[handler.functions]

A C++ program may install different handler functions during execution, by supplying a pointer to a function defined in the program or the library as an argument to (respectively):

(2.1)
set_new_handler
(2.2)
set_terminate

See also subclauses [alloc.errors], Storage allocation errors, and [support.exception], Exception handling.

A C++ program can get a pointer to the current handler function by calling the following functions:

(3.1)
get_new_handler
(3.2)
get_terminate

Calling the set_* and get_* functions shall not incur a data race ([intro.races]).

A call to any of the set_* functions synchronizes with subsequent calls to the same set_* function and to the corresponding get_* function.