392 lines
8.4 KiB
Groff
392 lines
8.4 KiB
Groff
.\" Copyright (c) 2015 Conrad Meyer <cem@FreeBSD.org>
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
|
|
.\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
|
|
.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
.\" POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd October 20, 2015
|
|
.Dt BITSET 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm bitset(9)
|
|
\(em
|
|
.Nm BITSET_DEFINE ,
|
|
.Nm BITSET_T_INITIALIZER ,
|
|
.Nm BITSET_FSET ,
|
|
.Nm BIT_CLR ,
|
|
.Nm BIT_COPY ,
|
|
.Nm BIT_ISSET ,
|
|
.Nm BIT_SET ,
|
|
.Nm BIT_ZERO ,
|
|
.Nm BIT_FILL ,
|
|
.Nm BIT_SETOF ,
|
|
.Nm BIT_EMPTY ,
|
|
.Nm BIT_ISFULLSET ,
|
|
.Nm BIT_FFS ,
|
|
.Nm BIT_COUNT ,
|
|
.Nm BIT_SUBSET ,
|
|
.Nm BIT_OVERLAP ,
|
|
.Nm BIT_CMP ,
|
|
.Nm BIT_OR ,
|
|
.Nm BIT_AND ,
|
|
.Nm BIT_NAND ,
|
|
.Nm BIT_CLR_ATOMIC ,
|
|
.Nm BIT_SET_ATOMIC ,
|
|
.Nm BIT_SET_ATOMIC_ACQ ,
|
|
.Nm BIT_AND_ATOMIC ,
|
|
.Nm BIT_OR_ATOMIC ,
|
|
.Nm BIT_COPY_STORE_REL
|
|
.Nd bitset manipulation macros
|
|
.Sh SYNOPSIS
|
|
.In sys/_bitset.h
|
|
.In sys/bitset.h
|
|
.\"
|
|
.Fn BITSET_DEFINE "STRUCTNAME" "const SETSIZE"
|
|
.Fn BITSET_T_INITIALIZER "ARRAY_CONTENTS"
|
|
.Fn BITSET_FSET "N_WORDS"
|
|
.\"
|
|
.Fn BIT_CLR "const SETSIZE" "size_t bit" "struct STRUCTNAME *bitset"
|
|
.Fn BIT_COPY "const SETSIZE" "struct STRUCTNAME *from" "struct STRUCTNAME *to"
|
|
.Ft bool
|
|
.Fn BIT_ISSET "const SETSIZE" "size_t bit" "struct STRUCTNAME *bitset"
|
|
.Fn BIT_SET "const SETSIZE" "size_t bit" "struct STRUCTNAME *bitset"
|
|
.Fn BIT_ZERO "const SETSIZE" "struct STRUCTNAME *bitset"
|
|
.Fn BIT_FILL "const SETSIZE" "struct STRUCTNAME *bitset"
|
|
.Fn BIT_SETOF "const SETSIZE" "size_t bit" "struct STRUCTNAME *bitset"
|
|
.Ft bool
|
|
.Fn BIT_EMPTY "const SETSIZE" "struct STRUCTNAME *bitset"
|
|
.Ft bool
|
|
.Fn BIT_ISFULLSET "const SETSIZE" "struct STRUCTNAME *bitset"
|
|
.Ft size_t
|
|
.Fn BIT_FFS "const SETSIZE" "struct STRUCTNAME *bitset"
|
|
.Ft size_t
|
|
.Fn BIT_COUNT "const SETSIZE" "struct STRUCTNAME *bitset"
|
|
.\"
|
|
.Ft bool
|
|
.Fo BIT_SUBSET
|
|
.Fa "const SETSIZE" "struct STRUCTNAME *haystack" "struct STRUCTNAME *needle"
|
|
.Fc
|
|
.Ft bool
|
|
.Fo BIT_OVERLAP
|
|
.Fa "const SETSIZE" "struct STRUCTNAME *bitset1" "struct STRUCTNAME *bitset2"
|
|
.Fc
|
|
.Ft bool
|
|
.Fo BIT_CMP
|
|
.Fa "const SETSIZE" "struct STRUCTNAME *bitset1" "struct STRUCTNAME *bitset2"
|
|
.Fc
|
|
.Fn BIT_OR "const SETSIZE" "struct STRUCTNAME *dst" "struct STRUCTNAME *src"
|
|
.Fn BIT_AND "const SETSIZE" "struct STRUCTNAME *dst" "struct STRUCTNAME *src"
|
|
.Fn BIT_NAND "const SETSIZE" "struct STRUCTNAME *dst" "struct STRUCTNAME *src"
|
|
.\"
|
|
.Fn BIT_CLR_ATOMIC "const SETSIZE" "size_t bit" "struct STRUCTNAME *bitset"
|
|
.Fn BIT_SET_ATOMIC "const SETSIZE" "size_t bit" "struct STRUCTNAME *bitset"
|
|
.Fn BIT_SET_ATOMIC_ACQ "const SETSIZE" "size_t bit" "struct STRUCTNAME *bitset"
|
|
.\"
|
|
.Fo BIT_AND_ATOMIC
|
|
.Fa "const SETSIZE" "struct STRUCTNAME *dst" "struct STRUCTNAME *src"
|
|
.Fc
|
|
.Fo BIT_OR_ATOMIC
|
|
.Fa "const SETSIZE" "struct STRUCTNAME *dst" "struct STRUCTNAME *src"
|
|
.Fc
|
|
.Fo BIT_COPY_STORE_REL
|
|
.Fa "const SETSIZE" "struct STRUCTNAME *from" "struct STRUCTNAME *to"
|
|
.Fc
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
family of macros provide a flexible and efficient bitset implementation if the
|
|
maximum size of the set is known at compilation.
