[Tarantool-patches] [PATCH v2 12/16] raft: move synchro queue clear to the worker fiber
sergepetrenko at tarantool.org
Fri Nov 20 12:07:00 MSK 2020
20.11.2020 02:46, Vladislav Shpilevoy пишет:
> The synchro queue was cleared from the Raft on_update trigger
> installed by box. It was fine as long as the trigger is called
> from the worker fiber, because it won't block the state machine,
> while the synchro queue clearance yields.
> But the trigger is going to be called from the Raft state machine
> directly soon. Because it will need to call
> box_update_ro_summary() right after Raft state is updated, without
> a yield to switch to the worker fiber. This will be done in scope
> of getting rid of box in the Raft library.
> It means, the trigger can't call box_clear_synchro_queue(). But it
> can schedule its execution for later, since the worker fiber now
> belongs to box. The patch does it.
> Part of #5303
Thanks for the patch! LGTM.
> src/box/raft.c | 22 ++++++++++++++++++----
> 1 file changed, 18 insertions(+), 4 deletions(-)
> diff --git a/src/box/raft.c b/src/box/raft.c
> index 0027230da..5ccfb3449 100644
> --- a/src/box/raft.c
> +++ b/src/box/raft.c
> @@ -80,6 +80,19 @@ box_raft_request_to_msg(const struct raft_request *req, struct raft_msg *msg)
> +static void
> +box_raft_update_synchro_queue(struct raft *raft)
> + assert(raft == box_raft());
> + /*
> + * When the node became a leader, it means it will ignore all records
> + * from all the other nodes, and won't get late CONFIRM messages anyway.
> + * Can clear the queue without waiting for confirmations.
> + */
> + if (raft->state == RAFT_STATE_LEADER)
> + box_clear_synchro_queue(false);
> static int
> box_raft_worker_f(va_list args)
> @@ -90,6 +103,7 @@ box_raft_worker_f(va_list args)
> box_raft_has_work = false;
> + box_raft_update_synchro_queue(raft);
> if (!box_raft_has_work)
> @@ -142,11 +156,11 @@ box_raft_on_update_f(struct trigger *trigger, void *event)
> if (raft->state != RAFT_STATE_LEADER)
> return 0;
> - * When the node became a leader, it means it will ignore all records
> - * from all the other nodes, and won't get late CONFIRM messages anyway.
> - * Can clear the queue without waiting for confirmations.
> + * If the node became a leader, time to clear the synchro queue. But it
> + * must be done in the worker fiber so as not to block the state
> + * machine, which called this trigger.
> - box_clear_synchro_queue(false);
> + box_raft_schedule_async(raft);
> return 0;
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