1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
/* clock_gettime -- Get the current time from a POSIX clockid_t. Unix version.
Copyright (C) 1999-2016 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;
}
/* 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 (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)
|
