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paxrole.cpp
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paxrole.cpp
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// TODO The implemation of opertaions taken by diffrent roles
#include "paxrole.h"
#include "paxserver.h"
#include "log.h"
#include <assert.h>
#include <stdio.h>
#include <map>
#include <signal.h>
/** leader functions **/
leader_t::leader_t(paxserver *_server) {
server = _server;
do_first_TO = true;
//initialize p1info for prepare phase
p1info.pending_count = 0;
p1info.ready_count = 0;
p1info.highest_ready = -1;
p1info.first_to_check = 0;
p1info.last_to_check = 0;
//initialize p2info
p2info.current_iid = -1;
phase1_to_tick = 0;
phase2_to_tick = PHASE2_TO_TICK;
for (int i = 0; i < PROPOSER_ARRAY_SIZE; i++){
proposer_array[i] = {};
proposer_array[i].promises.resize(server->get_serv_cnt(server->vc_state.view)+1);
}
}
void leader_t::execute_phase1() {
proposer_record_t *rec;
int from = (p1info.highest_ready + 1);
int to = (from + PROPOSER_PREEXEC_WIN_SIZE);
vector<prepare_msg_t> messages;
LOG(l::DEBUG, "(tick "<< server->net->now() <<")Leader pre-executing phase 1 from " << from << " to " << to << "\n");
for(int i = from; i <= to; i++) {
rec = &proposer_array[GET_PRO_INDEX(i)];
if(rec->iid < i || rec->status == p1_new) {
p1info.pending_count++;
rec->iid = i;
rec->status = p1_pending;
rec->ballot = FIRST_BALLOT(server->nid);
rec->promise_count = 0;
for(auto promise : rec->promises) {
promise.iid = -1;
promise.value_ballot = -1;
promise.value = NULL;
}
//send_prepare_msg_to_acceptor
prepare_msg_t prepare_msg(rec->iid, rec->ballot);
messages.push_back(prepare_msg);
}
}
if(p1info.last_to_check < to) {
p1info.last_to_check = to;
}
if(p1info.first_to_check > from) {
p1info.first_to_check = from;
}
if(!messages.empty()) {
server->broadcast<prepare_batch_msg_t>(messages);
}
}
void leader_t::phase1_check_cb(){
//Check answer from last time
std::vector<prepare_msg_t> messages;
for(int i = p1info.first_to_check; i <= p1info.last_to_check; i++) {
proposer_record_t & rec = proposer_array[GET_PRO_INDEX(i)];
if (rec.iid == i && rec.status == p1_pending) {
//add prepare to sendbuf
rec.ballot = BALLOT_NEXT(rec.ballot);
rec.promise_count = 0;
for(auto promise : rec.promises) {
promise.iid = -1;
promise.value_ballot = -1;
promise.value = NULL;
}
prepare_msg_t msg (rec.iid,rec.ballot);
messages.push_back(msg);
}
}
if (p1info.pending_count + p1info.ready_count < (PROPOSER_PREEXEC_WIN_SIZE/2)) {
execute_phase1(); //add some stuff to sendbuf
}
if(!messages.empty()) {
server->broadcast<prepare_batch_msg_t> (messages);
}
}
leader_t::promise_info_t* leader_t::phase2_getMax_promise(proposer_record_t &rec) {
int max_ballot = -1;
promise_info_t* pi = NULL;
// check if we have simple majority in quorum -> safe to choose value
std::map<int, unsigned int> majority_set;
for (auto && prom_info : rec.promises) {
if (prom_info.iid == -1 )
continue;
if (prom_info.value_ballot != -1) {
if (majority_set.find(prom_info.value_ballot) != majority_set.end()) {
majority_set[prom_info.value_ballot]++;
} else {
majority_set[prom_info.value_ballot] = 1;
}
if (majority_set[prom_info.value_ballot] > server->get_quorum() / 2 + 1) {
return &prom_info;
}
}
}
for (auto && prom_info : rec.promises) {
if (prom_info.iid == -1 )
continue;
if (prom_info.value_ballot != -1) {
if(prom_info.value_ballot > max_ballot) {
max_ballot = prom_info.value_ballot;
pi = &prom_info;
}
}
}
return pi;
}
void leader_t::phase2_check_cb(){
LOG(l::DEBUG, "Leader periodic p2 check at tick " << server->net->now() << "\n");
LOG(l::DEBUG, "No progress from last time, current_iid "<< current_iid <<
" p2info.current_iid " << p2info.current_iid <<"\n");
// TODO leaner should update leader::current_iid
// int x;
// std::cin >> x;
if (current_iid == p2info.current_iid) {
//Check in learner:
//Quorum has my ballot?
