On Wed, Jan 17, 2001 at 11:45:08AM +0100, Juergen Schoenwaelder wrote:
> It is IMHO the job of the libc coders to make strdup() and everything
> else fast (and I think some libc's do real magic to achieve this).
Are there any platforms with a libc that does anything fancier in
"strdup()" than
char *
strdup(str)
const char *str;
{
size_t len;
char *copy;
len = strlen(str) + 1;
if ((copy = malloc(len)) == NULL)
return (NULL);
memcpy(copy, str, len);
return (copy);
}
(FreeBSD 3.4, but this is probably just the 4.4-Lite one), or
char *
__strdup (const char *s)
{
size_t len = strlen (s) + 1;
void *new = malloc (len);
if (new == NULL)
return NULL;
return (char *) memcpy (new, s, len);
}
(glibc 2.1.2)?
There may also be cases where the libc routine's goal is to handle a
large number of cases well and, as a result, it may not handle some
cases as efficiently as it could if it were optimized only for those
cases. Replacing that routine *could* make a difference to some
applications.
In this particular case, "savestr()" didn't seem to speed things up on
the capture file on which I tried it; I don't know whether the LBL guys
had some application where it *did* make a difference, and just started
using "savestr()" everywhere even where it didn't make a difference, or
whether they somehow had a case where it made a difference to tcpdump,
or what.
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