No longer use GDBusObjectMangaerClient and gdbus-codegen generated classes
for the NMClient cache. Instead, use GDBusConnection directly and a
custom implementation (NMLDBusObject) for caching D-Bus' ObjectManager
data.
CHANGES
-------
- This is a complete rework. I think the previous implementation was
difficult to understand. There were unfixed bugs and nobody understood
the code well enough to fix them. Maybe somebody out there understood the
code, but I certainly did not. At least nobody provided patches to fix those
issues. I do believe that this implementation is more straightforward and
easier to understand. It removes a lot of layers of code. Whether this claim
of simplicity is true, each reader must decide for himself/herself. Note
that it is still fairly complex.
- There was a lingering performance issue with large number of D-Bus
objects. The patch tries hard that the implementation scales well. Of
course, when we cache N objects that have N-to-M references to other,
we still are fundamentally O(N*M) for runtime and memory consumption (with
M being the number of references between objects). But each part should behave
efficiently and well.
- Play well with GMainContext. libnm code (NMClient) is generally not
thread safe. However, it should work to use multiple instances in
parallel, as long as each access to a NMClient is through the caller's
GMainContext. This follows glib's style and effectively allows to use NMClient
in a multi threaded scenario. This implies to stick to a main context
upon construction and ensure that callbacks are only invoked when
iterating that context. Also, NMClient itself shall never iterate the
caller's context. This also means, libnm must never use g_idle_add() or
g_timeout_add(), as those enqueue sources in the g_main_context_default()
context.
- Get ordering of messages right. All events are consistently enqueued
in a GMainContext and processed strictly in order. For example,
previously "nm-object.c" tried to combine signals and emit them on an
idle handler. That is wrong, signals must be emitted in the right order
and when they happen. Note that when using GInitable's synchronous initialization
to initialize the NMClient instance, NMClient internally still operates fully
asynchronously. In that case NMClient has an internal main context.
- NMClient takes over most of the functionality. When using D-Bus'
ObjectManager interface, one needs to handle basically the entire state
of the D-Bus interface. That cannot be separated well into distinct
parts, and even if you try, you just end up having closely related code
in different source files. Spreading related code does not make it
easier to understand, on the contrary. That means, NMClient is
inherently complex as it contains most of the logic. I think that is
not avoidable, but it's not as bad as it sounds.
- NMClient processes D-Bus messages and state changes in separate steps.
First NMClient unpacks the message (e.g. _dbus_handle_properties_changed()) and
keeps track of the changed data. Then we update the GObject instances
(_dbus_handle_obj_changed_dbus()) without emitting any signals yet. Finally,
we emit all signals and notifications that were collected
(_dbus_handle_changes_commit()). Note that for example during the initial
GetManagedObjects() reply, NMClient receive a large amount of state at once.
But we first apply all the changes to our GObject instances before
emitting any signals. The result is that signals are always emitted in a moment
when the cache is consistent. The unavoidable downside is that when you receive
a property changed signal, possibly many other properties changed
already and more signals are about to be emitted.
- NMDeviceWifi no longer modifies the content of the cache from client side
during poke_wireless_devices_with_rf_status(). The content of the cache
should be determined by D-Bus alone and follow what NetworkManager
service exposes. Local modifications should be avoided.
- This aims to bring no API/ABI change, though it does of course bring
various subtle changes in behavior. Those should be all for the better, but the
goal is not to break any existing clients. This does change internal
(albeit externally visible) API, like dropping NM_OBJECT_DBUS_OBJECT_MANAGER
property and NMObject no longer implementing GInitableIface and GAsyncInitableIface.
- Some uses of gdbus-codegen classes remain in NMVpnPluginOld, NMVpnServicePlugin
and NMSecretAgentOld. These are independent of NMClient/NMObject and
should be reworked separately.
- While we no longer use generated classes from gdbus-codegen, we don't
need more glue code than before. Also before we constructed NMPropertiesInfo and
a had large amount of code to propagate properties from NMDBus* to NMObject.
That got completely reworked, but did not fundamentally change. You still need
about the same effort to create the NMLDBusMetaIface. Not using
generated bindings did not make anything worse (which tells about the
usefulness of generated code, at least in the way it was used).
