MALLOC_GET_STATE(3)					     Linux Programmer's Manual					       MALLOC_GET_STATE(3)

NAME

       malloc_get_state, malloc_set_state - record and restore state of malloc implementation

SYNOPSIS

       #include <stdlib.h>

       void* malloc_get_state(void);

       int malloc_set_state(void *state);

DESCRIPTION

       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.

RETURN VALUE

       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.

CONFORMING TO

       These functions are GNU extensions.

NOTES

       These functions are especially 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 the 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.

SEE ALSO

       malloc(3), mallopt(3)

COLOPHON

       This  page is part of release 3.53 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2012-05-04						       MALLOC_GET_STATE(3)