homework-jianmu/source/libs/sync/src/syncElection.c

89 lines
3.0 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
*
* This program is free software: you can use, redistribute, and/or modify
* it under the terms of the GNU Affero General Public License, version 3
* or later ("AGPL"), as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "syncElection.h"
#include "syncMessage.h"
#include "syncRaftStore.h"
#include "syncVoteMgr.h"
// TLA+ Spec
// RequestVote(i, j) ==
// /\ state[i] = Candidate
// /\ j \notin votesResponded[i]
// /\ Send([mtype |-> RequestVoteRequest,
// mterm |-> currentTerm[i],
// mlastLogTerm |-> LastTerm(log[i]),
// mlastLogIndex |-> Len(log[i]),
// msource |-> i,
// mdest |-> j])
// /\ UNCHANGED <<serverVars, candidateVars, leaderVars, logVars>>
//
int32_t syncNodeRequestVotePeers(SSyncNode* pSyncNode) {
assert(pSyncNode->state == TAOS_SYNC_STATE_CANDIDATE);
int32_t ret = 0;
for (int i = 0; i < pSyncNode->peersNum; ++i) {
SyncRequestVote* pMsg = syncRequestVoteBuild();
pMsg->srcId = pSyncNode->myRaftId;
pMsg->destId = pSyncNode->peersId[i];
pMsg->term = pSyncNode->pRaftStore->currentTerm;
pMsg->lastLogIndex = pSyncNode->pLogStore->getLastIndex(pSyncNode->pLogStore);
pMsg->lastLogTerm = pSyncNode->pLogStore->getLastTerm(pSyncNode->pLogStore);
ret = syncNodeRequestVote(pSyncNode, &pSyncNode->peersId[i], pMsg);
assert(ret == 0);
syncRequestVoteDestroy(pMsg);
}
return ret;
}
int32_t syncNodeElect(SSyncNode* pSyncNode) {
int32_t ret = 0;
if (pSyncNode->state == TAOS_SYNC_STATE_FOLLOWER) {
syncNodeFollower2Candidate(pSyncNode);
}
assert(pSyncNode->state == TAOS_SYNC_STATE_CANDIDATE);
// start election
raftStoreNextTerm(pSyncNode->pRaftStore);
raftStoreClearVote(pSyncNode->pRaftStore);
voteGrantedReset(pSyncNode->pVotesGranted, pSyncNode->pRaftStore->currentTerm);
votesRespondReset(pSyncNode->pVotesRespond, pSyncNode->pRaftStore->currentTerm);
syncNodeVoteForSelf(pSyncNode);
if (voteGrantedMajority(pSyncNode->pVotesGranted)) {
// only myself, to leader
assert(!pSyncNode->pVotesGranted->toLeader);
syncNodeCandidate2Leader(pSyncNode);
pSyncNode->pVotesGranted->toLeader = true;
return ret;
}
ret = syncNodeRequestVotePeers(pSyncNode);
assert(ret == 0);
syncNodeResetElectTimer(pSyncNode);
return ret;
}
int32_t syncNodeRequestVote(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncRequestVote* pMsg) {
sTrace("syncNodeRequestVote pSyncNode:%p ", pSyncNode);
int32_t ret = 0;
SRpcMsg rpcMsg;
syncRequestVote2RpcMsg(pMsg, &rpcMsg);
syncNodeSendMsgById(destRaftId, pSyncNode, &rpcMsg);
return ret;
}