- NMLDBusMetaIface and other meta data is static and immutable. This
avoids copying them around. Also, macros like NML_DBUS_META_PROPERTY_INIT_U()
have compile time checks to ensure the property types matches. It's pretty hard
to misuse them because it won't compile.
- The meta data now explicitly encodes the expected D-Bus types and
makes sure never to accept wrong data. That would only matter when the
server (accidentally or intentionally) exposes unexpected types on
D-Bus. I don't think that was previously ensured in all cases.
For example, demarshal_generic() only cared about the GObject property
type, it didn't know the expected D-Bus type.
- Previously GDBusObjectManager would sometimes emit warnings (g_log()). Those
probably indicated real bugs. In any case, it prevented us from running CI
with G_DEBUG=fatal-warnings, because there would be just too many
unrelated crashes. Now we log debug messages that can be enabled with
"LIBNM_CLIENT_DEBUG=trace". Some of these messages can also be turned
into g_warning()/g_critical() by setting LIBNM_CLIENT_DEBUG=warning,error.
Together with G_DEBUG=fatal-warnings, this turns them into assertions.
Note that such "assertion failures" might also happen because of a server
bug (or change). Thus these are not common assertions that indicate a bug
in libnm and are thus not armed unless explicitly requested. In our CI we
should now always run with LIBNM_CLIENT_DEBUG=warning,error and
G_DEBUG=fatal-warnings and to catch bugs. Note that currently
NetworkManager has bugs in this regard, so enabling this will result in
assertion failures. That should be fixed first.
- Note that this changes the order in which we emit "notify:devices" and
"device-added" signals. I think it makes the most sense to emit first
"device-removed", then "notify:devices", and finally "device-added"
signals.
This changes behavior for commit 52ae28f6e5 ('libnm: queue
added/removed signals and suppress uninitialized notifications'),
but I don't think that users should actually rely on the order. Still,
the new order makes the most sense to me.
- In NetworkManager, profiles can be invisible to the user by setting
"connection.permissions". Such profiles would be hidden by NMClient's
nm_client_get_connections() and their "connection-added"/"connection-removed"
signals.
Note that NMActiveConnection's nm_active_connection_get_connection()
and NMDevice's nm_device_get_available_connections() still exposes such
hidden NMRemoteConnection instances. This behavior was preserved.
NUMBERS
-------
I compared 3 versions of libnm.
[1] 962297f908, current tip of nm-1-20 branch
[2] 4fad8c7c64, current master, immediate parent of this patch
[3] this patch
All tests were done on Fedora 31, x86_64, gcc 9.2.1-1.fc31.
The libraries were build with
$ ./contrib/fedora/rpm/build_clean.sh -g -w test -W debug
Note that RPM build already stripped the library.
---
N1) File size of libnm.so.0.1.0 in bytes. There currently seems to be a issue
on Fedora 31 generating wrong ELF notes. Usually, libnm is smaller but
in these tests it had large (and bogus) ELF notes. Anyway, the point
is to show the relative sizes, so it doesn't matter).
[1] 4075552 (102.7%)
[2] 3969624 (100.0%)
[3] 3705208 ( 93.3%)
---
N2) `size /usr/lib64/libnm.so.0.1.0`:
text data bss dec hex filename
[1] 1314569 (102.0%) 69980 ( 94.8%) 10632 ( 80.4%) 1395181 (101.4%) 1549ed /usr/lib64/libnm.so.0.1.0
[2] 1288410 (100.0%) 73796 (100.0%) 13224 (100.0%) 1375430 (100.0%) 14fcc6 /usr/lib64/libnm.so.0.1.0
[3] 1229066 ( 95.4%) 65248 ( 88.4%) 13400 (101.3%) 1307714 ( 95.1%) 13f442 /usr/lib64/libnm.so.0.1.0
---
N3) Performance test with test-client.py. With checkout of [2], run
```
prepare_checkout() {
rm -rf /tmp/nm-test && \
git checkout -B test 4fad8c7c64 && \
git clean -fdx && \
./autogen.sh --prefix=/tmp/nm-test && \
make -j 5 install && \
make -j 5 check-local-clients-tests-test-client
}
prepare_test() {
NM_TEST_REGENERATE=1 NM_TEST_CLIENT_BUILDDIR="/data/src/NetworkManager" NM_TEST_CLIENT_NMCLI_PATH=/usr/bin/nmcli python3 ./clients/tests/test-client.py -v
}
do_test() {
for i in {1..10}; do
NM_TEST_CLIENT_BUILDDIR="/data/src/NetworkManager" NM_TEST_CLIENT_NMCLI_PATH=/usr/bin/nmcli python3 ./clients/tests/test-client.py -v || return -1
done
echo "done!"
