dbus/end_to_end_async_unittest.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 <algorithm>
   6 #include <string>
   7 #include <vector>
   8
   9 #include "base/bind.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/stl_util.h"
  13 #include "base/test/test_timeouts.h"
  14 #include "base/threading/thread.h"
  15 #include "base/threading/thread_restrictions.h"
  16 #include "dbus/bus.h"
  17 #include "dbus/message.h"
  18 #include "dbus/object_path.h"
  19 #include "dbus/object_proxy.h"
  20 #include "dbus/test_service.h"
  21 #include "testing/gtest/include/gtest/gtest.h"
  22
  23 namespace dbus {
  24
  25 namespace {
  26
  27 // See comments in ObjectProxy::RunResponseCallback() for why the number was
  28 // chosen.
  29 const int kHugePayloadSize = 64 << 20;  // 64 MB
  30
  31 }  // namespace
  32
  33 // The end-to-end test exercises the asynchronous APIs in ObjectProxy and
  34 // ExportedObject.
  35 class EndToEndAsyncTest : public testing::Test {
  36  public:
  37   EndToEndAsyncTest() : on_disconnected_call_count_(0) {}
  38
  39   virtual void SetUp() {
  40     // Make the main thread not to allow IO.
  41     base::ThreadRestrictions::SetIOAllowed(false);
  42
  43     // Start the D-Bus thread.
  44     dbus_thread_.reset(new base::Thread("D-Bus Thread"));
  45     base::Thread::Options thread_options;
  46     thread_options.message_loop_type = base::MessageLoop::TYPE_IO;
  47     ASSERT_TRUE(dbus_thread_->StartWithOptions(thread_options));
  48
  49     // Start the test service, using the D-Bus thread.
  50     TestService::Options options;
  51     options.dbus_task_runner = dbus_thread_->message_loop_proxy();
  52     test_service_.reset(new TestService(options));
  53     ASSERT_TRUE(test_service_->StartService());
  54     ASSERT_TRUE(test_service_->WaitUntilServiceIsStarted());
  55     ASSERT_TRUE(test_service_->HasDBusThread());
  56
  57     // Create the client, using the D-Bus thread.
  58     Bus::Options bus_options;
  59     bus_options.bus_type = Bus::SESSION;
  60     bus_options.connection_type = Bus::PRIVATE;
  61     bus_options.dbus_task_runner = dbus_thread_->message_loop_proxy();
  62     bus_options.disconnected_callback =
  63         base::Bind(&EndToEndAsyncTest::OnDisconnected, base::Unretained(this));
  64     bus_ = new Bus(bus_options);
  65     object_proxy_ = bus_->GetObjectProxy(
  66         "org.chromium.TestService",
  67         ObjectPath("/org/chromium/TestObject"));
  68     ASSERT_TRUE(bus_->HasDBusThread());
  69
  70     // Connect to the "Test" signal of "org.chromium.TestInterface" from
  71     // the remote object.
  72     object_proxy_->ConnectToSignal(
  73         "org.chromium.TestInterface",
  74         "Test",
  75         base::Bind(&EndToEndAsyncTest::OnTestSignal,
  76                    base::Unretained(this)),
  77         base::Bind(&EndToEndAsyncTest::OnConnected,
  78                    base::Unretained(this)));
  79     // Wait until the object proxy is connected to the signal.
  80     message_loop_.Run();
  81
  82     // Connect to the "Test2" signal of "org.chromium.TestInterface" from
  83     // the remote object. There was a bug where we were emitting error
  84     // messages like "Requested to remove an unknown match rule: ..." at
  85     // the shutdown of Bus when an object proxy is connected to more than
  86     // one signal of the same interface. See crosbug.com/23382 for details.
  87     object_proxy_->ConnectToSignal(
  88         "org.chromium.TestInterface",
  89         "Test2",
  90         base::Bind(&EndToEndAsyncTest::OnTest2Signal,
  91                    base::Unretained(this)),
  92         base::Bind(&EndToEndAsyncTest::OnConnected,
  93                    base::Unretained(this)));
  94     // Wait until the object proxy is connected to the signal.
  95     message_loop_.Run();
  96
  97     // Create a second object proxy for the root object.
  98     root_object_proxy_ = bus_->GetObjectProxy("org.chromium.TestService",
  99                                               ObjectPath("/"));
 100     ASSERT_TRUE(bus_->HasDBusThread());
 101
 102     // Connect to the "Test" signal of "org.chromium.TestInterface" from
 103     // the root remote object too.
