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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 <stdint.h>
21 #include <time.h>
22 
23 #include <chrono>
24 #include <optional>
25 #include <string>
26 
27 #include "perfetto/base/build_config.h"
28 #include "perfetto/base/logging.h"
29 
30 #if PERFETTO_BUILDFLAG(PERFETTO_OS_APPLE)
31 #include <mach/mach_init.h>
32 #include <mach/mach_port.h>
33 #include <mach/mach_time.h>
34 #include <mach/thread_act.h>
35 #endif
36 
37 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WASM)
38 #include <emscripten/emscripten.h>
39 #endif
40 
41 #if PERFETTO_BUILDFLAG(PERFETTO_ARCH_CPU_X86_64)
42 #if PERFETTO_BUILDFLAG(PERFETTO_COMPILER_MSVC)
43 #include <intrin.h>
44 #endif
45 #endif
46 
47 namespace perfetto {
48 namespace base {
49 
50 using TimeSeconds = std::chrono::seconds;
51 using TimeMillis = std::chrono::milliseconds;
52 using TimeNanos = std::chrono::nanoseconds;
53 
FromPosixTimespec(const struct timespec & ts)54 inline TimeNanos FromPosixTimespec(const struct timespec& ts) {
55   return TimeNanos(ts.tv_sec * 1000000000LL + ts.tv_nsec);
56 }
57 
58 void SleepMicroseconds(unsigned interval_us);
59 void InitializeTime();
60 
61 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
62 
63 TimeNanos GetWallTimeNs();
64 TimeNanos GetThreadCPUTimeNs();
GetWallTimeRawNs()65 inline TimeNanos GetWallTimeRawNs() {
66   return GetWallTimeNs();
67 }
68 
69 // TODO: Clock that counts time during suspend is not implemented on Windows.
GetBootTimeNs()70 inline TimeNanos GetBootTimeNs() {
71   return GetWallTimeNs();
72 }
73 
74 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_APPLE)
75 
GetWallTimeNs()76 inline TimeNanos GetWallTimeNs() {
77   auto init_timebase_info = []() -> mach_timebase_info_data_t {
78     mach_timebase_info_data_t timebase_info;
79     mach_timebase_info(&timebase_info);
80     return timebase_info;
81   };
82 
83   static mach_timebase_info_data_t timebase_info = init_timebase_info();
84   uint64_t mach_time = mach_absolute_time();
85 
86   // Take the fast path when the conversion is 1:1. The result will for sure fit
87   // into an int_64 because we're going from nanoseconds to microseconds.
88   if (timebase_info.numer == timebase_info.denom) {
89     return TimeNanos(mach_time);
90   }
91 
92   // Nanoseconds is mach_time * timebase.numer // timebase.denom. Divide first
93   // to reduce the chance of overflow. Also stash the remainder right now,
94   // a likely byproduct of the division.
95   uint64_t nanoseconds = mach_time / timebase_info.denom;
96   const uint64_t mach_time_remainder = mach_time % timebase_info.denom;
97 
98   // Now multiply, keeping an eye out for overflow.
99   PERFETTO_CHECK(!__builtin_umulll_overflow(nanoseconds, timebase_info.numer,
100                                             &nanoseconds));
101 
102   // By dividing first we lose precision. Regain it by adding back the
103   // nanoseconds from the remainder, with an eye out for overflow.
104   uint64_t least_significant_nanoseconds =
105       (mach_time_remainder * timebase_info.numer) / timebase_info.denom;
106   PERFETTO_CHECK(!__builtin_uaddll_overflow(
107       nanoseconds, least_significant_nanoseconds, &nanoseconds));
108 
109   return TimeNanos(nanoseconds);
110 }
111 
GetWallTimeRawNs()112 inline TimeNanos GetWallTimeRawNs() {
113   return GetWallTimeNs();
114 }
115 
116 // TODO: Clock that counts time during suspend is not implemented on Mac.
GetBootTimeNs()117 inline TimeNanos GetBootTimeNs() {
118   return GetWallTimeNs();
119 }
120 
121 // Before MacOS 10.12 clock_gettime() was not implemented.
