malloc_get_state, malloc_set_state — record and restore state of malloc implementation
#include <malloc.h>
void*malloc_get_state( |
void) ; |
int
malloc_set_state( |
void *state) ; |
The malloc_get_state
()
function records the current state of all malloc(3) internal
bookkeeping variables (but not the actual contents of the
heap or the state of malloc_hook(3) functions
pointers). The state is recorded in a system-dependent opaque
data structure dynamically allocated via malloc(3), and a pointer to
that data structure is returned as the function result. (It
is the caller's responsibility to free(3) this memory.)
The malloc_set_state
()
function restores the state of all malloc(3) internal
bookkeeping variables to the values recorded in the opaque
data structure pointed to by state
.
On success, malloc_get_state
() returns a pointer to a
newly allocated opaque data structure. On error (for example,
memory could not be allocated for the data structure),
malloc_get_state
() returns
NULL.
On success, malloc_set_state
() returns 0. If the
implementation detects that state
does not point to a
correctly formed data structure, malloc_set_state
() returns −1. If the
implementation detects that the version of the data structure
referred to by state
is a more recent version than this implementation knows
about, malloc_set_state
()
returns −2.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
malloc_get_state (), malloc_set_state () |
Thread safety | MT-Safe |
These functions are useful when using this malloc(3) implementation as part of a shared library, and the heap contents are saved/restored via some other method. This technique is used by GNU Emacs to implement its "dumping" function.
Hook function pointers are never saved or restored by
these functions, with two exceptions: if malloc checking (see
mallopt(3)) was in use when
malloc_get_state
() was called,
then malloc_set_state
() resets
malloc checking hooks if possible; if malloc checking was not
in use in the recorded state, but the caller has requested
malloc checking, then the hooks are reset to 0.
This page is part of release 4.07 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 |