}
prepare_checkout
prepare_test
time do_test
```
[1] real 2m14.497s (101.3%) user 5m26.651s (100.3%) sys 1m40.453s (101.4%)
[2] real 2m12.800s (100.0%) user 5m25.619s (100.0%) sys 1m39.065s (100.0%)
[3] real 1m54.915s ( 86.5%) user 4m18.585s ( 79.4%) sys 1m32.066s ( 92.9%)
---
N4) Performance. Run NetworkManager from build [2] and setup a large number
of profiles (551 profiles and 515 devices, mostly unrealized). This
setup is already at the edge of what NetworkManager currently can
handle. Of course, that is a different issue. Here we just check how
long plain `nmcli` takes on the system.
```
do_cleanup() {
for UUID in $(nmcli -g NAME,UUID connection show | sed -n 's/^xx-c-.*:\([^:]\+\)$/\1/p'); do
nmcli connection delete uuid "$UUID"
done
for DEVICE in $(nmcli -g DEVICE device status | grep '^xx-i-'); do
nmcli device delete "$DEVICE"
done
}
do_setup() {
do_cleanup
for i in {1..30}; do
nmcli connection add type bond autoconnect no con-name xx-c-bond-$i ifname xx-i-bond-$i ipv4.method disabled ipv6.method ignore
for j in $(seq $i 30); do
nmcli connection add type vlan autoconnect no con-name xx-c-vlan-$i-$j vlan.id $j ifname xx-i-vlan-$i-$j vlan.parent xx-i-bond-$i ipv4.method disabled ipv6.method ignore
done
done
systemctl restart NetworkManager.service
sleep 5
}
do_test() {
perf stat -r 50 -B nmcli 1>/dev/null
}
do_test
```
[1]
Performance counter stats for 'nmcli' (50 runs):
456.33 msec task-clock:u # 1.093 CPUs utilized ( +- 0.44% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
5,900 page-faults:u # 0.013 M/sec ( +- 0.02% )
1,408,675,453 cycles:u # 3.087 GHz ( +- 0.48% )
1,594,741,060 instructions:u # 1.13 insn per cycle ( +- 0.02% )
368,744,018 branches:u # 808.061 M/sec ( +- 0.02% )
4,566,058 branch-misses:u # 1.24% of all branches ( +- 0.76% )
0.41761 +- 0.00282 seconds time elapsed ( +- 0.68% )
[2]
Performance counter stats for 'nmcli' (50 runs):
477.99 msec task-clock:u # 1.088 CPUs utilized ( +- 0.36% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
5,948 page-faults:u # 0.012 M/sec ( +- 0.03% )
1,471,133,482 cycles:u # 3.078 GHz ( +- 0.36% )
1,655,275,369 instructions:u # 1.13 insn per cycle ( +- 0.02% )
382,595,152 branches:u # 800.433 M/sec ( +- 0.02% )
4,746,070 branch-misses:u # 1.24% of all branches ( +- 0.49% )
0.43923 +- 0.00242 seconds time elapsed ( +- 0.55% )
[3]
Performance counter stats for 'nmcli' (50 runs):
352.36 msec task-clock:u # 1.027 CPUs utilized ( +- 0.32% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
4,790 page-faults:u # 0.014 M/sec ( +- 0.26% )
1,092,341,186 cycles:u # 3.100 GHz ( +- 0.26% )
1,209,045,283 instructions:u # 1.11 insn per cycle ( +- 0.02% )
281,708,462 branches:u # 799.499 M/sec ( +- 0.01% )
3,101,031 branch-misses:u # 1.10% of all branches ( +- 0.61% )
0.34296 +- 0.00120 seconds time elapsed ( +- 0.35% )
---
N5) same setup as N4), but run `PAGER= /bin/time -v nmcli`:
[1]
Command being timed: "nmcli"
User time (seconds): 0.42
System time (seconds): 0.04
Percent of CPU this job got: 107%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.43
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 34456
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 6128
Voluntary context switches: 1298
Involuntary context switches: 1106
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
[2]
Command being timed: "nmcli"
User time (seconds): 0.44
System time (seconds): 0.04
Percent of CPU this job got: 108%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.44
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 34452
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 6169
Voluntary context switches: 1849
Involuntary context switches: 142
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
[3]
Command being timed: "nmcli"
User time (seconds): 0.32
System time (seconds): 0.02
Percent of CPU this job got: 102%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.34
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 29196
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 5059
Voluntary context switches: 919
Involuntary context switches: 685
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
---
N6) same setup as N4), but run `nmcli monitor` and look at `ps aux` for
the RSS size.