 104     root_object_proxy_->ConnectToSignal(
 105         "org.chromium.TestInterface",
 106         "Test",
 107         base::Bind(&EndToEndAsyncTest::OnRootTestSignal,
 108                    base::Unretained(this)),
 109         base::Bind(&EndToEndAsyncTest::OnConnected,
 110                    base::Unretained(this)));
 111     // Wait until the root object proxy is connected to the signal.
 112     message_loop_.Run();
 113   }
 114
 115   virtual void TearDown() {
 116     bus_->ShutdownOnDBusThreadAndBlock();
 117
 118     // Shut down the service.
 119     test_service_->ShutdownAndBlock();
 120
 121     // Reset to the default.
 122     base::ThreadRestrictions::SetIOAllowed(true);
 123
 124     // Stopping a thread is considered an IO operation, so do this after
 125     // allowing IO.
 126     test_service_->Stop();
 127   }
 128
 129  protected:
 130   // Replaces the bus with a broken one.
 131   void SetUpBrokenBus() {
 132     // Shut down the existing bus.
 133     bus_->ShutdownOnDBusThreadAndBlock();
 134
 135     // Create new bus with invalid address.
 136     const char kInvalidAddress[] = "";
 137     Bus::Options bus_options;
 138     bus_options.bus_type = Bus::CUSTOM_ADDRESS;
 139     bus_options.address = kInvalidAddress;
 140     bus_options.connection_type = Bus::PRIVATE;
 141     bus_options.dbus_task_runner = dbus_thread_->message_loop_proxy();
 142     bus_ = new Bus(bus_options);
 143     ASSERT_TRUE(bus_->HasDBusThread());
 144
 145     // Create new object proxy.
 146     object_proxy_ = bus_->GetObjectProxy(
 147         "org.chromium.TestService",
 148         ObjectPath("/org/chromium/TestObject"));
 149   }
 150
 151   // Calls the method asynchronously. OnResponse() will be called once the
 152   // response is received.
 153   void CallMethod(MethodCall* method_call,
 154                   int timeout_ms) {
 155     object_proxy_->CallMethod(method_call,
 156                               timeout_ms,
 157                               base::Bind(&EndToEndAsyncTest::OnResponse,
 158                                          base::Unretained(this)));
 159   }
 160
 161   // Calls the method asynchronously. OnResponse() will be called once the
 162   // response is received without error, otherwise OnError() will be called.
 163   void CallMethodWithErrorCallback(MethodCall* method_call,
 164                                    int timeout_ms) {
 165     object_proxy_->CallMethodWithErrorCallback(
 166         method_call,
 167         timeout_ms,
 168         base::Bind(&EndToEndAsyncTest::OnResponse, base::Unretained(this)),
 169         base::Bind(&EndToEndAsyncTest::OnError, base::Unretained(this)));
 170   }
 171
 172   // Wait for the give number of responses.
 173   void WaitForResponses(size_t num_responses) {
 174     while (response_strings_.size() < num_responses) {
 175       message_loop_.Run();
 176     }
 177   }
 178
 179   // Called when the response is received.
 180   void OnResponse(Response* response) {
 181     // |response| will be deleted on exit of the function. Copy the
 182     // payload to |response_strings_|.
 183     if (response) {
 184       MessageReader reader(response);
 185       std::string response_string;
 186       ASSERT_TRUE(reader.PopString(&response_string));
 187       response_strings_.push_back(response_string);
 188     } else {
 189       response_strings_.push_back(std::string());
 190     }
 191     message_loop_.Quit();
 192   };
 193
 194   // Wait for the given number of errors.
 195   void WaitForErrors(size_t num_errors) {
 196     while (error_names_.size() < num_errors) {
 197       message_loop_.Run();
 198     }
 199   }
 200
 201   // Called when an error is received.
 202   void OnError(ErrorResponse* error) {
 203     // |error| will be deleted on exit of the function. Copy the payload to
 204     // |error_names_|.
 205     if (error) {
 206       ASSERT_NE("", error->GetErrorName());
 207       error_names_.push_back(error->GetErrorName());
 208     } else {
 209       error_names_.push_back(std::string());
 210     }
 211     message_loop_.Quit();
 212   }
 213
 214   // Called when the "Test" signal is received, in the main thread.
