From ff010fe97025a093f2938dded6be4a0be72460ee Mon Sep 17 00:00:00 2001
From: Georgiy Lebedev <g.lebedev@tarantool.org>
Date: Fri, 24 May 2024 12:07:25 +0300
Subject: [PATCH] box: refactor `box_demote` to make it more comprehensible
Suggested by Nikita Zheleztsov in the scope of #9855.
Needed for #9855
NO_CHANGELOG=<refactoring>
NO_DOC=<refactoring>
NO_TEST=<refactoring>
Co-authored-by: Nikita Zheleztsov <n.zheleztsov@proton.me>
---
src/box/box.cc | 39 +++++++++++++++++++--------------------
1 file changed, 19 insertions(+), 20 deletions(-)
diff --git a/src/box/box.cc b/src/box/box.cc
index 5af1148081..22d957b81c 100644
--- a/src/box/box.cc
+++ b/src/box/box.cc
@@ -3080,24 +3080,7 @@ box_demote(void)
return 0;
const struct raft *raft = box_raft();
- if (box_election_mode == ELECTION_MODE_OFF) {
- assert(raft->state == RAFT_STATE_FOLLOWER);
- if (raft->leader != REPLICA_ID_NIL) {
- diag_set(ClientError, ER_NOT_LEADER, raft->leader);
- return -1;
- }
- if (txn_limbo.owner_id == REPLICA_ID_NIL)
- return 0;
- /*
- * If the limbo term is up to date with Raft, then it might have
- * a valid owner right now. Demotion would disrupt it. In this
- * case the user has to explicitly overthrow the old owner with
- * local promote(), or call demote() on the actual owner.
- */
- if (txn_limbo.promote_greatest_term == raft->term &&
- txn_limbo.owner_id != instance_id)
- return 0;
- } else {
+ if (box_election_mode != ELECTION_MODE_OFF) {
if (txn_limbo_replica_term(&txn_limbo, instance_id) !=
raft->term)
return 0;
@@ -3105,11 +3088,27 @@ box_demote(void)
return 0;
if (raft->state != RAFT_STATE_LEADER)
return 0;
+ return box_trigger_elections();
}
- if (box_trigger_elections() != 0)
+
+ assert(raft->state == RAFT_STATE_FOLLOWER);
+ if (raft->leader != REPLICA_ID_NIL) {
+ diag_set(ClientError, ER_NOT_LEADER, raft->leader);
return -1;
- if (box_election_mode != ELECTION_MODE_OFF)
+ }
+ if (txn_limbo.owner_id == REPLICA_ID_NIL)
return 0;
+ /*
+ * If the limbo term is up to date with Raft, then it might have
+ * a valid owner right now. Demotion would disrupt it. In this
+ * case the user has to explicitly overthrow the old owner with
+ * local promote(), or call demote() on the actual owner.
+ */
+ if (txn_limbo.promote_greatest_term == raft->term &&
+ txn_limbo.owner_id != instance_id)
+ return 0;
+ if (box_trigger_elections() != 0)
+ return -1;
if (box_try_wait_confirm(2 * replication_synchro_timeout) < 0)
return -1;
int64_t wait_lsn = box_wait_limbo_acked(replication_synchro_timeout);
--
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