// Y -> directly 2a with v (collision)
// N -> (my any was lost?
// another leader?
// no proposer sending value?)
//Restart from p1
// (collect promises and send any/accept)
std::vector<prepare_msg_t> messages;
proposer_record_t * rec = &proposer_array[GET_PRO_INDEX(current_iid)];
MASSERT(rec->iid == current_iid, "phase2_check_cb(): current_iid Mismatch\n");
if(rec->status == p1_finished) {
p1info.ready_count--;
p1info.pending_count++;
rec->status = p1_pending;
}
rec->ballot = BALLOT_NEXT(rec->ballot);
rec->promise_count = 0;
for(unsigned int i = 0; i < rec->promises.size(); ++ i) {
rec->promises[i].iid = -1;
rec->promises[i].value_ballot = -1;
rec->promises[i].value = NULL;
}
messages.emplace_back(rec->iid,rec->ballot);
LOG(l::DEBUG, "Resending prepare for ballot " << rec->ballot << "\n");
server->broadcast<prepare_batch_msg_t>(messages);
}
}
void leader_t::resolve_cflt_send_accept
(proposer_record_t & rec, promise_info_t * pi){
LOG(l::DEBUG, "Leader is resolving conflict for iid: " << rec.iid << " accepted ballot: "
<< rec.ballot << " accepted cid: " << pi->cid <<" rid: " << pi->rid <<"\n");
rec.cid = pi->cid;
rec.rid = pi->rid;
server->broadcast<accept_msg_t>(rec.iid, rec.ballot, VALUE_OWNER(pi->value_ballot), pi->cid, pi->rid, pi->value);
}
void leader_t::execute_phase2(int first_iid, int last_iid) {
int ballot = -1;
promise_info_t* pi = NULL;
std::vector<int> messages;
for(int i = first_iid; i <= last_iid; ++i) {
proposer_record_t &rec = proposer_array[GET_PRO_INDEX(i)];
if (rec.status != p1_ready)
continue;
if ((pi = phase2_getMax_promise(rec)) == NULL) {
if (rec.ballot > ballot) {
ballot = rec.ballot;
}
messages.push_back(i);
}
else {
// TODO resolve conflict
resolve_cflt_send_accept(rec, pi);
}
rec.status = p1_finished;
}
if (!messages.empty()) {
server->broadcast<anyval_batch_msg_t>(messages, ballot);
}
}
void leader_t::handle_promise(const struct promise_msg_t &msg, int acceptor_id, struct proposer_record_t &rec){
//Ignore because there is no info about
//this iid in proposer_array
if(rec.iid != msg.iid) {
LOG(l::DEBUG, "(tick "<< server->net->now() <<")handle_promise: Promise for " << msg.iid << " ignored, no info in array\n");
return;
}
//This promise is not relevant, because
//we are not waiting for promises for instance iid
if(rec.status != p1_pending) {
LOG(l::DEBUG, "(tick "<< server->net->now() <<")handle_promise: Promise for " << msg.iid << " ignored, instance is not p1_pending\n");
return;
}
//This promise is old, or belongs to another
if(rec.ballot != msg.ballot) {
LOG(l::DEBUG, "(tick "<< server->net->now() <<")handle_promise: Promise for " << msg.iid << " ignored, not our ballot\n");
LOG(l::DEBUG, "rec ballot " << rec.ballot << " msg ballot " << msg.ballot << "\n");
return;
}
//Already received this promise
if(rec.promises[acceptor_id].iid != -1 && rec.ballot == msg.ballot) {
LOG(l::DEBUG, "(tick "<< server->net->now() <<")handle_promise: Already received this promise " << server->nid << "\n");
LOG(l::DEBUG, "acceptor_id "<< acceptor_id <<" iid " << rec.promises[acceptor_id].iid <<
" rec.ballot " << rec.ballot <<"\n");
return;
}
rec.promises[acceptor_id] = msg;
rec.promise_count++;
if (rec.promise_count < server->get_quorum()) {
LOG(l::DEBUG, "(tick "<< server->net->now() <<")handle_promise: Quorum not reached, rec ballot "<<
rec.ballot << "msg ballot" << msg.ballot <<"\n");
return;
}
LOG(l::DEBUG, "(tick "<< server->net->now() <<")handle_promise: Quorum reached\n");
// quorum reached.
