dbus/object_proxy.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "dbus/bus.h"
   6
   7 #include "base/bind.h"
   8 #include "base/logging.h"
   9 #include "base/message_loop/message_loop.h"
  10 #include "base/metrics/histogram.h"
  11 #include "base/strings/string_piece.h"
  12 #include "base/strings/stringprintf.h"
  13 #include "base/task_runner_util.h"
  14 #include "base/threading/thread.h"
  15 #include "base/threading/thread_restrictions.h"
  16 #include "dbus/dbus_statistics.h"
  17 #include "dbus/message.h"
  18 #include "dbus/object_path.h"
  19 #include "dbus/object_proxy.h"
  20 #include "dbus/scoped_dbus_error.h"
  21 #include "dbus/util.h"
  22
  23 namespace dbus {
  24
  25 namespace {
  26
  27 const char kErrorServiceUnknown[] = "org.freedesktop.DBus.Error.ServiceUnknown";
  28 const char kErrorObjectUnknown[] = "org.freedesktop.DBus.Error.UnknownObject";
  29
  30 // Used for success ratio histograms. 1 for success, 0 for failure.
  31 const int kSuccessRatioHistogramMaxValue = 2;
  32
  33 // The path of D-Bus Object sending NameOwnerChanged signal.
  34 const char kDBusSystemObjectPath[] = "/org/freedesktop/DBus";
  35
  36 // The D-Bus Object interface.
  37 const char kDBusSystemObjectInterface[] = "org.freedesktop.DBus";
  38
  39 // The D-Bus Object address.
  40 const char kDBusSystemObjectAddress[] = "org.freedesktop.DBus";
  41
  42 // The NameOwnerChanged member in |kDBusSystemObjectInterface|.
  43 const char kNameOwnerChangedMember[] = "NameOwnerChanged";
  44
  45 // An empty function used for ObjectProxy::EmptyResponseCallback().
  46 void EmptyResponseCallbackBody(Response* /*response*/) {
  47 }
  48
  49 }  // namespace
  50
  51 ObjectProxy::ObjectProxy(Bus* bus,
  52                          const std::string& service_name,
  53                          const ObjectPath& object_path,
  54                          int options)
  55     : bus_(bus),
  56       service_name_(service_name),
  57       object_path_(object_path),
  58       filter_added_(false),
  59       ignore_service_unknown_errors_(
  60           options & IGNORE_SERVICE_UNKNOWN_ERRORS) {
  61 }
  62
  63 ObjectProxy::~ObjectProxy() {
  64 }
  65
  66 // Originally we tried to make |method_call| a const reference, but we
  67 // gave up as dbus_connection_send_with_reply_and_block() takes a
  68 // non-const pointer of DBusMessage as the second parameter.
  69 scoped_ptr<Response> ObjectProxy::CallMethodAndBlockWithErrorDetails(
  70     MethodCall* method_call, int timeout_ms, ScopedDBusError* error) {
  71   bus_->AssertOnDBusThread();
  72
  73   if (!bus_->Connect() ||
  74       !method_call->SetDestination(service_name_) ||
  75       !method_call->SetPath(object_path_))
  76     return scoped_ptr<Response>();
  77
  78   DBusMessage* request_message = method_call->raw_message();
  79
  80   // Send the message synchronously.
  81   const base::TimeTicks start_time = base::TimeTicks::Now();
  82   DBusMessage* response_message =
  83       bus_->SendWithReplyAndBlock(request_message, timeout_ms, error->get());
  84   // Record if the method call is successful, or not. 1 if successful.
  85   UMA_HISTOGRAM_ENUMERATION("DBus.SyncMethodCallSuccess",
  86                             response_message ? 1 : 0,
  87                             kSuccessRatioHistogramMaxValue);
  88   statistics::AddBlockingSentMethodCall(service_name_,
  89                                         method_call->GetInterface(),
  90                                         method_call->GetMember());
  91
  92   if (!response_message) {
  93     LogMethodCallFailure(method_call->GetInterface(),
  94                          method_call->GetMember(),
  95                          error->is_set() ? error->name() : "unknown error type",
  96                          error->is_set() ? error->message() : "");
  97     return scoped_ptr<Response>();
  98   }
  99   // Record time spent for the method call. Don't include failures.
