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- // Copyright (c) 2012 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #ifndef DBUS_EXPORTED_OBJECT_H_
- #define DBUS_EXPORTED_OBJECT_H_
- #include <dbus/dbus.h>
- #include <map>
- #include <memory>
- #include <string>
- #include <utility>
- #include "base/callback.h"
- #include "base/memory/ref_counted.h"
- #include "base/synchronization/waitable_event.h"
- #include "base/threading/platform_thread.h"
- #include "base/time/time.h"
- #include "dbus/dbus_export.h"
- #include "dbus/object_path.h"
- namespace dbus {
- class Bus;
- class MethodCall;
- class Response;
- class Signal;
- // ExportedObject is used to export objects and methods to other D-Bus
- // clients.
- //
- // ExportedObject is a ref counted object, to ensure that |this| of the
- // object is alive when callbacks referencing |this| are called.
- class CHROME_DBUS_EXPORT ExportedObject
- : public base::RefCountedThreadSafe<ExportedObject> {
- public:
- // Client code should use Bus::GetExportedObject() instead of this
- // constructor.
- ExportedObject(Bus* bus, const ObjectPath& object_path);
- // Called to send a response from an exported method. |response| is the
- // response message. Callers should pass nullptr in the event of an error that
- // prevents the sending of a response.
- using ResponseSender =
- base::OnceCallback<void(std::unique_ptr<Response> response)>;
- // Called when an exported method is called. |method_call| is the request
- // message. |sender| is the callback that's used to send a response.
- //
- // |method_call| is owned by ExportedObject, hence client code should not
- // delete |method_call|.
- using MethodCallCallback =
- base::RepeatingCallback<void(MethodCall* method_call,
- ResponseSender sender)>;
- // Called when method exporting is done.
- // |success| indicates whether exporting was successful or not.
- using OnExportedCallback =
- base::OnceCallback<void(const std::string& interface_name,
- const std::string& method_name,
- bool success)>;
- // Called when method unexporting is done.
- // |success| indicates whether unexporting was successful or not.
- using OnUnexportedCallback =
- base::OnceCallback<void(const std::string& interface_name,
- const std::string& method_name,
- bool success)>;
- // Exports the method specified by |interface_name| and |method_name|,
- // and blocks until exporting is done. Returns true on success.
- //
- // |method_call_callback| will be called in the origin thread, when the
- // exported method is called. As it's called in the origin thread,
- // |method_callback| can safely reference objects in the origin thread
- // (i.e. UI thread in most cases).
- //
- // IMPORTANT NOTE: You should export all methods before requesting a
- // service name by Bus::RequestOwnership/AndBlock(). If you do it in the
- // wrong order (i.e. request a service name then export methods), there
- // will be a short time period where your service is unable to respond to
- // method calls because these methods aren't yet exposed. This race is a
- // real problem as clients may start calling methods of your service as
- // soon as you acquire a service name, by watching the name owner change.
- //
- // BLOCKING CALL.
- virtual bool ExportMethodAndBlock(
- const std::string& interface_name,
- const std::string& method_name,
- const MethodCallCallback& method_call_callback);
- // Unexports the method specified by |interface_name| and |method_name|,
- // and blocks until unexporting is done. Returns true on success.
- virtual bool UnexportMethodAndBlock(const std::string& interface_name,
- const std::string& method_name);
- // Requests to export the method specified by |interface_name| and
- // |method_name|. See Also ExportMethodAndBlock().
- //
- // |on_exported_callback| is called when the method is exported or
- // failed to be exported, in the origin thread.
- //
- // Must be called in the origin thread.
- virtual void ExportMethod(const std::string& interface_name,
- const std::string& method_name,
- const MethodCallCallback& method_call_callback,
- OnExportedCallback on_exported_callback);
- // Requests to unexport the method specified by |interface_name| and
- // |method_name|. See also UnexportMethodAndBlock().
- //
- // |on_unexported_callback| is called when the method is unexported or
- // failed to be unexported, in the origin thread.
- //
- // Must be called in the origin thread.
- virtual void UnexportMethod(const std::string& interface_name,
- const std::string& method_name,
- OnUnexportedCallback on_unexported_callback);
- // Requests to send the signal from this object. The signal will be sent
- // synchronously if this method is called from the message loop in the D-Bus
- // thread and asynchronously otherwise.
- virtual void SendSignal(Signal* signal);
- // Unregisters the object from the bus. The Bus object will take care of
- // unregistering so you don't have to do this manually.
- //
- // BLOCKING CALL.
- virtual void Unregister();
- protected:
- // This is protected, so we can define sub classes.
- virtual ~ExportedObject();
- private:
- friend class base::RefCountedThreadSafe<ExportedObject>;
- // Helper function for ExportMethod().
- void ExportMethodInternal(const std::string& interface_name,
- const std::string& method_name,
- const MethodCallCallback& method_call_callback,
- OnExportedCallback exported_callback);
- // Helper function for UnexportMethod().
- void UnexportMethodInternal(const std::string& interface_name,
- const std::string& method_name,
- OnUnexportedCallback unexported_callback);
- // Called when the object is exported.
- void OnExported(OnExportedCallback on_exported_callback,
- const std::string& interface_name,
- const std::string& method_name,
- bool success);
- // Called when a method is unexported.
- void OnUnexported(OnExportedCallback on_unexported_callback,
- const std::string& interface_name,
- const std::string& method_name,
- bool success);
- // Helper function for SendSignal().
- void SendSignalInternal(base::TimeTicks start_time,
- DBusMessage* signal_message);
- // Registers this object to the bus.
- // Returns true on success, or the object is already registered.
- //
- // BLOCKING CALL.
- bool Register();
- // Handles the incoming request messages and dispatches to the exported
- // methods.
- DBusHandlerResult HandleMessage(DBusConnection* connection,
- DBusMessage* raw_message);
- // Runs the method. Helper function for HandleMessage().
- void RunMethod(const MethodCallCallback& method_call_callback,
- std::unique_ptr<MethodCall> method_call,
- base::TimeTicks start_time);
- // Callback invoked by service provider to send a response to a method call.
- // Can be called immediately from a MethodCallCallback to implement a
- // synchronous service or called later to implement an asynchronous service.
- void SendResponse(base::TimeTicks start_time,
- std::unique_ptr<MethodCall> method_call,
- std::unique_ptr<Response> response);
- // Called on completion of the method run from SendResponse().
- // Takes ownership of |method_call| and |response|.
- void OnMethodCompleted(std::unique_ptr<MethodCall> method_call,
- std::unique_ptr<Response> response,
- base::TimeTicks start_time);
- // Called when the object is unregistered.
- void OnUnregistered(DBusConnection* connection);
- // Redirects the function call to HandleMessage().
- static DBusHandlerResult HandleMessageThunk(DBusConnection* connection,
- DBusMessage* raw_message,
- void* user_data);
- // Redirects the function call to OnUnregistered().
- static void OnUnregisteredThunk(DBusConnection* connection,
- void* user_data);
- scoped_refptr<Bus> bus_;
- ObjectPath object_path_;
- bool object_is_registered_;
- // The method table where keys are absolute method names (i.e. interface
- // name + method name), and values are the corresponding callbacks.
- typedef std::map<std::string, MethodCallCallback> MethodTable;
- MethodTable method_table_;
- };
- } // namespace dbus
- #endif // DBUS_EXPORTED_OBJECT_H_
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