From 9eddae8fc775ee3f204dbcf25a9f5ee7bad11c4e Mon Sep 17 00:00:00 2001
From: Jung-Sang Ahn <jungsang.ahn@gmail.com>
Date: Sun, 8 Dec 2019 17:58:50 +0900
Subject: [PATCH] Allow election timer on restart_election_timer API (#82)

* Election timer flag should be updated on election timer restart,
as the flag will not be effective anymore if timer is initiated.
---
 include/libnuraft/raft_server.hxx | 2 ++
 src/handle_timeout.cxx            | 6 ++++++
 src/raft_server.cxx               | 4 ----
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/libnuraft/raft_server.hxx b/include/libnuraft/raft_server.hxx
index f9e55118..193dab3f 100644
--- a/include/libnuraft/raft_server.hxx
+++ b/include/libnuraft/raft_server.hxx
@@ -194,6 +194,8 @@ public:
 
     /**
      * Start the election timer on this server, if this server is a follower.
+     * It will allow the election timer permanently, if it was disabled
+     * by state manager.
      */
     void restart_election_timer();
 
diff --git a/src/handle_timeout.cxx b/src/handle_timeout.cxx
index a0fe9c72..6721cae5 100644
--- a/src/handle_timeout.cxx
+++ b/src/handle_timeout.cxx
@@ -120,6 +120,12 @@ void raft_server::restart_election_timer() {
         return;
     }
 
+    // If election timer was not allowed, clear the flag.
+    if (!state_->is_election_timer_allowed()) {
+        state_->allow_election_timer(true);
+        ctx_->state_mgr_->save_state(*state_);
+    }
+
     if (election_task_) {
         p_tr("cancel existing timer");
         cancel_task(election_task_);
diff --git a/src/raft_server.cxx b/src/raft_server.cxx
index 036ebf64..be9e8b3a 100644
--- a/src/raft_server.cxx
+++ b/src/raft_server.cxx
@@ -960,10 +960,6 @@ bool raft_server::update_term(ulong term) {
         become_follower();
         return true;
     }
-    if (!state_->is_election_timer_allowed()) {
-        state_->allow_election_timer(true);
-        ctx_->state_mgr_->save_state(*state_);
-    }
     return false;
 }