NAME

       sd_event_source_unref, sd_event_source_unrefp, sd_event_source_ref - Increase or decrease
       event source reference counters

SYNOPSIS

       #include <systemd/sd-event.h>

       sd_event_source* sd_event_source_unref(sd_event_source *source);

       void sd_event_source_unrefp(sd_event_source **source);

       sd_event_source* sd_event_source_ref(sd_event_source *source);

DESCRIPTION

       sd_event_source_unref() may be used to decrement by one the reference counter of the event
       source object specified as source. The reference counter is initially set to one, when the
       event source is created with calls such as sd_event_add_io(3) or sd_event_add_time(3).
       When the reference counter reaches zero it is removed from its event loop object and
       destroyed.

       sd_event_source_unrefp() is similar to sd_event_source_unref() but takes a pointer to a
       pointer to an sd_event_source object. This call is useful in conjunction with GCC's and
       LLVM's Clean-up Variable Attribute[1]. Note that this function is defined as inline
       function.

       sd_event_source_ref() may be used to increase by one the reference counter of the event
       source object specified as source.

       sd_event_source_unref(), sd_bus_creds_unrefp() and sd_bus_creds_ref() execute no operation
       if the passed event source object is NULL.

       Note that event source objects stay alive and may be dispatched as long as they have a
       reference counter greater than zero. In order to drop a reference of an event source and
       make sure the associated event source handler function is not called anymore it is
       recommended to combine a call of sd_event_source_unref() with a prior call to
       sd_event_source_set_enabled() with SD_EVENT_OFF.

RETURN VALUE

       sd_event_source_unref() always returns NULL.  sd_event_source_ref() always returns the
       event source object passed in.

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

       sd-event(3), sd_event_add_io(3), sd_event_add_time(3), sd_event_add_child(3),
       sd_event_add_signal(3), sd_event_add_defer(3), sd_event_source_set_enabled(3)

NOTES

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