xref: /freebsd/share/man/man9/microuptime.9 (revision 8fc257994d0ce2396196d7a06d50d20c8015f4b7)
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25.\" $FreeBSD$
26.\"
27.Dd September 16, 2004
28.Dt MICROUPTIME 9
29.Os
30.Sh NAME
31.Nm binuptime ,
32.Nm getbinuptime ,
33.Nm microuptime ,
34.Nm getmicrouptime ,
35.Nm nanouptime ,
36.Nm getnanouptime
37.Nd get the time elapsed since boot
38.Sh SYNOPSIS
39.In sys/time.h
40.Ft void
41.Fn binuptime "struct bintime *bt"
42.Ft void
43.Fn getbinuptime "struct bintime *bt"
44.Ft void
45.Fn microuptime "struct timeval *tv"
46.Ft void
47.Fn getmicrouptime "struct timeval *tv"
48.Ft void
49.Fn nanouptime "struct timespec *ts"
50.Ft void
51.Fn getnanouptime "struct timespec *tsp"
52.Sh DESCRIPTION
53The
54.Fn binuptime
55and
56.Fn getbinuptime
57functions store the time elapsed since boot as a
58.Vt "struct bintime"
59at the address specified by
60.Fa bt .
61The
62.Fn microuptime
63and
64.Fn getmicrouptime
65functions perform the same utility, but record the elapsed time as a
66.Vt "struct timeval"
67instead.
68Similarly the
69.Fn nanouptime
70and
71.Fn getnanouptime
72functions store the elapsed time as a
73.Vt "struct timespec" .
74.Pp
75The
76.Fn binuptime ,
77.Fn microuptime ,
78and
79.Fn nanouptime
80functions
81always query the timecounter to return the current time as precisely as
82possible.
83Whereas
84.Fn getbinuptime ,
85.Fn getmicrouptime ,
86and
87.Fn getnanouptime
88functions are abstractions which return a less precise, but
89faster to obtain, time.
90.Pp
91The intent of the
92.Fn getbinuptime ,
93.Fn getmicrouptime ,
94and
95.Fn getnanouptime
96functions is to enforce the user's preference for timer accuracy versus
97execution time.
98.Sh SEE ALSO
99.Xr bintime 9 ,
100.Xr getbintime 9 ,
101.Xr getmicrotime 9 ,
102.Xr getnanotime 9 ,
103.Xr microtime 9 ,
104.Xr nanotime 9 ,
105.Xr tvtohz 9
106.Sh AUTHORS
107This manual page was written by
108.An Kelly Yancey Aq kbyanc@posi.net .
109