 100   UMA_HISTOGRAM_TIMES("DBus.SyncMethodCallTime",
 101                       base::TimeTicks::Now() - start_time);
 102
 103   return Response::FromRawMessage(response_message);
 104 }
 105
 106 scoped_ptr<Response> ObjectProxy::CallMethodAndBlock(MethodCall* method_call,
 107                                                      int timeout_ms) {
 108   ScopedDBusError error;
 109   return CallMethodAndBlockWithErrorDetails(method_call, timeout_ms, &error);
 110 }
 111
 112 void ObjectProxy::CallMethod(MethodCall* method_call,
 113                              int timeout_ms,
 114                              ResponseCallback callback) {
 115   CallMethodWithErrorCallback(method_call, timeout_ms, callback,
 116                               base::Bind(&ObjectProxy::OnCallMethodError,
 117                                          this,
 118                                          method_call->GetInterface(),
 119                                          method_call->GetMember(),
 120                                          callback));
 121 }
 122
 123 void ObjectProxy::CallMethodWithErrorCallback(MethodCall* method_call,
 124                                               int timeout_ms,
 125                                               ResponseCallback callback,
 126                                               ErrorCallback error_callback) {
 127   bus_->AssertOnOriginThread();
 128
 129   const base::TimeTicks start_time = base::TimeTicks::Now();
 130
 131   if (!method_call->SetDestination(service_name_) ||
 132       !method_call->SetPath(object_path_)) {
 133     // In case of a failure, run the error callback with NULL.
 134     DBusMessage* response_message = NULL;
 135     base::Closure task = base::Bind(&ObjectProxy::RunResponseCallback,
 136                                     this,
 137                                     callback,
 138                                     error_callback,
 139                                     start_time,
 140                                     response_message);
 141     bus_->GetOriginTaskRunner()->PostTask(FROM_HERE, task);
 142     return;
 143   }
 144
 145   // Increment the reference count so we can safely reference the
 146   // underlying request message until the method call is complete. This
 147   // will be unref'ed in StartAsyncMethodCall().
 148   DBusMessage* request_message = method_call->raw_message();
 149   dbus_message_ref(request_message);
 150
 151   base::Closure task = base::Bind(&ObjectProxy::StartAsyncMethodCall,
 152                                   this,
 153                                   timeout_ms,
 154                                   request_message,
 155                                   callback,
 156                                   error_callback,
 157                                   start_time);
 158   statistics::AddSentMethodCall(service_name_,
 159                                 method_call->GetInterface(),
 160                                 method_call->GetMember());
 161
 162   // Wait for the response in the D-Bus thread.
 163   bus_->GetDBusTaskRunner()->PostTask(FROM_HERE, task);
 164 }
 165
 166 void ObjectProxy::ConnectToSignal(const std::string& interface_name,
 167                                   const std::string& signal_name,
 168                                   SignalCallback signal_callback,
 169                                   OnConnectedCallback on_connected_callback) {
 170   bus_->AssertOnOriginThread();
 171
 172   base::PostTaskAndReplyWithResult(
 173       bus_->GetDBusTaskRunner(),
 174       FROM_HERE,
 175       base::Bind(&ObjectProxy::ConnectToSignalInternal,
 176                  this,
 177                  interface_name,
 178                  signal_name,
 179                  signal_callback),
 180       base::Bind(on_connected_callback,
 181                  interface_name,
 182                  signal_name));
 183 }
 184
 185 void ObjectProxy::SetNameOwnerChangedCallback(
 186     NameOwnerChangedCallback callback) {
 187   bus_->AssertOnOriginThread();
 188
 189   name_owner_changed_callback_ = callback;
 190 }
 191
 192 void ObjectProxy::WaitForServiceToBeAvailable(
 193     WaitForServiceToBeAvailableCallback callback) {
 194   bus_->AssertOnOriginThread();
 195
 196   wait_for_service_to_be_available_callbacks_.push_back(callback);
 197   bus_->GetDBusTaskRunner()->PostTask(
 198       FROM_HERE,
 199       base::Bind(&ObjectProxy::WaitForServiceToBeAvailableInternal, this));
 200 }
 201
 202 void ObjectProxy::Detach() {
 203   bus_->AssertOnDBusThread();
 204
 205   if (filter_added_) {
 206     if (!bus_->RemoveFilterFunction(&ObjectProxy::HandleMessageThunk, this)) {
 207       LOG(ERROR) << "Failed to remove filter function";
 208     }
 209   }
 210
 211   for (std::set<std::string>::iterator iter = match_rules_.begin();
 212        iter != match_rules_.end(); ++iter) {
 213     ScopedDBusError error;
 214     bus_->RemoveMatch(*iter, error.get());
 215     if (error.is_set()) {
 216       // There is nothing we can do to recover, so just print the error.