rec.status = p1_ready;
p1info.pending_count--;
p1info.ready_count++;
if (p1info.highest_ready < rec.iid) {
p1info.highest_ready = rec.iid;
}
if (p1info.last_to_check < rec.iid) {
p1info.last_to_check = rec.iid;
}
return;
}
void leader_t::handle_promise_batch(const struct promise_batch_msg_t &promise_batch_msg) {
int first_iid = promise_batch_msg.messages.front().iid;
int last_iid = promise_batch_msg.messages.back().iid;
proposer_record_t rec;
for (auto prom_msg : promise_batch_msg.messages){
handle_promise(prom_msg, promise_batch_msg.acceptor_id, proposer_array[GET_PRO_INDEX(prom_msg.iid)]);
}
execute_phase2(first_iid, last_iid);
}
void leader_t::do_leader_timeout(phase12_t phase) {
switch (phase){
case phase12_t::phase1:{
if(do_first_TO) {
execute_phase1();
do_first_TO = false;
} else {
// check phase1 cb
phase1_check_cb();
}
phase1_to_tick = PHASE1_TO_TICK;
break;
}
case phase12_t::phase2:{
phase2_check_cb();
phase2_to_tick = PHASE2_TO_TICK;
p2info.current_iid = current_iid;
break;
}
default: {
MASSERT(0, "Phase not recognized in leader timeout.\n Destruct sequence initiated. 3..2..1..run!\n");
}
}
}
void leader_t::leader_deliver_value(int iid) {
current_iid = iid + 1;
p1info.ready_count--;
}
/** proposer functions **/
proposer_t::proposer_t(paxserver *_server) {
server = _server;
fixed_ballot = MAX_PROPOSERS + server->get_nid(); //TODO: add MAX_PROPOSER to config
current_iid = 0;
has_value = false;
}
// handling single submit request at the same time
// TODO(drop the message if already working)
void proposer_t::proposer_submit_value(const struct execute_arg& ex_arg) {
LOG(l::DEBUG, "Execute received from cid " << ex_arg.nid << ",rid " << ex_arg.rid <<" \n");
if(has_value)
LOG(l::DEBUG, "Current working iid" << current_iid << " cid " << current_cid <<",rid " << current_rid <<" \n");
// TODO(goyalankit) UNCOMMENT THIS FOR MULTIPLE CLIENTS
// HANDLE LEARN SHOULD UPDATE
if (has_value) {
// TODO send fail message so that client can send to another proposer
server->net->drop(server,ex_arg,"");
return;
}
// checking for duplicate request from client.
for (auto it = server->exec_rid_cache.begin(), ie = server->exec_rid_cache.end();
it != ie; ++it ){
if (((*it).first == ex_arg.nid) && ((*it).second == ex_arg.rid)) {
server->net->drop(server, ex_arg, "Duplicate Execute Message");
return;
}
}
has_value = true;
last_accept_hash = 1;
last_accept_iid = current_iid;
current_cid = ex_arg.nid;
current_rid = ex_arg.rid;
ti.instance_id = current_iid;
ti.hash = 1; // first_hash
current_request = std::move(ex_arg.request);
server->broadcast<accept_msg_t>(current_iid, fixed_ballot, server->get_nid(), ex_arg.nid, ex_arg.rid, current_request);
}
void proposer_t::do_proposer_timeout() {
//Nothing new since our last accept, retry to send it
if( has_value && ti.instance_id == last_accept_iid && ti.hash == last_accept_hash) {
LOG(l::DEBUG, "S0" << server->nid <<" Instance: " << ti.instance_id <<" timed-out ( " << last_accept_hash << " times)"
", re-sending accept, cid " << current_cid << " rid " << current_rid <<"\n");
last_accept_hash++;
ti.hash = last_accept_hash;
//Resend in same instance
LOG(l::DEBUG, "Proposer: " << server->get_nid() << "\n");
server->broadcast<accept_msg_t>(current_iid, fixed_ballot, server->get_nid(), current_cid, current_rid, current_request);
proposer_to_tick = PROPOSER_TO_TICK;
} else {
LOG(l::DEBUG, "Timeout out-of-date, removed\n");
//Something changed, stop
// (decided or outdated timeout)
// TODO: need to check how to handle this.
