glibc/sysdeps/unix/clock_settime.c

128 lines
3.3 KiB
C

/* Copyright (C) 1999-2014 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 <time.h>
#include <sys/time.h>
#include <libc-internal.h>
#include <ldsodefs.h>
#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
/* 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 void __pthread_clock_settime (clockid_t clock_id, hp_timing_t offset)
__attribute__ ((__weak__));
static int
hp_timing_settime (clockid_t clock_id, const struct timespec *tp)
{
hp_timing_t tsc;
hp_timing_t usertime;
/* First thing is to get the current time. */
HP_TIMING_NOW (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;
}
/* Convert the user-provided time into CPU ticks. */
usertime = tp->tv_sec * freq + (tp->tv_nsec * freq) / 1000000000ull;
/* Determine the offset and use it as the new base value. */
if (clock_id == CLOCK_PROCESS_CPUTIME_ID
|| __pthread_clock_settime == NULL)
GL(dl_cpuclock_offset) = tsc - usertime;
else
__pthread_clock_settime (clock_id, tsc - usertime);
return 0;
}
#endif
/* Set CLOCK to value TP. */
int
__clock_settime (clockid_t clock_id, const struct timespec *tp)
{
int retval;
/* Make sure the time cvalue is OK. */
if (tp->tv_nsec < 0 || tp->tv_nsec >= 1000000000)
{
__set_errno (EINVAL);
return -1;
}
switch (clock_id)
{
#define HANDLE_REALTIME \
do { \
struct timeval tv; \
TIMESPEC_TO_TIMEVAL (&tv, tp); \
\
retval = settimeofday (&tv, NULL); \
} while (0)
#ifdef SYSDEP_SETTIME
SYSDEP_SETTIME;
#endif
#ifndef HANDLED_REALTIME
case CLOCK_REALTIME:
HANDLE_REALTIME;
break;
#endif
default:
#ifdef SYSDEP_SETTIME_CPU
SYSDEP_SETTIME_CPU;
#endif
#ifndef HANDLED_CPUTIME
# if HP_TIMING_AVAIL
if (CPUCLOCK_WHICH (clock_id) == CLOCK_PROCESS_CPUTIME_ID
|| CPUCLOCK_WHICH (clock_id) == CLOCK_THREAD_CPUTIME_ID)
retval = hp_timing_settime (clock_id, tp);
else
# endif
{
__set_errno (EINVAL);
retval = -1;
}
#endif
break;
}
return retval;
}
weak_alias (__clock_settime, clock_settime)