 215   // Copy the string payload to |test_signal_string_|.
 216   void OnTestSignal(Signal* signal) {
 217     MessageReader reader(signal);
 218     ASSERT_TRUE(reader.PopString(&test_signal_string_));
 219     message_loop_.Quit();
 220   }
 221
 222   // Called when the "Test" signal is received, in the main thread, by
 223   // the root object proxy. Copy the string payload to
 224   // |root_test_signal_string_|.
 225   void OnRootTestSignal(Signal* signal) {
 226     MessageReader reader(signal);
 227     ASSERT_TRUE(reader.PopString(&root_test_signal_string_));
 228     message_loop_.Quit();
 229   }
 230
 231   // Called when the "Test2" signal is received, in the main thread.
 232   void OnTest2Signal(Signal* signal) {
 233     MessageReader reader(signal);
 234     message_loop_.Quit();
 235   }
 236
 237   // Called when connected to the signal.
 238   void OnConnected(const std::string& interface_name,
 239                    const std::string& signal_name,
 240                    bool success) {
 241     ASSERT_TRUE(success);
 242     message_loop_.Quit();
 243   }
 244
 245   // Called when the connection with dbus-daemon is disconnected.
 246   void OnDisconnected() {
 247     message_loop_.Quit();
 248     ++on_disconnected_call_count_;
 249   }
 250
 251   // Wait for the hey signal to be received.
 252   void WaitForTestSignal() {
 253     // OnTestSignal() will quit the message loop.
 254     message_loop_.Run();
 255   }
 256
 257   base::MessageLoop message_loop_;
 258   std::vector<std::string> response_strings_;
 259   std::vector<std::string> error_names_;
 260   scoped_ptr<base::Thread> dbus_thread_;
 261   scoped_refptr<Bus> bus_;
 262   ObjectProxy* object_proxy_;
 263   ObjectProxy* root_object_proxy_;
 264   scoped_ptr<TestService> test_service_;
 265   // Text message from "Test" signal.
 266   std::string test_signal_string_;
 267   // Text message from "Test" signal delivered to root.
 268   std::string root_test_signal_string_;
 269   int on_disconnected_call_count_;
 270 };
 271
 272 TEST_F(EndToEndAsyncTest, Echo) {
 273   const char* kHello = "hello";
 274
 275   // Create the method call.
 276   MethodCall method_call("org.chromium.TestInterface", "Echo");
 277   MessageWriter writer(&method_call);
 278   writer.AppendString(kHello);
 279
 280   // Call the method.
 281   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 282   CallMethod(&method_call, timeout_ms);
 283
 284   // Check the response.
 285   WaitForResponses(1);
 286   EXPECT_EQ(kHello, response_strings_[0]);
 287 }
 288
 289 TEST_F(EndToEndAsyncTest, EchoWithErrorCallback) {
 290   const char* kHello = "hello";
 291
 292   // Create the method call.
 293   MethodCall method_call("org.chromium.TestInterface", "Echo");
 294   MessageWriter writer(&method_call);
 295   writer.AppendString(kHello);
 296
 297   // Call the method.
 298   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 299   CallMethodWithErrorCallback(&method_call, timeout_ms);
 300
 301   // Check the response.
 302   WaitForResponses(1);
 303   EXPECT_EQ(kHello, response_strings_[0]);
 304   EXPECT_TRUE(error_names_.empty());
 305 }
 306
 307 // Call Echo method three times.
 308 TEST_F(EndToEndAsyncTest, EchoThreeTimes) {
 309   const char* kMessages[] = { "foo", "bar", "baz" };
 310
 311   for (size_t i = 0; i < arraysize(kMessages); ++i) {
 312     // Create the method call.
 313     MethodCall method_call("org.chromium.TestInterface", "Echo");
 314     MessageWriter writer(&method_call);
 315     writer.AppendString(kMessages[i]);
 316
 317     // Call the method.
 318     const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 319     CallMethod(&method_call, timeout_ms);
 320   }
 321
 322   // Check the responses.
 323   WaitForResponses(3);
 324   // Sort as the order of the returned messages is not deterministic.
 325   std::sort(response_strings_.begin(), response_strings_.end());
 326   EXPECT_EQ("bar", response_strings_[0]);
 327   EXPECT_EQ("baz", response_strings_[1]);
 328   EXPECT_EQ("foo", response_strings_[2]);
 329 }
 330
 331 TEST_F(EndToEndAsyncTest, Echo_HugePayload) {
 332   const std::string kHugePayload(kHugePayloadSize, 'o');
 333
 334   // Create the method call with a huge payload.