//free(ti);
}
}
void proposer_t::exit_if_done() {
bool all_done = true;
// std::cout << "CONDITIONCHECK Server Checking: " << server->get_nid() << std::endl;
for (int i = 1; i < (int)server->get_serv_cnt(server->vc_state.view) ; i++) {
// std::cout << "CONDITIONCHECK " << server->net->learner_request_count[i] << " total " << server->net->num_total_requests << std::endl;
if (server->net->learner_request_count[i] < server->net->num_total_requests) {
all_done = false;
} else {
all_done &= true;
}
}
if (all_done) {
raise(SIGINT);
}
}
void proposer_t::deliver_function(paxobj::request req, int iid, int ballot, node_id_t cid, rid_t rid, int proposer) {
int just_accepted;
if (server->primary()) {
server->leader->leader_deliver_value(iid);
}
just_accepted = current_iid;
current_iid++;
assert(just_accepted == iid);
auto result = server->paxop_on_paxobj(req, cid, rid);
server->net->learner_request_count[server->get_nid()]++;
exit_if_done();
if(!has_value) {
LOG(l::DEBUG, "Value delivered for iid "<< just_accepted << "for client: " << cid << " rid: " << rid <<" accepted, client is not waiting\n");
return;
}
if (has_value && current_cid == cid && current_rid == rid) {
has_value = false;
// Send response back to client
LOG(l::DEBUG, "Sending response back for client: " << cid << " for rid: " << rid << " iid: " << iid << "\n");
auto ex_success = std::make_unique<struct execute_success>(result, rid);
server->send_msg(cid, std::move(ex_success));
} else {
//Send for next instance
LOG(l::DEBUG, "Someone else's value delivered my id" << server->nid <<" (iid: "<< current_iid << "), try next instance.\n");
last_accept_iid = just_accepted;
last_accept_hash++;
server->broadcast<accept_msg_t>(current_iid, fixed_ballot, server->get_nid(), current_cid, current_rid, current_request);
proposer_to_tick = PROPOSER_TO_TICK;
ti.instance_id = current_iid;
ti.hash = last_accept_hash;
}
}
/** acceptor functions **/
acceptor_t::acceptor_t(paxserver *_server){
server = _server;
}
void acceptor_t::apply_accept(acceptor_record_t *rec, const accept_msg_t *amsg) {
//Update record
rec->iid = amsg->iid;
rec->ballot = amsg->ballot;
rec->value_ballot = amsg->ballot;
rec->proposer_id = amsg->proposer_id;
rec->value = amsg->value;
rec->cid = amsg->cid;
rec->rid = amsg->rid;
paxlog_update_record(*rec);
}
void acceptor_t::handle_accept(const struct accept_msg_t& amsg) {
LOG(l::DEBUG, ("Received accept message\n"));
acceptor_record_t* rec;
//Lookup
rec = &acceptor_array[GET_ACC_INDEX(amsg.iid)];
// std::cout << "ACCEPT CID " << amsg.cid << std::endl;
//Found record previously written
if (amsg.iid == rec->iid) {
LOG(l::DEBUG, "|HANDLE_ACCEPT| " << "amsg.iid" << amsg.iid << " rec.iid" << rec->iid << " any"<< rec->any_enabled << "; Ballot: " << amsg.ballot << "; rec->ballot" << rec->ballot << "; Min ballot" << min_ballot<< "\n");
if (rec->any_enabled || (amsg.ballot >= rec->ballot && amsg.ballot >= min_ballot)) {
if (rec->any_enabled) {
rec->any_enabled = 0;
LOG(l::DEBUG, "Accepting value for instance " << amsg.iid << ", any message enabled\n");
} else {
LOG(l::DEBUG, "Accepting value for instance " << amsg.iid << " with ballot "<< amsg.ballot << "\n");
}
apply_accept(rec, &amsg);
server->broadcast<learn_msg_t>(server->nid, rec->iid, rec->ballot,
rec->proposer_id, rec->cid, rec->rid, rec->value );
return;
}
LOG(l::DEBUG, "Ignoring value for instance " << amsg.iid << " with ballot "<< amsg.ballot << "\n");
