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1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef INCLUDE_PERFETTO_BASE_TIME_H_
18 #define INCLUDE_PERFETTO_BASE_TIME_H_
19 
20 #include <time.h>
21 
22 #include <chrono>
23 #include <optional>
24 #include <string>
25 
26 #include "perfetto/base/build_config.h"
27 #include "perfetto/base/logging.h"
28 
29 #if PERFETTO_BUILDFLAG(PERFETTO_OS_APPLE)
30 #include <mach/mach_init.h>
31 #include <mach/mach_port.h>
32 #include <mach/mach_time.h>
33 #include <mach/thread_act.h>
34 #endif
35 
36 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WASM)
37 #include <emscripten/emscripten.h>
38 #endif
39 
40 #if PERFETTO_BUILDFLAG(PERFETTO_ARCH_CPU_X86_64)
41 #if PERFETTO_BUILDFLAG(PERFETTO_COMPILER_MSVC)
42 #include <intrin.h>
43 #endif
44 #endif
45 
46 namespace perfetto {
47 namespace base {
48 
49 using TimeSeconds = std::chrono::seconds;
50 using TimeMillis = std::chrono::milliseconds;
51 using TimeNanos = std::chrono::nanoseconds;
52 
FromPosixTimespec(const struct timespec & ts)53 inline TimeNanos FromPosixTimespec(const struct timespec& ts) {
54   return TimeNanos(ts.tv_sec * 1000000000LL + ts.tv_nsec);
55 }
56 
57 void SleepMicroseconds(unsigned interval_us);
58 void InitializeTime();
59 
60 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
61 
62 TimeNanos GetWallTimeNs();
63 TimeNanos GetThreadCPUTimeNs();
GetWallTimeRawNs()64 inline TimeNanos GetWallTimeRawNs() {
65   return GetWallTimeNs();
66 }
67 
68 // TODO: Clock that counts time during suspend is not implemented on Windows.
GetBootTimeNs()69 inline TimeNanos GetBootTimeNs() {
70   return GetWallTimeNs();
71 }
72 
73 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_APPLE)
74 
GetWallTimeNs()75 inline TimeNanos GetWallTimeNs() {
76   auto init_timebase_info = []() -> mach_timebase_info_data_t {
77     mach_timebase_info_data_t timebase_info;
78     mach_timebase_info(&timebase_info);
79     return timebase_info;
80   };
81 
82   static mach_timebase_info_data_t timebase_info = init_timebase_info();
83   uint64_t mach_time = mach_absolute_time();
84 
85   // Take the fast path when the conversion is 1:1. The result will for sure fit
86   // into an int_64 because we're going from nanoseconds to microseconds.
87   if (timebase_info.numer == timebase_info.denom) {
88     return TimeNanos(mach_time);
89   }
90 
91   // Nanoseconds is mach_time * timebase.numer // timebase.denom. Divide first
92   // to reduce the chance of overflow. Also stash the remainder right now,
93   // a likely byproduct of the division.
94   uint64_t nanoseconds = mach_time / timebase_info.denom;
95   const uint64_t mach_time_remainder = mach_time % timebase_info.denom;
96 
97   // Now multiply, keeping an eye out for overflow.
98   PERFETTO_CHECK(!__builtin_umulll_overflow(nanoseconds, timebase_info.numer,
99                                             &nanoseconds));
100 
101   // By dividing first we lose precision. Regain it by adding back the
102   // nanoseconds from the remainder, with an eye out for overflow.
103   uint64_t least_significant_nanoseconds =
104       (mach_time_remainder * timebase_info.numer) / timebase_info.denom;
105   PERFETTO_CHECK(!__builtin_uaddll_overflow(
106       nanoseconds, least_significant_nanoseconds, &nanoseconds));
107 
108   return TimeNanos(nanoseconds);
109 }
110 
GetWallTimeRawNs()111 inline TimeNanos GetWallTimeRawNs() {
112   return GetWallTimeNs();
113 }
114 
115 // TODO: Clock that counts time during suspend is not implemented on Mac.
