sd_bus_slot_set_destroy_callback, sd_bus_slot_get_destroy_callback, sd_bus_track_set_destroy_callback, sd_bus_track_get_destroy_callback, sd_bus_destroy_t — Define the callback function for resource cleanup
callback as the callback
function to be called right before the bus slot object
slot is deallocated. The
userdata pointer from the slot object will be passed as the
parameter. This pointer can be set by an argument to the constructor functions, see
sd_bus_add_match(3), or directly,
This callback function is called even if
NULL. Note that
this callback is invoked at a time where the bus slot object itself is already invalidated, and executing
operations or taking new references to the bus slot object is not permissible.
sd_bus_slot_get_destroy_callback() returns the current callback
slot in the
sd_bus_track_get_destroy_callback() provide equivalent functionality for the
userdata pointer associated with bus peer tracking objects. For details about bus peer
tracking objects, see
sd_bus_track_set_destroy_callback() return 0 or a positive integer. On failure, they
return a negative errno-style error code.
sd_bus_track_get_destroy_callback() return positive if the destroy callback function
is set, 0 if not. On failure, they return a negative errno-style error code.
Functions described here are available as a shared
library, which can be compiled against and linked to with the
The code described here uses
which is declared to be not multi-thread-safe. This means that the code calling the functions described
here must not call
from a parallel thread. It is recommended to only do calls to
from an early phase of the program when no other threads have been started.
sd_bus_track_get_destroy_callback() were added in version 239.