Re: Optional message handling

[Justin F. <vh...@us...>]

Alexey Zakhlestine wrote:
> I was thinking about such function during the last week. It would be
> useful for the startup-verifier, I was mentioning to you verbally.

I'm not sure if I understand how queue chaining could help ensure that 
all modules have loaded.

> On the other hand, parabellym is vulnerable to hijacking already, as
> there is no "official way" to identify the recipient. Parabellym,
> currently, is the system, where _anyone_ can give any command to the
> unknown _someone_. It's just the question of knowing the correct
> command, and being lucky to be the first subscriber.

Well, pb is not that much a hostile environment.  Like in any other 
application, any part of the code can call any other part of the code 
and you don't know who the caller is.  This is partially covered by the 
build-in C++ access restrictions, but it usually prevents one from 
making a call by mistake, not on purpose.  Same thing with pb: if you 
send a normal message now, it either arrives to the right target and 
everything works well, or it doesn't arrive at all.  If a module 
intercepts a message, it just won't come to the other module, and the 
system will fail to function.

Perhaps the best way out would be to use hooks.  That is, the previously 
discussed callback mechanism: you send the callback message id to the 
main handler and it then calls you when necessary.