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

NAME
       mallocgetstate, mallocsetstate - record and restore state of malloc
       implementation

SYNOPSIS
       #include 

       void* mallocgetstate(void);

       int mallocsetstate(void *state);

DESCRIPTION
       The mallocgetstate() function records the current state of  all  mal‐
       loc(3)  internal  bookkeeping variables (but not the actual contents of
       the heap or the state of mallochook(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 mallocsetstate() 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, mallocgetstate() returns a pointer to a  newly  allocated
       opaque  data  structure.   On  error  (for example, memory could not be
       allocated for the data structure), mallocgetstate() returns NULL.

       On  success,  mallocsetstate()  returns  0.   If  the  implementation
       detects that state does not point to a correctly formed data structure,
       mallocsetstate() 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,   mallocsetstate()
       returns -2.

CONFORMING TO
       These functions are GNU extensions.

NOTES
       These  functions are especially useful when using this malloc(3) imple‐
       mentation 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 mallocgetstate() was called, then mallocsetstate() resets mal‐
       loc  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               MALLOCGETSTATE(3)