 217       LOG(ERROR) << "Failed to remove match rule: " << *iter;
 218     }
 219   }
 220   match_rules_.clear();
 221 }
 222
 223 // static
 224 ObjectProxy::ResponseCallback ObjectProxy::EmptyResponseCallback() {
 225   return base::Bind(&EmptyResponseCallbackBody);
 226 }
 227
 228 ObjectProxy::OnPendingCallIsCompleteData::OnPendingCallIsCompleteData(
 229     ObjectProxy* in_object_proxy,
 230     ResponseCallback in_response_callback,
 231     ErrorCallback in_error_callback,
 232     base::TimeTicks in_start_time)
 233     : object_proxy(in_object_proxy),
 234       response_callback(in_response_callback),
 235       error_callback(in_error_callback),
 236       start_time(in_start_time) {
 237 }
 238
 239 ObjectProxy::OnPendingCallIsCompleteData::~OnPendingCallIsCompleteData() {
 240 }
 241
 242 void ObjectProxy::StartAsyncMethodCall(int timeout_ms,
 243                                        DBusMessage* request_message,
 244                                        ResponseCallback response_callback,
 245                                        ErrorCallback error_callback,
 246                                        base::TimeTicks start_time) {
 247   bus_->AssertOnDBusThread();
 248
 249   if (!bus_->Connect() || !bus_->SetUpAsyncOperations()) {
 250     // In case of a failure, run the error callback with NULL.
 251     DBusMessage* response_message = NULL;
 252     base::Closure task = base::Bind(&ObjectProxy::RunResponseCallback,
 253                                     this,
 254                                     response_callback,
 255                                     error_callback,
 256                                     start_time,
 257                                     response_message);
 258     bus_->GetOriginTaskRunner()->PostTask(FROM_HERE, task);
 259
 260     dbus_message_unref(request_message);
 261     return;
 262   }
 263
 264   DBusPendingCall* pending_call = NULL;
 265
 266   bus_->SendWithReply(request_message, &pending_call, timeout_ms);
 267
 268   // Prepare the data we'll be passing to OnPendingCallIsCompleteThunk().
 269   // The data will be deleted in OnPendingCallIsCompleteThunk().
 270   OnPendingCallIsCompleteData* data =
 271       new OnPendingCallIsCompleteData(this, response_callback, error_callback,
 272                                       start_time);
 273
 274   // This returns false only when unable to allocate memory.
 275   const bool success = dbus_pending_call_set_notify(
 276       pending_call,
 277       &ObjectProxy::OnPendingCallIsCompleteThunk,
 278       data,
 279       NULL);
 280   CHECK(success) << "Unable to allocate memory";
 281   dbus_pending_call_unref(pending_call);
 282
 283   // It's now safe to unref the request message.
 284   dbus_message_unref(request_message);
 285 }
 286
 287 void ObjectProxy::OnPendingCallIsComplete(DBusPendingCall* pending_call,
 288                                           ResponseCallback response_callback,
 289                                           ErrorCallback error_callback,
 290                                           base::TimeTicks start_time) {
 291   bus_->AssertOnDBusThread();
 292
 293   DBusMessage* response_message = dbus_pending_call_steal_reply(pending_call);
 294   base::Closure task = base::Bind(&ObjectProxy::RunResponseCallback,
 295                                   this,
 296                                   response_callback,
 297                                   error_callback,
 298                                   start_time,
 299                                   response_message);
 300   bus_->GetOriginTaskRunner()->PostTask(FROM_HERE, task);
 301 }
 302
 303 void ObjectProxy::RunResponseCallback(ResponseCallback response_callback,
 304                                       ErrorCallback error_callback,
 305                                       base::TimeTicks start_time,
 306                                       DBusMessage* response_message) {
 307   bus_->AssertOnOriginThread();
 308
 309   bool method_call_successful = false;
 310   if (!response_message) {
 311     // The response is not received.
