With g_clear_pointer(pptr, g_free), pptr is cast to a non-const pointer,
and hence there is no compiler warning about calling g_free() in a const
pointer. However, it still feels ugly to pass a const pointer to
g_clear_pointer(). We should either add an explicity cast, or just
make the pointer non-const.
I guess part of the problem is that C's "const char *" means that the
string itself is immutable, but also that it cannot be freed. We most
often want a different semantic: the string itself is immutable after
being initialized once, but the memory itself can and will be freed.
Such a notion of immutable C strings cannot be expressed.
For that, just remove the "const" from the declarations. Although we
don't want to modify the (content of the) string, it's still more a
mutable string.
Only in _vt_cmd_obj_copy_lnk_vlan(), add an explicity cast but keep the
type as const. The reason is, that we really want that NMPObject
instances are immutable (in the sense that they don't modify while
existing), but that doesn't mean the memory cannot be freed.
Previously, we used the generated GDBusInterfaceSkeleton types and glued
them via the NMExportedObject base class to our NM types. We also used
GDBusObjectManagerServer.
Don't do that anymore. The resulting code was more complicated despite (or
because?) using generated classes. It was hard to understand, complex, had
ordering-issues, and had a runtime and memory overhead.
This patch refactors this entirely and uses the lower layer API GDBusConnection
directly. It replaces the generated code, GDBusInterfaceSkeleton, and
GDBusObjectManagerServer. All this is now done by NMDbusObject and NMDBusManager
and static descriptor instances of type GDBusInterfaceInfo.
This adds a net plus of more then 1300 lines of hand written code. I claim
that this implementation is easier to understand. Note that previously we
also required extensive and complex glue code to bind our objects to the
generated skeleton objects. Instead, now glue our objects directly to
GDBusConnection. The result is more immediate and gets rid of layers of
code in between.
Now that the D-Bus glue us more under our control, we can address issus and
bottlenecks better, instead of adding code to bend the generated skeletons
to our needs.
Note that the current implementation now only supports one D-Bus connection.
That was effectively the case already, although there were places (and still are)
where the code pretends it could also support connections from a private socket.
We dropped private socket support mainly because it was unused, untested and
buggy, but also because GDBusObjectManagerServer could not export the same
objects on multiple connections. Now, it would be rather straight forward to
fix that and re-introduce ObjectManager on each private connection. But this
commit doesn't do that yet, and the new code intentionally supports only one
D-Bus connection.
Also, the D-Bus startup was simplified. There is no retry, either nm_dbus_manager_start()
succeeds, or it detects the initrd case. In the initrd case, bus manager never tries to
connect to D-Bus. Since the initrd scenario is not yet used/tested, this is good enough
for the moment. It could be easily extended later, for example with polling whether the
system bus appears (like was done previously). Also, restart of D-Bus daemon isn't
supported either -- just like before.
Note how NMDBusManager now implements the ObjectManager D-Bus interface
directly.
Also, this fixes race issues in the server, by no longer delaying
PropertiesChanged signals. NMExportedObject would collect changed
properties and send the signal out in idle_emit_properties_changed()
on idle. This messes up the ordering of change events w.r.t. other
signals and events on the bus. Note that not only NMExportedObject
messed up the ordering. Also the generated code would hook into
notify() and process change events in and idle handle, exhibiting the
same ordering issue too.
No longer do that. PropertiesChanged signals will be sent right away
by hooking into dispatch_properties_changed(). This means, changing
a property in quick succession will no longer be combined and is
guaranteed to emit signals for each individual state. Quite possibly
we emit now more PropertiesChanged signals then before.
However, we are now able to group a set of changes by using standard
g_object_freeze_notify()/g_object_thaw_notify(). We probably should
make more use of that.
Also, now that our signals are all handled in the right order, we
might find places where we still emit them in the wrong order. But that
is then due to the order in which our GObjects emit signals, not due
to an ill behavior of the D-Bus glue. Possibly we need to identify
such ordering issues and fix them.
Numbers (for contrib/rpm --without debug on x86_64):
- the patch changes the code size of NetworkManager by
- 2809360 bytes
+ 2537528 bytes (-9.7%)
- Runtime measurements are harder because there is a large variance
during testing. In other words, the numbers are not reproducible.
