raft.go
func (r *Raft) verifyLeader(v *verifyFuture) {
	// Current leader always votes for self
	v.votes = 1

	// Set the quorum size, hot-path for single node
	v.quorumSize = r.quorumSize()
	if v.quorumSize == 1 {
		v.respond(nil)
		return
	}

	// Track this request
	v.notifyCh = r.verifyCh
	r.leaderState.notify[v] = struct{}{}

	// Trigger immediate heartbeats
	for _, repl := range r.leaderState.replState {
		repl.notifyLock.Lock()
		repl.notify[v] = struct{}{}
		repl.notifyLock.Unlock()
		asyncNotifyCh(repl.notifyCh)
	}
}
func (r *Raft) verifyLeader(v *verifyFuture) {
	// Current leader always votes for self
	v.votes = 1

	// Set the quorum size, hot-path for single node
	v.quorumSize = r.quorumSize()
	if v.quorumSize == 1 {
		v.respond(nil)
		return
	}

	// Track this request
	v.notifyCh = r.verifyCh
	r.leaderState.notify[v] = struct{}{}

	// Trigger immediate heartbeats
	for _, repl := range r.leaderState.replState {
		repl.notifyLock.Lock()
		repl.notify[v] = struct{}{}
		repl.notifyLock.Unlock()
		asyncNotifyCh(repl.notifyCh)
	}
}
// verifyLeader must be called from the main thread for safety.
// Causes the followers to attempt an immediate heartbeat.