0100
> Corinna Vinschen wrote:
> > Sorry if I'm slow, but I was just mulling over this code snippet again,
> > and I was wondering if we couldn't do without the HeapAlloc loop.
> > Assuming you use a tmp_pathbuf here, you'd have space for 16384
> > processes per console.  Shouldn't that be more than enough?  I.e.
> > 
> > static DWORD
> > get_console_process_id (DWORD pid, bool match)
> > {
> >   tmp_pathbuf tp;
> >   DWORD *list = (DWORD *) tp.w_get ();
> >   const DWORD num = NT_MAX_PATH * sizeof (WCHAR) / sizeof (DWORD);
> >   DWORD res = 0;
> > 
> >   num = GetConsoleProcessList (&list, num);
> > 
> >   /* Last one is the oldest. */
> >   /* https://github.com/microsoft/terminal/issues/95 */
> >   for (int i = (int) num - 1; i >= 0; i--)
> >     if ((match && list[i] == pid) || (!match && list[i] != pid))
> >       {
> > 	res = list[i];
> > 	break;
> >       }
> >   return res;
> > }
> > 
> > 
> > What do you think?
> 
> That's more that enough. I will submit v3 patch. Thanks again.
> By the way, why do you think tmp_pathbuf is better than HeapAlloc()?

tmp_pathbuf never frees the buffers it used at least once. so
chances are hight that the call just returns the next free
pointer to an already alloocated buffer.


Corinna