Currently, the implementation performs no caching of GVariants at all,
but it would be rather simple to add it, if that turns out to be
useful.
Anyway, without strong claim, it seems that the new form tends to
perform slightly better. That would be no surprise.
$ time (for i in {1..1000}; do nmcli >/dev/null || break; echo -n .; done)
- real 1m39.355s
+ real 1m37.432s
$ time (for i in {1..2000}; do busctl call org.freedesktop.NetworkManager /org/freedesktop org.freedesktop.DBus.ObjectManager GetManagedObjects > /dev/null || break; echo -n .; done)
- real 0m26.843s
+ real 0m25.281s
- Regarding RSS size, just looking at the processes in similar
conditions, doesn't give a large difference. On my system they
consume about 19MB RSS. It seems that the new version has a
slightly smaller RSS size.
- 19356 RSS
+ 18660 RSS
The error should be freed by callback functions, but only
_monitor_bridges_cb() actually does it. Simplify this by letting the
caller own the error.
Fixes: 830a5a14cb
When NM quits it destroys all singletons including NMOvsdb, which
invokes callbacks for every pending method call. In the shutdown,
extra care must be taken to not access objects that are already in a
inconsistent state; for example here, the callback changes the device
state, and this causes an access to data that has already been
cleared:
#0 _g_log_abort (breakpoint=breakpoint@entry=1) at gmessages.c:554
#1 g_logv (log_domain=0x5635653b6817 "NetworkManager", log_level=G_LOG_LEVEL_CRITICAL, format=<optimized out>, args=args@entry=0x7fffb4b2c1e0) at gmessages.c:1362
#2 g_log (log_domain=log_domain@entry=0x5635653b6817 "NetworkManager", log_level=log_level@entry=G_LOG_LEVEL_CRITICAL, format=format@entry=0x7fbb3f58fa4a "%s: assertion '%s' failed") at gmessages.c:1403
#3 g_return_if_fail_warning (log_domain=log_domain@entry=0x5635653b6817 "NetworkManager", pretty_function=pretty_function@entry=0x5635653b6b00 <__func__.34463> "nm_device_factory_manager_find_factory_for_connection", expression=expression@entry=0x5635653b6719 "factories_by_setting") at gmessages.c:2702
#4 nm_device_factory_manager_find_factory_for_connection (connection=connection@entry=0x56356627e0e0) at src/devices/nm-device-factory.c:243
#5 nm_manager_get_connection_iface (self=0x563566241080 [NMManager], connection=connection@entry=0x56356627e0e0, out_parent=out_parent@entry=0x0, error=error@entry=0x0) at src/nm-manager.c:1458
#6 check_connection_compatible (self=<optimized out>, connection=0x56356627e0e0) at src/devices/nm-device.c:4679
#7 check_connection_compatible (device=0x56356647b1b0 [NMDeviceOvsInterface], connection=0x56356627e0e0) at src/devices/ovs/nm-device-ovs-interface.c:95
#8 _nm_device_check_connection_available (self=0x56356647b1b0 [NMDeviceOvsInterface], connection=0x56356627e0e0, flags=NM_DEVICE_CHECK_CON_AVAILABLE_NONE, specific_object=0x0) at src/devices/nm-device.c:12102
#9 nm_device_check_connection_available (self=self@entry=0x56356647b1b0 [NMDeviceOvsInterface], connection=0x56356627e0e0, flags=flags@entry=NM_DEVICE_CHECK_CON_AVAILABLE_NONE, specific_object=specific_object@entry=0x0) at src/devices/nm-device.c:12131
#10 nm_device_recheck_available_connections (self=self@entry=0x56356647b1b0 [NMDeviceOvsInterface]) at src/devices/nm-device.c:12238
#11 _set_state_full (self=self@entry=0x56356647b1b0 [NMDeviceOvsInterface], state=state@entry=NM_DEVICE_STATE_FAILED, reason=reason@entry=NM_DEVICE_STATE_REASON_OVSDB_FAILED, quitting=quitting@entry=0) at src/devices/nm-device.c:13065
#12 nm_device_state_changed (self=self@entry=0x56356647b1b0 [NMDeviceOvsInterface], state=state@entry=NM_DEVICE_STATE_FAILED, reason=reason@entry=NM_DEVICE_STATE_REASON_OVSDB_FAILED) at src/devices/nm-device.c:13328
#13 del_iface_cb (error=<optimized out>, user_data=0x56356647b1b0) at src/devices/ovs/nm-device-ovs-port.c:160
