sd_bus_slot_ref(3) — Linux manual page


SD_BUS_SLOT_REF(3)           sd_bus_slot_ref          SD_BUS_SLOT_REF(3)

NAME         top

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

SYNOPSIS         top

       #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);

DESCRIPTION         top

       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.

RETURN VALUE         top

       sd_bus_slot_ref() always returns the argument.

       sd_bus_slot_unref() always returns NULL.

NOTES         top

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

SEE ALSO         top

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

NOTES         top

        1. Clean-up Variable Attribute

COLOPHON         top

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systemd 249                                           SD_BUS_SLOT_REF(3)

Pages that refer to this page: sd_bus_add_match(3)sd_bus_add_node_enumerator(3)sd_bus_add_object(3)sd_bus_add_object_manager(3)sd_bus_call(3)sd_bus_request_name(3)sd_bus_slot_set_description(3)