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89fb683558
__clock_gettime and other __clock_* functions could result in an extra PLT reference within libc.so if it actually gets used. None of the code currently uses them, which is why this probably went unnoticed.
119 lines
2.9 KiB
C
119 lines
2.9 KiB
C
/* clock_getres -- Get the resolution of a POSIX clockid_t.
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Copyright (C) 1999-2013 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 <errno.h>
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#include <stdint.h>
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#include <time.h>
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#include <unistd.h>
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#include <sys/param.h>
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#include <libc-internal.h>
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#if HP_TIMING_AVAIL
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static long int nsec; /* Clock frequency of the processor. */
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static int
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hp_timing_getres (struct timespec *res)
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{
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if (__builtin_expect (nsec == 0, 0))
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{
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hp_timing_t freq;
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/* This can only happen if we haven't initialized the `nsec'
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variable yet. Do this now. We don't have to protect this
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code against multiple execution since all of them should
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lead to the same result. */
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freq = __get_clockfreq ();
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if (__builtin_expect (freq == 0, 0))
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/* Something went wrong. */
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return -1;
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nsec = MAX (UINT64_C (1000000000) / freq, 1);
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}
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/* Fill in the values.
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The seconds are always zero (unless we have a 1Hz machine). */
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res->tv_sec = 0;
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res->tv_nsec = nsec;
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return 0;
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}
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#endif
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static inline int
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realtime_getres (struct timespec *res)
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{
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long int clk_tck = sysconf (_SC_CLK_TCK);
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if (__builtin_expect (clk_tck != -1, 1))
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{
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/* This implementation assumes that the realtime clock has a
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resolution higher than 1 second. This is the case for any
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reasonable implementation. */
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res->tv_sec = 0;
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res->tv_nsec = 1000000000 / clk_tck;
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return 0;
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}
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return -1;
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}
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/* Get resolution of clock. */
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int
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__clock_getres (clockid_t clock_id, struct timespec *res)
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{
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int retval = -1;
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switch (clock_id)
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{
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#ifdef SYSDEP_GETRES
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SYSDEP_GETRES;
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#endif
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#ifndef HANDLED_REALTIME
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case CLOCK_REALTIME:
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retval = realtime_getres (res);
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break;
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#endif /* handled REALTIME */
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default:
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#ifdef SYSDEP_GETRES_CPU
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SYSDEP_GETRES_CPU;
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#endif
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#if HP_TIMING_AVAIL
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if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1))
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== CLOCK_THREAD_CPUTIME_ID)
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retval = hp_timing_getres (res);
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else
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#endif
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__set_errno (EINVAL);
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break;
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#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
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case CLOCK_PROCESS_CPUTIME_ID:
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case CLOCK_THREAD_CPUTIME_ID:
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retval = hp_timing_getres (res);
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break;
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#endif
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}
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return retval;
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}
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weak_alias (__clock_getres, clock_getres)
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