| // 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. |
| |
| #include "dbus/exported_object.h" |
| |
| #include <stdint.h> |
| #include <utility> |
| |
| #include "base/bind.h" |
| #include "base/logging.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "base/task_runner.h" |
| #include "base/threading/thread_restrictions.h" |
| #include "base/time/time.h" |
| #include "dbus/bus.h" |
| #include "dbus/message.h" |
| #include "dbus/object_path.h" |
| #include "dbus/scoped_dbus_error.h" |
| #include "dbus/util.h" |
| |
| namespace dbus { |
| |
| namespace { |
| |
| // Used for success ratio histograms. 1 for success, 0 for failure. |
| const int kSuccessRatioHistogramMaxValue = 2; |
| |
| } // namespace |
| |
| ExportedObject::ExportedObject(Bus* bus, |
| const ObjectPath& object_path) |
| : bus_(bus), |
| object_path_(object_path), |
| object_is_registered_(false) { |
| LOG_IF(FATAL, !object_path_.IsValid()) << object_path_.value(); |
| } |
| |
| ExportedObject::~ExportedObject() { |
| DCHECK(!object_is_registered_); |
| } |
| |
| bool ExportedObject::ExportMethodAndBlock( |
| const std::string& interface_name, |
| const std::string& method_name, |
| MethodCallCallback method_call_callback) { |
| bus_->AssertOnDBusThread(); |
| |
| // Check if the method is already exported. |
| const std::string absolute_method_name = |
| GetAbsoluteMemberName(interface_name, method_name); |
| if (method_table_.find(absolute_method_name) != method_table_.end()) { |
| LOG(ERROR) << absolute_method_name << " is already exported"; |
| return false; |
| } |
| |
| if (!bus_->Connect()) |
| return false; |
| if (!bus_->SetUpAsyncOperations()) |
| return false; |
| if (!Register()) |
| return false; |
| |
| // Add the method callback to the method table. |
| method_table_[absolute_method_name] = method_call_callback; |
| |
| return true; |
| } |
| |
| bool ExportedObject::UnexportMethodAndBlock(const std::string& interface_name, |
| const std::string& method_name) { |
| bus_->AssertOnDBusThread(); |
| |
| const std::string absolute_method_name = |
| GetAbsoluteMemberName(interface_name, method_name); |
| MethodTable::const_iterator iter = method_table_.find(absolute_method_name); |
| if (iter == method_table_.end()) { |
| LOG(ERROR) << absolute_method_name << " is not exported"; |
| return false; |
| } |
| |
| method_table_.erase(iter); |
| |
| return true; |
| } |
| |
| void ExportedObject::ExportMethod(const std::string& interface_name, |
| const std::string& method_name, |
| MethodCallCallback method_call_callback, |
| OnExportedCallback on_exported_calback) { |
| bus_->AssertOnOriginThread(); |
| |
| base::Closure task = base::Bind(&ExportedObject::ExportMethodInternal, |
| this, |
| interface_name, |
| method_name, |
| method_call_callback, |
| on_exported_calback); |
| bus_->GetDBusTaskRunner()->PostTask(FROM_HERE, task); |
| } |
| |
| void ExportedObject::UnexportMethod( |
| const std::string& interface_name, |
| const std::string& method_name, |
| OnUnexportedCallback on_unexported_calback) { |
| bus_->AssertOnOriginThread(); |
| |
| base::Closure task = |
| base::Bind(&ExportedObject::UnexportMethodInternal, this, interface_name, |
| method_name, on_unexported_calback); |
| bus_->GetDBusTaskRunner()->PostTask(FROM_HERE, task); |
| } |
| |
| void ExportedObject::SendSignal(Signal* signal) { |
| // For signals, the object path should be set to the path to the sender |
| // object, which is this exported object here. |
| CHECK(signal->SetPath(object_path_)); |
| |
| // Increment the reference count so we can safely reference the |
| // underlying signal message until the signal sending is complete. This |
| // will be unref'ed in SendSignalInternal(). |
| DBusMessage* signal_message = signal->raw_message(); |
| dbus_message_ref(signal_message); |
| |
| const base::TimeTicks start_time = base::TimeTicks::Now(); |
| if (bus_->GetDBusTaskRunner()->RunsTasksInCurrentSequence()) { |
| // The Chrome OS power manager doesn't use a dedicated TaskRunner for |
| // sending DBus messages. Sending signals asynchronously can cause an |
| // inversion in the message order if the power manager calls |
