8be918b7bb
* conform/data/sys/time.h-data: Allow sys/select.h. * conform/data/sys/un.h-data: Fix typo. * time/sys/time.h: Don't include all of <time.h>, just struct timeval. * sysdeps/posix/clock_getres.c: Include <time.h> instead of <sys/time.h>. * sysdeps/unix/clock_nanosleep.c: Likewise. * sysdeps/unix/i386/clock_getcpuclockid.c: Likewise. * sysdeps/unix/i386/i586/clock_getres.c: Likewise. * sysdeps/unix/clock_gettime.c: Also include <time.h>. * sysdeps/unix/clock_settime.c: Likewise. * sysdeps/generic/pselect.c: Include <stddef.h> for NULL. * login/getutent.c: Likewise. * login/getutid.c: Likewise. * login/getutline.c: Likewise. * socket/sys/un.h: Define SUN_LEN only if __USE_MISC.
77 lines
3.2 KiB
C
77 lines
3.2 KiB
C
/* Copyright (C) 1999, 2000, 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. */
|
|
|
|
#include <time.h>
|
|
#include <libc-internal.h>
|
|
|
|
/* This implementation uses the TSC register in modern (i586 and up) IA-32
|
|
processors (most modern clones also provide it). Since we need the
|
|
resolution of the clock and since determining this is not cheap, we
|
|
cache the value. But this means that systems with processors running
|
|
at different speeds or process migration to machines with slower or
|
|
faster processors will not work without changes. */
|
|
|
|
|
|
/* Clock frequency of the processor. We make it a 64-bit variable
|
|
because some jokers are already playing with processors with more
|
|
than 4GHz. */
|
|
static unsigned long long int freq;
|
|
|
|
|
|
/* We add an limitation here: we assume that the machine is not up as
|
|
long as it takes to wrap-around the 64-bit timestamp counter. On a
|
|
4GHz machine it would take 136 years of uptime to wrap around so
|
|
this "limitation" is not severe.
|
|
|
|
We use this clock also as the monotonic clock since we don't allow
|
|
setting the CPU-time clock. If this should ever change we will have
|
|
to separate the two. */
|
|
#define EXTRA_CLOCK_CASES \
|
|
case CLOCK_PROCESS_CPUTIME_ID: \
|
|
case CLOCK_THREAD_CPUTIME_ID: \
|
|
{ \
|
|
unsigned long long int tsc; \
|
|
\
|
|
if (__builtin_expect (freq == 0, 0)) \
|
|
{ \
|
|
/* This can only happen if we haven't initialized the `freq' \
|
|
variable yet. Do this now. We don't have to protect this \
|
|
code against multiple execution since all of them should \
|
|
lead to the same result. */ \
|
|
freq = __get_clockfreq (); \
|
|
if (__builtin_expect (freq == 0, 0)) \
|
|
/* Something went wrong. */ \
|
|
break; \
|
|
} \
|
|
\
|
|
/* Get the current counter. */ \
|
|
asm volatile ("rdtsc" : "=A" (tsc)); \
|
|
\
|
|
/* Compute the seconds. */ \
|
|
tp->tv_sec = tsc / freq; \
|
|
\
|
|
/* And the nanoseconds. This computation should be stable until \
|
|
we get machines with about 16GHz frequency. */ \
|
|
tp->tv_nsec = ((tsc % freq) * 1000000000ull) / freq; \
|
|
\
|
|
retval = 0; \
|
|
} \
|
|
break;
|
|
|
|
#include <sysdeps/unix/clock_gettime.c>
|