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
[1] me 1492900 21.0 0.2 461348 33248 pts/10 Sl+ 15:02 0:00 nmcli monitor
[2] me 1490721 5.0 0.2 461496 33548 pts/10 Sl+ 15:00 0:00 nmcli monitor
[3] me 1495801 16.5 0.1 459476 28692 pts/10 Sl+ 15:04 0:00 nmcli monitor
These types are all subclasses of NMObject. These instances are commonly
created by NMClient itself. It makes no sense that a user would
instantiate the type. Much less does it make sense to subclass them.
Hide the object and class structures from public API.
This is an API and ABI break, but of something that is very likely
unused.
This is mainly done to embed the private structure in the object itself.
This has benefits for performance and debugability. But most
importantly, we can obtain a static offset where to access the private data.
That means, we can use the information to access the data pointer
generically, as we will need later.
This is not done for the internal types NMManager, NMRemoteSettings,
and NMDnsManager. These types will be dropped later.
This looks up the GParamSpec from the obj_properties and is
thus more efficient. Also, the generated _notify() function
has the proper argument type and is thus generally preferable.
This is not merely cosmetic. I will need the obj_properties
array to lookup GParamSpec by their PROP_* enum value. The
alternative would be lookup by name, which is more expensive.
Also, implement nm_remote_connection_commit_changes_async() by calling
nm_remote_connection_update2(). It already was also calling the
Update2() D-Bus method.
Note that D-Bus is fundamentally asynchronous. Doing blocking calls
on top of D-Bus is odd, especially for libnm's NMClient. That is because
NMClient essentially is a client-side cache of the objects from the D-Bus
interface. This cache should be filled exclusively by (asynchronous) D-Bus
events (PropertiesChanged). So, making a blocking D-Bus call means to wait
for a response and return it, while queuing all messages that are received
in the meantime.
Basically there are three ways how a synchronous API on NMClient could behave:
1) the call just calls g_dbus_connection_call_sync(). This means
that libnm sends a D-Bus request via GDBusConnection, and blockingly
waits for the response. All D-Bus messages that get received in the
meantime are queued in the GMainContext that belongs to NMClient.
That means, none of these D-Bus events are processed until we
iterate the GMainContext after the call returns. The effect is,
that NMClient (and all cached objects in there) are unaffected by
the D-Bus request.
Most of the synchronous API calls in libnm are of this kind.
The problem is that the strict ordering of D-Bus events gets
violated.
For some API this is not an immediate problem. Take for example
nm_device_wifi_request_scan(). The call merely blockingly tells
NetworkManager to start scanning, but since NetworkManager's D-Bus
API does not directly expose any state that tells whether we are
currently scanning, this out of order processing of the D-Bus
request is a small issue.
The problem is more obvious for nm_client_networking_set_enabled().
After calling it, NM_CLIENT_NETWORKING_ENABLED is still unaffected
and unchanged, because the PropertiesChanged signal from D-Bus
is not yet processed.
