xref: /freebsd/share/man/man9/microtime.9 (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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25.\" $FreeBSD$
26.\"
27.Dd September 16, 2004
28.Dt MICROTIME 9
29.Os
30.Sh NAME
31.Nm bintime ,
32.Nm getbintime ,
33.Nm microtime ,
34.Nm getmicrotime ,
35.Nm nanotime ,
36.Nm getnanotime
37.Nd get the current time
38.Sh SYNOPSIS
39.In sys/time.h
40.Ft void
41.Fn bintime "struct bintime *bt"
42.Ft void
43.Fn getbintime "struct bintime *bt"
44.Ft void
45.Fn microtime "struct timeval *tv"
46.Ft void
47.Fn getmicrotime "struct timeval *tv"
48.Ft void
49.Fn nanotime "struct timespec *ts"
50.Ft void
51.Fn getnanotime "struct timespec *tsp"
52.Sh DESCRIPTION
53The
54.Fn bintime
55and
56.Fn getbintime
57functions store the system time as a
58.Vt "struct bintime"
59at the addresses specified by
60.Fa bt .
61The
62.Fn microtime
63and
64.Fn getmicrotime
65functions perform the same utility, but record the time as a
66.Vt "struct timeval"
67instead.
68Similarly the
69.Fn nanotime
70and
71.Fn getnanotime
72functions store the time as a
73.Vt "struct timespec" .
74.Pp
75The
76.Fn bintime ,
77.Fn microtime ,
78and
79.Fn nanotime
80functions
81always query the timecounter to return the current time as precisely as
82possible.
83Whereas
84.Fn getbintime ,
85.Fn getmicrotime ,
86and
87.Fn getnanotime
88functions are abstractions which return a less precise, but
89faster to obtain, time.
90.Pp
91The intent of the
92.Fn getbintime ,
93.Fn getmicrotime ,
94and
95.Fn getnanotime
96functions is to enforce the user's preference for timer accuracy versus
97execution time.
98.Sh SEE ALSO
99.Xr binuptime 9 ,
100.Xr getbinuptime 9 ,
101.Xr getmicrouptime 9 ,
102.Xr getnanouptime 9 ,
103.Xr microuptime 9 ,
104.Xr nanouptime 9 ,
105.Xr tvtohz 9
106.Sh HISTORY
107The
108.Nm bintime
109functions first appeared in
110.Fx 5.0 .
111The
112.Nm microtime
113and
114.Nm nanotime
115functions first appeared in
116.Fx 3.0
117but have existed in other incarnations since
118.Bx 4.4 .
119.Sh AUTHORS
120This manual page was written by
121.An Kelly Yancey Aq Mt kbyanc@posi.net .
122