//Opens instances at the "end" of the proposer state array
//Those instances were not opened before
static void
leader_open_instances_p1() {
int active_count = p1_info.pending_count + p1_info.ready_count;
assert(active_count >= 0);
if(inf_prepare_info.status == empty) {
//Ask for infinite p1 instances
//Create an empty prepare batch in send buffer
sendbuf_clear(to_acceptors, prepare_reqs, this_proposer_id);
//Send prepare to acceptors
sendbuf_add_prepare_req(to_acceptors, INF_PREPARE_REQ, FIRST_BALLOT);
//Send if something is still there
sendbuf_flush(to_acceptors);
//Keep track of pending count
inf_prepare_info.status = p1_pending;
inf_prepare_info.my_ballot = FIRST_BALLOT;
LOG(DBG, ("Opened %d new instances\n", 1));
return;
}
}
/*发送prepare_req到所有的acceptor进行第一阶段的提议*/
static void send_prepares(struct evproposer* p, prepare_req* pr)
{
int i;
for(i = 0; i < peers_count(p->acceptors); i ++){
struct bufferevent* bev = peers_get_buffer(p->acceptors, i);
sendbuf_add_prepare_req(bev, pr);
}
}
static void
leader_check_p1_pending() {
iid_t iid_iterator;
p_inst_info * ii;
//Create an empty prepare batch in send buffer
sendbuf_clear(to_acceptors, prepare_reqs, this_proposer_id);
LOG(DBG, ("Checking pending phase 1 from %lu to %lu\n",
current_iid, p1_info.highest_open));
//Get current time for checking expired
struct timeval time_now;
gettimeofday(&time_now, NULL);
for(iid_iterator = current_iid;
iid_iterator <= p1_info.highest_open; iid_iterator++) {
//Get instance from state array
ii = GET_PRO_INSTANCE(iid_iterator);
assert(ii->iid == iid_iterator);
//Still pending -> it's expired
if(ii->status == p1_pending && leader_is_expired(&ii->timeout, &time_now)) {
LOG(DBG, ("Phase 1 of instance %ld expired!\n", ii->iid));
//Reset fields used for previous phase 1
ii->promises_bitvector = 0;
ii->promises_count = 0;
ii->p1_value_ballot = 0;
if(ii->p1_value != NULL) {
PAX_FREE(ii->p1_value);
}
ii->p1_value = NULL;
//Ballot is incremented
ii->my_ballot = NEXT_BALLOT(ii->my_ballot);
//Send prepare to acceptors
sendbuf_add_prepare_req(to_acceptors, ii->iid, ii->my_ballot);
leader_set_expiration(ii, P1_TIMEOUT_INTERVAL);
COUNT_EVENT(p1_timeout);
}
}
//Send if something is still there
sendbuf_flush(to_acceptors);
}
static void
leader_periodic_p2_check(int fd, short event, void *arg) {
UNUSED_ARG(fd);
UNUSED_ARG(event);
UNUSED_ARG(arg);
// create a prepare batch for expired instances
sendbuf_clear(to_acceptors, prepare_reqs, this_proposer_id);
struct timeval now;
gettimeofday(&now, NULL);
// from current to highest open, check deadline
// if instances in status p2_pending
iid_t i;
p_inst_info * ii;
for(i = current_iid; i < p2_info.next_unused_iid; i++) {
ii = GET_PRO_INSTANCE(i);
//Not p2_pending, skip
if(ii->status != p2_pending) {
continue;
}
//Check if it was closed in the meanwhile
// (but not delivered yet)
if(learner_is_closed(i)) {
ii->status = p2_completed;
p2_info.open_count -= 1;
//The rest (i.e. answering client)
// is done when the value is actually delivered
LOG(VRB, ("Instance %lu closed, waiting for deliver\n", i));
continue;
}
//Not expired yet, skip
if(!leader_is_expired(&ii->timeout, &now)) {
continue;
}
//Expired and not closed: must restart from phase 1
ii->status = p1_pending;
p1_info.pending_count += 1;
ii->my_ballot = NEXT_BALLOT(ii->my_ballot);
//Send prepare to acceptors
sendbuf_add_prepare_req(to_acceptors, ii->iid, ii->my_ballot);
leader_set_expiration(ii, P1_TIMEOUT_INTERVAL);
LOG(VRB, ("Instance %lu restarts from phase 1\n", i));
COUNT_EVENT(p2_timeout);
}
//Flush last message if any
sendbuf_flush(to_acceptors);
//Open new instances
leader_open_instances_p2_new();
//Set next invokation of this function
leader_set_next_p2_check();
}