Hi,
On 08/04/2016 03:05 PM, ba_f wrote:
Hello L4-Hackers,
can you tell me, what are the capabilities of Fiasco.OC when it comes to 'dynamic reconfiguration'?
As far as I know, (almost) all the configurations is made in conf.cfg and hw.io, right?
But, is it also possible to do some configuration during run-time i.e. dynamic reconfiguration? Here are two examples I can think of:
Well, it depends ...
- IPC-Channels: Instead of defining Server and its Clients in conf.cfg
statically, is it possible to create IPC-Channel during run-time? Let's say, I have a L4re-App in conf.cfg defined as IPC-Server but, no Clients, yet. Now, may any L4re-App create a IPC-Channel by itself and such link to that IPC-Server?
The answer is 'Yes.' and 'No'. The answer to the first question is that this is exactly what ned is doing. Ned creates an IPC gate object and maps it into the tasks as specified in the provided Lua configuration.
The second is not possible for multiple reasons. The first one is, that the server side already needs the IPC gate object to bind its server loop to. Another task has no means to "lookup" the existing IPC gate object. In fact that's the idea behind a capability system.
- New Tasks: Is a L4re-App able to create a new task? I.e. push a thread
into its own address-space? The new task would require some access rights, too.
Yes. Ned and L4Linux are just two examples doing this.
Best, Matthias.