#14 _transact_cb (self=self@entry=0x5635662b9ba0 [NMOvsdb], result=result@entry=0x0, error=0x563566259a10, user_data=user_data@entry=0x5635662ff320) at src/devices/ovs/nm-ovsdb.c:1449
#15 ovsdb_disconnect (self=self@entry=0x5635662b9ba0 [NMOvsdb]) at src/devices/ovs/nm-ovsdb.c:1331
#16 dispose (object=0x5635662b9ba0 [NMOvsdb]) at src/devices/ovs/nm-ovsdb.c:1558
#17 g_object_unref (_object=0x5635662b9ba0) at gobject.c:3293
#18 _nm_singleton_instance_destroy () at src/nm-core-utils.c:138
#19 _dl_fini () at dl-fini.c:253
#20 __run_exit_handlers (status=status@entry=0, listp=0x7fbb3e1ad6c8 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:77
#21 __GI_exit (status=status@entry=0) at exit.c:99
#22 main (argc=1, argv=0x7fffb4b2cc38) at src/main.c:468
Add a new error code to indicate to callbacks that we are quitting and
no further action must be taken. This is preferable to having
additional references because it allows us to free the resources owned
by callbacks immediately, while references can easily create loops.
https://bugzilla.redhat.com/show_bug.cgi?id=1543871
NM_DEVICE_OVS_INTERFACE_GET_PRIVATE() is implemented via the _NM_GET_PRIVATE()
macro. This macro uses C11's _Generic() to provide additional compiler checks
when casting from an incompatible pointer type.
As such,
NMDevice *device = ...;
NMDeviceOvsInterfacePrivate *priv;
priv = NM_DEVICE_OVS_INTERFACE_GET_PRIVATE (device);
causes a compilation error:
error: ‘_Generic’ selector of type ‘NMDevice * {aka struct _NMDevice *}’ is not compatible with any association
One workaround would be to cast the pointer first:
priv = NM_DEVICE_OVS_INTERFACE_GET_PRIVATE ((NMDeviceOvsInterface *) device);
A better fix is to mark NMDevice as a compatible pointer in _NM_GET_PRIVATE(),
which this patch does.
Previously, this went unnoticed, because due to bug "a43bf3388 build: fix configure
check for CC support of _Generic() and __auto_type", we failed to detect support
for _Generic() when compiling with -Werror. That essentially disables this check,
and NM_DEVICE_OVS_INTERFACE_GET_PRIVATE() would do a direct cast.
A workaround for this build failure might be to build with -Werror, which accidentally
results in not using _Generic().
https://bugzilla.gnome.org/show_bug.cgi?id=793183
Fixes: 8ad310f8e3
OvsInterface can postpone the stage3_ip[46]_config until the link
actually appears. It ought to restart the stage only when the link
appears, not upon further changes to it (which would trip an assertion
when starting the DHCP client while one already exists).
https://bugzilla.redhat.com/show_bug.cgi?id=1540063
We also unconditionally use them with autotools.
Also, the detection for have_version_script does
not seem correct to me. At least, it didn't work
with clang.
Some targets are missing dependencies on some generated sources in
the meson port. These makes the build to fail due to missing source
files on a highly parallelized build.
These dependencies have been resolved by taking advantage of meson's
internal dependencies which can be used to pass source files,
include directories, libraries and compiler flags.
One of such internal dependencies called `core_dep` was already in
use. However, in order to avoid any confusion with another new
internal dependency called `nm_core_dep`, which is used to include
directories and source files from the `libnm-core` directory, the
`core_dep` dependency has been renamed to `nm_dep`.
These changes have allowed minimizing the build details which are
inherited by using those dependencies. The parallelized build has
also been improved.
- nm-ovsdb.c uses json_load_callback(), which is jansson v2.4.
Hence, it cannot build the OVS plugin in our Travis-CI, which is
still on Ubuntu Precise. Disable building the plugin in travis and
add a compiler warning when building against an older version.
- since jansson v2.3, there is json_object_key_to_iter() to implement
the for-each macros. Use it in json_object_foreach_safe() when
available.