| // ObjectProxy::CallMethodAndBlock() before going back to the top level of |
| // the MessageLoop: crbug.com/472361. |
| SendSignalInternal(start_time, signal_message); |
| } else { |
| bus_->GetDBusTaskRunner()->PostTask( |
| FROM_HERE, base::BindOnce(&ExportedObject::SendSignalInternal, this, |
| start_time, signal_message)); |
| } |
| } |
| |
| void ExportedObject::Unregister() { |
| bus_->AssertOnDBusThread(); |
| |
| if (!object_is_registered_) |
| return; |
| |
| bus_->UnregisterObjectPath(object_path_); |
| object_is_registered_ = false; |
| } |
| |
| void ExportedObject::ExportMethodInternal( |
| const std::string& interface_name, |
| const std::string& method_name, |
| MethodCallCallback method_call_callback, |
| OnExportedCallback on_exported_calback) { |
| bus_->AssertOnDBusThread(); |
| |
| const bool success = ExportMethodAndBlock(interface_name, |
| method_name, |
| method_call_callback); |
| bus_->GetOriginTaskRunner()->PostTask( |
| FROM_HERE, |
| base::BindOnce(&ExportedObject::OnExported, this, on_exported_calback, |
| interface_name, method_name, success)); |
| } |
| |
| void ExportedObject::UnexportMethodInternal( |
| const std::string& interface_name, |
| const std::string& method_name, |
| OnUnexportedCallback on_unexported_calback) { |
| bus_->AssertOnDBusThread(); |
| |
| const bool success = UnexportMethodAndBlock(interface_name, method_name); |
| bus_->GetOriginTaskRunner()->PostTask( |
| FROM_HERE, |
| base::BindOnce(&ExportedObject::OnUnexported, this, on_unexported_calback, |
| interface_name, method_name, success)); |
| } |
| |
| void ExportedObject::OnExported(OnExportedCallback on_exported_callback, |
| const std::string& interface_name, |
| const std::string& method_name, |
| bool success) { |
| bus_->AssertOnOriginThread(); |
| |
| on_exported_callback.Run(interface_name, method_name, success); |
| } |
| |
| void ExportedObject::OnUnexported(OnExportedCallback on_unexported_callback, |
| const std::string& interface_name, |
| const std::string& method_name, |
| bool success) { |
| bus_->AssertOnOriginThread(); |
| |
| on_unexported_callback.Run(interface_name, method_name, success); |
| } |
| |
| void ExportedObject::SendSignalInternal(base::TimeTicks start_time, |
| DBusMessage* signal_message) { |
| uint32_t serial = 0; |
| bus_->Send(signal_message, &serial); |
| dbus_message_unref(signal_message); |
| // Record time spent to send the the signal. This is not accurate as the |
| // signal will actually be sent from the next run of the message loop, |
| // but we can at least tell the number of signals sent. |
| UMA_HISTOGRAM_TIMES("DBus.SignalSendTime", |
| base::TimeTicks::Now() - start_time); |
| } |
| |
| bool ExportedObject::Register() { |
| bus_->AssertOnDBusThread(); |
| |
| if (object_is_registered_) |
| return true; |
| |
| ScopedDBusError error; |
| |
| DBusObjectPathVTable vtable = {}; |
| vtable.message_function = &ExportedObject::HandleMessageThunk; |
| vtable.unregister_function = &ExportedObject::OnUnregisteredThunk; |
| const bool success = bus_->TryRegisterObjectPath(object_path_, |
| &vtable, |
| this, |
| error.get()); |
| if (!success) { |
| LOG(ERROR) << "Failed to register the object: " << object_path_.value() |
| << ": " << (error.is_set() ? error.message() : ""); |
| return false; |
| } |
| |
| object_is_registered_ = true; |
| return true; |
| } |
| |
| DBusHandlerResult ExportedObject::HandleMessage( |
| DBusConnection* connection, |
| DBusMessage* raw_message) { |
| bus_->AssertOnDBusThread(); |
| // ExportedObject only handles method calls. Ignore other message types (e.g. |
| // signal). |
| if (dbus_message_get_type(raw_message) != DBUS_MESSAGE_TYPE_METHOD_CALL) |
| return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; |
| |
| // raw_message will be unrefed on exit of the function. Increment the |
| // reference so we can use it in MethodCall. |
| dbus_message_ref(raw_message); |
| std::unique_ptr<MethodCall> method_call( |
| MethodCall::FromRawMessage(raw_message)); |
| const std::string interface = method_call->GetInterface(); |
| const std::string member = method_call->GetMember(); |
