xref: /freebsd/share/man/man9/microuptime.9 (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
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25.Dd February 21, 2015
26.Dt MICROUPTIME 9
27.Os
28.Sh NAME
29.Nm binuptime ,
30.Nm getbinuptime ,
31.Nm microuptime ,
32.Nm getmicrouptime ,
33.Nm nanouptime ,
34.Nm getnanouptime ,
35.Nm sbinuptime ,
36.Nm getsbinuptime
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.Ft sbintime_t
53.Fn sbinuptime "void"
54.Ft sbintime_t
55.Fn getsbinuptime "void"
56.Sh DESCRIPTION
57The
58.Fn binuptime
59and
60.Fn getbinuptime
61functions store the time elapsed since boot as a
62.Vt "struct bintime"
63at the address specified by
64.Fa bt .
65The
66.Fn microuptime
67and
68.Fn getmicrouptime
69functions perform the same utility, but record the elapsed time as a
70.Vt "struct timeval"
71instead.
72Similarly the
73.Fn nanouptime
74and
75.Fn getnanouptime
76functions store the elapsed time as a
77.Vt "struct timespec" .
78The
79.Fn sbinuptime
80and
81.Fn getsbinuptime
82functions return the time elapsed since boot as a
83.Vt "sbintime_t" .
84.Pp
85The
86.Fn binuptime ,
87.Fn microuptime ,
88.Fn nanouptime ,
89and
90.Fn sbinuptime
91functions
92always query the timecounter to return the current time as precisely as
93possible.
94Whereas
95.Fn getbinuptime ,
96.Fn getmicrouptime ,
97.Fn getnanouptime ,
98and
99.Fn getsbinuptime
100functions are abstractions which return a less precise, but
101faster to obtain, time.
102.Pp
103The intent of the
104.Fn getbinuptime ,
105.Fn getmicrouptime ,
106.Fn getnanouptime ,
107and
108.Fn getsbinuptime
109functions is to enforce the user's preference for timer accuracy versus
110execution time.
111.Sh SEE ALSO
112.Xr bintime 9 ,
113.Xr get_cyclecount 9 ,
114.Xr getbintime 9 ,
115.Xr getmicrotime 9 ,
116.Xr getnanotime 9 ,
117.Xr microtime 9 ,
118.Xr nanotime 9 ,
119.Xr tvtohz 9
120.Sh AUTHORS
121This manual page was written by
122.An Kelly Yancey Aq Mt kbyanc@posi.net .
123