x SuSE Linux 13.1-RELEASE x
x SuSE Linux 13.1-RELEASEx
SD_BUS_SLOT_SET_DESTROYsd_bus_slot_set_destSD_BUS_SLOT_SET_DESTROY_CALLBACK(3)
NAME
sd_bus_slot_set_destroy_callback, sd_bus_slot_get_destroy_callback,
sd_bus_track_set_destroy_callback, sd_bus_track_get_destroy_callback,
sd_bus_destroy_t - Define the callback function for resource cleanup
SYNOPSIS
#include <systemd/sd-bus.h>
typedef int (*sd_bus_destroy_t)(void *userdata);
int sd_bus_slot_set_destroy_callback(sd_bus_slot *slot,
sd_bus_destroy_t callback);
int sd_bus_slot_get_destroy_callback(sd_bus_slot *slot,
sd_bus_destroy_t *callback);
int sd_bus_track_set_destroy_callback(sd_bus_track *track,
sd_bus_destroy_t callback);
int sd_bus_track_get_destroy_callback(sd_bus_track *track,
sd_bus_destroy_t *callback);
DESCRIPTION
sd_bus_slot_set_destroy_callback() sets callback as the callback
function to be called right before the bus slot object slot is
deallocated. The userdata pointer from the slot object will be passed
as the userdata parameter. This pointer can be set by an argument to
the constructor functions, see sd_bus_add_match(3), or directly, see
sd_bus_slot_set_userdata(3). This callback function is called even if
userdata is NULL. Note that this callback is invoked at a time where
the bus slot object itself is already invalidated, and executing
operations or taking new references to the bus slot object is not
permissible.
sd_bus_slot_get_destroy_callback() returns the current callback for
slot in the callback parameter.
sd_bus_track_set_destroy_callback() and
sd_bus_track_get_destroy_callback() provide equivalent functionality
for the userdata pointer associated with bus peer tracking objects. For
details about bus peer tracking objects, see sd_bus_track_new(3).
RETURN VALUE
On success, sd_bus_slot_set_destroy_callback() and
sd_bus_track_set_destroy_callback() return 0 or a positive integer. On
failure, they return a negative errno-style error code.
sd_bus_slot_get_destroy_callback() and
sd_bus_track_get_destroy_callback() return positive if the destroy
callback function is set, 0 if not. On failure, they return a negative
errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
The slot or track parameter is NULL.
NOTES
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.
SEE ALSO
systemd(1), sd-bus(3), sd_bus_slot_set_floating(3),
sd_bus_add_match(3), sd_bus_track_new(3), sd_bus_slot_set_userdata(3),
sd_bus_track_set_userdata(3)
systemd 254 SD_BUS_SLOT_SET_DESTROY_CALLBACK(3)
Want to link to this manual page? Use this URL:
<http://star2.abcm.com/cgi-bin/bsdi-man?query=sd_bus_slot_set_destroy_callback&sektion=3&manpath=>