This means, while you make such a blocking call, NMClient's state
does not change. But usually you perform the synchronous call
to change some state. In this form, the blocking call is not useful,
because NMClient only changes the state after iterating the GMainContext,
and not after the blocking call returns.
2) like 1), but after making the blocking g_dbus_connection_call_sync(),
update the NMClient cache artificially. This is what
nm_manager_check_connectivity() does, to "fix" bgo#784629.
This also has the problem of out-of-order events, but it kinda
solves the problem of not changing the state during the blocking
call. But it does so by hacking the state of the cache. I think
this is really wrong because the state should only be updated from
the ordered stream of D-Bus messages (PropertiesChanged signal and
similar). When libnm decides to modify the state, there may be already
D-Bus messages queued that affect this very state.
3) instead of calling g_dbus_connection_call_sync(), use the
asynchronous g_dbus_connection_call(). If we would use a sepaate
GMainContext for all D-Bus related calls, we could ensure that
while we block for the response, we iterate that internal main context.
This might be nice, because all events are processed in order and
after the blocking call returns, the NMClient state is up to date.
The are problems however: current blocking API does not do this,
so it's a significant change in behavior. Also, it might be
unexpected to the user that during the blocking call the entire
content of NMClient's cache might change and all pointers to the
cache might be invalidated. Also, of course NMClient would invoke
signals for all the changes that happen.
Another problem is that this would be more effort to implement
and it involves a small performance overhead for all D-Bus related
calls (because we have to serialize all events in an internal
GMainContext first and then invoke them on the caller's context).
Also, if the users wants this behavior, they could implement it themself
by running libnm in their own GMainContext. Note that libnm might
have bugs to make that really working, but that should be fixed
instead of adding such synchrnous API behavior.
Read also [1], for why blocking calls are wrong.
[1] https://smcv.pseudorandom.co.uk/2008/11/nonblocking/
So, all possible behaviors for synchronous API have severe behavioural
issues. Mark all this API as deprecated. Also, this serves the purpose of
identifying blocking D-Bus calls in libnm.
Note that "deprecated" here does not really mean that the API is going
to be removed. We don't break API. The user may:
- continue to use this API. It's deprecated, awkward and discouraged,
but if it works, by all means use it.
- use asynchronous API. That's the only sensible way to use D-Bus.
If libnm lacks a certain asynchronous counterpart, it should be
added.
- use GDBusConnection directly. There really isn't anything wrong
with D-Bus or GDBusConnection. This deprecated API is just a wrapper
around g_dbus_connection_call_sync(). You may call it directly
without feeling dirty.
---
The only other remainging API is the synchronous GInitable call for
NMClient. That is an entirely separate beast and not particularly
wrong (from an API point of view).
Note that synchronous API in NMSecretAgentOld, NMVpnPluginOld and
NMVpnServicePlugin as not deprecated here. These types are not part
of the D-Bus cache and while they have similar issues, it's less severe
because they have less state.
We no longer add these. If you use Emacs, configure it yourself.
Also, due to our "smart-tab" usage the editor anyway does a subpar
job handling our tabs. However, on the upside every user can choose
whatever tab-width he/she prefers. If "smart-tabs" are used properly
(like we do), every tab-width will work.
No manual changes, just ran commands:
F=($(git grep -l -e '-\*-'))
sed '1 { /\/\* *-\*- *[mM]ode.*\*\/$/d }' -i "${F[@]}"
sed '1,4 { /^\(#\|--\|dnl\) *-\*- [mM]ode/d }' -i "${F[@]}"
Check remaining lines with:
git grep -e '-\*-'
The ultimate purpose of this is to cleanup our files and eventually use
SPDX license identifiers. For that, first get rid of the boilerplate lines.
The D-Bus interface already has a boolean property "Unsaved".
While that is nicer too look at (in the API), adding a new flag
is very cumbersome, and also has more overhead. For example,
it requires extending the D-Bus API, all the way down to libnm.
Add a flags argument, that will allow to add future boolean
flags easier.
If an operation is cancelled through the GCancellable, then the idiom is
that the operation is always cancelled, even if it has finished
successfully. To ensure this is the case, add calls to
g_simple_async_result_set_check_cancellable everywhere.
