Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 22 Jul 2014 20:44:38 +0400
From:      Andrey Chernov <ache@freebsd.org>
To:        "Pedro F. Giffuni" <pfg@FreeBSD.org>, src-committers@freebsd.org,  svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   Re: svn commit: r268984 - head/lib/libc/stdio
Message-ID:  <53CE94F6.3090003@freebsd.org>
In-Reply-To: <201407221619.s6MGJ10G068003@svn.freebsd.org>
References:  <201407221619.s6MGJ10G068003@svn.freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Producing physical writes on ftell cause great performance degradation.
You should check for __SAPP flag before calling sflush to do this only
for append-mode files.

On 22.07.2014 20:19, Pedro F. Giffuni wrote:
> Author: pfg
> Date: Tue Jul 22 16:19:01 2014
> New Revision: 268984
> URL: http://svnweb.freebsd.org/changeset/base/268984
> 
> Log:
>   ftello: return 1 when seeking offset on an append stream.
>   
>   Obtained from:	Apple Inc. (Libc 997.90.3)
>   Phabric:	D442
>   MFC after:	2 weeks
> 
> Modified:
>   head/lib/libc/stdio/ftell.c
> 
> Modified: head/lib/libc/stdio/ftell.c
> ==============================================================================
> --- head/lib/libc/stdio/ftell.c	Tue Jul 22 16:10:56 2014	(r268983)
> +++ head/lib/libc/stdio/ftell.c	Tue Jul 22 16:19:01 2014	(r268984)
> @@ -97,6 +97,8 @@ _ftello(FILE *fp, fpos_t *offset)
>  	 * Find offset of underlying I/O object, then
>  	 * adjust for buffered bytes.
>  	 */
> +	if (__sflush(fp))	/* may adjust seek offset on append stream */
> +		return (1);
>  	if (fp->_flags & __SOFF)
>  		pos = fp->_offset;
>  	else {
> 


-- 
http://ache.vniz.net/



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?53CE94F6.3090003>