|
|
Throughout this manual page, the name
|
|
.Fa SETSIZE
|
|
refers to the size of the bitset in bits.
|
|
Individual bits in bitsets are referenced with indices zero through
|
|
.Fa SETSIZE - 1 .
|
|
One example use of
|
|
.In sys/bitset.h
|
|
is
|
|
.In sys/cpuset.h .
|
|
.Pp
|
|
The
|
|
.Fn BITSET_DEFINE
|
|
macro defines a bitset struct
|
|
.Fa STRUCTNAME
|
|
with room to represent
|
|
.Fa SETSIZE
|
|
bits.
|
|
.Pp
|
|
The
|
|
.Fn BITSET_T_INITIALIZER
|
|
macro allows one to initialize a bitset struct with a compile time literal
|
|
value.
|
|
.Pp
|
|
The
|
|
.Fn BITSET_FSET
|
|
macro generates a compile time literal, usable by
|
|
.Fn BITSET_T_INITIALIZER ,
|
|
representing a full bitset (all bits set).
|
|
For examples of
|
|
.Fn BITSET_T_INITIALIZER
|
|
and
|
|
.Fn BITSET_FSET
|
|
usage, see the
|
|
.Sx BITSET_T_INITIALIZER EXAMPLE
|
|
section.
|
|
The
|
|
.Fa N_WORDS
|
|
parameter to
|
|
.Fn BITSET_FSET
|
|
should be:
|
|
.Bd -literal -offset indent
|
|
__bitset_words(SETSIZE)
|
|
.Ed
|
|
.Pp
|
|
The
|
|
.Fn BIT_CLR
|
|
macro clears bit
|
|
.Fa bit
|
|
in the bitset pointed to by
|
|
.Fa bitset .
|
|
The
|
|
.Fn BIT_CLR_ATOMIC
|
|
macro is identical, but the bit is cleared atomically.
|
|
.Pp
|
|
The
|
|
.Fn BIT_COPY
|
|
macro copies the contents of the bitset
|
|
.Fa from
|
|
to the bitset
|
|
.Fa to .
|
|
.Fn BIT_COPY_STORE_REL
|
|
is similar, but copies component machine words from
|
|
.Fa from
|
|
and writes them to
|
|
.Fa to
|
|
with atomic store with release semantics.
|
|
(That is, if
|
|
.Fa to
|
|
is composed of multiple machine words,
|
|
.Fn BIT_COPY_STORE_REL
|
|
performs multiple individually atomic operations.)
|
|
.Pp
|
|
The
|
|
.Fn BIT_SET
|
|
macro sets bit
|
|
.Fa bit
|
|
in the bitset pointed to by
|
|
.Fa bitset .
|
|
The
|
|
.Fn BIT_SET_ATOMIC
|
|
macro is identical, but the bit is set atomically.
|
|
The
|
|
.Fn BIT_SET_ATOMIC_ACQ
|
|
macro sets the bit with acquire semantics.
|
|
.Pp
|
|
The
|
|
.Fn BIT_ZERO
|
|
macro clears all bits in
|
|
.Fa bitset .
|
|
.Pp
|
|
The
|
|
.Fn BIT_FILL
|
|
macro sets all bits in
|
|
.Fa bitset .
|
|
.Pp
|
|
The
|
|
.Fn BIT_SETOF
|
|
macro clears all bits in
|
|
.Fa bitset
|
|
before setting only bit
|
|
.Fa bit .
|
|
.Pp
|
|
The
|
|
.Fn BIT_EMPTY
|
|
macro returns
|
|
.Dv true
|
|
if
|
|
.Fa bitset
|
|
is empty.
|
|
.Pp
|
|
The
|
|
.Fn BIT_ISFULLSET
|
|
macro returns
|
|
.Dv true
|
|
if
|
|
.Fa bitset
|
|
is full (all bits set).
