sd_event_source_set_description, sd_event_source_get_description — Set or retrieve descriptive names of event sources
|const char *description|
|const char **description|
be used to set an arbitrary descriptive name for the event source
object specified as
source. This name will
be used in debugging messages generated by
for this event source, and may be queried using
debugging purposes. The
description parameter shall
point to a
NUL-terminated string or be
NULL. In the latter case, the descriptive
name will be unset. The string is copied internally, hence the
description argument is not referenced
after the function returns.
be used to query the current descriptive name assigned to the
event source object
source. It returns a
pointer to the current name in
stored in memory internal to the event source. The memory is
invalidated when the event source is destroyed or the descriptive
name is changed.
Event source objects generally have no description set when
they are created, except for UNIX signal event sources created
whose descriptive name is initialized to the signal's C constant
name (e.g. "
sd_event_source_get_description() return a non-negative integer. On failure, they
return a negative errno-style error code.
Returned errors may indicate the following problems:
source is not a valid pointer to an
sd_event_source object or the
Not enough memory to copy the name.
The event loop has been created in a different process, library or module instance.
No name was set for the event source.
Functions described here are available as a shared
library, which can be compiled against and linked to with the
The code described here uses
which is declared to be not multi-thread-safe. This means that the code calling the functions described
here must not call
from a parallel thread. It is recommended to only do calls to
from an early phase of the program when no other threads have been started.