| |
| if (interface.empty()) { |
| // We don't support method calls without interface. |
| LOG(WARNING) << "Interface is missing: " << method_call->ToString(); |
| return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; |
| } |
| |
| // Check if we know about the method. |
| const std::string absolute_method_name = GetAbsoluteMemberName( |
| interface, member); |
| MethodTable::const_iterator iter = method_table_.find(absolute_method_name); |
| if (iter == method_table_.end()) { |
| // Don't know about the method. |
| LOG(WARNING) << "Unknown method: " << method_call->ToString(); |
| return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; |
| } |
| |
| const base::TimeTicks start_time = base::TimeTicks::Now(); |
| if (bus_->HasDBusThread()) { |
| // Post a task to run the method in the origin thread. |
| bus_->GetOriginTaskRunner()->PostTask( |
| FROM_HERE, |
| base::BindOnce(&ExportedObject::RunMethod, this, iter->second, |
| std::move(method_call), start_time)); |
| } else { |
| // If the D-Bus thread is not used, just call the method directly. |
| MethodCall* method = method_call.get(); |
| iter->second.Run(method, |
| base::Bind(&ExportedObject::SendResponse, |
| this, |
| start_time, |
| base::Passed(&method_call))); |
| } |
| |
| // It's valid to say HANDLED here, and send a method response at a later |
| // time from OnMethodCompleted() asynchronously. |
| return DBUS_HANDLER_RESULT_HANDLED; |
| } |
| |
| void ExportedObject::RunMethod(MethodCallCallback method_call_callback, |
| std::unique_ptr<MethodCall> method_call, |
| base::TimeTicks start_time) { |
| bus_->AssertOnOriginThread(); |
| MethodCall* method = method_call.get(); |
| method_call_callback.Run(method, |
| base::Bind(&ExportedObject::SendResponse, |
| this, |
| start_time, |
| base::Passed(&method_call))); |
| } |
| |
| void ExportedObject::SendResponse(base::TimeTicks start_time, |
| std::unique_ptr<MethodCall> method_call, |
| std::unique_ptr<Response> response) { |
| DCHECK(method_call); |
| if (bus_->HasDBusThread()) { |
| bus_->GetDBusTaskRunner()->PostTask( |
| FROM_HERE, base::BindOnce(&ExportedObject::OnMethodCompleted, this, |
| std::move(method_call), std::move(response), |
| start_time)); |
| } else { |
| OnMethodCompleted(std::move(method_call), std::move(response), start_time); |
| } |
| } |
| |
| void ExportedObject::OnMethodCompleted(std::unique_ptr<MethodCall> method_call, |
| std::unique_ptr<Response> response, |
| base::TimeTicks start_time) { |
| bus_->AssertOnDBusThread(); |
| |
| // Record if the method call is successful, or not. 1 if successful. |
| UMA_HISTOGRAM_ENUMERATION("DBus.ExportedMethodHandleSuccess", |
| response ? 1 : 0, |
| kSuccessRatioHistogramMaxValue); |
| |
| // Check if the bus is still connected. If the method takes long to |
| // complete, the bus may be shut down meanwhile. |
| if (!bus_->IsConnected()) |
| return; |
| |
| if (!response) { |
| // Something bad happened in the method call. |
| std::unique_ptr<ErrorResponse> error_response(ErrorResponse::FromMethodCall( |
| method_call.get(), DBUS_ERROR_FAILED, |
| "error occurred in " + method_call->GetMember())); |
| bus_->Send(error_response->raw_message(), nullptr); |
| return; |
| } |
| |
| // The method call was successful. |
| bus_->Send(response->raw_message(), nullptr); |
| |
| // Record time spent to handle the the method call. Don't include failures. |
| UMA_HISTOGRAM_TIMES("DBus.ExportedMethodHandleTime", |
| base::TimeTicks::Now() - start_time); |
| } |
| |
| void ExportedObject::OnUnregistered(DBusConnection* connection) { |
| } |
| |
| DBusHandlerResult ExportedObject::HandleMessageThunk( |
| DBusConnection* connection, |
| DBusMessage* raw_message, |
| void* user_data) { |
| ExportedObject* self = reinterpret_cast<ExportedObject*>(user_data); |
| return self->HandleMessage(connection, raw_message); |
| } |
| |
| void ExportedObject::OnUnregisteredThunk(DBusConnection *connection, |
| void* user_data) { |
| ExportedObject* self = reinterpret_cast<ExportedObject*>(user_data); |
| return self->OnUnregistered(connection); |
| } |
| |
| } // namespace dbus |