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/* Copyright (C) 2001-2015 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; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stdlib.h>
#include <time.h>
#include <libc-internal.h>
#include "pthreadP.h"
#if HP_TIMING_AVAIL
int
__pthread_clock_gettime (clockid_t clock_id, hp_timing_t freq,
struct timespec *tp)
{
hp_timing_t tsc;
/* Get the current counter. */
HP_TIMING_NOW (tsc);
/* This is the ID of the thread we are looking for. */
pid_t tid = ((unsigned int) clock_id) >> CLOCK_IDFIELD_SIZE;
/* Compute the offset since the start time of the process. */
if (tid == 0 || tid == THREAD_GETMEM (THREAD_SELF, tid))
/* Our own clock. */
tsc -= THREAD_GETMEM (THREAD_SELF, cpuclock_offset);
else
{
/* This is more complicated. We have to locate the thread based
on the ID. This means walking the list of existing
threads. */
struct pthread *thread = __find_thread_by_id (tid);
if (thread == NULL)
{
__set_errno (EINVAL);
return -1;
}
/* There is a race here. The thread might terminate and the stack
become unusable. But this is the user's problem. */
tsc -= thread->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) * 1000000000ull) / freq;
return 0;
}
#endif
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