Without this, e.g. gnome-control-center will crash when switching away
from the power panel quickly, as the NMClient creation finishes
asynchronously and g-c-c assume that G_IO_ERROR_CANCELLED is returned to
ensure it doesn't access the now invalid user_data parameter.
https://bugzilla.gnome.org/show_bug.cgi?id=794088
- only add an async version. I think sync requests are fundamentally flawed
because they mess up the order of D-Bus messages. Hence, also don't
call the function *_async(), like we do for other functions. As there
is only the async form, it doesn't have a suffix.
- Don't accept a NMConnection as @settings argument, but a GVariant.
In general, keep the libnm API closer to the D-Bus API and don't hide
the underlying function with a less powerful form. The user still can
conveniently call the function with
nm_remote_connection_update2 (connection,
nm_connection_to_dbus (NM_CONNECTION (connection),
NM_CONNECTION_SERIALIZE_ALL),
save_to_disk
? NM_SETTINGS_UPDATE2_FLAG_TO_DISK
: NM_SETTINGS_UPDATE2_FLAG_IN_MEMORY,
NULL,
cancellable,
callback,
user_data);
I believe the parts of libnm that invoke D-Bus methods, should be
close to the D-Bus API. Not like nm_remote_connection_commit_changes()
which has no corresponding D-Bus method.
We already have Update(), UpdateUnsaved() and Save(), which serve
similar purposes. We will need a form of update with another argument.
Most notably, to block autoconnect while doing the update.
Other use cases could be to prevent reapplying connection.zone and
connection.metered, to to reapply all changes.
Instead of adding a specific update function that only serves that
new use-case, add a extensible Update2() function. It can be extended
to cope with future variants of update.
GNOME Settings 3.26 is crashing every time a VPN connection changed its
state. After some digging, a debug message was put on dispose, and this
issue was found:
libnm-Message: Object 0x55555633c070 disposed
libnm-Message: Object 0x55555633c730 disposed
libnm-Message: Object 0x55555633eae0 disposed
libnm-Message: Object 0x555556340a80 disposed
Thread 1 "gnome-control-c" received signal SIGSEGV, Segmentation fault.
g_type_check_instance_cast (type_instance=type_instance@entry=0x55555633c070, iface_type=93825006537856) at /.../glib/gobject/gtype.c:4057
4057 node = lookup_type_node_I (type_instance->g_class->g_type);
(gdb) bt
NetworkManager is calling callbacks on disposed objects, which leads to
crashes in clients (e.g. GNOME Settings).
Fix this issue by disconnecting signal handlers when the objects are
disposed.
Patch originally by Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
https://bugzilla.gnome.org/show_bug.cgi?id=787893
This makes it easier to install the files with proper names.
Also, it makes the makefile rules slightly simpler.
Lastly, the documentation is now generated into docs/api, which makes it
possible to get rid of the awkward relative file names in docbook.
This speeds up the initial object tree load significantly. Also, it
reduces the object management complexity by shifting the duties to
GDBusObjectManager.
The lifetime of all NMObjects is now managed by the NMClient via the
object manager. The NMClient creates the NMObjects for GDBus objects,
triggers the initialization and serves as an object registry (replaces
the nm-cache).
The ObjectManager uses the o.fd.DBus.ObjectManager API to learn of the
object creation, removal and property changes. It takes care of the
property changes so that we don't have to and lets us always see a
consistent object state. Thus at the time we learn of a new object we
already know its properties.
The NMObject unfortunately can't be made synchronously initializable as
the NMRemoteConnection's settings are not managed with standard
o.fd.DBus Properties and ObjectManager APIs and thus are not known to
the ObjectManager. Thus most of the asynchronous object property
changing code in nm-object.c is preserved. The objects notify the
properties that reference them of their initialization in from their
init_finish() methods, thus the asynchronously created objects are not
allowed to fail creation (or the dependees would wait forever). Not a
problem -- if a connection can't get its Settings, it's either invisible
or being removed (presumably we'd learn of the removal from the object
manager soon).
The NMObjects can't be created by the object manager itself, since we
can't determine the resulting object type in proxy_type() yet (we can't
tell from the name and can't access the interface list). Therefore the
GDBusObject is coupled with a NMObject later on.
