On Tue, Mar 22, 2016 at 11:24:14PM +0200, Liran Schour wrote: > Ben Pfaff <b...@ovn.org> wrote on 22/03/2016 07:23:33 PM: > > > On Fri, Mar 04, 2016 at 08:08:59AM +0000, Liran Schour wrote: > > > Hold session's conditions in ovsdb_monitor_session_condition. Pass it > > > to ovsdb_monitor for generating "update2" notifications. > > > Add functions that can generate "update2" notification for a > > > "monitor_cond" session. > > > JSON cache is enabled only for session's with true condition only. > > > "monitor_cond" and "monitor_cond_change" are RFC 7047 extensions > > > described by ovsdb-server(1) manpage. > > > > > > Signed-off-by: Liran Schour <lir...@il.ibm.com> > > > > I think that ovsdb_monitor_table_condition_set() has a memory leak in > > the error case; it does not free the 'error' returned to it. > > > > Right. Will fix that. > > > I'm a little confused about ovsdb_monitor_session_condition. Why is > > this a separate data structure? That is, why is there a separate shash > > of conditions rather than incorporating a condition into > > ovsdb_monitor_table? > > > > A single ovsdb_monitor instance can be used by many jsonrpc sessions (as > long as they share the same set of tables and columns). > Ovsdb_monitor_condition_session is holding the condition state per each > jsonrpc session. Each session, in ovsdb_monitor, can have a different set > of conditions and it is being represented by > ovsdb_monitor_session_condition with ovsdb_monitor_table_condition per > table. > The trivial option was to divide ovsdb_monitor into 2 different instances > if we have 2 sessions with different sets of conditions. But, condition is > changing during the lifetime of monitor session. And by holding sessions > with different conditions under the same ovsdb_monitor we can reduce the > computation needed to insert row changes to ovsdb_monitor. (insert once > instead of twice)
Those downsides of having a monitor per (monitored columns, condition) seem pretty minor. It also seems to me like the "obvious" way to implement this. It seems like, for example, the problem of caching with conditions is much easier if the data structures are organized this way. Did you actually try implementing it that way and determine that there was some insuperable difficulty? _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