 312     error_callback.Run(NULL);
 313   } else if (dbus_message_get_type(response_message) ==
 314              DBUS_MESSAGE_TYPE_ERROR) {
 315     // This will take |response_message| and release (unref) it.
 316     scoped_ptr<ErrorResponse> error_response(
 317         ErrorResponse::FromRawMessage(response_message));
 318     error_callback.Run(error_response.get());
 319     // Delete the message  on the D-Bus thread. See below for why.
 320     bus_->GetDBusTaskRunner()->PostTask(
 321         FROM_HERE,
 322         base::Bind(&base::DeletePointer<ErrorResponse>,
 323                    error_response.release()));
 324   } else {
 325     // This will take |response_message| and release (unref) it.
 326     scoped_ptr<Response> response(Response::FromRawMessage(response_message));
 327     // The response is successfully received.
 328     response_callback.Run(response.get());
 329     // The message should be deleted on the D-Bus thread for a complicated
 330     // reason:
 331     //
 332     // libdbus keeps track of the number of bytes in the incoming message
 333     // queue to ensure that the data size in the queue is manageable. The
 334     // bookkeeping is partly done via dbus_message_unref(), and immediately
 335     // asks the client code (Chrome) to stop monitoring the underlying
 336     // socket, if the number of bytes exceeds a certian number, which is set
 337     // to 63MB, per dbus-transport.cc:
 338     //
 339     //   /* Try to default to something that won't totally hose the system,
 340     //    * but doesn't impose too much of a limitation.
 341     //    */
 342     //   transport->max_live_messages_size = _DBUS_ONE_MEGABYTE * 63;
 343     //
 344     // The monitoring of the socket is done on the D-Bus thread (see Watch
 345     // class in bus.cc), hence we should stop the monitoring from D-Bus
 346     // thread, not from the current thread here, which is likely UI thread.
 347     bus_->GetDBusTaskRunner()->PostTask(
 348         FROM_HERE,
 349         base::Bind(&base::DeletePointer<Response>, response.release()));
 350
 351     method_call_successful = true;
 352     // Record time spent for the method call. Don't include failures.
 353     UMA_HISTOGRAM_TIMES("DBus.AsyncMethodCallTime",
 354                         base::TimeTicks::Now() - start_time);
 355   }
 356   // Record if the method call is successful, or not. 1 if successful.
 357   UMA_HISTOGRAM_ENUMERATION("DBus.AsyncMethodCallSuccess",
 358                             method_call_successful,
 359                             kSuccessRatioHistogramMaxValue);
 360 }
 361
 362 void ObjectProxy::OnPendingCallIsCompleteThunk(DBusPendingCall* pending_call,
 363                                                void* user_data) {
 364   OnPendingCallIsCompleteData* data =
 365       reinterpret_cast<OnPendingCallIsCompleteData*>(user_data);
 366   ObjectProxy* self = data->object_proxy;
 367   self->OnPendingCallIsComplete(pending_call,
 368                                 data->response_callback,
 369                                 data->error_callback,
 370                                 data->start_time);
 371   delete data;
 372 }
 373
 374 bool ObjectProxy::ConnectToNameOwnerChangedSignal() {
 375   bus_->AssertOnDBusThread();
 376
 377   if (!bus_->Connect() || !bus_->SetUpAsyncOperations())
 378     return false;
 379
 380   // We should add the filter only once. Otherwise, HandleMessage() will
 381   // be called more than once.
 382   if (!filter_added_) {
 383     if (bus_->AddFilterFunction(&ObjectProxy::HandleMessageThunk, this)) {
 384       filter_added_ = true;
 385     } else {
 386       LOG(ERROR) << "Failed to add filter function";
 387     }
 388   }
 389   // Add a match_rule listening NameOwnerChanged for the well-known name
 390   // |service_name_|.
 391   const std::string name_owner_changed_match_rule =
 392       base::StringPrintf(
 393           "type='signal',interface='org.freedesktop.DBus',"
 394           "member='NameOwnerChanged',path='/org/freedesktop/DBus',"
 395           "sender='org.freedesktop.DBus',arg0='%s'",
 396           service_name_.c_str());
 397
 398   const bool success =
 399       AddMatchRuleWithoutCallback(name_owner_changed_match_rule,
 400                                   "org.freedesktop.DBus.NameOwnerChanged");
 401
 402   // Try getting the current name owner. It's not guaranteed that we can get
 403   // the name owner at this moment, as the service may not yet be started. If
 404   // that's the case, we'll get the name owner via NameOwnerChanged signal,
 405   // as soon as the service is started.
