glibc/resource/vtimes.c

/* Copyright (C) 1991-2024 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <stddef.h>
#include <sys/resource.h>
#include <shlib-compat.h>

#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_33)

/* Granularity of the `vm_utime' and `vm_stime' fields of a `struct vtimes'.
   (This is the frequency of the machine's power supply, in Hz.)  */
# define VTIMES_UNITS_PER_SECOND 60

struct vtimes
{
  /* User time used in units of 1/VTIMES_UNITS_PER_SECOND seconds.  */
  int vm_utime;
  /* System time used in units of 1/VTIMES_UNITS_PER_SECOND seconds.  */
  int vm_stime;

  /* Amount of data and stack memory used (kilobyte-seconds).  */
  unsigned int vm_idsrss;
  /* Amount of text memory used (kilobyte-seconds).  */
  unsigned int vm_ixrss;
  /* Maximum resident set size (text, data, and stack) (kilobytes).  */
  int vm_maxrss;

  /* Number of hard page faults (i.e. those that required I/O).  */
  int vm_majflt;
  /* Number of soft page faults (i.e. those serviced by reclaiming
     a page from the list of pages awaiting reallocation.  */
  int vm_minflt;

  /* Number of times a process was swapped out of physical memory.  */
  int vm_nswap;

  /* Number of input operations via the file system.  Note: This
     and `ru_oublock' do not include operations with the cache.  */
  int vm_inblk;
  /* Number of output operations via the file system.  */
  int vm_oublk;
};

/* Return the number of 1/VTIMES_UNITS_PER_SECOND-second
   units in the `struct timeval' TV.  */
# define TIMEVAL_TO_VTIMES(tv) \
  ((tv.tv_sec * VTIMES_UNITS_PER_SECOND) \
   + (tv.tv_usec * VTIMES_UNITS_PER_SECOND / 1000000))

/* If VT is not NULL, write statistics for WHO into *VT.
   Return 0 for success, -1 for failure.  */
static int
vtimes_one (struct vtimes *vt, enum __rusage_who who)
{
  if (vt != NULL)
    {
      struct rusage usage;

      if (__getrusage (who, &usage) < 0)
	return -1;

      vt->vm_utime = TIMEVAL_TO_VTIMES (usage.ru_utime);
      vt->vm_stime = TIMEVAL_TO_VTIMES (usage.ru_stime);
      vt->vm_idsrss = usage.ru_idrss + usage.ru_isrss;
      vt->vm_majflt = usage.ru_majflt;
      vt->vm_minflt = usage.ru_minflt;
      vt->vm_nswap = usage.ru_nswap;
      vt->vm_inblk = usage.ru_inblock;
      vt->vm_oublk = usage.ru_oublock;
    }
  return 0;
}

/* If CURRENT is not NULL, write statistics for the current process into
   *CURRENT.  If CHILD is not NULL, write statistics for all terminated child
   processes into *CHILD.  Returns 0 for success, -1 for failure.  */
int
__vtimes (struct vtimes *current, struct vtimes *child)
{
  if (vtimes_one (current, RUSAGE_SELF) < 0
      || vtimes_one (child, RUSAGE_CHILDREN) < 0)
    return -1;
  return 0;
}
compat_symbol (libc, __vtimes, vtimes, GLIBC_2_0);

#endif /* SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_33)  */