Date: Mon, 27 May 2013 22:19:02 +0000 (UTC) From: Garance A Drosehn <gad@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r251044 - head/usr.sbin/lpr/common_source Message-ID: <201305272219.r4RMJ2lL081629@svn.freebsd.org>
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Author: gad Date: Mon May 27 22:19:01 2013 New Revision: 251044 URL: http://svnweb.freebsd.org/changeset/base/251044 Log: Change the closeallfds() routine to use closefrom() when it is available (closefrom() was added to FreeBSD in 8.0-release). The selection is made at compile-time, as I still compile a FreeBSD-based version of lpr&friends on other platforms. While testing I out that (at least on my system) lpd has been closing 11095 fd's, when there are only 6 fd's open. The old code took 120 times more clocktime than calling closefrom(). (although that was still less than 2/1000-ths of a second!) Reviewed by: jilles MFC after: 2 weeks Modified: head/usr.sbin/lpr/common_source/common.c head/usr.sbin/lpr/common_source/lp.cdefs.h Modified: head/usr.sbin/lpr/common_source/common.c ============================================================================== --- head/usr.sbin/lpr/common_source/common.c Mon May 27 22:18:04 2013 (r251043) +++ head/usr.sbin/lpr/common_source/common.c Mon May 27 22:19:01 2013 (r251044) @@ -757,16 +757,22 @@ fatal(const struct printer *pp, const ch /* * Close all file descriptors from START on up. - * This is a horrific kluge, since getdtablesize() might return - * ``infinity'', in which case we will be spending a long time - * closing ``files'' which were never open. Perhaps it would - * be better to close the first N fds, for some small value of N. */ void closeallfds(int start) { - int stop = getdtablesize(); - for (; start < stop; start++) - close(start); + int stop; + + if (USE_CLOSEFROM) /* The faster, modern solution */ + closefrom(start); + else { + /* This older logic can be pretty awful on some OS's. The + * getdtablesize() might return ``infinity'', and then this + * will waste a lot of time closing file descriptors which + * had never been open()-ed. */ + stop = getdtablesize(); + for (; start < stop; start++) + close(start); + } } Modified: head/usr.sbin/lpr/common_source/lp.cdefs.h ============================================================================== --- head/usr.sbin/lpr/common_source/lp.cdefs.h Mon May 27 22:18:04 2013 (r251043) +++ head/usr.sbin/lpr/common_source/lp.cdefs.h Mon May 27 22:19:01 2013 (r251044) @@ -1,6 +1,6 @@ /*- * ------+---------+---------+---------+---------+---------+---------+---------* - * Copyright (c) 2003 - Garance Alistair Drosehn <gad@FreeBSD.org>. + * Copyright (c) 2003,2013 - Garance Alistair Drosehn <gad@FreeBSD.org>. * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -56,6 +56,21 @@ #endif /* + * FreeBSD added a closefrom() routine in release 8.0. When compiling + * `lpr' on other platforms you might want to include bsd-closefrom.c + * from the portable-openssh project. + */ +#ifndef USE_CLOSEFROM +# if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) +# define USE_CLOSEFROM 1 +# endif +#endif +/* The macro USE_CLOSEFROM must be defined with a value of 0 or 1. */ +#ifndef USE_CLOSEFROM +# define USE_CLOSEFROM 0 +#endif + +/* * __unused is a compiler-specific trick which can be used to avoid * warnings about a variable which is defined but never referenced. * Some lpr files use this, so define a null version if it was not
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