// return type
// 事件循环主函数
int
socket_server_poll(struct socket_server *ss, struct socket_message * result, int * more) {
for (;;) {
// 如果需要监测指令
if (ss->checkctrl) {
// 如果有指令输入
if (has_cmd(ss)) {
// 读入指令并执行对应逻辑
int type = ctrl_cmd(ss, result);
if (type != -1) {
// 正常执行
clear_closed_event(ss, result, type);
return type;
} else
continue;
} else {
ss->checkctrl = 0;
}
}
if (ss->event_index == ss->event_n) {
// 如果事件循环无可读事件，等待新的事件产生
// 同时打开指令监测标识
ss->event_n = sp_wait(ss->event_fd, ss->ev, MAX_EVENT);
ss->checkctrl = 1;
if (more) {
*more = 0;
}
ss->event_index = 0;
if (ss->event_n <= 0) {
ss->event_n = 0;
return -1;
}
}
// 读取一个事件
struct event *e = &ss->ev[ss->event_index++];
struct socket *s = e->s;
if (s == NULL) {
// dispatch pipe message at beginning
continue;
}
switch (s->type) {
case SOCKET_TYPE_CONNECTING:
// 返回 SOCKET_OPEN，修改socket为CONNECTED类型
return report_connect(ss, s, result);
case SOCKET_TYPE_LISTEN: {
// 返回 SOCKET_ACCEPT，生成被动套接字
int ok = report_accept(ss, s, result);
if (ok > 0) {
return SOCKET_ACCEPT;
} if (ok < 0 ) {
return SOCKET_ERROR;
}
// when ok == 0, retry
break;
}
case SOCKET_TYPE_INVALID:
fprintf(stderr, "socket-server: invalid socket\n");
break;
default:
// 读取数据
if (e->read) {
// 如果事件可读
int type;
// forward_message_tcp/udp 正常返回 SOCKET_DATA
if (s->protocol == PROTOCOL_TCP) {
type = forward_message_tcp(ss, s, result);
} else {
type = forward_message_udp(ss, s, result);
if (type == SOCKET_UDP) {
// try read again
--ss->event_index;
return SOCKET_UDP;
}
}
if (e->write && type != SOCKET_CLOSE && type != SOCKET_ERROR) {
// 如果同时可写，回滚索引关闭可写标识，等待下一次循环进入可写逻辑
// Try to dispatch write message next step if write flag set.
e->read = false;
--ss->event_index;
}
if (type == -1)
break;
return type;
}
// 写入数据
if (e->write) {
// 如果事件可写
// 发送链表缓冲区数据
int type = send_buffer(ss, s, result);
if (type == -1)
break;
return type;
}
break;
}
}
}
// return type
int
socket_server_poll(struct socket_server *ss, struct socket_message * result, int * more) {
for (;;) {
if (ss->checkctrl) {
if (has_cmd(ss)) {
int type = ctrl_cmd(ss, result);
if (type != -1) {
clear_closed_event(ss, result, type);
return type;
} else
continue;
} else {
ss->checkctrl = 0;
}
}
if (ss->event_index == ss->event_n) {
ss->event_n = sp_wait(ss->event_fd, ss->ev, MAX_EVENT);
ss->checkctrl = 1;
if (more) {
*more = 0;
}
ss->event_index = 0;
if (ss->event_n <= 0) {
ss->event_n = 0;
return -1;
}
}
struct event *e = &ss->ev[ss->event_index++];
struct socket *s = e->s;
if (s == NULL) {
// dispatch pipe message at beginning
continue;
}
switch (s->type) {
case SOCKET_TYPE_CONNECTING:
return report_connect(ss, s, result);
case SOCKET_TYPE_LISTEN:
if (report_accept(ss, s, result)) {
return SOCKET_ACCEPT;
}
break;
case SOCKET_TYPE_INVALID:
fprintf(stderr, "socket-server: invalid socket\n");
break;
default:
if (e->read) {
int type;
if (s->protocol == PROTOCOL_TCP) {
type = forward_message_tcp(ss, s, result);
} else {
type = forward_message_udp(ss, s, result);
if (type == SOCKET_UDP) {
// try read again
--ss->event_index;
return SOCKET_UDP;
}
}
if (e->write) {
// Try to dispatch write message next step if write flag set.
e->read = false;
--ss->event_index;
}
if (type == -1)
break;
clear_closed_event(ss, result, type);
return type;
}
if (e->write) {
int type = send_buffer(ss, s, result);
if (type == -1)
break;
clear_closed_event(ss, result, type);
return type;
}
break;
}
}
}