 406   UpdateNameOwnerAndBlock();
 407
 408   return success;
 409 }
 410
 411 bool ObjectProxy::ConnectToSignalInternal(const std::string& interface_name,
 412                                           const std::string& signal_name,
 413                                           SignalCallback signal_callback) {
 414   bus_->AssertOnDBusThread();
 415
 416   if (!ConnectToNameOwnerChangedSignal())
 417     return false;
 418
 419   const std::string absolute_signal_name =
 420       GetAbsoluteMemberName(interface_name, signal_name);
 421
 422   // Add a match rule so the signal goes through HandleMessage().
 423   const std::string match_rule =
 424       base::StringPrintf("type='signal', interface='%s', path='%s'",
 425                          interface_name.c_str(),
 426                          object_path_.value().c_str());
 427   return AddMatchRuleWithCallback(match_rule,
 428                                   absolute_signal_name,
 429                                   signal_callback);
 430 }
 431
 432 void ObjectProxy::WaitForServiceToBeAvailableInternal() {
 433   bus_->AssertOnDBusThread();
 434
 435   if (!ConnectToNameOwnerChangedSignal()) {  // Failed to connect to the signal.
 436     const bool service_is_ready = false;
 437     bus_->GetOriginTaskRunner()->PostTask(
 438         FROM_HERE,
 439         base::Bind(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
 440                    this, service_is_ready));
 441     return;
 442   }
 443
 444   const bool service_is_available = !service_name_owner_.empty();
 445   if (service_is_available) {  // Service is already available.
 446     bus_->GetOriginTaskRunner()->PostTask(
 447         FROM_HERE,
 448         base::Bind(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
 449                    this, service_is_available));
 450     return;
 451   }
 452 }
 453
 454 DBusHandlerResult ObjectProxy::HandleMessage(
 455     DBusConnection* connection,
 456     DBusMessage* raw_message) {
 457   bus_->AssertOnDBusThread();
 458
 459   if (dbus_message_get_type(raw_message) != DBUS_MESSAGE_TYPE_SIGNAL)
 460     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 461
 462   // raw_message will be unrefed on exit of the function. Increment the
 463   // reference so we can use it in Signal.
 464   dbus_message_ref(raw_message);
 465   scoped_ptr<Signal> signal(
 466       Signal::FromRawMessage(raw_message));
 467
 468   // Verify the signal comes from the object we're proxying for, this is
 469   // our last chance to return DBUS_HANDLER_RESULT_NOT_YET_HANDLED and
 470   // allow other object proxies to handle instead.
 471   const ObjectPath path = signal->GetPath();
 472   if (path != object_path_) {
 473     if (path.value() == kDBusSystemObjectPath &&
 474         signal->GetMember() == kNameOwnerChangedMember) {
 475       // Handle NameOwnerChanged separately
 476       return HandleNameOwnerChanged(signal.Pass());
 477     }
 478     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 479   }
 480
 481   const std::string interface = signal->GetInterface();
 482   const std::string member = signal->GetMember();
 483
 484   statistics::AddReceivedSignal(service_name_, interface, member);
 485
 486   // Check if we know about the signal.
 487   const std::string absolute_signal_name = GetAbsoluteMemberName(
 488       interface, member);
 489   MethodTable::const_iterator iter = method_table_.find(absolute_signal_name);
 490   if (iter == method_table_.end()) {
 491     // Don't know about the signal.
 492     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 493   }
 494   VLOG(1) << "Signal received: " << signal->ToString();
 495
 496   std::string sender = signal->GetSender();
 497   if (service_name_owner_ != sender) {
 498     LOG(ERROR) << "Rejecting a message from a wrong sender.";
 499     UMA_HISTOGRAM_COUNTS("DBus.RejectedSignalCount", 1);
 500     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 501   }
 502
 503   const base::TimeTicks start_time = base::TimeTicks::Now();
 504   if (bus_->HasDBusThread()) {
 505     // Post a task to run the method in the origin thread.
 506     // Transfer the ownership of |signal| to RunMethod().
 507     // |released_signal| will be deleted in RunMethod().
