gdbsupport/run-time-clock.h

   1 /* User/system CPU time clocks that follow the std::chrono interface.
   2    Copyright (C) 2016-2023 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef COMMON_RUN_TIME_CLOCK_H
  20 #define COMMON_RUN_TIME_CLOCK_H
  21
  22 #include <chrono>
  23
  24 /* Count the total amount of time spent executing in user mode.  */
  25
  26 struct user_cpu_time_clock
  27 {
  28   using duration = std::chrono::microseconds;
  29   using rep = duration::rep;
  30   using period = duration::period;
  31   using time_point = std::chrono::time_point<user_cpu_time_clock>;
  32
  33   static constexpr bool is_steady = true;
  34
  35   /* Use run_time_clock::now instead.  */
  36   static time_point now () noexcept = delete;
  37 };
  38
  39 /* Count the total amount of time spent executing in kernel mode.  */
  40
  41 struct system_cpu_time_clock
  42 {
  43   using duration = std::chrono::microseconds;
  44   using rep = duration::rep;
  45   using period = duration::period;
  46   using time_point = std::chrono::time_point<system_cpu_time_clock>;
  47
  48   static constexpr bool is_steady = true;
  49
  50   /* Use run_time_clock::now instead.  */
  51   static time_point now () noexcept = delete;
  52 };
  53
  54 /* Count the total amount of time spent executing in userspace+kernel
  55    mode.  */
  56
  57 struct run_time_clock
  58 {
  59   using duration = std::chrono::microseconds;
  60   using rep = duration::rep;
  61   using period = duration::period;
  62   using time_point = std::chrono::time_point<run_time_clock>;
  63
  64   static constexpr bool is_steady = true;
  65
  66   static time_point now () noexcept;
  67
  68   /* Return the user/system time as separate time points, if
  69      supported.  If not supported, then the combined user+kernel time
  70      is returned in USER and SYSTEM is set to zero.  */
  71   static void now (user_cpu_time_clock::time_point &user,
  72                    system_cpu_time_clock::time_point &system) noexcept;
  73 };
  74
  75 #endif /* COMMON_RUN_TIME_CLOCK_H */