|
|
.Pp
|
|
The
|
|
.Fn BIT_FFS
|
|
macro returns the 1-index of the first (lowest) set bit in
|
|
.Fa bitset ,
|
|
or zero if
|
|
.Fa bitset
|
|
is empty.
|
|
Like with
|
|
.Xr ffs 3 ,
|
|
to use the non-zero result of
|
|
.Fn BIT_FFS
|
|
as a
|
|
.Fa bit
|
|
index parameter to any other
|
|
.Nm
|
|
macro, you must subtract one from the result.
|
|
.Pp
|
|
The
|
|
.Fn BIT_COUNT
|
|
macro returns the total number of set bits in
|
|
.Fa bitset .
|
|
.Pp
|
|
The
|
|
.Fn BIT_SUBSET
|
|
macro returns
|
|
.Dv true
|
|
if
|
|
.Fa needle
|
|
is a subset of
|
|
.Fa haystack .
|
|
.Pp
|
|
The
|
|
.Fn BIT_OVERLAP
|
|
macro returns
|
|
.Dv true
|
|
if
|
|
.Fa bitset1
|
|
and
|
|
.Fa bitset2
|
|
have any common bits.
|
|
(That is, if
|
|
.Fa bitset1
|
|
AND
|
|
.Fa bitset2
|
|
is not the empty set.)
|
|
.Pp
|
|
The
|
|
.Fn BIT_CMP
|
|
macro returns
|
|
.Dv true
|
|
if
|
|
.Fa bitset1
|
|
is NOT equal to
|
|
.Fa bitset2 .
|
|
.Pp
|
|
The
|
|
.Fn BIT_OR
|
|
macro sets bits present in
|
|
.Fa src
|
|
in
|
|
.Fa dst .
|
|
(It is the
|
|
.Nm
|
|
equivalent of the scalar:
|
|
.Fa dst
|
|
|=
|
|
.Fa src . )
|
|
.Fn BIT_OR_ATOMIC
|
|
is similar, but sets bits in the component machine words in
|
|
.Fa dst
|
|
atomically.
|
|
(That is, if
|
|
.Fa dst
|
|
is composed of multiple machine words,
|
|
.Fn BIT_OR_ATOMIC
|
|
performs multiple individually atomic operations.)
|
|
.Pp
|
|
The
|
|
.Fn BIT_AND
|
|
macro clears bits absent from
|
|
.Fa src
|
|
from
|
|
.Fa dst .
|
|
(It is the
|
|
.Nm
|
|
equivalent of the scalar:
|
|
.Fa dst
|
|
&=
|
|
.Fa src . )
|
|
.Fn BIT_AND_ATOMIC
|
|
is similar, with the same atomic semantics as
|
|
.Fn BIT_OR_ATOMIC .
|
|
.Pp
|
|
The
|
|
.Fn BIT_NAND
|
|
macro clears bits set in
|
|
.Fa src
|
|
from
|
|
.Fa dst .
|
|
(It is the
|
|
.Nm
|
|
equivalent of the scalar:
|
|
.Fa dst
|
|
&=
|
|
.Fa ~ src . )
|
|
.Sh BITSET_T_INITIALIZER EXAMPLE
|
|
.Bd -literal
|
|
BITSET_DEFINE(_myset, MYSETSIZE);
|
|
|
|
struct _myset myset;
|
|
|
|
/* Initialize myset to filled (all bits set) */
|
|
myset = BITSET_T_INITIALIZER(BITSET_FSET(__bitset_words(MYSETSIZE)));
|
|
|
|
/* Initialize myset to only the lowest bit set */
|
|
myset = BITSET_T_INITIALIZER(0x1);
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr bitstring 3 ,
|
|
.Xr cpuset 9
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
macros first appeared in
|
|
.Fx 10.0
|
|
in January 2014.
|
|
They were MFCed to
|
|
.Fx 9.3 ,
|
|
released in July 2014.
|
|
.Pp
|
|
This manual page first appeared in
|
|
.Fx 11.0 .
|
|
.Sh AUTHORS
|
|
.An -nosplit
|
|
The
|
|
.Nm
|
|
macros were generalized and pulled out of
|
|
.In sys/cpuset.h
|
|
as
|
|
.In sys/_bitset.h
|
|
and
|
|
.In sys/bitset.h
|
|
by
|
|
.An Attilio Rao Aq Mt attilio@FreeBSD.org .
|
|
This manual page was written by
|
|
.An Conrad Meyer Aq Mt cem@FreeBSD.org .
|
|
.Sh CAVEATS
|
|
The
|
|
.Fa SETSIZE
|
|
argument to all of these macros must match the value given to
|
|
.Fn BITSET_DEFINE .
|
|
.Pp
|
|
Unlike every other reference to individual set members, which are zero-indexed,
|
|
.Fn BIT_FFS
|
|
returns a one-indexed result (or zero if the set is empty).
|