 335   MethodCall method_call("org.chromium.TestInterface", "Echo");
 336   MessageWriter writer(&method_call);
 337   writer.AppendString(kHugePayload);
 338
 339   // Call the method.
 340   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 341   CallMethod(&method_call, timeout_ms);
 342
 343   // This caused a DCHECK failure before. Ensure that the issue is fixed.
 344   WaitForResponses(1);
 345   EXPECT_EQ(kHugePayload, response_strings_[0]);
 346 }
 347
 348 TEST_F(EndToEndAsyncTest, BrokenBus) {
 349   const char* kHello = "hello";
 350
 351   // Set up a broken bus.
 352   SetUpBrokenBus();
 353
 354   // Create the method call.
 355   MethodCall method_call("org.chromium.TestInterface", "Echo");
 356   MessageWriter writer(&method_call);
 357   writer.AppendString(kHello);
 358
 359   // Call the method.
 360   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 361   CallMethod(&method_call, timeout_ms);
 362   WaitForResponses(1);
 363
 364   // Should fail because of the broken bus.
 365   ASSERT_EQ("", response_strings_[0]);
 366 }
 367
 368 TEST_F(EndToEndAsyncTest, BrokenBusWithErrorCallback) {
 369   const char* kHello = "hello";
 370
 371   // Set up a broken bus.
 372   SetUpBrokenBus();
 373
 374   // Create the method call.
 375   MethodCall method_call("org.chromium.TestInterface", "Echo");
 376   MessageWriter writer(&method_call);
 377   writer.AppendString(kHello);
 378
 379   // Call the method.
 380   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 381   CallMethodWithErrorCallback(&method_call, timeout_ms);
 382   WaitForErrors(1);
 383
 384   // Should fail because of the broken bus.
 385   ASSERT_TRUE(response_strings_.empty());
 386   ASSERT_EQ("", error_names_[0]);
 387 }
 388
 389 TEST_F(EndToEndAsyncTest, Timeout) {
 390   const char* kHello = "hello";
 391
 392   // Create the method call.
 393   MethodCall method_call("org.chromium.TestInterface", "SlowEcho");
 394   MessageWriter writer(&method_call);
 395   writer.AppendString(kHello);
 396
 397   // Call the method with timeout of 0ms.
 398   const int timeout_ms = 0;
 399   CallMethod(&method_call, timeout_ms);
 400   WaitForResponses(1);
 401
 402   // Should fail because of timeout.
 403   ASSERT_EQ("", response_strings_[0]);
 404 }
 405
 406 TEST_F(EndToEndAsyncTest, TimeoutWithErrorCallback) {
 407   const char* kHello = "hello";
 408
 409   // Create the method call.
 410   MethodCall method_call("org.chromium.TestInterface", "SlowEcho");
 411   MessageWriter writer(&method_call);
 412   writer.AppendString(kHello);
 413
 414   // Call the method with timeout of 0ms.
 415   const int timeout_ms = 0;
 416   CallMethodWithErrorCallback(&method_call, timeout_ms);
 417   WaitForErrors(1);
 418
 419   // Should fail because of timeout.
 420   ASSERT_TRUE(response_strings_.empty());
 421   ASSERT_EQ(DBUS_ERROR_NO_REPLY, error_names_[0]);
 422 }
 423
 424 // Tests calling a method that sends its reply asynchronously.
 425 TEST_F(EndToEndAsyncTest, AsyncEcho) {
 426   const char* kHello = "hello";
 427
 428   // Create the method call.
 429   MethodCall method_call("org.chromium.TestInterface", "AsyncEcho");
 430   MessageWriter writer(&method_call);
 431   writer.AppendString(kHello);
 432
 433   // Call the method.
 434   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 435   CallMethod(&method_call, timeout_ms);
 436
 437   // Check the response.
 438   WaitForResponses(1);
 439   EXPECT_EQ(kHello, response_strings_[0]);
 440 }
 441
 442 TEST_F(EndToEndAsyncTest, NonexistentMethod) {
 443   MethodCall method_call("org.chromium.TestInterface", "Nonexistent");
 444
 445   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 446   CallMethod(&method_call, timeout_ms);
 447   WaitForResponses(1);
 448
 449   // Should fail because the method is nonexistent.
