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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 #include "perfetto/base/build_config.h"
     18 #include "perfetto/base/time.h"
     19 
     20 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
     21 #include <Windows.h>
     22 #else
     23 #include <unistd.h>
     24 #endif
     25 
     26 namespace perfetto {
     27 namespace base {
     28 
     29 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
     30 
     31 TimeNanos GetWallTimeNs() {
     32   LARGE_INTEGER freq;
     33   ::QueryPerformanceFrequency(&freq);
     34   LARGE_INTEGER counter;
     35   ::QueryPerformanceCounter(&counter);
     36   double elapsed_nanoseconds = (1e9 * counter.QuadPart) / freq.QuadPart;
     37   return TimeNanos(static_cast<uint64_t>(elapsed_nanoseconds));
     38 }
     39 
     40 TimeNanos GetThreadCPUTimeNs() {
     41   FILETIME dummy, kernel_ftime, user_ftime;
     42   ::GetThreadTimes(GetCurrentThread(), &dummy, &dummy, &kernel_ftime,
     43                    &user_ftime);
     44   uint64_t kernel_time = kernel_ftime.dwHighDateTime * 0x100000000 +
     45                          kernel_ftime.dwLowDateTime;
     46   uint64_t user_time = user_ftime.dwHighDateTime * 0x100000000 +
     47                        user_ftime.dwLowDateTime;
     48 
     49   return TimeNanos((kernel_time + user_time) * 100);
     50 }
     51 
     52 void SleepMicroseconds(unsigned interval_us) {
     53   // The Windows Sleep function takes a millisecond count. Round up so that
     54   // short sleeps don't turn into a busy wait. Note that the sleep granularity
     55   // on Windows can dynamically vary from 1 ms to ~16 ms, so don't count on this
     56   // being a short sleep.
     57   ::Sleep(static_cast<DWORD>((interval_us + 999) / 1000));
     58 }
     59 
     60 #else  // PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
     61 
     62 void SleepMicroseconds(unsigned interval_us) {
     63   ::usleep(static_cast<useconds_t>(interval_us));
     64 }
     65 
     66 #endif  // PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
     67 
     68 }  // namespace base
     69 }  // namespace perfetto
     70