From f2615995a753b80dd8d9fce55f5e87e8105f2d82 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Mon, 19 Mar 2001 23:34:54 +0000 Subject: Update. * sysdeps/unix/i386/i686/tempname.c: New file. * sysdeps/posix/tempname.c (__gen_tempname): If RANDOM_BITS is defined use this macro to get some bits of randomness instead of the usual gettimeofday or time calls. 2001-03-16 Paul Eggert * sysdeps/posix/tempname.c (uint64_t): Define to uintmax_t if not defined, and if UINT64_MAX is not defined. 2001-03-19 Ulrich Drepper --- sysdeps/unix/i386/i686/tempname.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 sysdeps/unix/i386/i686/tempname.c (limited to 'sysdeps/unix/i386') diff --git a/sysdeps/unix/i386/i686/tempname.c b/sysdeps/unix/i386/i686/tempname.c new file mode 100644 index 0000000000..3d2476e612 --- /dev/null +++ b/sysdeps/unix/i386/i686/tempname.c @@ -0,0 +1,35 @@ +/* Copyright (C) 2001 Free Software Foundation, Inc. + 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. + + 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. + + 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. */ + +/* For i686 and up we have a better and faster source of random bits in the + form of the time stamp counter. */ +#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; \ + } \ + __asm__ __volatile__ ("rdtsc" : "=A" (Var)) + +#include_next -- cgit v1.2.3