xref: /freebsd/share/man/man9/microtime.9 (revision 4f8f43b06ed07e96a250855488cc531799d5b78f)
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25.Dd September 16, 2004
26.Dt MICROTIME 9
27.Os
28.Sh NAME
29.Nm bintime ,
30.Nm getbintime ,
31.Nm microtime ,
32.Nm getmicrotime ,
33.Nm nanotime ,
34.Nm getnanotime
35.Nd get the current time
36.Sh SYNOPSIS
37.In sys/time.h
38.Ft void
39.Fn bintime "struct bintime *bt"
40.Ft void
41.Fn getbintime "struct bintime *bt"
42.Ft void
43.Fn microtime "struct timeval *tv"
44.Ft void
45.Fn getmicrotime "struct timeval *tv"
46.Ft void
47.Fn nanotime "struct timespec *ts"
48.Ft void
49.Fn getnanotime "struct timespec *tsp"
50.Sh DESCRIPTION
51The
52.Fn bintime
53and
54.Fn getbintime
55functions store the system time as a
56.Vt "struct bintime"
57at the addresses specified by
58.Fa bt .
59The
60.Fn microtime
61and
62.Fn getmicrotime
63functions perform the same utility, but record the time as a
64.Vt "struct timeval"
65instead.
66Similarly the
67.Fn nanotime
68and
69.Fn getnanotime
70functions store the time as a
71.Vt "struct timespec" .
72.Pp
73The
74.Fn bintime ,
75.Fn microtime ,
76and
77.Fn nanotime
78functions
79always query the timecounter to return the current time as precisely as
80possible.
81Whereas
82.Fn getbintime ,
83.Fn getmicrotime ,
84and
85.Fn getnanotime
86functions are abstractions which return a less precise, but
87faster to obtain, time.
88.Pp
89The intent of the
90.Fn getbintime ,
91.Fn getmicrotime ,
92and
93.Fn getnanotime
94functions is to enforce the user's preference for timer accuracy versus
95execution time.
96.Sh SEE ALSO
97.Xr binuptime 9 ,
98.Xr getbinuptime 9 ,
99.Xr getmicrouptime 9 ,
100.Xr getnanouptime 9 ,
101.Xr microuptime 9 ,
102.Xr nanouptime 9 ,
103.Xr tvtohz 9
104.Sh HISTORY
105The
106.Nm bintime
107functions first appeared in
108.Fx 5.0 .
109The
110.Nm microtime
111and
112.Nm nanotime
113functions first appeared in
114.Fx 3.0
115but have existed in other incarnations since
116.Bx 4.4 .
117.Sh AUTHORS
118This manual page was written by
119.An Kelly Yancey Aq Mt kbyanc@posi.net .
120