Lastly, now that all the objects are managed by the object manager, the
NMRemoteSettings and NMManager go away when the daemon is stopped. The
complexity of dealing with calls to NMClient that would require any of
the resources that these objects manage (connection or device lists,
etc.) had to be moved to NMClient. The bright side is that his allows
for removal all of the daemon presence tracking from NMObject.
Relax our error checking which will allow us to try harder to
make the best out of whatever NetworkManager sends us.
Also, drop the g_warning(). First, now we really don't expect this
function to fail. And even in that case, raising a g_warning() from
the library is not very friendly to the user of libnm.
GError codes are only unique per domain, so logging the code without
also indicating the domain is not helpful. And anyway, if the error
messages are not distinctive enough to tell the whole story then we
should fix the error messages.
Based-on-patch-by: Dan Winship <danw@gnome.org>
Functions that take a GError** MUST fill it in on error. There is no
need to check whether error is NULL if the function it was passed to
had a failing return value.
Likewise, a proper GError must have a non-NULL message, so there's no
need to double-check that either.
Based-on-patch-by: Dan Winship <danw@gnome.org>
- 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
connection_added() can be called before init_get_settings_cb(), and we can't
complete the connection until it is visible, else it would be uninitialized.
Test case:
* have 'em1' interface
$ nmcli con add type ethernet con-name myeth ifname em1 autoconnect no
(process:9039): libnm-CRITICAL **: nm_connection_get_id: assertion 's_con != NULL' failed
Connection '(null)' ((null)) successfully added.
$ nmcli con add type ethernet con-name myeth ifname em1X autoconnect no
Connection 'myeth' (71159504-c2af-4773-8ca9-a3626aa0da33) successfully added.
https://bugzilla.gnome.org/show_bug.cgi?id=754767https://bugzilla.gnome.org/show_bug.cgi?id=754794
[lkundrak@v3.sk: This is not quite the correct fix, we shouldn't emit
NMObject:connection-added for an unfinished object. Nevertheless, let's go with
it until we have a better one. Will revert this afterwards. See linked bugs.]
The localization headers are now included via "nm-default.h".
Also fixes several places, where we wrongly included <glib/gi18n-lib.h>
instead of <glib/gi18n.h>. For example under "clients/" directory.
Rather than randomly including one or more of <glib.h>,
<glib-object.h>, and <gio/gio.h> everywhere (and forgetting to include
"nm-glib-compat.h" most of the time), rename nm-glib-compat.h to
nm-glib.h, include <gio/gio.h> from there, and then change all .c
files in NM to include "nm-glib.h" rather than including the glib
headers directly.
(Public headers files still have to include the real glib headers,
since nm-glib.h isn't installed...)
Also, remove glib includes from header files that are already
including a base object header file (which must itself already include
the glib headers).
(process:6888): GLib-GObject-WARNING **: invalid unclassed pointer in cast to 'GDBusProxy'
Program received signal SIGTRAP, Trace/breakpoint trap.