 450   ASSERT_EQ("", response_strings_[0]);
 451 }
 452
 453 TEST_F(EndToEndAsyncTest, NonexistentMethodWithErrorCallback) {
 454   MethodCall method_call("org.chromium.TestInterface", "Nonexistent");
 455
 456   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 457   CallMethodWithErrorCallback(&method_call, timeout_ms);
 458   WaitForErrors(1);
 459
 460   // Should fail because the method is nonexistent.
 461   ASSERT_TRUE(response_strings_.empty());
 462   ASSERT_EQ(DBUS_ERROR_UNKNOWN_METHOD, error_names_[0]);
 463 }
 464
 465 TEST_F(EndToEndAsyncTest, BrokenMethod) {
 466   MethodCall method_call("org.chromium.TestInterface", "BrokenMethod");
 467
 468   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 469   CallMethod(&method_call, timeout_ms);
 470   WaitForResponses(1);
 471
 472   // Should fail because the method is broken.
 473   ASSERT_EQ("", response_strings_[0]);
 474 }
 475
 476 TEST_F(EndToEndAsyncTest, BrokenMethodWithErrorCallback) {
 477   MethodCall method_call("org.chromium.TestInterface", "BrokenMethod");
 478
 479   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 480   CallMethodWithErrorCallback(&method_call, timeout_ms);
 481   WaitForErrors(1);
 482
 483   // Should fail because the method is broken.
 484   ASSERT_TRUE(response_strings_.empty());
 485   ASSERT_EQ(DBUS_ERROR_FAILED, error_names_[0]);
 486 }
 487
 488 TEST_F(EndToEndAsyncTest, InvalidObjectPath) {
 489   // Trailing '/' is only allowed for the root path.
 490   const ObjectPath invalid_object_path("/org/chromium/TestObject/");
 491
 492   // Replace object proxy with new one.
 493   object_proxy_ = bus_->GetObjectProxy("org.chromium.TestService",
 494                                        invalid_object_path);
 495
 496   MethodCall method_call("org.chromium.TestInterface", "Echo");
 497
 498   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 499   CallMethodWithErrorCallback(&method_call, timeout_ms);
 500   WaitForErrors(1);
 501
 502   // Should fail because of the invalid path.
 503   ASSERT_TRUE(response_strings_.empty());
 504   ASSERT_EQ("", error_names_[0]);
 505 }
 506
 507 TEST_F(EndToEndAsyncTest, InvalidServiceName) {
 508   // Bus name cannot contain '/'.
 509   const std::string invalid_service_name = ":1/2";
 510
 511   // Replace object proxy with new one.
 512   object_proxy_ = bus_->GetObjectProxy(
 513       invalid_service_name, ObjectPath("org.chromium.TestObject"));
 514
 515   MethodCall method_call("org.chromium.TestInterface", "Echo");
 516
 517   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 518   CallMethodWithErrorCallback(&method_call, timeout_ms);
 519   WaitForErrors(1);
 520
 521   // Should fail because of the invalid bus name.
 522   ASSERT_TRUE(response_strings_.empty());
 523   ASSERT_EQ("", error_names_[0]);
 524 }
 525
 526 TEST_F(EndToEndAsyncTest, EmptyResponseCallback) {
 527   const char* kHello = "hello";
 528
 529   // Create the method call.
 530   MethodCall method_call("org.chromium.TestInterface", "Echo");
 531   MessageWriter writer(&method_call);
 532   writer.AppendString(kHello);
 533
 534   // Call the method with an empty callback.
 535   const int timeout_ms = ObjectProxy::TIMEOUT_USE_DEFAULT;
 536   object_proxy_->CallMethod(&method_call,
 537                             timeout_ms,
 538                             ObjectProxy::EmptyResponseCallback());
 539   // Post a delayed task to quit the message loop.
 540   message_loop_.PostDelayedTask(FROM_HERE,
 541                                 base::MessageLoop::QuitClosure(),
 542                                 TestTimeouts::tiny_timeout());
 543   message_loop_.Run();
 544   // We cannot tell if the empty callback is called, but at least we can
 545   // check if the test does not crash.
 546 }
 547
 548 TEST_F(EndToEndAsyncTest, TestSignal) {
 549   const char kMessage[] = "hello, world";
 550   // Send the test signal from the exported object.
