From: Fabrice Popineau <fabrice.popineau@gmail.com>
To: emacs-devel@gnu.org
Subject: Question about mmap buffers
Date: Fri, 25 Apr 2014 11:20:36 +0000 (UTC) [thread overview]
Message-ID: <loom.20140425T131540-411@post.gmane.org> (raw)
I'm in the process of revamping memory allocation for Win32 and adding
virtual memory allocation support for buffers.
Reading the code in src/buffer.c, I wonder about the mmap_set_vars()
function.
This function sets the beginning of text address to NULL before dumping,
and later in init_buffer() the same address is tested for being NULL, in
which case the buffer memory is allocated.
Why can't this be written as the Win32 code below:
void
init_buffer (void)
{
char *pwd;
Lisp_Object temp;
ptrdiff_t len;
#ifdef USE_MMAP_FOR_BUFFERS
{
/* When using the ralloc implementation based on mmap(2), buffer
text pointers will have been set to null in the dumped Emacs.
Map new memory. */
struct buffer *b;
#ifdef WINDOWSNT
/* Who cares: no buffer can be dumped with a meaningful address.
We can as well force their values at NULL here. */
FOR_EACH_BUFFER (b)
{
b->text->beg = NULL;
enlarge_buffer_text (b, 0);
}
#else
FOR_EACH_BUFFER (b)
if (b->text->beg == NULL)
enlarge_buffer_text (b, 0);
#endif
}
#endif /* USE_MMAP_FOR_BUFFERS */
and forget about the mmap_set_vars() function?
If this is correct and a change along these lines could be applied, that
would slightly simplify my patch to come.
Thanks for any comments,
Fabrice
next reply other threads:[~2014-04-25 11:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-25 11:20 Fabrice Popineau [this message]
2014-04-29 16:24 ` Question about mmap buffers Fabrice Popineau
2014-05-14 18:06 ` Eli Zaretskii
2014-05-17 7:16 ` Eli Zaretskii
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