g_logv (log_domain=0x3149a3b224 "GLib-GObject", log_level=G_LOG_LEVEL_WARNING, format=<optimized out>, args=args@entry=0x7fffffffda70) at gmessages.c:1046
1046 g_private_set (&g_log_depth, GUINT_TO_POINTER (depth));
(gdb) bt
#0 0x0000003148e50c70 in g_logv (log_domain=0x3149a3b224 "GLib-GObject", log_level=G_LOG_LEVEL_WARNING, format=<optimized out>, args=args@entry=0x7fffffffda70) at gmessages.c:1046
#1 0x0000003148e50eaf in g_log (log_domain=log_domain@entry=0x3149a3b224 "GLib-GObject", log_level=log_level@entry=G_LOG_LEVEL_WARNING, format=format@entry=0x3149a42690 "invalid unclassed pointer in cast to '%s'") at gmessages.c:1079
#2 0x0000003149a34171 in g_type_check_instance_cast (type_instance=type_instance@entry=0x6fc530, iface_type=<optimized out>) at gtype.c:4030
#3 0x00007ffff7d6b016 in nmdbus_settings_connection_call_get_settings_finish (proxy=0x6fc530, out_settings=out_settings@entry=0x7fffffffdbb8, res=res@entry=0x6fe150, error=error@entry=0x0)
at nmdbus-settings-connection.c:1303
#4 0x00007ffff7ce8813 in updated_get_settings_cb (proxy=<optimized out>, result=0x6fe150, user_data=user_data@entry=0x6fc650) at nm-remote-connection.c:588
#5 0x000000314a27640d in g_simple_async_result_complete (simple=0x6fe150 [GSimpleAsyncResult]) at gsimpleasyncresult.c:763
#6 0x000000314a2df47c in reply_cb (connection=<optimized out>, res=0x6fe0e0, user_data=user_data@entry=0x6fe150) at gdbusproxy.c:2623
#7 0x000000314a27640d in g_simple_async_result_complete (simple=0x6fe0e0 [GSimpleAsyncResult]) at gsimpleasyncresult.c:763
#8 0x000000314a2d48cc in g_dbus_connection_call_done (source=<optimized out>, result=<optimized out>, user_data=user_data@entry=0x7fffec01a320) at gdbusconnection.c:5502
#9 0x000000314a27640d in g_simple_async_result_complete (simple=0x6e5f40 [GSimpleAsyncResult]) at gsimpleasyncresult.c:763
#10 0x000000314a27647c in complete_in_idle_cb (data=0x6e5f40) at gsimpleasyncresult.c:775
#11 0x0000003148e49b6b in g_main_context_dispatch (context=0x687970) at gmain.c:3064
#12 0x0000003148e49b6b in g_main_context_dispatch (context=context@entry=0x687970) at gmain.c:3663
#13 0x0000003148e49f08 in g_main_context_iterate (context=0x687970, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3734
#14 0x0000003148e4a232 in g_main_loop_run (loop=0x687a80) at gmain.c:3928
#15 0x00000000004136a1 in main (argc=<optimized out>, argv=<optimized out>) at nmcli.c:632
(gdb)
Libraries need to include <gi18n-lib.h>, not <gi18n.h>, so that _()
will get defined to "dgettext (GETTEXT_DOMAIN, string)" rather than
"gettext (string)" (which will use the program's default domain, which
works fine for programs in the NetworkManager tree, but not for
external users). Likewise, we need to call bindtextdomain() so that
gettext can find the translations if the library is installed in a
different prefix from the program using it (and
bind_textdomain_codeset(), so it will know the translations are in
UTF-8 even if the locale isn't).
(The fact that no one noticed this was broken before is because the
libraries didn't really start returning useful translated strings much
until 0.9.10, and none of the out-of-tree clients have been updated to
actually show those strings to users yet.)
config.h should be included from every .c file, and it should be
included before any other include. Fix that.
(As a side effect of how I did this, this also changes us to
consistently use "config.h" rather than <config.h>. To the extent that
it matters [which is not much], quotes are more correct anyway, since
we're talking about a file in our own build tree, not a system
include.)
NMRemoteConnection used to return
NM_REMOTE_CONNECTION_ERROR_DISCONNECTED if you tried to operate on a
connection that had been disconnected from its D-Bus proxy. But this
disappeared in the gdbus port (since gdbus doesn't emit a signal when
it happens, so it's harder to notice. And it's not clear why
NMRemoteConnection did this when no other class did anyway...).
Add the missing variant in most places in the API where previously
there was either only a synchronous version or only an asynchronous
version.
There is not yet a synchronous nm_client_activate_connection(),
nm_client_add_and_activate_connection(), or
nm_remote_settings_add_connection(), because the existing async code
depends on waiting for other asynchronous events, so making them run
synchronously is slightly more complicated. But these APIs can be
added later.
Make synchronous APIs take GCancellables, and make asynchronous APIs
use GAsyncReadyCallbacks and have names ending in "_async", with
"_finish" functions to retrieve the results.
Also, make nm_client_activate_connection_finish(),
nm_client_add_and_activate_finish(), and
nm_remote_settings_add_connection_finish() be (transfer full) rather
than (transfer none), because the refcounting semantics become
slightly confusing in some edge cases otherwise.
