The libnm API fir checkpoints was only introduced with 1.11. It
is not yet stable, so there is still time to adjust it. Note that
this changes API/ABI of the development branch.
Changes:
- we only add async variants of the checkpoint functions. I believe
that synchronous D-Bus methods are fundamentally flawed, because
they mess up the ordering of events.
Rename the async functions by removing the "_async" suffix. This
matches glib style, for which the async form is also not specially
marked.
- for function that refere to a particular checkpoint (rollback and
destroy), accept the D-Bus path as string, instead of an NMCheckpoint
instance. This form is more flexible, because it allows to use
the function without having a NMCheckpoint instance at hand. On the
other hand, if one has a NMCheckpoint instance, he can trivially
obtain the path to make the call.
This allows to adjust the timeout of an existing checkpoint.
The main usecase of checkpoints, is to have a fail-safe when
configuring the network remotely. By allowing to reset the timeout,
the user can perform a series of actions, and keep bumping the
timeout. That way, the entire series is still guarded by the same
checkpoint, but the user can start with short timeout, and
re-adjust the timeout as he goes along.
The libnm API only implements the async form (at least for now).
Sync methods are fundamentally wrong with D-Bus, and it's probably
not needed. Also, follow glib convenction, where the async form
doesn't have the _async name suffix. Also, accept a D-Bus path
as argument, not a NMCheckpoint instance. The libnm API should
not be more restricted than the underlying D-Bus API. It would
be cumbersome to require the user to lookup the NMCheckpoint
instance first, especially since libnm doesn't provide an efficient
or convenient lookup-by-path method. On the other hand, retrieving
the path from a NMCheckpoint instance is always possible.
Note that:
- we compile some source files multiple times. Most notably those
under "shared/".
- we include a default header "shared/nm-default.h" in every source
file. This header is supposed to setup a common environment by defining
and including parts that are commonly used. As we always include the
same header, the header must behave differently depending
one whether the compilation is for libnm-core, NetworkManager or
libnm-glib. E.g. it must include <glib/gi18n.h> or <glib/gi18n-lib.h>
depending on whether we compile a library or an application.
For that, the source files need the NETWORKMANAGER_COMPILATION #define
to behave accordingly.
Extend the define to be composed of flags. These flags are all named
NM_NETWORKMANAGER_COMPILATION_WITH_*, they indicate which part of the
build are available. E.g. when building libnm-core.la itself, then
WITH_LIBNM_CORE, WITH_LIBNM_CORE_INTERNAL, and WITH_LIBNM_CORE_PRIVATE
are available. When building NetworkManager, WITH_LIBNM_CORE_PRIVATE
is not available but the internal parts are still accessible. When
building nmcli, only WITH_LIBNM_CORE (the public part) is available.
This granularily controls the build.
In practice, this should only matter when there are multiple
header files with the same name. That is something we try
to avoid already, by giving headers a distinct name.
When building NetworkManager itself, we clearly want to use
double-quotes for including our own headers.
But we also want to do that in our public headers. For example:
./a.c
#include <stdio.h>
#include <nm-1.h>
void main() {
printf ("INCLUDED %s/nm-2.h\n", SYMB);
}
./1/nm-1.h
#include <nm-2.h>
./1/nm-2.h
#define SYMB "1"
./2/nm-2.h
#define SYMB "2"
$ cc -I./2 -I./1 ./a.c
$ ./a.out
INCLUDED 2/nm-2.h
Exceptions to this are
- headers in "shared/nm-utils" that include <NetworkManager.h>. These
headers are copied into projects and hence used like headers owned by
those projects.
- examples/C
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.
This is required to add objects in the "Types and Values" section and
in the API index. Later, we may want to add useful content in those
empty comments.
