posix: Fix and simplify default p{read,write}v implementation
[glibc.git] / resource / vtimes.c
blob20aae81228cc9269b5bdaf2aa24baf4401d63f94
1 /* Copyright (C) 1991-2017 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
18 #include <stddef.h>
19 #include <sys/vtimes.h>
20 #include <sys/resource.h>
22 /* Return the number of 1/VTIMES_UNITS_PER_SECOND-second
23 units in the `struct timeval' TV. */
24 #define TIMEVAL_TO_VTIMES(tv) \
25 ((tv.tv_sec * VTIMES_UNITS_PER_SECOND) + \
26 (tv.tv_usec * VTIMES_UNITS_PER_SECOND / 1000000))
28 /* If VT is not NULL, write statistics for WHO into *VT.
29 Return 0 for success, -1 for failure. */
30 static int
31 vtimes_one (struct vtimes *vt, enum __rusage_who who)
33 if (vt != NULL)
35 struct rusage usage;
37 if (__getrusage (who, &usage) < 0)
38 return -1;
40 vt->vm_utime = TIMEVAL_TO_VTIMES (usage.ru_utime);
41 vt->vm_stime = TIMEVAL_TO_VTIMES (usage.ru_stime);
42 vt->vm_idsrss = usage.ru_idrss + usage.ru_isrss;
43 vt->vm_majflt = usage.ru_majflt;
44 vt->vm_minflt = usage.ru_minflt;
45 vt->vm_nswap = usage.ru_nswap;
46 vt->vm_inblk = usage.ru_inblock;
47 vt->vm_oublk = usage.ru_oublock;
49 return 0;
52 /* If CURRENT is not NULL, write statistics for the current process into
53 *CURRENT. If CHILD is not NULL, write statistics for all terminated child
54 processes into *CHILD. Returns 0 for success, -1 for failure. */
55 int
56 vtimes (struct vtimes *current, struct vtimes *child)
58 if (vtimes_one (current, RUSAGE_SELF) < 0
59 || vtimes_one (child, RUSAGE_CHILDREN) < 0)
60 return -1;
61 return 0;