/*建立一个proposer对象，并启动它*/
struct evproposer* evproposer_init(int id, const char* config, struct event_base* b)
{
int port, acceptor_count;
struct evproposer* p;
/*读取配置文件*/
struct evpaxos_config* conf = evpaxos_config_read(config);
if(conf == NULL)
return NULL;
/*非法的proposer id*/
if (id < 0 || id >= MAX_N_OF_PROPOSERS) {
paxos_log_error("Invalid proposer id: %d", id);
return NULL;
}
/*读取proposer的监听端口*/
port = evpaxos_proposer_listen_port(conf, id);
/*读取acceptor的数量*/
acceptor_count = evpaxos_acceptor_count(conf);
p = (struct evproposer *)malloc(sizeof(struct evproposer));
p->id = id;
p->base = b;
/*获得同时提交的议案数量*/
p->preexec_window = paxos_config.proposer_preexec_window;
/*产生一个网络消息接收器*/
p->receiver = tcp_receiver_new(b, port, handle_request, p);
/*产生一个acceptor的管理器*/
p->acceptors = peers_new(b);
/*对每个acceptor发起连接*/
peers_connect_to_acceptors(p->acceptors, conf, handle_request, p);
/*设置定时器*/
p->tv.tv_sec = paxos_config.proposer_timeout;
p->tv.tv_usec = 0;
/*产生一个libevent定时器事件对象,并设置一个定时器*/
p->timeout_ev = evtimer_new(b, proposer_check_timeouts, p);
event_add(p->timeout_ev, &p->tv);
/*产生一个proposer 消息处理器*/
p->state = proposer_new(p->id, acceptor_count);
/*试探性执行prepare过程(提案第一阶段)*/
proposer_preexecute(p);
evpaxos_config_free(conf);
return p;
}
struct evproposer*
evproposer_init(int id, const char* config_file, struct event_base* b)
{
int i;
struct evproposer* p;
struct config* conf = read_config(config_file); //读取配置文件
if (conf == NULL)
return NULL;
// Check id validity of proposer_id
if (id < 0 || id >= MAX_N_OF_PROPOSERS) { //检查proposerid
paxos_log_error("Invalid proposer id: %d", id);
return NULL;
}
p = malloc(sizeof(struct evproposer));
p->id = id;
p->base = b;
p->preexec_window = paxos_config.proposer_preexec_window; //128
// Setup client listener
p->receiver = tcp_receiver_new(b, &conf->proposers[id], handle_request, p); //创建新的接收器
// Setup connections to acceptors
p->acceptors = peers_new(b, conf->acceptors_count); //连接池
for (i = 0; i < conf->acceptors_count; i++)
peers_connect(p->acceptors, &conf->acceptors[i], handle_request, p); //连接各个acceptor
// Setup timeout
p->tv.tv_sec = paxos_config.proposer_timeout;
p->tv.tv_usec = 0;
p->timeout_ev = evtimer_new(b, proposer_check_timeouts, p);
event_add(p->timeout_ev, &p->tv); //添加超时事件
p->state = proposer_new(p->id, conf->acceptors_count); //创建新的proposer状态机
free_config(conf);
return p;
}