summaryrefslogtreecommitdiffstats
path: root/lib/libc/gen/times.3
blob: a77c69f227a0ef0752ed60248632beab7a1fbba1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
.\" Copyright (c) 1990, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)times.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd December 1, 2008
.Dt TIMES 3
.Os
.Sh NAME
.Nm times
.Nd process times
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/times.h
.Ft clock_t
.Fn times "struct tms *tp"
.Sh DESCRIPTION
.Bf -symbolic
This interface is obsoleted by
.Xr getrusage 2
and
.Xr gettimeofday 2 .
.Ef
.Pp
The
.Fn times
function returns the value of time in
.Dv CLK_TCK Ns 's
of a second since the system startup time.
The current value of
.Dv CLK_TCK ,
the frequency of the statistics clock in ticks per second, may be
obtained through the
.Xr sysconf 3
interface.
.Pp
It also fills in the structure pointed to by
.Fa tp
with time-accounting information.
.Pp
The
.Vt tms
structure is defined as follows:
.Bd -literal -offset indent
struct tms {
	clock_t tms_utime;
	clock_t tms_stime;
	clock_t tms_cutime;
	clock_t tms_cstime;
};
.Ed
.Pp
The elements of this structure are defined as follows:
.Bl -tag -width ".Va tms_cutime"
.It Va tms_utime
The
.Tn CPU
time charged for the execution of user instructions.
.It Va tms_stime
The
.Tn CPU
time charged for execution by the system on behalf of
the process.
.It Va tms_cutime
The sum of the
.Va tms_utime Ns s
and
.Va tms_cutime Ns s
of the child processes.
.It Va tms_cstime
The sum of the
.Fa tms_stime Ns s
and
.Fa tms_cstime Ns s
of the child processes.
.El
.Pp
All times are in
.Dv CLK_TCK Ns 's
of a second.
.Pp
The times of a terminated child process are included in the
.Va tms_cutime
and
.Va tms_cstime
elements of the parent when one of the
.Xr wait 2
functions returns the process ID of the terminated child to the parent.
If an error occurs,
.Fn times
returns the value
.Pq Po Vt clock_t Pc Ns \-1 ,
and sets
.Va errno
to indicate the error.
.Sh ERRORS
The
.Fn times
function
may fail and set the global variable
.Va errno
for any of the errors specified for the library
routines
.Xr getrusage 2
and
.Xr gettimeofday 2 .
.Sh SEE ALSO
.Xr time 1 ,
.Xr getrusage 2 ,
.Xr gettimeofday 2 ,
.Xr wait 2 ,
.Xr sysconf 3 ,
.Xr clocks 7
.Sh STANDARDS
The
.Fn times
function
conforms to
.St -p1003.1-88 .
OpenPOWER on IntegriCloud