From 84c497292a27d75b83305d053e734ab5659ffe41 Mon Sep 17 00:00:00 2001 From: Yuri Kunde Schlesner Date: Tue, 6 Jun 2017 21:20:52 -0700 Subject: Service: Add new ServiceFramework framework for writing HLE services The old "Interface" class had a few problems such as using free functions (Which didn't allow you to write the service handler as if it were a regular class.) which weren't very extensible. (Only received one parameter with a pointer to the Interface object.) The new ServiceFramework aims to solve these problems by working with member functions and passing a generic context struct as parameter. This struct can be extended in the future without having to update all existing service implementations. --- src/core/hle/service/service.h | 150 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) (limited to 'src/core/hle/service/service.h') diff --git a/src/core/hle/service/service.h b/src/core/hle/service/service.h index 8933d57cc..281ff99bb 100644 --- a/src/core/hle/service/service.h +++ b/src/core/hle/service/service.h @@ -18,11 +18,16 @@ namespace Kernel { class ClientPort; +class ServerPort; class ServerSession; } namespace Service { +namespace SM { +class ServiceManager; +} + static const int kMaxPortSize = 8; ///< Maximum size of a port name (8 characters) /// Arbitrary default number of maximum connections to an HLE service. static const u32 DefaultMaxSessions = 10; @@ -30,6 +35,9 @@ static const u32 DefaultMaxSessions = 10; /** * Framework for implementing HLE service handlers which dispatch incoming SyncRequests based on a * table mapping header ids to handler functions. + * + * @deprecated Use ServiceFramework for new services instead. It allows services to be stateful and + * is more extensible going forward. */ class Interface : public Kernel::SessionRequestHandler { public: @@ -101,6 +109,146 @@ private: boost::container::flat_map m_functions; }; +/** + * This is an non-templated base of ServiceFramework to reduce code bloat and compilation times, it + * is not meant to be used directly. + * + * @see ServiceFramework + */ +class ServiceFrameworkBase : public Kernel::SessionRequestHandler { +public: + /// Returns the string identifier used to connect to the service. + std::string GetServiceName() const { + return service_name; + } + + /** + * Returns the maximum number of sessions that can be connected to this service at the same + * time. + */ + u32 GetMaxSessions() const { + return max_sessions; + } + + /// Creates a port pair and registers this service with the given ServiceManager. + void InstallAsService(SM::ServiceManager& service_manager); + /// Creates a port pair and registers it on the kernel's global port registry. + void InstallAsNamedPort(); + + void HandleSyncRequest(Kernel::SharedPtr server_session) override; + +protected: + /// Member-function pointer type of SyncRequest handlers. + template + using HandlerFnP = void (Self::*)(Kernel::HLERequestContext&); + +private: + template + friend class ServiceFramework; + + struct FunctionInfoBase { + u32 expected_header; + HandlerFnP handler_callback; + const char* name; + }; + + using InvokerFn = void(ServiceFrameworkBase* object, HandlerFnP member, + Kernel::HLERequestContext& ctx); + + ServiceFrameworkBase(const char* service_name, u32 max_sessions, InvokerFn* handler_invoker); + ~ServiceFrameworkBase(); + + void RegisterHandlersBase(const FunctionInfoBase* functions, size_t n); + void ReportUnimplementedFunction(u32* cmd_buf, const FunctionInfoBase* info); + + /// Identifier string used to connect to the service. + std::string service_name; + /// Maximum number of concurrent sessions that this service can handle. + u32 max_sessions; + + /** + * Port where incoming connections will be received. Only created when InstallAsService() or + * InstallAsNamedPort() are called. + */ + Kernel::SharedPtr port; + + /// Function used to safely up-cast pointers to the derived class before invoking a handler. + InvokerFn* handler_invoker; + boost::container::flat_map handlers; +}; + +/** + * Framework for implementing HLE services. Dispatches on the header id of incoming SyncRequests + * based on a table mapping header ids to handler functions. Service implementations should inherit + * from ServiceFramework using the CRTP (`class Foo : public ServiceFramework { ... };`) and + * populate it with handlers by calling #RegisterHandlers. + * + * In order to avoid duplicating code in the binary and exposing too many implementation details in + * the header, this class is split into a non-templated base (ServiceFrameworkBase) and a template + * deriving from it (ServiceFramework). The functions in this class will mostly only erase the type + * of the passed in function pointers and then delegate the actual work to the implementation in the + * base class. + */ +template +class ServiceFramework : public ServiceFrameworkBase { +protected: + /// Contains information about a request type which is handled by the service. + struct FunctionInfo : FunctionInfoBase { + // TODO(yuriks): This function could be constexpr, but clang is the only compiler that + // doesn't emit an ICE or a wrong diagnostic because of the static_cast. + + /** + * Constructs a FunctionInfo for a function. + * + * @param expected_header request header in the command buffer which will trigger dispatch + * to this handler + * @param handler_callback member function in this service which will be called to handle + * the request + * @param name human-friendly name for the request. Used mostly for logging purposes. + */ + FunctionInfo(u32 expected_header, HandlerFnP handler_callback, const char* name) + : FunctionInfoBase{ + expected_header, + // Type-erase member function pointer by casting it down to the base class. + static_cast>(handler_callback), name} {} + }; + + /** + * Initializes the handler with no functions installed. + * @param max_sessions Maximum number of sessions that can be + * connected to this service at the same time. + */ + ServiceFramework(const char* service_name, u32 max_sessions = DefaultMaxSessions) + : ServiceFrameworkBase(service_name, max_sessions, Invoker) {} + + /// Registers handlers in the service. + template + void RegisterHandlers(const FunctionInfo (&functions)[N]) { + RegisterHandlers(functions, N); + } + + /** + * Registers handlers in the service. Usually prefer using the other RegisterHandlers + * overload in order to avoid needing to specify the array size. + */ + void RegisterHandlers(const FunctionInfo* functions, size_t n) { + RegisterHandlersBase(functions, n); + } + +private: + /** + * This function is used to allow invocation of pointers to handlers stored in the base class + * without needing to expose the type of this derived class. Pointers-to-member may require a + * fixup when being up or downcast, and thus code that does that needs to know the concrete type + * of the derived class in order to invoke one of it's functions through a pointer. + */ + static void Invoker(ServiceFrameworkBase* object, HandlerFnP member, + Kernel::HLERequestContext& ctx) { + // Cast back up to our original types and call the member function + (static_cast(object)->*static_cast>(member))(ctx); + } +}; + /// Initialize ServiceManager void Init(); @@ -110,6 +258,8 @@ void Shutdown(); /// Map of named ports managed by the kernel, which can be retrieved using the ConnectToPort SVC. extern std::unordered_map> g_kernel_named_ports; +/// Adds a port to the named port table +void AddNamedPort(std::string name, Kernel::SharedPtr port); /// Adds a service to the services table void AddService(Interface* interface_); -- cgit v1.2.3