MMORPG大型游戏设计与开发（part3 of net）

这一部分需要向大家介绍的是服务器的select以及收发包的具体流程，从核心代码功能上分析网络交互具体过程。

　　首先大家要看第二部分（part2 of net）的代码结构图，因为在接下来的流程过程中会用到其中模块的名称，若是不知道大致的功能那么接下来的解说可能就成为天书了。

　　总体流程为：服务器管理器初始化并创建主套接字连接，进入主循环等待新连接（select），如果有新的连接则将新连接加入连接管理器。不管有没有新的连接，循环会依次处理连接的异常->输入流->输出流->命令处理。其中异常即连接包发送错误的处理，输入流即套接字输入流中如果大小长度不为空则重新拼接包，输出流进行包的拼接，并将未发送的流进行发送，命令处理其实是对输入流的处理，处理（handler）发送过来的包。

　　以下详细说明这几个流程从代码上的实现，以及所在的模块。

　　1、  服务器管理器初始化（servermanager）

bool ServerManager::init() { __ENTER_FUNCTION serversocket_ = new pap_server_common_net::Socket(g_config.billing_info_.port_); Assert(serversocket_); serversocket_->set_nonblocking(); socketid_ = serversocket_->getid(); Assert(socketid_ != SOCKET_INVALID); FD_SET(socketid_, &readfds_[kSelectFull]); FD_SET(socketid_, &exceptfds_[kSelectFull]); minfd_ = maxfd_ = socketid_; timeout_[kSelectFull].tv_sec = 0; timeout_[kSelectFull].tv_usec = 0; threadid_ = pap_common_sys::get_current_thread_id(); uint16_t i; for (i = 0; i < OVER_SERVER_MAX; ++i) { serverhash_[i] = ID_INVALID; } return true; __LEAVE_FUNCTION return false; }

　　2、  服务器管理器进入主循环（servermanager）

 

void ServerManager::loop() { __ENTER_FUNCTION while (isactive()) { bool result = false; try { result = select(); Assert(result); //ERRORPRINTF("select"); result = processexception(); Assert(result); //ERRORPRINTF("processexception"); result = processinput(); Assert(result); //ERRORPRINTF("processinput"); result = processoutput(); Assert(result); //ERRORPRINTF("processoutput");  } catch(...) { } try { result = processcommand(); Assert(result); //ERRORPRINTF("processcommand");  } catch(...) { } try { result = heartbeat(); Assert(result); } catch(...) { } } __LEAVE_FUNCTION }

loop

 

　　3、  服务器线程进入select模式

 

bool ServerManager::select() { __ENTER_FUNCTION timeout_[kSelectUse].tv_sec = timeout_[kSelectFull].tv_sec; timeout_[kSelectUse].tv_usec = timeout_[kSelectFull].tv_usec; readfds_[kSelectUse] = readfds_[kSelectFull]; writefds_[kSelectUse] = writefds_[kSelectFull]; exceptfds_[kSelectUse] = exceptfds_[kSelectFull]; pap_common_base::util::sleep(100); int32_t result = SOCKET_ERROR; try { result = pap_common_net::socket::Base::select( maxfd_ + 1, &readfds_[kSelectUse], &writefds_[kSelectUse], &exceptfds_[kSelectUse], &timeout_[kSelectUse]); Assert(result != SOCKET_ERROR); } catch(...) { g_log->fast_save_log(kBillingLogFile, "ServerManager::select have error, result: %d", result); } return true; __LEAVE_FUNCTION return false; }

select

 

　　4、  服务器线程进行异常处理

 

bool ServerManager::processexception() { __ENTER_FUNCTION if (SOCKET_INVALID == minfd_ && SOCKET_INVALID == maxfd_) return true; uint16_t connectioncount = billingconnection::Manager::getcount(); billingconnection::Server* serverconnection = NULL; uint16_t i; for (i = 0; i < connectioncount; ++i) { if (ID_INVALID == connectionids_[i]) continue; serverconnection = g_connectionpool->get(connectionids_[i]); Assert(serverconnection); int32_t socketid = serverconnection->getsocket()->getid(); if (socketid_ == socketid) { Assert(false); continue; } if (FD_ISSET(socketid, &exceptfds_[kSelectUse])) { removeconnection(serverconnection); } } return true; __LEAVE_FUNCTION return false; }

processexception

 

　　5、  服务器线程进行输入流处理

 

bool ServerManager::processinput() { __ENTER_FUNCTION if (SOCKET_INVALID == minfd_ && SOCKET_INVALID == maxfd_) return true; //no connection  uint16_t i; if (FD_ISSET(socketid_, &readfds_[kSelectUse])) { for (i = 0; i < kOneStepAccept; ++i) { if (!accept_newconnection()) break; } } uint16_t connectioncount = billingconnection::Manager::getcount(); for (i = 0; i < connectioncount; ++i) { if (ID_INVALID == connectionids_[i]) continue; billingconnection::Server* serverconnection = NULL; serverconnection = g_connectionpool->get(connectionids_[i]); Assert(serverconnection); int32_t socketid = serverconnection->getsocket()->getid(); if (socketid_ == socketid) continue; if (FD_ISSET(socketid, &readfds_[kSelectUse])) { //read information if (serverconnection->getsocket()->iserror()) { removeconnection(serverconnection); } else { try { if (!serverconnection->processinput()) removeconnection(serverconnection); } catch(...) { removeconnection(serverconnection); } } } } return true; __LEAVE_FUNCTION return false; }

processinput

 

　　6、  服务器线程进行输出流处理

 

bool ServerManager::processoutput() { __ENTER_FUNCTION if (SOCKET_INVALID == maxfd_&& SOCKET_INVALID == minfd_) return false; uint16_t i; uint16_t connectioncount = billingconnection::Manager::getcount(); for (i = 0; i < connectioncount; ++i) { if (ID_INVALID == connectionids_[i]) continue; billingconnection::Server* serverconnection = NULL; serverconnection = g_connectionpool->get(connectionids_[i]); Assert(serverconnection); int32_t socketid = serverconnection->getsocket()->getid(); if (socketid_ == socketid) continue; if (FD_ISSET(socketid, &writefds_[kSelectUse])) { if (serverconnection->getsocket()->iserror()) { removeconnection(serverconnection); } else { try { if (!serverconnection->processoutput()) removeconnection(serverconnection); } catch(...) { removeconnection(serverconnection); } } } } return true; __LEAVE_FUNCTION return false; }

processoutput

 

　　7、  服务器线程进行命令处理

bool ServerManager::processcommand() { __ENTER_FUNCTION if (SOCKET_INVALID == maxfd_&& SOCKET_INVALID == minfd_) return false; uint16_t i; uint16_t connectioncount = billingconnection::Manager::getcount(); for (i = 0; i < connectioncount; ++i) { if (ID_INVALID == connectionids_[i]) continue; billingconnection::Server* serverconnection = NULL; serverconnection = g_connectionpool->get(connectionids_[i]); //serverconnection = &billing_serverconnection_;  Assert(serverconnection); int32_t socketid = serverconnection->getsocket()->getid(); if (socketid_ == socketid) continue; if (serverconnection->getsocket()->iserror()) { removeconnection(serverconnection); } else { //connection is ok try { if (!serverconnection->processcommand(false)) removeconnection(serverconnection); } catch(...) { removeconnection(serverconnection); } } } return true; __LEAVE_FUNCTION return false; }

processcommand

 

　　下一部分，我将讲解在网络部分一些重要的代码块。