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 internal reference counter of
slot by one.
sd_bus_slot_unref() decreases the internal 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_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.
Functions described here are available as a shared
library, which can be compiled against and linked to with the
libsystemd pkg-config(1)
file.
The code described here uses
getenv(3),
which is declared to be not multi-thread-safe. This means that the code calling the functions described
here must not call
setenv(3)
from a parallel thread. It is recommended to only do calls to setenv()
from an early phase of the program when no other threads have been started.