We need to define a state to be used while the modem is being initialized, so
that we forbid any operation on the modem on already exported interfaces, while
there are interfaces pending to get exported.
This Initializing state will also cover the state between having the SIM
unlocked (which launches re-initialization) and being completely initialized.
Instead of the `_in_port()' variants, we'll provide more generic
`_full()' methods. These should be used either if we want to send commands
to a specific port, or if we want to use a specific user-provided GCancellable.
In addition to this user-provided GCancellable, we keep the internal modem-wide
one.
* mm_base_modem_peek_port_* () will return either a port object (no new
reference), or NULL if none available.
You would usually peek() a port if you're going to use it just in the current
method, as there is no way to that reference to get invalid (we're single
threaded).
* mm_base_modem_get_port_* () will return either NEW references to valid
port objects, or NULL if none available.
And, you would usually get() a port, whenever you want the port object to be
valid even out of the current method, for example when keeping it in the
context of an async operation.
Also, we need to consider that the primary AT port MAY BE NULL when you
peek() or get() it. This is due to the fact that we may be releasing ports
(due to device disconnection) in the middle of async operations.
Usually, if not always, the connection stored in the SIM object never exists
when disposing it, as we clear the connection property in the Modem object
before destroying it, and both properties are bound. But just in case, in order
to avoid ending up with a zombie object in DBus, we make sure we unexport it.
Aleksander Morgado