1SD_BUS_SLOT_REF(3)              sd_bus_slot_ref             SD_BUS_SLOT_REF(3)
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NAME

6       sd_bus_slot_ref, sd_bus_slot_unref, sd_bus_slot_unrefp,
7       sd_bus_slot_get_bus - Create and destroy references to a bus slot
8       object
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SYNOPSIS

11       #include <systemd/sd-bus.h>
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13       sd_bus_slot *sd_bus_slot_ref(sd_bus_slot *slot);
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15       sd_bus_slot *sd_bus_slot_unref(sd_bus_slot *slot);
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17       void sd_bus_slot_unrefp(sd_bus_slot **slotp);
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19       sd_bus *sd_bus_slot_get_bus(sd_bus_slot *m);
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DESCRIPTION

22       sd_bus_slot_ref() increases the reference counter of slot by one.
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24       sd_bus_slot_unref() decreases the reference counter of slot by one.
25       Once the reference count has dropped to zero, slot object is destroyed
26       and cannot be used anymore, so further calls to sd_bus_slot_ref() or
27       sd_bus_slot_unref() are illegal.
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29       sd_bus_slot_unrefp() is similar to sd_bus_slot_unref() but takes a
30       pointer to a pointer to an sd_bus_slot object. This call is useful in
31       conjunction with GCC's and LLVM's Clean-up Variable Attribute[1]. See
32       sd_bus_new(3) for an example how to use the cleanup attribute.
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34       sd_bus_slot_ref() and sd_bus_slot_unref() execute no operation if the
35       passed in bus object address is NULL.  sd_bus_slot_unrefp() will first
36       dereference its argument, which must not be NULL, and will execute no
37       operation if that is NULL.
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39       sd_bus_slot_get_bus() returns the bus object that message slot is
40       attached to.
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RETURN VALUE

43       sd_bus_slot_ref() always returns the argument.
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45       sd_bus_slot_unref() always returns NULL.
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47       sd_bus_slot_get_bus() always returns the bus object.
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NOTES

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

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

58        1. Clean-up Variable Attribute
59           https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html
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63systemd 243                                                 SD_BUS_SLOT_REF(3)
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