[Tarantool-patches] [PATCH v2 14/16] raft: move RO summary update to box-Raft

[Vladislav Shpilevoy]

RO summary update is supposed to make the instance read-only, when
it becomes a follower, and read-write when becomes a leader.

But it makes Raft depend on box, and prevents Raft move to a
separate library.

The patch moves the RO update to box-Raft.

This became possible after some preparatory work was done to make
Raft update triggers non-yielding, and invoked right after state
change (without a yield between the change and the triggers).

Part of #5303
---
 src/box/raft.c    | 8 ++++++++
 src/box/raftlib.c | 8 --------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/box/raft.c b/src/box/raft.c
index 5ccfb3449..c5a27cdec 100644
--- a/src/box/raft.c
+++ b/src/box/raft.c
@@ -153,6 +153,14 @@ box_raft_on_update_f(struct trigger *trigger, void *event)
 	(void)trigger;
 	struct raft *raft = (struct raft *)event;
 	assert(raft == box_raft());
+	/*
+	 * XXX: in case the instance became a leader, RO must be updated only
+	 * after clearing the synchro queue.
+	 *
+	 * When the instance became a follower, then on the contrary - make it
+	 * read-only ASAP, this is good.
+	 */
+	box_update_ro_summary();
 	if (raft->state != RAFT_STATE_LEADER)
 		return 0;
 	/*
diff --git a/src/box/raftlib.c b/src/box/raftlib.c
index f64a66942..6e6bc658f 100644
--- a/src/box/raftlib.c
+++ b/src/box/raftlib.c
@@ -33,7 +33,6 @@
 #include "error.h"
 #include "fiber.h"
 #include "small/region.h"
-#include "box.h"
 #include "tt_static.h"
 
 /**
@@ -618,8 +617,6 @@ raft_sm_become_leader(struct raft *raft)
 	raft->state = RAFT_STATE_LEADER;
 	raft->leader = raft->self;
 	ev_timer_stop(loop(), &raft->timer);
-	/* Make read-write (if other subsystems allow that. */
-	box_update_ro_summary();
 	/* State is visible and it is changed - broadcast. */
 	raft_schedule_broadcast(raft);
 }
@@ -670,7 +667,6 @@ raft_sm_schedule_new_term(struct raft *raft, uint64_t new_term)
 	raft->volatile_vote = 0;
 	raft->leader = 0;
 	raft->state = RAFT_STATE_FOLLOWER;
-	box_update_ro_summary();
 	raft_sm_pause_and_dump(raft);
 	/*
 	 * State is visible and it is changed - broadcast. Term is also visible,
@@ -701,7 +697,6 @@ raft_sm_schedule_new_election(struct raft *raft)
 	/* Everyone is a follower until its vote for self is persisted. */
 	raft_sm_schedule_new_term(raft, raft->term + 1);
 	raft_sm_schedule_new_vote(raft, raft->self);
-	box_update_ro_summary();
 }
 
 static void
@@ -786,7 +781,6 @@ raft_sm_start(struct raft *raft)
 		 */
 		raft_sm_wait_leader_found(raft);
 	}
-	box_update_ro_summary();
 	/*
 	 * Nothing changed. But when raft was stopped, its state wasn't sent to
 	 * replicas. At least this was happening at the moment of this being
@@ -808,7 +802,6 @@ raft_sm_stop(struct raft *raft)
 		raft->leader = 0;
 	raft->state = RAFT_STATE_FOLLOWER;
 	ev_timer_stop(loop(), &raft->timer);
-	box_update_ro_summary();
 	/* State is visible and changed - broadcast. */
 	raft_schedule_broadcast(raft);
 }
@@ -894,7 +887,6 @@ raft_cfg_is_candidate(struct raft *raft, bool is_candidate)
 			raft_schedule_broadcast(raft);
 		}
 	}
-	box_update_ro_summary();
 }
 
 void
-- 
2.24.3 (Apple Git-128)