|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
SD_EVENT_SOURCE_SET_DESTROY_CALLBACK(3)_destroy_callback_DESTROY_CALLBACK(3)
sd_event_source_set_destroy_callback,
sd_event_source_get_destroy_callback, sd_event_destroy_t - Define the
callback function for resource cleanup
#include <systemd/sd-event.h>
typedef int (*sd_event_destroy_t)(void *userdata);
int sd_event_source_set_destroy_callback(sd_event_source *source,
sd_event_destroy_t callback);
int sd_event_source_get_destroy_callback(sd_event_source *source,
sd_event_destroy_t *callback);
sd_event_source_set_destroy_callback() sets callback as the callback
function to be called right before the event source object source is
deallocated. The userdata pointer from the event source object will
be passed as the userdata parameter. This pointer can be set by an
argument to the constructor functions, see sd_event_add_io(3), or
directly, see sd_event_source_set_userdata(3). This callback function
is called even if userdata is NULL. Note that this callback is
invoked at a time where the event source object itself is already
invalidated, and executing operations or taking new references to the
event source object is not permissible.
sd_event_source_get_destroy_callback() returns the current callback
for source in the callback parameter.
On success, sd_event_source_set_destroy_callback() returns 0 or a
positive integer. On failure, it returns a negative errno-style error
code.
sd_event_source_get_destroy_callback() returns positive if the
destroy callback function is set, 0 if not. On failure, returns a
negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
The source parameter is NULL.
These APIs are implemented as a shared library, which can be compiled
and linked to with the libsystemd pkg-config(1) file.
systemd(1), sd-event(3), sd_event_add_io(3), sd_event_add_time(3),
sd_event_add_signal(3), sd_event_add_child(3),
sd_event_add_inotify(3), sd_event_add_defer(3),
sd_event_source_set_userdata(3)
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project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
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systemd 246 SD_EVENT_SOURCE_SET_DESTROY_CALLBACK(3)
Pages that refer to this page: 30-systemd-environment-d-generator(7) , systemd.index(7)