1 /*
2 * Copyright (c) Meta Platforms, Inc. and affiliates.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
11
12 /* === Dependencies === */
13
14 #include "timefn.h"
15 #include "platform.h" /* set _POSIX_C_SOURCE */
16 #include <time.h> /* CLOCK_MONOTONIC, TIME_UTC */
17
18 /*-****************************************
19 * Time functions
20 ******************************************/
21
22 #if defined(_WIN32) /* Windows */
23
24 #include <windows.h> /* LARGE_INTEGER */
25 #include <stdlib.h> /* abort */
26 #include <stdio.h> /* perror */
27
UTIL_getTime(void)28 UTIL_time_t UTIL_getTime(void)
29 {
30 static LARGE_INTEGER ticksPerSecond;
31 static int init = 0;
32 if (!init) {
33 if (!QueryPerformanceFrequency(&ticksPerSecond)) {
34 perror("timefn::QueryPerformanceFrequency");
35 abort();
36 }
37 init = 1;
38 }
39 { UTIL_time_t r;
40 LARGE_INTEGER x;
41 QueryPerformanceCounter(&x);
42 r.t = (PTime)(x.QuadPart * 1000000000ULL / ticksPerSecond.QuadPart);
43 return r;
44 }
45 }
46
47
48 #elif defined(__APPLE__) && defined(__MACH__)
49
50 #include <mach/mach_time.h> /* mach_timebase_info_data_t, mach_timebase_info, mach_absolute_time */
51
UTIL_getTime(void)52 UTIL_time_t UTIL_getTime(void)
53 {
54 static mach_timebase_info_data_t rate;
55 static int init = 0;
56 if (!init) {
57 mach_timebase_info(&rate);
58 init = 1;
59 }
60 { UTIL_time_t r;
61 r.t = mach_absolute_time() * (PTime)rate.numer / (PTime)rate.denom;
62 return r;
63 }
64 }
65
66 /* POSIX.1-2001 (optional) */
67 #elif defined(CLOCK_MONOTONIC)
68
69 #include <stdlib.h> /* abort */
70 #include <stdio.h> /* perror */
71
UTIL_getTime(void)72 UTIL_time_t UTIL_getTime(void)
73 {
74 /* time must be initialized, othersize it may fail msan test.
75 * No good reason, likely a limitation of timespec_get() for some target */
76 struct timespec time = { 0, 0 };
77 if (clock_gettime(CLOCK_MONOTONIC, &time) != 0) {
78 perror("timefn::clock_gettime(CLOCK_MONOTONIC)");
79 abort();
80 }
81 { UTIL_time_t r;
82 r.t = (PTime)time.tv_sec * 1000000000ULL + (PTime)time.tv_nsec;
83 return r;
84 }
85 }
86
87
88 /* C11 requires support of timespec_get().
89 * However, FreeBSD 11 claims C11 compliance while lacking timespec_get().
90 * Double confirm timespec_get() support by checking the definition of TIME_UTC.
91 * However, some versions of Android manage to simultaneously define TIME_UTC
92 * and lack timespec_get() support... */
93 #elif (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) /* C11 */) \
94 && defined(TIME_UTC) && !defined(__ANDROID__)
95
96 #include <stdlib.h> /* abort */
97 #include <stdio.h> /* perror */
98
UTIL_getTime(void)99 UTIL_time_t UTIL_getTime(void)
100 {
101 /* time must be initialized, othersize it may fail msan test.
102 * No good reason, likely a limitation of timespec_get() for some target */
103 struct timespec time = { 0, 0 };
104 if (timespec_get(&time, TIME_UTC) != TIME_UTC) {
105 perror("timefn::timespec_get(TIME_UTC)");
106 abort();
107 }
108 { UTIL_time_t r;
109 r.t = (PTime)time.tv_sec * 1000000000ULL + (PTime)time.tv_nsec;
110 return r;
111 }
112 }
113
114
115 #else /* relies on standard C90 (note : clock_t produces wrong measurements for multi-threaded workloads) */
116
UTIL_getTime(void)117 UTIL_time_t UTIL_getTime(void)
118 {
119 UTIL_time_t r;
120 r.t = (PTime)clock() * 1000000000ULL / CLOCKS_PER_SEC;
121 return r;
122 }
123
124 #define TIME_MT_MEASUREMENTS_NOT_SUPPORTED
125
126 #endif
127
128 /* ==== Common functions, valid for all time API ==== */
129
UTIL_getSpanTimeNano(UTIL_time_t clockStart,UTIL_time_t clockEnd)130 PTime UTIL_getSpanTimeNano(UTIL_time_t clockStart, UTIL_time_t clockEnd)
131 {
132 return clockEnd.t - clockStart.t;
133 }
134
UTIL_getSpanTimeMicro(UTIL_time_t begin,UTIL_time_t end)135 PTime UTIL_getSpanTimeMicro(UTIL_time_t begin, UTIL_time_t end)
136 {
137 return UTIL_getSpanTimeNano(begin, end) / 1000ULL;
138 }
139
UTIL_clockSpanMicro(UTIL_time_t clockStart)140 PTime UTIL_clockSpanMicro(UTIL_time_t clockStart )
141 {
142 UTIL_time_t const clockEnd = UTIL_getTime();
143 return UTIL_getSpanTimeMicro(clockStart, clockEnd);
144 }
145
UTIL_clockSpanNano(UTIL_time_t clockStart)146 PTime UTIL_clockSpanNano(UTIL_time_t clockStart )
147 {
148 UTIL_time_t const clockEnd = UTIL_getTime();
149 return UTIL_getSpanTimeNano(clockStart, clockEnd);
150 }
151
UTIL_waitForNextTick(void)152 void UTIL_waitForNextTick(void)
153 {
154 UTIL_time_t const clockStart = UTIL_getTime();
155 UTIL_time_t clockEnd;
156 do {
157 clockEnd = UTIL_getTime();
158 } while (UTIL_getSpanTimeNano(clockStart, clockEnd) == 0);
159 }
160
UTIL_support_MT_measurements(void)161 int UTIL_support_MT_measurements(void)
162 {
163 # if defined(TIME_MT_MEASUREMENTS_NOT_SUPPORTED)
164 return 0;
165 # else
166 return 1;
167 # endif
168 }
169