Mercurial > hg > octave-nkf > gnulib-hg
changeset 3653:574daaf59139
Merge with version from libc.
author | Jim Meyering <jim@meyering.net> |
---|---|
date | Tue, 27 Nov 2001 12:54:58 +0000 |
parents | 55dda65539d1 |
children | 60143dd95a31 |
files | lib/tempname.c |
diffstat | 1 files changed, 50 insertions(+), 17 deletions(-) [+] |
line wrap: on
line diff
--- a/lib/tempname.c +++ b/lib/tempname.c @@ -2,19 +2,19 @@ This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Library General Public License as - published by the Free Software Foundation; either version 2 of the - License, or (at your option) any later version. + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Library General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU Library General Public - License along with the GNU C Library; see the file COPYING.LIB. If not, - write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, - Boston, MA 02111-1307, USA. */ + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ #if HAVE_CONFIG_H # include <config.h> @@ -32,6 +32,9 @@ #ifndef P_tmpdir # define P_tmpdir "/tmp" #endif +#ifndef TMP_MAX +# define TMP_MAX 238328 +#endif #ifndef __GT_FILE # define __GT_FILE 0 # define __GT_BIGFILE 1 @@ -111,6 +114,25 @@ # endif #endif +#ifdef _LIBC +# include <hp-timing.h> +# if HP_TIMING_AVAIL +# define RANDOM_BITS(Var) \ + if (__builtin_expect (value == UINT64_C (0), 0)) \ + { \ + /* If this is the first time this function is used initialize \ + the variable we accumulate the value in to some somewhat \ + random value. If we'd not do this programs at startup time \ + might have a reduced set of possible names, at least on slow \ + machines. */ \ + struct timeval tv; \ + __gettimeofday (&tv, NULL); \ + value = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec; \ + } \ + HP_TIMING_NOW (Var) +# endif +#endif + /* Use the widest available unsigned type if uint64_t is not available. The algorithm below extracts a number less than 62**6 (approximately 2**35.725) from uint64_t, so ancient hosts where @@ -120,11 +142,6 @@ # define uint64_t uintmax_t #endif -/* The total number of temporary file names that can exist for a given - template is 62**6. On ancient hosts where uint64_t is really 32 - bits, TEMPORARIES evaluates to 965660736, which is good enough. */ -#define TEMPORARIES ((uint64_t) 62 * 62 * 62 * 62 * 62 * 62) - /* Return nonzero if DIR is an existent directory. */ static int direxists (const char *dir) @@ -221,11 +238,23 @@ char *XXXXXX; static uint64_t value; uint64_t random_time_bits; - uint64_t count; + unsigned int count; int fd = -1; int save_errno = errno; struct_stat64 st; + /* A lower bound on the number of temporary files to attempt to + generate. The maximum total number of temporary file names that + can exist for a given template is 62**6. It should never be + necessary to try all these combinations. Instead if a reasonable + number of names is tried (we define reasonable as 62**3) fail to + give the system administrator the chance to remove the problems. */ + unsigned int attempts_min = 62 * 62 * 62; + + /* The number of times to attempt to generate a temporary file. To + conform to POSIX, this must be no smaller than TMP_MAX. */ + unsigned int attempts = attempts_min < TMP_MAX ? TMP_MAX : attempts_min; + len = strlen (tmpl); if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX")) { @@ -237,18 +266,22 @@ XXXXXX = &tmpl[len - 6]; /* Get some more or less random data. */ -#if HAVE_GETTIMEOFDAY || _LIBC +#ifdef RANDOM_BITS + RANDOM_BITS (random_time_bits); +#else +# if HAVE_GETTIMEOFDAY || _LIBC { struct timeval tv; __gettimeofday (&tv, NULL); random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec; } -#else +# else random_time_bits = time (NULL); +# endif #endif value += random_time_bits ^ __getpid (); - for (count = 0; count < TEMPORARIES; value += 7777, ++count) + for (count = 0; count < attempts; value += 7777, ++count) { uint64_t v = value;