GetBootTimeNs()116 inline TimeNanos GetBootTimeNs() {
117   return GetWallTimeNs();
118 }
119 
120 // Before MacOS 10.12 clock_gettime() was not implemented.
121 #if __MAC_OS_X_VERSION_MIN_REQUIRED < 101200
GetThreadCPUTimeNs()122 inline TimeNanos GetThreadCPUTimeNs() {
123   mach_port_t this_thread = mach_thread_self();
124   mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
125   thread_basic_info_data_t info{};
126   kern_return_t kr =
127       thread_info(this_thread, THREAD_BASIC_INFO,
128                   reinterpret_cast<thread_info_t>(&info), &count);
129   mach_port_deallocate(mach_task_self(), this_thread);
130 
131   if (kr != KERN_SUCCESS) {
132     PERFETTO_DFATAL("Failed to get CPU time.");
133     return TimeNanos(0);
134   }
135   return TimeNanos(info.user_time.seconds * 1000000000LL +
136                    info.user_time.microseconds * 1000LL +
137                    info.system_time.seconds * 1000000000LL +
138                    info.system_time.microseconds * 1000LL);
139 }
140 #else
GetThreadCPUTimeNs()141 inline TimeNanos GetThreadCPUTimeNs() {
142   struct timespec ts = {};
143   PERFETTO_CHECK(clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts) == 0);
144   return FromPosixTimespec(ts);
145 }
146 #endif
147 
148 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_WASM)
149 
GetWallTimeNs()150 inline TimeNanos GetWallTimeNs() {
151   return TimeNanos(static_cast<uint64_t>(emscripten_get_now()) * 1000000);
152 }
153 
GetWallTimeRawNs()154 inline TimeNanos GetWallTimeRawNs() {
155   return GetWallTimeNs();
156 }
157 
GetThreadCPUTimeNs()158 inline TimeNanos GetThreadCPUTimeNs() {
159   return TimeNanos(0);
160 }
161 
162 // TODO: Clock that counts time during suspend is not implemented on WASM.
GetBootTimeNs()163 inline TimeNanos GetBootTimeNs() {
164   return GetWallTimeNs();
165 }
166 
167 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_NACL)
168 
169 // Tracing time doesn't need to work on NaCl since its going away shortly. We
170 // just need to compile on it. The only function NaCl could support is
171 // GetWallTimeNs(), but to prevent false hope we leave it unimplemented.
172 
GetWallTimeNs()173 inline TimeNanos GetWallTimeNs() {
174   return TimeNanos(0);
175 }
176 
GetWallTimeRawNs()177 inline TimeNanos GetWallTimeRawNs() {
178   return TimeNanos(0);
179 }
180 
GetThreadCPUTimeNs()181 inline TimeNanos GetThreadCPUTimeNs() {
182   return TimeNanos(0);
183 }
184 
GetBootTimeNs()185 inline TimeNanos GetBootTimeNs() {
186   return TimeNanos(0);
187 }
188 
189 #else  // posix
190 
191 constexpr clockid_t kWallTimeClockSource = CLOCK_MONOTONIC;
192 
GetTimeInternalNs(clockid_t clk_id)193 inline TimeNanos GetTimeInternalNs(clockid_t clk_id) {
194   struct timespec ts = {};
195   PERFETTO_CHECK(clock_gettime(clk_id, &ts) == 0);
196   return FromPosixTimespec(ts);
197 }
198 
199 // Return ns from boot. Conversely to GetWallTimeNs, this clock counts also time
200 // during suspend (when supported).
GetBootTimeNs()201 inline TimeNanos GetBootTimeNs() {
202   // Determine if CLOCK_BOOTTIME is available on the first call.
