systemd sd_bus_slot_ref 3 sd_bus_slot_ref sd_bus_slot_unref sd_bus_slot_unrefp Create and destroy references to a bus slot object #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_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. See sd_bus_new3 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_ref() always returns the argument. sd_bus_slot_unref() always returns NULL. systemd1, sd-bus3, sd_bus_new3, sd_bus_message_new3, sd_bus_call_method_async3