The restart timer was racy and didn't allow for immediate restarts
from limits. Now the protocols stores the last restart time and in case
of too frequent autorestarts caused by exceeded limits, the protocol
gets disabled with an error message.
Also now there is a configuration knob for this.
There were some nasty problems with deferred protocol state updates and
race conditions on BGP startup, shutdown, and also with referencing the
cached states.
Now it looks fixed.
To allow reading of protocol states from other protocols or completely
different routines, we have to export these states to data structures
not requiring to lock the protocol loops.
On one hand, this doesn't give the reader the actual state "right now",
on the other hand, getting that is impossible in a properly
multithreaded environment and you will always get the information with
some (little but noteworthy) delay.
This implementation handles only the basic state information of the
protocols, common for all the protocols. Adding protocol-specific state
information should be done by implementing the protocol hook init_state().
Channel information is stored but not announced, as we don't need the
announcements for now.
For the upcoming rework of protocol state information propagation,
we need some more eattr types to be defined.
These types are probably not defined completely and before using
them for route attributes, you should check that they don't lack
some crucial methods.
closes#86
The uncork events are running from mainloop so these should just
dispatch the right event to the right loop. Doing anything long there
is bad for performance and latency as the uncork list may be huge.
the sync is actually needed when the pages get freed, not precisely
after every item cleanup, as the data technically stays intact until the
deferred free's are called.
This partially reverts commit d617801c31.
The common lockfree doesn't work well for high-volume structures like
eattr cache because it expects the structure to be cleaned up by a
sweeper routine ... which is very ineffective for >1M records.
OTOH, we need the deferred ea_free in all cases ... so keeping that.
