[TUHS] Did realloc ever zero the new memory?
arnold at skeeve.com
arnold at skeeve.com
Fri Sep 11 16:30:36 AEST 2015
> On Thu, Sep 10, 2015 at 4:21 PM, Larry McVoy <lm at mcvoy.com> wrote:
>
> > Am I the only one that remembers realloc() being buggy on some systems?
Clem Cole <clemc at ccc.com> wrote:
> Amen... it was rarely useful. I always found realloc to one of the
> part I could never trust. I do remember what you got back from any of the
> malloc calls could vary widely. Particularly pre-ANSI C and working on
> non-UNIX systems.
I would not say this applies today. The GLIBC realloc is very effective.
The place where I see this is in gawk, which special cases
a = a b # concatenate string b onto the end of string a
By using realloc to grow the contents of a and copying b's contents
onto the end I see a huge speedup over the dance of
char *p malloc(length(a) + length(b))
copy in a
copy in b
free old a
make a point at new storage
Arnold
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