203   static const clockid_t kBootTimeClockSource = [] {
204     struct timespec ts = {};
205     int res = clock_gettime(CLOCK_BOOTTIME, &ts);
206     return res == 0 ? CLOCK_BOOTTIME : kWallTimeClockSource;
207   }();
208   return GetTimeInternalNs(kBootTimeClockSource);
209 }
210 
GetWallTimeNs()211 inline TimeNanos GetWallTimeNs() {
212   return GetTimeInternalNs(kWallTimeClockSource);
213 }
214 
GetWallTimeRawNs()215 inline TimeNanos GetWallTimeRawNs() {
216   return GetTimeInternalNs(CLOCK_MONOTONIC_RAW);
217 }
218 
GetThreadCPUTimeNs()219 inline TimeNanos GetThreadCPUTimeNs() {
220   return GetTimeInternalNs(CLOCK_THREAD_CPUTIME_ID);
221 }
222 #endif
223 
GetBootTimeS()224 inline TimeSeconds GetBootTimeS() {
225   return std::chrono::duration_cast<TimeSeconds>(GetBootTimeNs());
226 }
227 
GetBootTimeMs()228 inline TimeMillis GetBootTimeMs() {
229   return std::chrono::duration_cast<TimeMillis>(GetBootTimeNs());
230 }
231 
GetWallTimeMs()232 inline TimeMillis GetWallTimeMs() {
233   return std::chrono::duration_cast<TimeMillis>(GetWallTimeNs());
234 }
235 
GetWallTimeS()236 inline TimeSeconds GetWallTimeS() {
237   return std::chrono::duration_cast<TimeSeconds>(GetWallTimeNs());
238 }
239 
ToPosixTimespec(TimeMillis time)240 inline struct timespec ToPosixTimespec(TimeMillis time) {
241   struct timespec ts {};
242   const long time_s = static_cast<long>(time.count() / 1000);
243   ts.tv_sec = time_s;
244   ts.tv_nsec = (static_cast<long>(time.count()) - time_s * 1000L) * 1000000L;
245   return ts;
246 }
247 
248 std::string GetTimeFmt(const std::string& fmt);
249 
TimeGm(struct tm * tms)250 inline int64_t TimeGm(struct tm* tms) {
251 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
252   return static_cast<int64_t>(_mkgmtime(tms));
253 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_NACL)
254   // NaCL has no timegm.
255   if (tms)  // Kinda if (true), but avoids "mark as noreturn" errors.
256     PERFETTO_FATAL("timegm not supported");
257   return -1;
258 #else
259   return static_cast<int64_t>(timegm(tms));
260 #endif
261 }
262 
263 // Creates a time_t-compatible timestamp (seconds since epoch) from a tuple of
264 // y-m-d-h-m-s. It's a saner version of timegm(). Some remarks:
265 // The year is just the actual year (it's Y-1900 in timegm()).
266 // The month ranges 1-12 (it's 0-11 in timegm()).
MkTime(int year,int month,int day,int h,int m,int s)267 inline int64_t MkTime(int year, int month, int day, int h, int m, int s) {
268   PERFETTO_DCHECK(year >= 1900);
269   PERFETTO_DCHECK(month > 0 && month <= 12);
270   PERFETTO_DCHECK(day > 0 && day <= 31);
271   struct tm tms {};
272   tms.tm_year = year - 1900;
273   tms.tm_mon = month - 1;
274   tms.tm_mday = day;
275   tms.tm_hour = h;
276   tms.tm_min = m;
277   tms.tm_sec = s;
278   return TimeGm(&tms);
279 }
280 
281 #if PERFETTO_BUILDFLAG(PERFETTO_ARCH_CPU_X86_64)
Rdtsc()282 inline uint64_t Rdtsc() {
283 #if PERFETTO_BUILDFLAG(PERFETTO_COMPILER_MSVC)
284   return static_cast<uint64_t>(__rdtsc());
285 #else
286   // Use inline asm for clang and gcc: rust ffi bindgen crashes in using
287   // intrinsics on ChromeOS.
288   uint64_t low, high;
289   __asm__ volatile("rdtsc" : "=a"(low), "=d"(high));
290   return (high << 32) | low;
291 #endif
292 }
293 #endif
294 
295 std::optional<int32_t> GetTimezoneOffsetMins();
296 
297 }  // namespace base
298 }  // namespace perfetto
299 
300 #endif  // INCLUDE_PERFETTO_BASE_TIME_H_
301