mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-15 01:21:06 +00:00
137 lines
3.5 KiB
C
137 lines
3.5 KiB
C
/* clock_gettime -- Get the current time from a POSIX clockid_t. Unix version.
|
|
Copyright (C) 1999-2017 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 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <stdint.h>
|
|
#include <time.h>
|
|
#include <sys/time.h>
|
|
#include <libc-internal.h>
|
|
#include <ldsodefs.h>
|
|
|
|
|
|
#if HP_TIMING_AVAIL
|
|
/* 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 hp_timing_t freq;
|
|
|
|
|
|
/* This function is defined in the thread library. */
|
|
extern int __pthread_clock_gettime (clockid_t clock_id, hp_timing_t freq,
|
|
struct timespec *tp)
|
|
__attribute__ ((__weak__));
|
|
|
|
static int
|
|
hp_timing_gettime (clockid_t clock_id, struct timespec *tp)
|
|
{
|
|
hp_timing_t tsc;
|
|
|
|
if (__glibc_unlikely (freq == 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 (__glibc_unlikely (freq == 0))
|
|
/* Something went wrong. */
|
|
return -1;
|
|
}
|
|
|
|
if (clock_id != CLOCK_PROCESS_CPUTIME_ID
|
|
&& __pthread_clock_gettime != NULL)
|
|
return __pthread_clock_gettime (clock_id, freq, tp);
|
|
|
|
/* Get the current counter. */
|
|
HP_TIMING_NOW (tsc);
|
|
|
|
/* Compute the offset since the start time of the process. */
|
|
tsc -= GL(dl_cpuclock_offset);
|
|
|
|
/* 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) * UINT64_C (1000000000)) / freq;
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
|
|
static inline int
|
|
realtime_gettime (struct timespec *tp)
|
|
{
|
|
struct timeval tv;
|
|
int retval = gettimeofday (&tv, NULL);
|
|
if (retval == 0)
|
|
/* Convert into `timespec'. */
|
|
TIMEVAL_TO_TIMESPEC (&tv, tp);
|
|
return retval;
|
|
}
|
|
|
|
|
|
/* Get current value of CLOCK and store it in TP. */
|
|
int
|
|
__clock_gettime (clockid_t clock_id, struct timespec *tp)
|
|
{
|
|
int retval = -1;
|
|
|
|
switch (clock_id)
|
|
{
|
|
#ifdef SYSDEP_GETTIME
|
|
SYSDEP_GETTIME;
|
|
#endif
|
|
|
|
#ifndef HANDLED_REALTIME
|
|
case CLOCK_REALTIME:
|
|
{
|
|
struct timeval tv;
|
|
retval = gettimeofday (&tv, NULL);
|
|
if (retval == 0)
|
|
TIMEVAL_TO_TIMESPEC (&tv, tp);
|
|
}
|
|
break;
|
|
#endif
|
|
|
|
default:
|
|
#ifdef SYSDEP_GETTIME_CPU
|
|
SYSDEP_GETTIME_CPU (clock_id, tp);
|
|
#endif
|
|
#if HP_TIMING_AVAIL
|
|
if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1))
|
|
== CLOCK_THREAD_CPUTIME_ID)
|
|
retval = hp_timing_gettime (clock_id, tp);
|
|
else
|
|
#endif
|
|
__set_errno (EINVAL);
|
|
break;
|
|
|
|
#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
|
|
case CLOCK_PROCESS_CPUTIME_ID:
|
|
retval = hp_timing_gettime (clock_id, tp);
|
|
break;
|
|
#endif
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
weak_alias (__clock_gettime, clock_gettime)
|
|
libc_hidden_def (__clock_gettime)
|