[Tarantool-patches] [PATCH v2 13/16] raft: invoke update triggers within state machine
sergepetrenko at tarantool.org
Fri Nov 20 12:10:27 MSK 2020
20.11.2020 02:46, Vladislav Shpilevoy пишет:
> Raft used to call on_update trigger from the worker fiber. It was
> done because it could yield. But it is not the case anymore. The
> only yielding operation was box_clear_synchro_queue(), which is
> not called from the trigger now.
> That makes possible to call the trigger from within of the state
> machine. And this removes the yield between the Raft state change
> and the trigger invocation.
> What, in turn, allows to move all box-related urgent updates to
> the trigger. Such as box_update_ro_summary().
> Part of #5303
> src/box/raftlib.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
> diff --git a/src/box/raftlib.c b/src/box/raftlib.c
> index 4457a784f..f64a66942 100644
> --- a/src/box/raftlib.c
> +++ b/src/box/raftlib.c
> @@ -574,7 +574,6 @@ raft_worker_handle_broadcast(struct raft *raft)
> req.vclock = raft->vclock;
> raft_broadcast(raft, &req);
> - trigger_run(&raft->on_update, raft);
> raft->is_broadcast_scheduled = false;
> @@ -967,6 +966,17 @@ raft_new_term(struct raft *raft)
> static void
> raft_schedule_broadcast(struct raft *raft)
> + /*
> + * Broadcast works not only for network, but also for other subsystems
> + * on the same node. The info is delivered to them via update triggers.
> + * But the broadcast happens from inside of the state machine, so it
> + * can't yield.
> + */
> + int csw = fiber()->csw;
> + trigger_run(&raft->on_update, raft);
> + assert(csw == fiber()->csw);
> + (void)csw;
> raft->is_broadcast_scheduled = true;
More information about the Tarantool-patches