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38cc11daa4
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
80 lines
2.5 KiB
C
80 lines
2.5 KiB
C
/* High-resolution sleep with the specified clock.
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Copyright (C) 2000-2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <errno.h>
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#include <time.h>
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#include <sysdep-cancel.h>
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/* This implementation assumes that these is only a `nanosleep' system
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call. So we have to remap all other activities. */
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int
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__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
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struct timespec *rem)
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{
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struct timespec now;
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if (__builtin_expect (req->tv_nsec, 0) < 0
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|| __builtin_expect (req->tv_nsec, 0) >= 1000000000)
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return EINVAL;
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if (clock_id == CLOCK_THREAD_CPUTIME_ID)
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return EINVAL; /* POSIX specifies EINVAL for this case. */
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if (clock_id < CLOCK_REALTIME || clock_id > CLOCK_THREAD_CPUTIME_ID)
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return EINVAL;
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/* If we got an absolute time, remap it. */
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if (flags == TIMER_ABSTIME)
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{
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long int nsec;
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long int sec;
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/* Make sure we use safe data types. */
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assert (sizeof (sec) >= sizeof (now.tv_sec));
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/* Get the current time for this clock. */
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if (__clock_gettime (clock_id, &now) != 0)
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return errno;
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/* Compute the difference. */
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nsec = req->tv_nsec - now.tv_nsec;
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sec = req->tv_sec - now.tv_sec - (nsec < 0);
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if (sec < 0)
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/* The time has already elapsed. */
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return 0;
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now.tv_sec = sec;
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now.tv_nsec = nsec + (nsec < 0 ? 1000000000 : 0);
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/* From now on this is our time. */
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req = &now;
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/* Make sure we are not modifying the struct pointed to by REM. */
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rem = NULL;
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}
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else if (flags != 0)
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return EINVAL;
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else if (clock_id != CLOCK_REALTIME)
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/* Not supported. */
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return ENOTSUP;
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return __nanosleep (req, rem), 0 ? errno : 0;
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}
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weak_alias (__clock_nanosleep, clock_nanosleep)
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