| /* clock_gettime -- Get the current time from a POSIX clockid_t. Unix version. |
| Copyright (C) 1999-2018 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> |
| |
| |
| #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 (__glibc_unlikely (freq == 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 (__glibc_unlikely (freq == 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; |
| } |
| |
| #if defined __clang__ && defined __powerpc64__ |
| /* On ppc, __clock_gettime's body eventually expands into asm code |
| that does a bctrl, but clang does not recognize the need to save |
| the link register, so calls loop infinitely instead of returning. |
| As workaround, make a dummy function call that forces a link |
| register save. */ |
| volatile int clock_gettime_dummy_glob; |
| |
| void __attribute__((noinline)) clock_gettime_dummy () |
| { |
| clock_gettime_dummy_glob = 45; |
| } |
| #endif |
| |
| /* Get current value of CLOCK and store it in TP. */ |
| int |
| __clock_gettime (clockid_t clock_id, struct timespec *tp) |
| { |
| int retval = -1; |
| |
| #if defined __clang__ && defined __powerpc64__ |
| clock_gettime_dummy (); |
| #endif |
| |
| 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 (clock_id, tp); |
| #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; |
| } |
| weak_alias (__clock_gettime, clock_gettime) |
| libc_hidden_def (__clock_gettime) |