glibc/sysdeps/unix/clock_gettime.c
Adhemerval Zanella 38cc11daa4 nptl: Remove pthread_clock_gettime pthread_clock_settime
This patch removes CLOCK_THREAD_CPUTIME_ID and CLOCK_PROCESS_CPUTIME_ID support
from clock_gettime and clock_settime generic implementation.  For Linux, kernel
already provides supports through the syscall and Hurd HTL lacks
__pthread_clock_gettime and __pthread_clock_settime internal implementation.

As described in clock_gettime man-page [1] on 'Historical note for SMP
system', implementing CLOCK_{THREAD,PROCESS}_CPUTIME_ID with timer registers
is error-prone and susceptible to timing and accurary issues that the libc
can not deal without kernel support.

This allows removes unused code which, however, still incur in some runtime
overhead in thread creation (the struct pthread cpuclock_offset
initialization).

If hurd eventually wants to support them it should either either implement as
a kernel facility (or something related due its architecture) or in system
specific implementation.

Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. I also
checked on a i686-gnu build.

	* nptl/Makefile (libpthread-routines): Remove pthread_clock_gettime and
	pthread_clock_settime.
	* nptl/pthreadP.h (__find_thread_by_id): Remove prototype.
	* elf/dl-support.c [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset): Remove.
	(_dl_non_dynamic_init): Remove _dl_cpuclock_offset setting.
	* elf/rtld.c (_dl_start_final): Likewise.
	* nptl/allocatestack.c (__find_thread_by_id): Remove function.
	* sysdeps/generic/ldsodefs.h [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset):
	Remove.
	* sysdeps/mach/hurd/dl-sysdep.c [!HP_TIMING_NOAVAIL]
	(_dl_cpuclock_offset): Remove.
	* nptl/descr.h (struct pthread): Rename cpuclock_offset to
	cpuclock_offset_ununsed.
	* nptl/nptl-init.c (__pthread_initialize_minimal_internal): Remove
	cpuclock_offset set.
	* nptl/pthread_create.c (START_THREAD_DEFN): Likewise.
	* sysdeps/nptl/fork.c (__libc_fork): Likewise.
	* nptl/pthread_clock_gettime.c: Remove file.
	* nptl/pthread_clock_settime.c: Likewise.
	* sysdeps/unix/clock_gettime.c (hp_timing_gettime): Remove function.
	[HP_TIMING_AVAIL] (realtime_gettime): Remove CLOCK_THREAD_CPUTIME_ID
	and CLOCK_PROCESS_CPUTIME_ID support.
	* sysdeps/unix/clock_settime.c (hp_timing_gettime): Likewise.
	[HP_TIMING_AVAIL] (realtime_gettime): Likewise.
	* sysdeps/posix/clock_getres.c (hp_timing_getres): Likewise.
	[HP_TIMING_AVAIL] (__clock_getres): Likewise.
	* sysdeps/unix/clock_nanosleep.c (CPUCLOCK_P, INVALID_CLOCK_P):
	Likewise.
	(__clock_nanosleep): Remove CPUCLOCK_P and INVALID_CLOCK_P usage.

[1] http://man7.org/linux/man-pages/man2/clock_gettime.2.html
2019-03-22 15:37:43 -03:00

65 lines
1.7 KiB
C

/* clock_gettime -- Get the current time from a POSIX clockid_t. Unix version.
Copyright (C) 1999-2019 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>
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)
{
case CLOCK_REALTIME:
{
struct timeval tv;
retval = __gettimeofday (&tv, NULL);
if (retval == 0)
TIMEVAL_TO_TIMESPEC (&tv, tp);
}
break;
default:
__set_errno (EINVAL);
break;
}
return retval;
}
weak_alias (__clock_gettime, clock_gettime)
libc_hidden_def (__clock_gettime)