Section (3) malloc_get_state
malloc_get_state, malloc_set_state — record and restore state of malloc implementation
these function are removed in glibc version 2.25.
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_zsingle_quotesz_s responsibility to free(3) this memory.)
function restores the state of all malloc(3) internal
bookkeeping variables to the values recorded in the opaque
data structure pointed to by
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_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
is a more recent version than this implementation knows
For an explanation of the terms used in this section, see attributes(7).
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,
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.
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