return;
}
//Record not found in acceptor array
if (amsg.iid > rec->iid) {
if (amsg.ballot >= min_ballot) {
LOG(l::DEBUG, "Accepting value for instance " << amsg.iid << " with ballot, "<< amsg.ballot << " never seen before\n");
apply_accept(rec, &amsg);
server->broadcast<learn_msg_t>(server->nid, rec->iid, rec->ballot,
rec->proposer_id, rec->cid, rec->rid, rec->value );
return;
} else {
LOG(l::DEBUG, "Ignoring value for instance " << amsg.iid << " with ballot "<< amsg.ballot << " never seen before\n");
return;
}
}
//Record was overwritten in acceptor array
//We must scan the logfile before accepting or not
if (amsg.iid < rec->iid) {
rec = paxlog_lookup_record(amsg.iid);
if (rec == NULL) {
if (amsg.ballot >= min_ballot) {
LOG(l::DEBUG, "Accepting value for instance " << amsg.iid << " with ballot, "<< amsg.ballot << " never seen before[infor from disk]\n");
apply_accept(rec, &amsg);
server->broadcast<learn_msg_t>(server->nid, rec->iid, rec->ballot,
rec->proposer_id, rec->cid, rec->rid, rec->value );
return;
} else {
LOG(l::DEBUG, "Ignoring value for instance " << amsg.iid << " with ballot, "<< amsg.ballot << " never seen before[infor from disk]\n");
return;
}
}
if (rec->any_enabled || (amsg.ballot >= rec->ballot && amsg.ballot >= min_ballot)) {
if (rec->any_enabled) {
rec->any_enabled = 0;
LOG(l::DEBUG, "Accepting value for instance " << amsg.iid << ", any message enabled" << "\n");
} else {
LOG(l::DEBUG, "Accepting value for instance " << amsg.iid << " with ballot, "<< amsg.ballot << " never seen before[infor from disk]\n");
}
apply_accept(rec, &amsg);
server->broadcast<learn_msg_t>(server->nid, rec->iid, rec->ballot,
rec->proposer_id, rec->cid, rec->rid, rec->value );
} else {
LOG(l::DEBUG, "Ignoring accept for instance " << amsg.iid << " with ballot, "<< amsg.ballot << " already given to ballot" << rec->ballot << " [infor from disk]\n");
}
delete rec;
}
return;
}
void acceptor_t::paxlog_update_record(acceptor_t::acceptor_record_t &rec) {
(server->paxlog).fastlog(rec.cid, rec.rid, rec.iid, rec.ballot, rec.value_ballot,
rec.value, server->net->now());
}
acceptor_t::acceptor_record_t * acceptor_t::paxlog_lookup_record(int iid) {
const Paxlog::tup* tup = (server->paxlog).get_tup(iid);
if (tup == nullptr) {
return nullptr;
} else {
return (new acceptor_record_t(tup));
}
}
void acceptor_t::apply_anyval(acceptor_record_t * rec, int iid, int ballot) {
//Update record
rec->iid = iid;
rec->ballot = ballot;
rec->value_ballot = -1;
rec->proposer_id = -1;
rec->value = NULL;
rec->any_enabled = 1;
//Write to disk
paxlog_update_record(*rec);
LOG(l::DEBUG, "Anyval for iid: "<< rec->iid << " applied\n" );
}
void acceptor_t::handle_anyval_batch(const struct anyval_batch_msg_t& anyval_msg) {
std::vector<int> iids = anyval_msg.messages;
int ballot = anyval_msg.ballot;
for (int iid : iids) {
// found in array ->
// not in array
// -> new
// -> old
// fetch from disk
// -> found
// -> not found
// found -> check ballot and enabled
// not found -> return 0
acceptor_record_t* rec;
//Lookup
rec = &acceptor_array[GET_ACC_INDEX(iid)];
//Found record previously written
if (iid == rec->iid) {
if (rec->any_enabled || (ballot >= rec->ballot)) {
LOG(l::DEBUG, "Accepting anyval for instance" << iid << " with ballot " << ballot << "\n" );
apply_anyval(rec, iid, ballot);
continue;
}
LOG(l::DEBUG, "Ignoring anyval for instance" << iid << " with ballot " << ballot << "\n" );
continue;