122 #if __MAC_OS_X_VERSION_MIN_REQUIRED < 101200
GetThreadCPUTimeNs()123 inline TimeNanos GetThreadCPUTimeNs() {
124   mach_port_t this_thread = mach_thread_self();
125   mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
126   thread_basic_info_data_t info{};
127   kern_return_t kr =
128       thread_info(this_thread, THREAD_BASIC_INFO,
129                   reinterpret_cast<thread_info_t>(&info), &count);
130   mach_port_deallocate(mach_task_self(), this_thread);
131 
132   if (kr != KERN_SUCCESS) {
133     PERFETTO_DFATAL("Failed to get CPU time.");
134     return TimeNanos(0);
135   }
136   return TimeNanos(info.user_time.seconds * 1000000000LL +
137                    info.user_time.microseconds * 1000LL +
138                    info.system_time.seconds * 1000000000LL +
139                    info.system_time.microseconds * 1000LL);
140 }
141 #else
GetThreadCPUTimeNs()142 inline TimeNanos GetThreadCPUTimeNs() {
143   struct timespec ts = {};
144   PERFETTO_CHECK(clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts) == 0);
145   return FromPosixTimespec(ts);
146 }
147 #endif
148 
149 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_WASM)
150 
GetWallTimeNs()151 inline TimeNanos GetWallTimeNs() {
152   return TimeNanos(static_cast<uint64_t>(emscripten_get_now()) * 1000000);
153 }
154 
GetWallTimeRawNs()155 inline TimeNanos GetWallTimeRawNs() {
156   return GetWallTimeNs();
157 }
158 
GetThreadCPUTimeNs()159 inline TimeNanos GetThreadCPUTimeNs() {
160   return TimeNanos(0);
161 }
162 
163 // TODO: Clock that counts time during suspend is not implemented on WASM.
GetBootTimeNs()164 inline TimeNanos GetBootTimeNs() {
165   return GetWallTimeNs();
166 }
167 
168 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_NACL)
169 
170 // Tracing time doesn't need to work on NaCl since its going away shortly. We
171 // just need to compile on it. The only function NaCl could support is
172 // GetWallTimeNs(), but to prevent false hope we leave it unimplemented.
173 
GetWallTimeNs()174 inline TimeNanos GetWallTimeNs() {
175   return TimeNanos(0);
176 }
177 
GetWallTimeRawNs()178 inline TimeNanos GetWallTimeRawNs() {
179   return TimeNanos(0);
180 }
181 
GetThreadCPUTimeNs()182 inline TimeNanos GetThreadCPUTimeNs() {
183   return TimeNanos(0);
184 }
185 
GetBootTimeNs()186 inline TimeNanos GetBootTimeNs() {
187   return TimeNanos(0);
188 }
189 
190 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_QNX)
191 
192 constexpr clockid_t kWallTimeClockSource = CLOCK_MONOTONIC;
193 
GetTimeInternalNs(clockid_t clk_id)194 inline TimeNanos GetTimeInternalNs(clockid_t clk_id) {
195   struct timespec ts = {};
196   PERFETTO_CHECK(clock_gettime(clk_id, &ts) == 0);
197   return FromPosixTimespec(ts);
198 }
199 
GetWallTimeNs()200 inline TimeNanos GetWallTimeNs() {
201   return GetTimeInternalNs(kWallTimeClockSource);
202 }
203 
GetWallTimeRawNs()204 inline TimeNanos GetWallTimeRawNs() {
205   return GetTimeInternalNs(CLOCK_MONOTONIC);
206 }
207 
GetThreadCPUTimeNs()208 inline TimeNanos GetThreadCPUTimeNs() {
209   return GetTimeInternalNs(CLOCK_THREAD_CPUTIME_ID);
210 }
211 
212 // TODO: Clock that counts time during suspend is not implemented on QNX.
GetBootTimeNs()213 inline TimeNanos GetBootTimeNs() {
214   return GetWallTimeNs();
215 }
216 
217 #else  // posix
218 
219 constexpr clockid_t kWallTimeClockSource = CLOCK_MONOTONIC;
220 
GetTimeInternalNs(clockid_t clk_id)221 inline TimeNanos GetTimeInternalNs(clockid_t clk_id) {
222   struct timespec ts = {};
223   PERFETTO_CHECK(clock_gettime(clk_id, &ts) == 0);
224   return FromPosixTimespec(ts);
225 }
226 
227 // Return ns from boot. Conversely to GetWallTimeNs, this clock counts also time
228 // during suspend (when supported).
GetBootTimeNs()229 inline TimeNanos GetBootTimeNs() {
230   // Determine if CLOCK_BOOTTIME is available on the first call.
