1.\" $NetBSD: mstohz.9,v 1.5 2003/10/05 17:48:49 bouyer Exp $ 2.\" 3.\" Copyright (c) 2002 Manuel Bouyer. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. All advertising materials mentioning features or use of this software 14.\" must display the following acknowledgement: 15.\" This product includes software developed by Manuel Bouyer. 16.\" 4. The name of the author may not be used to endorse or promote products 17.\" derived from this software without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" 32.Dd April 4, 2002 33.Dt MSTOHZ 9 34.Os 35.Sh NAME 36.Nm mstohz 37.Nd convert milliseconds to system clock ticks 38.Sh SYNOPSIS 39.In sys/param.h 40.Ft int 41.Fn mstohz "int ms" 42.Sh DESCRIPTION 43.Nm 44can be used to convert time in milliseconds to system clock ticks, as used 45by the 46.Xr callout 9 47facility, in an integer-overflow safe way. 48.Pp 49This function is implemented as a define in the 50.Em \*[Lt]sys/param.h\*[Gt] 51header. 52Individual ports can have a processor-specific, more efficient 53version implemented in their 54.Em \*[Lt]machine/param.h\*[Gt] 55header as a define. 56.Sh RETURN VALUES 57The return value is the number of clock ticks for the specified value. 58.Sh SEE ALSO 59.Xr callout 9 60.Sh BUGS 61The machine-independent 62.Fn mstohz 63function does not make use of expensive 64-bit integer arithmetic, so 64the result will be rounded down to one second if the parameter is larger 65than 131072 milliseconds. 66