The header files are not compiled directly, but always included while compiling
other source files. We already require every source file to include "nm-sd-adapt.h"
as first, thus we don't need the include in the headers too.
- All internal source files (except "examples", which are not internal)
should include "config.h" first. As also all internal source
files should include "nm-default.h", let "config.h" be included
by "nm-default.h" and include "nm-default.h" as first in every
source file.
We already wanted to include "nm-default.h" before other headers
because it might contains some fixes (like "nm-glib.h" compatibility)
that is required first.
- After including "nm-default.h", we optinally allow for including the
corresponding header file for the source file at hand. The idea
is to ensure that each header file is self contained.
- Don't include "config.h" or "nm-default.h" in any header file
(except "nm-sd-adapt.h"). Public headers anyway must not include
these headers, and internal headers are never included after
"nm-default.h", as of the first previous point.
- Include all internal headers with quotes instead of angle brackets.
In practice it doesn't matter, because in our public headers we must
include other headers with angle brackets. As we use our public
headers also to compile our interal source files, effectively the
result must be the same. Still do it for consistency.
- Except for <config.h> itself. Include it with angle brackets as suggested by
https://www.gnu.org/software/autoconf/manual/autoconf.html#Configuration-Headers
Differently from GLib timeout sources, systemd ones are always
one-shot and therefore we must return G_SOURCE_REMOVE in the callback,
otherwise the timer will be scheduled again.
In most cases things were working correctly because usually the
callback also unreferences the source event, but when this doesn't
happen the timer will trigger multiple times as reported in the bug
below.
https://bugzilla.redhat.com/show_bug.cgi?id=1278506
Fixes: 1b1222ffdf
sd_event_source is either used for sd_event_add_io() or sd_event_add_time().
Depending on the use, different fields of the struct are relevant. Refactor
the struct to have a union.
This reduces the size of the struct, but more importantly, it makes it
clear which fields are used in which context.
Systemd supports omitting the output source argument. In this case,
the created event source is floating and the reference count
is handled properly.
We have however no callers that make use of that functionality, so
instead of implementing floating references, assert that we don't
need it.
This isn't a change in behavior, because previously the could would just
SEGFAULT if a caller didn't want to take ownership of the created event.
