nm_dns_manager_get() is already a singleton. So users usually
can just get it whenever they need -- except during shutdown
after the singleton was destroyed. This is usually fine, because
users really should not try to get it late during shutdown.
However, if you subscribe a signal handler on the singleton, then you
will also eventually want to unsubscribe it. While the moment when you
subscribe it is clearly not during late-shutdown, it's not clear how
to ensure that the signal listener gets destroyed before the DNS manager
singleton.
So usually, whenever you are going to subscribe a signal, you need to
make sure that the target object stays alive long enough. Which may
mean to keep a reference to it.
Next, we will have NMDevice subscribe to the singleton. With above said,
that would mean that potentially every NMDevice needs to keep a
reference to the NMDnsManager. That is not best. Also, later NMManager
will face the same problem, because it will also subscribe to
NMDnsManager.
So, instead let NMManager own a reference to the NMDnsManager. This
ensures the lifetimes are properly guarded (NMDevice also references
NMManager already).
Also, access nm_dns_manager_get() lazy on first use, to only initialize
it when needed the first time (which might be quite late).
Introduce a RadioFlags property on the manager object. For now it
contains two bits WLAN_AVAILABLE, WWAN_AVAILABLE to indicate whether
any radio interface is present in the system. The presence of a radio
is detected by looking at devices and rfkill switches.
In future, any radio-related read-only boolean flag can be exposed via
this property, including the already existing WirelessHardwareEnabled
and WwanHardwareEnabled properties.
We use clang-format for automatic formatting of our source files.
Since clang-format is actively maintained software, the actual
formatting depends on the used version of clang-format. That is
unfortunate and painful, but really unavoidable unless clang-format
would be strictly bug-compatible.
So the version that we must use is from the current Fedora release, which
is also tested by our gitlab-ci. Previously, we were using Fedora 34 with
clang-tools-extra-12.0.1-1.fc34.x86_64.
As Fedora 35 comes along, we need to update our formatting as Fedora 35
comes with version "13.0.0~rc1-1.fc35".
An alternative would be to freeze on version 12, but that has different
problems (like, it's cumbersome to rebuild clang 12 on Fedora 35 and it
would be cumbersome for our developers which are on Fedora 35 to use a
clang that they cannot easily install).
The (differently painful) solution is to reformat from time to time, as we
switch to a new Fedora (and thus clang) version.
Usually we would expect that such a reformatting brings minor changes.
But this time, the changes are huge. That is mentioned in the release
notes [1] as
Makes PointerAligment: Right working with AlignConsecutiveDeclarations. (Fixes https://llvm.org/PR27353)
[1] https://releases.llvm.org/13.0.0/tools/clang/docs/ReleaseNotes.html#clang-format
Currently "src/" mostly contains the source code of the daemon.
I say mostly, because that is not true, there are also the device,
settings, wwan, ppp plugins, the initrd generator, the pppd and dhcp
helper, and probably more.
Also we have source code under libnm-core/, libnm/, clients/, and
shared/ directories. That is all confusing.
We should have one "src" directory, that contains subdirectories. Those
subdirectories should contain individual parts (libraries or
applications), that possibly have dependencies on other subdirectories.
There should be a flat hierarchy of directories under src/, which
contains individual modules.
As the name "src/" is already taken, that prevents any sensible
restructuring of the code.
As a first step, move "src/" to "src/core/". This gives space to
reorganize the code better by moving individual components into "src/".
For inspiration, look at systemd's "src/" directory.
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/743
