tree 624933100cf01b286b8b52882d4a77e345afef69
parent 688b4b7de755f4dd01ec516975ae01590cf9f438
author Markus Armbruster <armbru@redhat.com> 1444921711 +0200
committer Markus Armbruster <armbru@redhat.com> 1446125685 +0100

monitor: Simplify event throttling

The event throttling state machine is hard to understand.  I'm not
sure it's entirely correct.  Rewrite it in a more straightforward
manner:

State 1: No event sent recently (less than evconf->rate ns ago)

    Invariant: evstate->timer is not pending, evstate->qdict is null

    On event: send event, arm timer, goto state 2

State 2: Event sent recently, no additional event being delayed

    Invariant: evstate->timer is pending, evstate->qdict is null

    On event: store it in evstate->qdict, goto state 3

    On timer: goto state 1

State 3: Event sent recently, additional event being delayed

    Invariant: evstate->timer is pending, evstate->qdict is non-null

    On event: store it in evstate->qdict, goto state 3

    On timer: send evstate->qdict, clear evstate->qdict,
              arm timer, goto state 2

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1444921716-9511-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>