third-party/benchmark/src/sleep.cc

   1 // Copyright 2015 Google Inc. All rights reserved.
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 #include "sleep.h"
  16
  17 #include <cerrno>
  18 #include <cstdlib>
  19 #include <ctime>
  20
  21 #include "internal_macros.h"
  22
  23 #ifdef BENCHMARK_OS_WINDOWS
  24 #include <windows.h>
  25 #endif
  26
  27 #ifdef BENCHMARK_OS_ZOS
  28 #include <unistd.h>
  29 #endif
  30
  31 namespace benchmark {
  32 #ifdef BENCHMARK_OS_WINDOWS
  33 // Window's Sleep takes milliseconds argument.
  34 void SleepForMilliseconds(int milliseconds) { Sleep(milliseconds); }
  35 void SleepForSeconds(double seconds) {
  36   SleepForMilliseconds(static_cast<int>(kNumMillisPerSecond * seconds));
  37 }
  38 #else  // BENCHMARK_OS_WINDOWS
  39 void SleepForMicroseconds(int microseconds) {
  40 #ifdef BENCHMARK_OS_ZOS
  41   // z/OS does not support nanosleep. Instead call sleep() and then usleep() to
  42   // sleep for the remaining microseconds because usleep() will fail if its
  43   // argument is greater than 1000000.
  44   div_t sleepTime = div(microseconds, kNumMicrosPerSecond);
  45   int seconds = sleepTime.quot;
  46   while (seconds != 0) seconds = sleep(seconds);
  47   while (usleep(sleepTime.rem) == -1 && errno == EINTR)
  48     ;
  49 #else
  50   struct timespec sleep_time;
  51   sleep_time.tv_sec = microseconds / kNumMicrosPerSecond;
  52   sleep_time.tv_nsec = (microseconds % kNumMicrosPerSecond) * kNumNanosPerMicro;
  53   while (nanosleep(&sleep_time, &sleep_time) != 0 && errno == EINTR)
  54     ;  // Ignore signals and wait for the full interval to elapse.
  55 #endif
  56 }
  57
  58 void SleepForMilliseconds(int milliseconds) {
  59   SleepForMicroseconds(milliseconds * kNumMicrosPerMilli);
  60 }
  61
  62 void SleepForSeconds(double seconds) {
  63   SleepForMicroseconds(static_cast<int>(seconds * kNumMicrosPerSecond));
  64 }
  65 #endif  // BENCHMARK_OS_WINDOWS
  66 }  // end namespace benchmark