 551   test_service_->SendTestSignal(kMessage);
 552   // Receive the signal with the object proxy. The signal is handled in
 553   // EndToEndAsyncTest::OnTestSignal() in the main thread.
 554   WaitForTestSignal();
 555   ASSERT_EQ(kMessage, test_signal_string_);
 556 }
 557
 558 TEST_F(EndToEndAsyncTest, TestSignalFromRoot) {
 559   const char kMessage[] = "hello, world";
 560   // Object proxies are tied to a particular object path, if a signal
 561   // arrives from a different object path like "/" the first object proxy
 562   // |object_proxy_| should not handle it, and should leave it for the root
 563   // object proxy |root_object_proxy_|.
 564   test_service_->SendTestSignalFromRoot(kMessage);
 565   WaitForTestSignal();
 566   // Verify the signal was not received by the specific proxy.
 567   ASSERT_TRUE(test_signal_string_.empty());
 568   // Verify the string WAS received by the root proxy.
 569   ASSERT_EQ(kMessage, root_test_signal_string_);
 570 }
 571
 572 TEST_F(EndToEndAsyncTest, TestHugeSignal) {
 573   const std::string kHugeMessage(kHugePayloadSize, 'o');
 574
 575   // Send the huge signal from the exported object.
 576   test_service_->SendTestSignal(kHugeMessage);
 577   // This caused a DCHECK failure before. Ensure that the issue is fixed.
 578   WaitForTestSignal();
 579   ASSERT_EQ(kHugeMessage, test_signal_string_);
 580 }
 581
 582 TEST_F(EndToEndAsyncTest, DisconnectedSignal) {
 583   bus_->GetDBusTaskRunner()->PostTask(FROM_HERE,
 584                                       base::Bind(&Bus::ClosePrivateConnection,
 585                                                  base::Unretained(bus_.get())));
 586   // OnDisconnected callback quits message loop.
 587   message_loop_.Run();
 588   EXPECT_EQ(1, on_disconnected_call_count_);
 589 }
 590
 591 class SignalMultipleHandlerTest : public EndToEndAsyncTest {
 592  public:
 593   SignalMultipleHandlerTest() {
 594   }
 595
 596   virtual void SetUp() {
 597     // Set up base class.
 598     EndToEndAsyncTest::SetUp();
 599
 600     // Connect the root object proxy's signal handler to a new handler
 601     // so that we can verify that a second call to ConnectSignal() delivers
 602     // to both our new handler and the old.
 603     object_proxy_->ConnectToSignal(
 604         "org.chromium.TestInterface",
 605         "Test",
 606         base::Bind(&SignalMultipleHandlerTest::OnAdditionalTestSignal,
 607                    base::Unretained(this)),
 608         base::Bind(&SignalMultipleHandlerTest::OnAdditionalConnected,
 609                    base::Unretained(this)));
 610     // Wait until the object proxy is connected to the signal.
 611     message_loop_.Run();
 612   }
 613
 614  protected:
 615   // Called when the "Test" signal is received, in the main thread.
 616   // Copy the string payload to |additional_test_signal_string_|.
 617   void OnAdditionalTestSignal(Signal* signal) {
 618     MessageReader reader(signal);
 619     ASSERT_TRUE(reader.PopString(&additional_test_signal_string_));
 620     message_loop_.Quit();
 621   }
 622
 623   // Called when connected to the signal.
 624   void OnAdditionalConnected(const std::string& interface_name,
 625                              const std::string& signal_name,
 626                              bool success) {
 627     ASSERT_TRUE(success);
 628     message_loop_.Quit();
 629   }
 630
 631   // Text message from "Test" signal delivered to additional handler.
 632   std::string additional_test_signal_string_;
 633 };
 634
 635 TEST_F(SignalMultipleHandlerTest, TestMultipleHandlers) {
 636   const char kMessage[] = "hello, world";
 637   // Send the test signal from the exported object.
 638   test_service_->SendTestSignal(kMessage);
 639   // Receive the signal with the object proxy.
 640   WaitForTestSignal();
 641   // Verify the string WAS received by the original handler.
 642   ASSERT_EQ(kMessage, test_signal_string_);
 643   // Verify the signal WAS ALSO received by the additional handler.
 644   ASSERT_EQ(kMessage, additional_test_signal_string_);
 645 }
 646
 647 }  // namespace dbus