1.监听用户移除signal

//src\webserver_run.cpp
int run()
{...bmcweb::registerUserRemovedSignal();...
}

//include\user_monitor.hpp
inline void onUserRemoved(sdbusplus::message_t& msg)
{sdbusplus::message::object_path p;msg.read(p);std::string username = p.filename();persistent_data::SessionStore::getInstance().removeSessionsByUsername(username);
}inline void registerUserRemovedSignal()
{std::string userRemovedMatchStr =sdbusplus::bus::match::rules::interfacesRemoved("/xyz/openbmc_project/user");static sdbusplus::bus::match_t userRemovedMatch(*crow::connections::systemBus, userRemovedMatchStr, onUserRemoved);
}

关于注册signal，可以参考

sdbusplus：监听属性的变化_sdbusplus::bus::match::match-CSDN博客

这部分的作用是当发现某个用户被移除后，删除该用户的session

session部分后续再介绍

2.app.run获取socket

//src\webserver_run.cpp
int run()
{...app.run();systemBus->request_name("xyz.openbmc_project.bmcweb");io.run();crow::connections::systemBus = nullptr;return 0;
}

 其中app.run的定义如下：

//http\app.hpp
void run()
{validate();std::vector<Acceptor> acceptors = setupSocket();server.emplace(this, std::move(acceptors));server->run();
}

 validate();是用于检验route，这个后续跟路由一起解释

//http\http_server.hpp
struct Acceptor
{boost::asio::ip::tcp::acceptor acceptor;HttpType httpType;
};

//http\http_connect_types.hpp
enum class HttpType
{HTTPS, // Socket supports HTTPS onlyHTTP,  // Socket supports HTTP onlyBOTH   // Socket supports both HTTPS and HTTP, with HTTP Redirect
};

static std::vector<Acceptor> setupSocket() 的作用是获取socket，这个后续再详细解释

 3.app.run构造server对象

//http\http_server.hpp
template <typename Handler, typename Adaptor = boost::asio::ip::tcp::socket>
class Server
{
public:Server(Handler* handlerIn, std::vector<Acceptor>&& acceptorsIn) :acceptors(std::move(acceptorsIn)),// NOLINTNEXTLINE(misc-include-cleaner)signals(getIoContext(), SIGINT, SIGTERM, SIGHUP), handler(handlerIn){}...
private:std::vector<Acceptor> acceptors;Handler* handler;
}

OpenBMC：BmcWeb实例化App-CSDN博客

介绍了server类，但是当时没有构造server类的实例，

构造server类的实例是在app.run中

server.emplace(this, std::move(acceptors));完成的

将App做为handle传入Server，用于反向指回app对象

将setupSocket()获取的socket也传入了Server，用于后续接受连接请求。