xref: /freebsd/share/man/man9/microuptime.9 (revision 3416500aef140042c64bc149cb1ec6620483bc44)
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25.\" $FreeBSD$
26.\"
27.Dd February 21, 2015
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.Nm sbinuptime ,
38.Nm getsbinuptime
39.Nd get the time elapsed since boot
40.Sh SYNOPSIS
41.In sys/time.h
42.Ft void
43.Fn binuptime "struct bintime *bt"
44.Ft void
45.Fn getbinuptime "struct bintime *bt"
46.Ft void
47.Fn microuptime "struct timeval *tv"
48.Ft void
49.Fn getmicrouptime "struct timeval *tv"
50.Ft void
51.Fn nanouptime "struct timespec *ts"
52.Ft void
53.Fn getnanouptime "struct timespec *tsp"
54.Ft sbintime_t
55.Fn sbinuptime "void"
56.Ft sbintime_t
57.Fn getsbinuptime "void"
58.Sh DESCRIPTION
59The
60.Fn binuptime
61and
62.Fn getbinuptime
63functions store the time elapsed since boot as a
64.Vt "struct bintime"
65at the address specified by
66.Fa bt .
67The
68.Fn microuptime
69and
70.Fn getmicrouptime
71functions perform the same utility, but record the elapsed time as a
72.Vt "struct timeval"
73instead.
74Similarly the
75.Fn nanouptime
76and
77.Fn getnanouptime
78functions store the elapsed time as a
79.Vt "struct timespec" .
80The
81.Fn sbinuptime
82and
83.Fn getsbinuptime
84functions return the time elapsed since boot as a
85.Vt "sbintime_t" .
86.Pp
87The
88.Fn binuptime ,
89.Fn microuptime ,
90.Fn nanouptime ,
91and
92.Fn sbinuptime
93functions
94always query the timecounter to return the current time as precisely as
95possible.
96Whereas
97.Fn getbinuptime ,
98.Fn getmicrouptime ,
99.Fn getnanouptime ,
100and
101.Fn getsbinuptime
102functions are abstractions which return a less precise, but
103faster to obtain, time.
104.Pp
105The intent of the
106.Fn getbinuptime ,
107.Fn getmicrouptime ,
108.Fn getnanouptime ,
109and
110.Fn getsbinuptime
111functions is to enforce the user's preference for timer accuracy versus
112execution time.
113.Sh SEE ALSO
114.Xr bintime 9 ,
115.Xr get_cyclecount 9 ,
116.Xr getbintime 9 ,
117.Xr getmicrotime 9 ,
118.Xr getnanotime 9 ,
119.Xr microtime 9 ,
120.Xr nanotime 9 ,
121.Xr tvtohz 9
122.Sh AUTHORS
123This manual page was written by
124.An Kelly Yancey Aq Mt kbyanc@posi.net .
125