 508     Signal* released_signal = signal.release();
 509     bus_->GetOriginTaskRunner()->PostTask(FROM_HERE,
 510                                           base::Bind(&ObjectProxy::RunMethod,
 511                                                      this,
 512                                                      start_time,
 513                                                      iter->second,
 514                                                      released_signal));
 515   } else {
 516     const base::TimeTicks start_time = base::TimeTicks::Now();
 517     // If the D-Bus thread is not used, just call the callback on the
 518     // current thread. Transfer the ownership of |signal| to RunMethod().
 519     Signal* released_signal = signal.release();
 520     RunMethod(start_time, iter->second, released_signal);
 521   }
 522
 523   // We don't return DBUS_HANDLER_RESULT_HANDLED for signals because other
 524   // objects may be interested in them. (e.g. Signals from org.freedesktop.DBus)
 525   return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 526 }
 527
 528 void ObjectProxy::RunMethod(base::TimeTicks start_time,
 529                             std::vector<SignalCallback> signal_callbacks,
 530                             Signal* signal) {
 531   bus_->AssertOnOriginThread();
 532
 533   for (std::vector<SignalCallback>::iterator iter = signal_callbacks.begin();
 534        iter != signal_callbacks.end(); ++iter)
 535     iter->Run(signal);
 536
 537   // Delete the message on the D-Bus thread. See comments in
 538   // RunResponseCallback().
 539   bus_->GetDBusTaskRunner()->PostTask(
 540       FROM_HERE,
 541       base::Bind(&base::DeletePointer<Signal>, signal));
 542
 543   // Record time spent for handling the signal.
 544   UMA_HISTOGRAM_TIMES("DBus.SignalHandleTime",
 545                       base::TimeTicks::Now() - start_time);
 546 }
 547
 548 DBusHandlerResult ObjectProxy::HandleMessageThunk(
 549     DBusConnection* connection,
 550     DBusMessage* raw_message,
 551     void* user_data) {
 552   ObjectProxy* self = reinterpret_cast<ObjectProxy*>(user_data);
 553   return self->HandleMessage(connection, raw_message);
 554 }
 555
 556 void ObjectProxy::LogMethodCallFailure(
 557     const base::StringPiece& interface_name,
 558     const base::StringPiece& method_name,
 559     const base::StringPiece& error_name,
 560     const base::StringPiece& error_message) const {
 561   if (ignore_service_unknown_errors_ &&
 562       (error_name == kErrorServiceUnknown || error_name == kErrorObjectUnknown))
 563     return;
 564   logging::LogSeverity severity = logging::LOG_ERROR;
 565   // "UnknownObject" indicates that an object or service is no longer available,
 566   // e.g. a Shill network service has gone out of range. Treat these as warnings
 567   // not errors.
 568   if (error_name == kErrorObjectUnknown)
 569     severity = logging::LOG_WARNING;
 570   std::ostringstream msg;
 571   msg << "Failed to call method: " << interface_name << "." << method_name
 572       << ": object_path= " << object_path_.value()
 573       << ": " << error_name << ": " << error_message;
 574   logging::LogAtLevel(severity, msg.str());
 575 }
 576
 577 void ObjectProxy::OnCallMethodError(const std::string& interface_name,
 578                                     const std::string& method_name,
 579                                     ResponseCallback response_callback,
 580                                     ErrorResponse* error_response) {
 581   if (error_response) {
 582     // Error message may contain the error message as string.
 583     MessageReader reader(error_response);
 584     std::string error_message;
 585     reader.PopString(&error_message);
 586     LogMethodCallFailure(interface_name,
 587                          method_name,
 588                          error_response->GetErrorName(),
 589                          error_message);
 590   }
 591   response_callback.Run(NULL);
 592 }
 593
 594 bool ObjectProxy::AddMatchRuleWithCallback(
 595     const std::string& match_rule,
 596     const std::string& absolute_signal_name,
 597     SignalCallback signal_callback) {
 598   DCHECK(!match_rule.empty());
 599   DCHECK(!absolute_signal_name.empty());
 600   bus_->AssertOnDBusThread();
 601
 602   if (match_rules_.find(match_rule) == match_rules_.end()) {
 603     ScopedDBusError error;
 604     bus_->AddMatch(match_rule, error.get());
 605     if (error.is_set()) {
 606       LOG(ERROR) << "Failed to add match rule \"" << match_rule << "\". Got "
 607                  << error.name() << ": " << error.message();
 608       return false;
 609     } else {
 610       // Store the match rule, so that we can remove this in Detach().