}
//Record not found in acceptor array
if (iid > rec->iid) {
LOG(l::DEBUG, "Accepting anyval for instance" << iid << " with ballot " << ballot << ", never seen before\n" );
apply_anyval(rec, iid, ballot);
continue;
}
//Record was overwritten in acceptor array
//We must scan the logfile before accepting or not
if (iid < rec->iid) {
rec = paxlog_lookup_record(iid);
if (rec == NULL) {
LOG(l::DEBUG, "Accepting anyval for instance" << iid << " with ballot " << ballot << ", never seen before\n" );
apply_anyval(rec, iid, ballot);
continue;
}
if (rec->any_enabled || (ballot >= rec->ballot)) {
LOG(l::DEBUG, "Accepting anyval for instance" << iid << " with ballot " << ballot << " [info from disk]\n" );
apply_anyval(rec, iid, ballot);
} else {
LOG(l::DEBUG, "Ignoring anyval for instance" << iid << " with ballot " << ballot << ", already given to ballot " << rec->ballot << " [info from disk]\n" );
}
delete rec;
continue;
}
continue;
}
return;
}
void acceptor_t::handle_prepare(const struct prepare_msg_t &msg, std::vector<promise_msg_t> &promise_msgs) {
acceptor_t::acceptor_record_t* rec;
rec = &acceptor_array[GET_ACC_INDEX(msg.iid)];
// Handle a new instance,
// possibly get rid of an old instance
if (msg.iid > rec->iid) {
rec->iid = msg.iid;
rec->ballot = msg.ballot;
rec->value_ballot = -1;
rec->value = NULL;
rec->cid = -1;
rec->rid = -1;
//LOG(DBG, ("Promising for instance %d with ballot %d, never seen before\n", msg.iid, msg.ballot));
paxlog_update_record(*rec);
promise_msg_t prom_msg(rec->iid, rec->ballot, rec->value_ballot, rec->cid, rec->rid, rec->value);
promise_msgs.push_back(prom_msg);
return;
}
//Handle a previously written instance
if (msg.iid == rec->iid) {
if (msg.ballot <= rec->ballot) {
LOG(l::DEBUG, "Ignoring prepare for instance " << msg.iid <<" with ballot "
<< msg.ballot <<", already promised to " << rec->ballot << "\n");
return;
}
//Answer if ballot is greater then last one
LOG(l::DEBUG, "Promising for instance " << msg.iid <<" with ballot " <<
msg.ballot << ", previously promised to " << rec->ballot << "\n");
rec->ballot = msg.ballot;
paxlog_update_record(*rec);
promise_msg_t prom_msg(rec->iid, rec->ballot, rec->value_ballot, rec->cid, rec->rid, rec->value);
promise_msgs.push_back(prom_msg);
return;
}
//Record was overwritten in memory, retrieve from disk
if (msg.iid < rec->iid) {
rec = paxlog_lookup_record(msg.iid);
if(rec == NULL) {
//No record on disk
rec = new acceptor_record_t();
rec->iid = msg.iid;
rec->ballot = -1;
rec->value_ballot = -1;
rec->cid = -1;
rec->value = NULL;
}
if(msg.ballot > rec->ballot) {
rec->ballot = msg.ballot;
paxlog_update_record(*rec);
promise_msg_t prom_msg(rec->iid, rec->ballot, rec->value_ballot, rec->cid, rec->rid, rec->value);
promise_msgs.push_back(prom_msg);
} else {
//LOG(DBG, ("Ignoring prepare for instance %d with ballot %d, already promised to %d [info from disk]\n", msg.iid, msg.ballot, rec->ballot));
}
}
if(rec != NULL) {
delete(rec);
}
}
void acceptor_t::handle_prepare_batch(const struct prepare_batch_msg_t& prepare_batch_msg) {
std::vector<prepare_msg_t> messages = prepare_batch_msg.messages;
std::vector<promise_msg_t> promise_msgs;
for (auto prep_msg : messages) {
handle_prepare(prep_msg, promise_msgs);
}
if(!promise_msgs.empty()) {
node_id_t leader_id = server->vc_state.view.primary;
auto promise_msg = std::make_unique<promise_batch_msg_t>(promise_msgs, server->nid);
server->send_msg(leader_id, std::move(promise_msg));
