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      1 /* User/system CPU time clocks that follow the std::chrono interface.
      2    Copyright (C) 2016-2025 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 #include "run-time-clock.h"
     20 #if defined HAVE_SYS_RESOURCE_H
     21 #include <sys/resource.h>
     22 #endif
     23 
     24 using namespace std::chrono;
     25 
     26 run_time_clock::time_point
     27 run_time_clock::now () noexcept
     28 {
     29   return time_point (microseconds (get_run_time ()));
     30 }
     31 
     32 #ifdef HAVE_GETRUSAGE
     33 static std::chrono::microseconds
     34 timeval_to_microseconds (struct timeval *tv)
     35 {
     36   return (seconds (tv->tv_sec) + microseconds (tv->tv_usec));
     37 }
     38 #endif
     39 
     40 /* See run-time-clock.h.  */
     41 
     42 bool
     43 get_run_time_thread_scope_available ()
     44 {
     45 #if defined HAVE_GETRUSAGE && defined RUSAGE_THREAD
     46   return true;
     47 #else
     48   return false;
     49 #endif
     50 }
     51 
     52 void
     53 get_run_time (user_cpu_time_clock::time_point &user,
     54 	      system_cpu_time_clock::time_point &system,
     55 	      run_time_scope scope) noexcept
     56 {
     57 #ifdef HAVE_GETRUSAGE
     58 
     59   /* If we can't provide thread scope run time usage, fallback to
     60      process scope.  This will at least be right if GDB is built
     61      without threading support in the first place (or is set to use
     62      zero worker threads).  */
     63 # ifndef RUSAGE_THREAD
     64 #  define RUSAGE_THREAD RUSAGE_SELF
     65 # endif
     66 
     67   struct rusage rusage;
     68   int who;
     69 
     70   switch (scope)
     71     {
     72     case run_time_scope::thread:
     73       who = RUSAGE_THREAD;
     74       break;
     75 
     76     case run_time_scope::process:
     77       who = RUSAGE_SELF;
     78       break;
     79 
     80     default:
     81       gdb_assert_not_reached ("invalid run_time_scope value");
     82     }
     83 
     84   getrusage (who, &rusage);
     85 
     86   microseconds utime = timeval_to_microseconds (&rusage.ru_utime);
     87   microseconds stime = timeval_to_microseconds (&rusage.ru_stime);
     88   user = user_cpu_time_clock::time_point (utime);
     89   system = system_cpu_time_clock::time_point (stime);
     90 #else
     91   user = user_cpu_time_clock::time_point (microseconds (get_run_time ()));
     92   system = system_cpu_time_clock::time_point (microseconds::zero ());
     93 #endif
     94 }
     95