malloc_usable_size — obtain size of block of memory allocated from heap
#include <malloc.h>
size_t
malloc_usable_size( |
void *ptr); |
The malloc_usable_size()
function returns the number of usable bytes in the block
pointed to by ptr, a
pointer to a block of memory allocated by malloc(3) or a related
function.
malloc_usable_size() returns
the number of usable bytes in the block of allocated memory
pointed to by ptr. If
ptr is NULL, 0 is
returned.
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
malloc_usable_size() |
Thread safety | MT-Safe |
The value returned by malloc_usable_size() may be greater than
the requested size of the allocation because of alignment and
minimum size constraints. Although the excess bytes can be
overwritten by the application without ill effects, this is
not good programming practice: the number of excess bytes in
an allocation depends on the underlying implementation.
The main use of this function is for debugging and introspection.
This page is part of release 5.13 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
Copyright (c) 2012 by Michael Kerrisk <mtk.manpagesgmail.com> %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END |