 611       match_rules_.insert(match_rule);
 612       // Add the signal callback to the method table.
 613       method_table_[absolute_signal_name].push_back(signal_callback);
 614       return true;
 615     }
 616   } else {
 617     // We already have the match rule.
 618     method_table_[absolute_signal_name].push_back(signal_callback);
 619     return true;
 620   }
 621 }
 622
 623 bool ObjectProxy::AddMatchRuleWithoutCallback(
 624     const std::string& match_rule,
 625     const std::string& absolute_signal_name) {
 626   DCHECK(!match_rule.empty());
 627   DCHECK(!absolute_signal_name.empty());
 628   bus_->AssertOnDBusThread();
 629
 630   if (match_rules_.find(match_rule) != match_rules_.end())
 631     return true;
 632
 633   ScopedDBusError error;
 634   bus_->AddMatch(match_rule, error.get());
 635   if (error.is_set()) {
 636     LOG(ERROR) << "Failed to add match rule \"" << match_rule << "\". Got "
 637                << error.name() << ": " << error.message();
 638     return false;
 639   }
 640   // Store the match rule, so that we can remove this in Detach().
 641   match_rules_.insert(match_rule);
 642   return true;
 643 }
 644
 645 void ObjectProxy::UpdateNameOwnerAndBlock() {
 646   bus_->AssertOnDBusThread();
 647   // Errors should be suppressed here, as the service may not be yet running
 648   // when connecting to signals of the service, which is just fine.
 649   // The ObjectProxy will be notified when the service is launched via
 650   // NameOwnerChanged signal. See also comments in ConnectToSignalInternal().
 651   service_name_owner_ =
 652       bus_->GetServiceOwnerAndBlock(service_name_, Bus::SUPPRESS_ERRORS);
 653 }
 654
 655 DBusHandlerResult ObjectProxy::HandleNameOwnerChanged(
 656     scoped_ptr<Signal> signal) {
 657   DCHECK(signal);
 658   bus_->AssertOnDBusThread();
 659
 660   // Confirm the validity of the NameOwnerChanged signal.
 661   if (signal->GetMember() == kNameOwnerChangedMember &&
 662       signal->GetInterface() == kDBusSystemObjectInterface &&
 663       signal->GetSender() == kDBusSystemObjectAddress) {
 664     MessageReader reader(signal.get());
 665     std::string name, old_owner, new_owner;
 666     if (reader.PopString(&name) &&
 667         reader.PopString(&old_owner) &&
 668         reader.PopString(&new_owner) &&
 669         name == service_name_) {
 670       service_name_owner_ = new_owner;
 671       bus_->GetOriginTaskRunner()->PostTask(
 672           FROM_HERE,
 673           base::Bind(&ObjectProxy::RunNameOwnerChangedCallback,
 674                      this, old_owner, new_owner));
 675
 676       const bool service_is_available = !service_name_owner_.empty();
 677       if (service_is_available) {
 678         bus_->GetOriginTaskRunner()->PostTask(
 679             FROM_HERE,
 680             base::Bind(&ObjectProxy::RunWaitForServiceToBeAvailableCallbacks,
 681                        this, service_is_available));
 682       }
 683     }
 684   }
 685
 686   // Always return unhandled to let other object proxies handle the same
 687   // signal.
 688   return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 689 }
 690
 691 void ObjectProxy::RunNameOwnerChangedCallback(const std::string& old_owner,
 692                                               const std::string& new_owner) {
 693   bus_->AssertOnOriginThread();
 694   if (!name_owner_changed_callback_.is_null())
 695     name_owner_changed_callback_.Run(old_owner, new_owner);
 696 }
 697
 698 void ObjectProxy::RunWaitForServiceToBeAvailableCallbacks(
 699     bool service_is_available) {
 700   bus_->AssertOnOriginThread();
 701
 702   std::vector<WaitForServiceToBeAvailableCallback> callbacks;
 703   callbacks.swap(wait_for_service_to_be_available_callbacks_);
 704   for (size_t i = 0; i < callbacks.size(); ++i)
 705     callbacks[i].Run(service_is_available);
 706 }
 707
 708 }  // namespace dbus