}
}
void acceptor_t::handle_lsync(const learner_sync_msg_t & lsmsg) {
for (auto iid : lsmsg.iids) {
acceptor_record_t* rec;
//Lookup
rec = &acceptor_array[GET_ACC_INDEX(iid)];
//Found record in memory
if (iid == rec->iid) {
//A value was accepted
if (rec->value != NULL) {
LOG(l::DEBUG, "Answering to lsync for instance: " << iid << "\n");
// broadcast learn_msg
server->broadcast<learn_msg_t>(server->get_nid(), rec->iid, rec->ballot, rec->proposer_id, rec->cid, rec->rid, rec->value);
continue;
}
//No value was accepted
LOG(l::DEBUG, "Ignoring lsync for instance: " << iid <<" ,record present but no value accepted\n");
continue;
}
//Record was overwritten in acceptor array
//We must scan the logfile before answering
if (iid < rec->iid) {
rec = paxlog_lookup_record(iid);
//A record was found, we accepted something
if (rec != NULL) {
LOG(l::DEBUG, "Answering to lsync for instance: " << iid <<" [info from disk]\n");
server->broadcast<learn_msg_t>(server->get_nid(), rec->iid, rec->ballot, rec->proposer_id, rec->cid, rec->rid, rec->value);
delete rec;
continue;
} else {
//Nothing from disk, nothing accepted
LOG(l::DEBUG, "Ignoring lsync for instance: " << iid <<" , no value accepted [info from disk]\n");
}
}
//Record not found in acceptor array
//Nothing was accepted
LOG(l::DEBUG, "Ignoring lsync for instance: "<< iid <<" , no info is available\n");
continue;
}
return;
}
/** learner functions **/
learner_t::learner_t(paxserver *_server){
server = _server;
lsync_to_tick = LSYNC_TICK;
for (int i = 0; i < LEARNER_ARRAY_SIZE; i++){
learner_array[i] = {};
learner_array[i].learns.resize(server->get_serv_cnt(server->vc_state.view)+1);
}
}
void learner_t::do_learner_timeout() {
// reset the timer
lsync_to_tick = LSYNC_TICK;
if (highest_seen > highest_delivered) {
learner_record_t* rec;
std::vector<int> lsync_iids;
for(int i = highest_delivered+1; i < highest_seen; i++) {
rec = &learner_array[GET_LEA_INDEX(i)];
//Not closed or never seen, request sync
if((rec->iid == i && !is_closed(rec)) || rec->iid < i) {
LOG(l::DEBUG, "Adding" << i << "to next lsync message" << "\n");
lsync_iids.push_back(i);
}
}
//Flush send buffer if not empty
if(!lsync_iids.empty()) {
server->broadcast<learner_sync_msg_t>(lsync_iids);
LOG(l::DEBUG, "Requested " << lsync_iids.size() <<" lsyncs from " << highest_delivered+1 << " to " << highest_seen << "\n");
}
}
}
int learner_t::add_learn_to_record(learner_record_t *rec, const learn_msg_t* lmsg) {
learn_msg_t * old_learn, * new_learn;
//Check that is in bounds
if(lmsg->acceptor_id < 0 || lmsg->acceptor_id >= (int)(server->get_serv_cnt(server->vc_state.view) + 1)) {
MASSERT(0,"Error: received faulty acceptor_id\n");
LOG(l::DEBUG, "Dropping learn for instance too far in future: " << lmsg->acceptor_id << "\n");
return 0;
}
old_learn = rec->learns[lmsg->acceptor_id];
//First learn from this acceptor for this instance
if(old_learn == NULL) {
//LOG(DBG, "Got first learn for instance:%d, acceptor:%d\n", rec->iid, lmsg->acceptor_id));
//LOG(l::DEBUG, "Accepting anyval for instance" << iid << " with ballot " << ballot << ", never seen before\n" );
new_learn = new learn_msg_t(*lmsg);
rec->learns[lmsg->acceptor_id] = new_learn;
return 1;
}
//This message is old, drop
if(old_learn->ballot >= lmsg->ballot) {
// LOG(DBG, ("Dropping learn for instance:%d, more recent ballot already seen\n", rec->iid));
return 0;
}
