/* clock_gettime -- Get the current time from a POSIX clockid_t. Unix version. Copyright (C) 1999-2004, 2005, 2007 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include <errno.h> #include <stdint.h> #include <time.h> #include <sys/time.h> #include <libc-internal.h> #include <ldsodefs.h> #if HP_TIMING_AVAIL /* 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 int __pthread_clock_gettime (clockid_t clock_id, hp_timing_t freq, struct timespec *tp) __attribute__ ((__weak__)); static int hp_timing_gettime (clockid_t clock_id, struct timespec *tp) { hp_timing_t tsc; if (__builtin_expect (freq == 0, 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 (__builtin_expect (freq == 0, 0)) /* Something went wrong. */ return -1; } if (clock_id != CLOCK_PROCESS_CPUTIME_ID && __pthread_clock_gettime != NULL) return __pthread_clock_gettime (clock_id, freq, tp); /* Get the current counter. */ HP_TIMING_NOW (tsc); /* Compute the offset since the start time of the process. */ tsc -= GL(dl_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) * UINT64_C (1000000000)) / freq; return 0; } #endif 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) { #ifdef SYSDEP_GETTIME SYSDEP_GETTIME; #endif #ifndef HANDLED_REALTIME case CLOCK_REALTIME: { struct timeval tv; retval = gettimeofday (&tv, NULL); if (retval == 0) TIMEVAL_TO_TIMESPEC (&tv, tp); } break; #endif default: #ifdef SYSDEP_GETTIME_CPU SYSDEP_GETTIME_CPU; #endif #if HP_TIMING_AVAIL if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1)) == CLOCK_THREAD_CPUTIME_ID) retval = hp_timing_gettime (clock_id, tp); else #endif __set_errno (EINVAL); break; #if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME case CLOCK_PROCESS_CPUTIME_ID: retval = hp_timing_gettime (clock_id, tp); break; #endif } return retval; } librt_hidden_def (clock_gettime)