From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 08 Jan 2008 17:41:26 GMT
Subject: Re: [PATCH 1/2] sideband.c: Use xmalloc() instead of variable-sized arrays.
Message-ID: <7v4pdotdtl.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <4783A3B2.3060801@viscovery.net>

Johannes Sixt <j.sixt@viscovery.net> writes:

> From: Johannes Sixt <johannes.sixt@telecom.at>
>
> How come we got along with this not very portable construct for so long?
> Probably because the array sizes were computed from the results of
> strlen() of string constants. Anyway, a follow-up patch will make the
> lengths really non-constant.
>
> Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
> ---
>  sideband.c |   14 ++++++++++++--
>  1 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/sideband.c b/sideband.c
> index 756bbc2..513d7b3 100644
> --- a/sideband.c
> +++ b/sideband.c
> @@ -19,7 +19,10 @@ int recv_sideband(const char *me, int in_stream, int out, int err)
>  {
>  	unsigned pf = strlen(PREFIX);
>  	unsigned sf = strlen(SUFFIX);
> -	char buf[pf + LARGE_PACKET_MAX + sf + 1];
> +	char *buf, *save;
> +
> +	save = xmalloc(sf);
> +	buf = xmalloc(pf + LARGE_PACKET_MAX + sf + 1);

I have to wonder if the malloc() overhead is small enough
compared to the network bandwidth to make a two malloc-free
pairs per packet a non-issue...