NAME

       sd_bus_slot_ref, sd_bus_slot_unref, sd_bus_slot_unrefp, sd_bus_slot_get_bus - Create and
       destroy references to a bus slot object

SYNOPSIS

       #include <systemd/sd-bus.h>

       sd_bus_slot *sd_bus_slot_ref(sd_bus_slot *slot);

       sd_bus_slot *sd_bus_slot_unref(sd_bus_slot *slot);

       void sd_bus_slot_unrefp(sd_bus_slot **slotp);

       sd_bus *sd_bus_slot_get_bus(sd_bus_slot *m);

DESCRIPTION

       sd_bus_slot_ref() increases the reference counter of slot by one.

       sd_bus_slot_unref() decreases the reference counter of slot by one. Once the reference
       count has dropped to zero, slot object is destroyed and cannot be used anymore, so further
       calls to sd_bus_slot_ref() or sd_bus_slot_unref() are illegal.

       sd_bus_slot_unrefp() is similar to sd_bus_slot_unref() but takes a pointer to a pointer to
       an sd_bus_slot object. This call is useful in conjunction with GCC's and LLVM's Clean-up
       Variable Attribute[1]. See sd_bus_new(3) for an example how to use the cleanup attribute.

       sd_bus_slot_ref() and sd_bus_slot_unref() execute no operation if the passed in bus object
       address is NULL.  sd_bus_slot_unrefp() will first dereference its argument, which must not
       be NULL, and will execute no operation if that is NULL.

       sd_bus_slot_get_bus() returns the bus object that message slot is attached to.

RETURN VALUE

       sd_bus_slot_ref() always returns the argument.

       sd_bus_slot_unref() always returns NULL.

       sd_bus_slot_get_bus() always returns the bus object.

NOTES

       These APIs are implemented as a shared library, which can be compiled and linked to with
       the libsystemd pkg-config(1) file.

SEE ALSO

       systemd(1), sd-bus(3), sd_bus_new(3), sd_bus_message_new(3), sd_bus_slot_new_signal(3),
       sd_bus_call_method_async(3)

NOTES

        1. Clean-up Variable Attribute
           https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html