//This message is relevant! Overwrite previous learn
// LOG(DBG, ("Overwriting previous learn for instance %d\n", rec->iid));
delete(old_learn);
new_learn = new learn_msg_t (*lmsg);
rec->learns[lmsg->acceptor_id] = new_learn;
return 1;
}
bool learner_t::is_closed(learner_record_t* rec) {
return (rec->final_value != NULL);
}
int learner_t::update_record(const learn_msg_t *lmsg) {
learner_record_t * rec;
//We are late, drop to not overwrite
if(lmsg->iid >= highest_delivered + LEARNER_ARRAY_SIZE) {
LOG(l::DEBUG, "Dropping learn for instance too far in future: " << lmsg->iid << "\n");
return 0;
}
//Already sent to client, drop
if(lmsg->iid <= highest_delivered) {
LOG(l::DEBUG, "Dropping learn for already enqueued instance: " << lmsg->iid << "\n");
return 0;
}
//Retrieve record for this iid
rec = &learner_array[GET_LEA_INDEX(lmsg->iid)];
//First message for this iid
if(rec->iid != lmsg->iid) {
LOG(l::DEBUG, "Received first message for instance: " << lmsg->iid << "\n");
//Clean record
rec->iid = lmsg->iid;
rec->final_value.reset();
for (auto iter = rec->learns.begin(); iter!=rec->learns.end();++iter) {
*iter = NULL;
}
//Add
return add_learn_to_record(rec, lmsg);
//Found record containing some info
} else {
if(is_closed(rec)) {
//LOG(DBG, ("Dropping learn for closed instance:%d\n", lmsg->iid));
return 0;
}
//Add
return add_learn_to_record(rec, lmsg);
}
}
//Checks if we have a quorum and returns 1 if the case
bool learner_t::check_quorum(const learn_msg_t* lmsg) {
unsigned int count = 0;
learner_record_t* rec;
rec = &learner_array[GET_LEA_INDEX(lmsg->iid)];
for (auto && learn : rec->learns) {
//No value
if(learn == NULL)
continue;
//Different value
if(learn->ballot != lmsg->ballot)
continue;
//Same ballot
count++;
}
//Mark as closed, we have a value
if (count >= server->get_quorum()) {
LOG(l::DEBUG, "Reached quorum, instance: " << rec->iid << "is now closed! at server" << server->nid << " \n");
// std::cout << "REACHEDQUORUMINSTANCE " << rec->iid << " for server " << server->nid << " with client " << lmsg->cid << " and rid " << lmsg->rid << " Quorum size " << server->get_quorum() << " Count" << count << std::endl;
rec->ballot = lmsg->ballot;
rec->proposer_id = lmsg->proposer_id;
rec->final_value = lmsg->value;
rec->rid = lmsg->rid;
rec->cid = lmsg->cid;
return true;
}
return false;
}
void learner_t::deliver_values(int iid) {
while(1) {
learner_record_t* rec = &learner_array[GET_LEA_INDEX(iid)];
if(!is_closed(rec)) break;
server->proposer->deliver_function(rec->final_value, rec->iid, rec->ballot, rec->cid, rec->rid, rec->proposer_id);
//void proposer_t::deliver_function(paxobj::request *req, int iid, int ballot, node_id_t cid, rid_t rid, int proposer) {
//delfun(deliver_buffer, rec->final_value_size, instance_id, rec->ballot, rec->proposer_id);
rec->final_value.reset();
highest_delivered = iid;
iid++;
}
}
void learner_t::handle_learn_msg(const struct learn_msg_t& lmsg) {
if (lmsg.iid > highest_seen) {
highest_seen = lmsg.iid;
}
//for each message update instance record
int relevant = update_record(&lmsg);
if(!relevant) {
LOG(l::DEBUG, "Learner discarding learn for instance " << lmsg.iid << "\n");
return;
}
//if quorum reached, close the instance
int closed = check_quorum(&lmsg);
if(!closed) {
LOG(l::DEBUG, "Not yet a quorum for instance " << lmsg.iid << "\n");
return;
}
//If the closed instance is last delivered + 1
if (lmsg.iid == highest_delivered+1) {
deliver_values(lmsg.iid);
}
}