diff options
author | gad <gad@FreeBSD.org> | 2013-05-27 22:19:01 +0000 |
---|---|---|
committer | gad <gad@FreeBSD.org> | 2013-05-27 22:19:01 +0000 |
commit | 92ccb9a78d6194c4e65cdc15633b6750a5fefc67 (patch) | |
tree | e548d6fdbfc2fc87d1666b5be84b079204ac1817 /usr.sbin/lpr/common_source | |
parent | fa9e5ab43dccec826b1477c944db129ef3a76902 (diff) | |
download | FreeBSD-src-92ccb9a78d6194c4e65cdc15633b6750a5fefc67.zip FreeBSD-src-92ccb9a78d6194c4e65cdc15633b6750a5fefc67.tar.gz |
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
Diffstat (limited to 'usr.sbin/lpr/common_source')
-rw-r--r-- | usr.sbin/lpr/common_source/common.c | 20 | ||||
-rw-r--r-- | usr.sbin/lpr/common_source/lp.cdefs.h | 17 |
2 files changed, 29 insertions, 8 deletions
diff --git a/usr.sbin/lpr/common_source/common.c b/usr.sbin/lpr/common_source/common.c index 93657d9..52d6c9f 100644 --- a/usr.sbin/lpr/common_source/common.c +++ b/usr.sbin/lpr/common_source/common.c @@ -757,16 +757,22 @@ fatal(const struct printer *pp, const char *msg, ...) /* * 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); + } } diff --git a/usr.sbin/lpr/common_source/lp.cdefs.h b/usr.sbin/lpr/common_source/lp.cdefs.h index 19b1331..5806f39 100644 --- a/usr.sbin/lpr/common_source/lp.cdefs.h +++ b/usr.sbin/lpr/common_source/lp.cdefs.h @@ -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 |