231   static const clockid_t kBootTimeClockSource = [] {
232     struct timespec ts = {};
233     int res = clock_gettime(CLOCK_BOOTTIME, &ts);
234     return res == 0 ? CLOCK_BOOTTIME : kWallTimeClockSource;
235   }();
236   return GetTimeInternalNs(kBootTimeClockSource);
237 }
238 
GetWallTimeNs()239 inline TimeNanos GetWallTimeNs() {
240   return GetTimeInternalNs(kWallTimeClockSource);
241 }
242 
GetWallTimeRawNs()243 inline TimeNanos GetWallTimeRawNs() {
244   return GetTimeInternalNs(CLOCK_MONOTONIC_RAW);
245 }
246 
GetThreadCPUTimeNs()247 inline TimeNanos GetThreadCPUTimeNs() {
248   return GetTimeInternalNs(CLOCK_THREAD_CPUTIME_ID);
249 }
250 #endif
251 
GetBootTimeS()252 inline TimeSeconds GetBootTimeS() {
253   return std::chrono::duration_cast<TimeSeconds>(GetBootTimeNs());
254 }
255 
GetBootTimeMs()256 inline TimeMillis GetBootTimeMs() {
257   return std::chrono::duration_cast<TimeMillis>(GetBootTimeNs());
258 }
259 
GetWallTimeMs()260 inline TimeMillis GetWallTimeMs() {
261   return std::chrono::duration_cast<TimeMillis>(GetWallTimeNs());
262 }
263 
GetWallTimeS()264 inline TimeSeconds GetWallTimeS() {
265   return std::chrono::duration_cast<TimeSeconds>(GetWallTimeNs());
266 }
267 
ToPosixTimespec(TimeMillis time)268 inline struct timespec ToPosixTimespec(TimeMillis time) {
269   struct timespec ts {};
270   const long time_s = static_cast<long>(time.count() / 1000);
271   ts.tv_sec = time_s;
272   ts.tv_nsec = (static_cast<long>(time.count()) - time_s * 1000L) * 1000000L;
273   return ts;
274 }
275 
276 std::string GetTimeFmt(const std::string& fmt);
277 
TimeGm(struct tm * tms)278 inline int64_t TimeGm(struct tm* tms) {
279 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
280   return static_cast<int64_t>(_mkgmtime(tms));
281 #elif PERFETTO_BUILDFLAG(PERFETTO_OS_NACL)
282   // NaCL has no timegm.
283   if (tms)  // Kinda if (true), but avoids "mark as noreturn" errors.
284     PERFETTO_FATAL("timegm not supported");
285   return -1;
286 #else
287   return static_cast<int64_t>(timegm(tms));
288 #endif
289 }
290 
291 // Creates a time_t-compatible timestamp (seconds since epoch) from a tuple of
292 // y-m-d-h-m-s. It's a saner version of timegm(). Some remarks:
293 // The year is just the actual year (it's Y-1900 in timegm()).
294 // The month ranges 1-12 (it's 0-11 in timegm()).
MkTime(int year,int month,int day,int h,int m,int s)295 inline int64_t MkTime(int year, int month, int day, int h, int m, int s) {
296   PERFETTO_DCHECK(year >= 1900);
297   PERFETTO_DCHECK(month > 0 && month <= 12);
298   PERFETTO_DCHECK(day > 0 && day <= 31);
299   struct tm tms {};
300   tms.tm_year = year - 1900;
301   tms.tm_mon = month - 1;
302   tms.tm_mday = day;
303   tms.tm_hour = h;
304   tms.tm_min = m;
305   tms.tm_sec = s;
306   return TimeGm(&tms);
307 }
308 
309 #if PERFETTO_BUILDFLAG(PERFETTO_ARCH_CPU_X86_64)
Rdtsc()310 inline uint64_t Rdtsc() {
311 #if PERFETTO_BUILDFLAG(PERFETTO_COMPILER_MSVC)
312   return static_cast<uint64_t>(__rdtsc());
313 #else
314   // Use inline asm for clang and gcc: rust ffi bindgen crashes in using
315   // intrinsics on ChromeOS.
316   uint64_t low, high;
317   __asm__ volatile("rdtsc" : "=a"(low), "=d"(high));
318   return (high << 32) | low;
319 #endif
320 }
321 #endif
322 
323 std::optional<int32_t> GetTimezoneOffsetMins();
324 
325 }  // namespace base
326 }  // namespace perfetto
327 
328 #endif  // INCLUDE_PERFETTO_BASE_TIME_H_
329