1997-07-15 11:05:31 +04:00
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.\" $NetBSD: malloc.3,v 1.6 1997/07/15 07:05:31 mikel Exp $
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1995-12-28 11:51:55 +03:00
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.\"
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1993-03-21 12:45:37 +03:00
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.\" Copyright (c) 1980, 1991 Regents of the University of California.
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.\" All rights reserved.
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.\"
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.\" This code is derived from software contributed to Berkeley by
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.\" the American National Standards Committee X3, on Information
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.\" Processing Systems.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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1993-08-01 11:42:49 +04:00
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.\" from: @(#)malloc.3 6.7 (Berkeley) 6/29/91
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1993-03-21 12:45:37 +03:00
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.\"
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.Dd June 29, 1991
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.Dt MALLOC 3
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.Os BSD 4
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.Sh NAME
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1993-12-15 21:09:42 +03:00
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.Nm malloc
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1993-03-21 12:45:37 +03:00
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.Nd general memory allocation function
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.Sh SYNOPSIS
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.Fd #include <stdlib.h>
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.Ft void *
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.Fn malloc "size_t size"
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.Sh DESCRIPTION
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The
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.Fn malloc
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function allocates uninitialized space for an object whose
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size is specified by
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.Fa size .
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The
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.Fn malloc
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function maintains multiple lists of free blocks according to size, allocating
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space from the appropriate list.
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.Pp
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The allocated space is
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suitably aligned (after possible pointer
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coercion) for storage of any type of object. If the space is of
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.Em pagesize
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or larger, the memory returned will be page-aligned.
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.Sh RETURN VALUES
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The
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.Fn malloc
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function returns
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a pointer to the allocated space if successful; otherwise
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a null pointer is returned.
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.Sh SEE ALSO
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.Xr brk 2 ,
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.Xr alloca 3 ,
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.Xr calloc 3 ,
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.Xr free 3 ,
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.Xr getpagesize 3 ,
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.Xr memory 3 ,
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.Xr realloc 3
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1993-03-21 12:45:37 +03:00
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.Sh STANDARDS
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The
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.Fn malloc
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function conforms to
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.St -ansiC .
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.Sh BUGS
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The current implementation of
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1997-07-15 11:05:31 +04:00
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.Fn malloc
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does not always fail gracefully when system
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memory limits are approached.
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It may fail to allocate memory when larger free blocks could be broken
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up, or when limits are exceeded because the size is rounded up.
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It is optimized for sizes that are powers of two.
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