kc3-lang/gnulib/tests/test-getrusage.c

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• Hash : 7b089321
  Author :
  Date : 2025-01-01T09:24:36
  

  maint: run 'make update-copyright'
  

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• tests/test-getrusage.c

• /* Test of getting resource utilization.
     Copyright (C) 2012-2025 Free Software Foundation, Inc.
  
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation, either version 3 of the License, or
     (at your option) any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  
  /* Written by Bruno Haible <bruno@clisp.org>, 2012.  */
  
  #include <config.h>
  
  #include <sys/resource.h>
  
  #include "signature.h"
  SIGNATURE_CHECK (getrusage, int, (int, struct rusage *));
  
  #include <sys/time.h>
  
  #include "macros.h"
  
  volatile unsigned int counter;
  
  int
  main (void)
  {
    struct rusage before;
    struct rusage after;
    int ret;
  
    ret = getrusage (RUSAGE_SELF, &before);
    ASSERT (ret == 0);
  
    /* Busy-loop for one second.  */
    {
      struct timeval t0;
      ASSERT (gettimeofday (&t0, NULL) == 0);
  
      for (;;)
        {
          struct timeval t;
          int i;
  
          for (i = 0; i < 1000000; i++)
            counter++;
  
          ASSERT (gettimeofday (&t, NULL) == 0);
          if (t.tv_sec - t0.tv_sec > 1
              || (t.tv_sec - t0.tv_sec == 1 && t.tv_usec >= t0.tv_usec))
            break;
        }
    }
  
    ret = getrusage (RUSAGE_SELF, &after);
    ASSERT (ret == 0);
  
    ASSERT (after.ru_utime.tv_sec >= before.ru_utime.tv_sec);
    ASSERT (after.ru_stime.tv_sec >= before.ru_stime.tv_sec);
    {
      /* Compute time spent during busy-looping (in usec).  */
      unsigned int spent_utime =
        (after.ru_utime.tv_sec > before.ru_utime.tv_sec
         ? (after.ru_utime.tv_sec - before.ru_utime.tv_sec - 1) * 1000000U
           + after.ru_utime.tv_usec + (1000000U - before.ru_utime.tv_usec)
         : after.ru_utime.tv_usec - before.ru_utime.tv_usec);
      unsigned int spent_stime =
        (after.ru_stime.tv_sec > before.ru_stime.tv_sec
         ? (after.ru_stime.tv_sec - before.ru_stime.tv_sec - 1) * 1000000U
           + after.ru_stime.tv_usec + (1000000U - before.ru_stime.tv_usec)
         : after.ru_stime.tv_usec - before.ru_stime.tv_usec);
  
      ASSERT (spent_utime + spent_stime <= 2 * 1000000U);
      /* Assume that the load during this busy-looping was less than 100.  */
      ASSERT (spent_utime + spent_stime > 10000U);
    }
  
    return test_exit_status;
  }
  

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