base/message_loop/message_pump_glib_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 "base/message_loop/message_pump_glib.h"
   6
   7 #include <glib.h>
   8 #include <math.h>
   9
  10 #include <algorithm>
  11 #include <vector>
  12
  13 #include "base/bind.h"
  14 #include "base/bind_helpers.h"
  15 #include "base/callback.h"
  16 #include "base/memory/ref_counted.h"
  17 #include "base/message_loop/message_loop.h"
  18 #include "base/run_loop.h"
  19 #include "base/threading/thread.h"
  20 #include "testing/gtest/include/gtest/gtest.h"
  21
  22 namespace base {
  23 namespace {
  24
  25 // This class injects dummy "events" into the GLib loop. When "handled" these
  26 // events can run tasks. This is intended to mock gtk events (the corresponding
  27 // GLib source runs at the same priority).
  28 class EventInjector {
  29  public:
  30   EventInjector() : processed_events_(0) {
  31     source_ = static_cast<Source*>(g_source_new(&SourceFuncs, sizeof(Source)));
  32     source_->injector = this;
  33     g_source_attach(source_, NULL);
  34     g_source_set_can_recurse(source_, TRUE);
  35   }
  36
  37   ~EventInjector() {
  38     g_source_destroy(source_);
  39     g_source_unref(source_);
  40   }
  41
  42   int HandlePrepare() {
  43     // If the queue is empty, block.
  44     if (events_.empty())
  45       return -1;
  46     TimeDelta delta = events_[0].time - Time::NowFromSystemTime();
  47     return std::max(0, static_cast<int>(ceil(delta.InMillisecondsF())));
  48   }
  49
  50   bool HandleCheck() {
  51     if (events_.empty())
  52       return false;
  53     return events_[0].time <= Time::NowFromSystemTime();
  54   }
  55
  56   void HandleDispatch() {
  57     if (events_.empty())
  58       return;
  59     Event event = events_[0];
  60     events_.erase(events_.begin());
  61     ++processed_events_;
  62     if (!event.callback.is_null())
  63       event.callback.Run();
  64     else if (!event.task.is_null())
  65       event.task.Run();
  66   }
  67
  68   // Adds an event to the queue. When "handled", executes |callback|.
  69   // delay_ms is relative to the last event if any, or to Now() otherwise.
  70   void AddEvent(int delay_ms, const Closure& callback) {
  71     AddEventHelper(delay_ms, callback, Closure());
  72   }
  73
  74   void AddDummyEvent(int delay_ms) {
  75     AddEventHelper(delay_ms, Closure(), Closure());
  76   }
  77
  78   void AddEventAsTask(int delay_ms, const Closure& task) {
  79     AddEventHelper(delay_ms, Closure(), task);
  80   }
  81
  82   void Reset() {
  83     processed_events_ = 0;
  84     events_.clear();
  85   }
  86
  87   int processed_events() const { return processed_events_; }
  88
  89  private:
  90   struct Event {
  91     Time time;
  92     Closure callback;
  93     Closure task;
  94   };
  95
  96   struct Source : public GSource {
  97     EventInjector* injector;
  98   };
  99
 100   void AddEventHelper(
 101       int delay_ms, const Closure& callback, const Closure& task) {
 102     Time last_time;
 103     if (!events_.empty())
 104       last_time = (events_.end()-1)->time;
 105     else
 106       last_time = Time::NowFromSystemTime();
 107
 108     Time future = last_time + TimeDelta::FromMilliseconds(delay_ms);
 109     EventInjector::Event event = {future, callback, task};
 110     events_.push_back(event);
 111   }
 112
 113   static gboolean Prepare(GSource* source, gint* timeout_ms) {
 114     *timeout_ms = static_cast<Source*>(source)->injector->HandlePrepare();
 115     return FALSE;
 116   }
 117
 118   static gboolean Check(GSource* source) {
 119     return static_cast<Source*>(source)->injector->HandleCheck();
 120   }
 121
 122   static gboolean Dispatch(GSource* source,
 123                            GSourceFunc unused_func,
 124                            gpointer unused_data) {
 125     static_cast<Source*>(source)->injector->HandleDispatch();
 126     return TRUE;
 127   }
 128
 129   Source* source_;
 130   std::vector<Event> events_;
 131   int processed_events_;
 132   static GSourceFuncs SourceFuncs;
 133   DISALLOW_COPY_AND_ASSIGN(EventInjector);
 134 };
 135
 136 GSourceFuncs EventInjector::SourceFuncs = {
 137   EventInjector::Prepare,
 138   EventInjector::Check,
 139   EventInjector::Dispatch,
 140   NULL
 141 };
 142
 143 void IncrementInt(int *value) {
 144   ++*value;
 145 }
 146
 147 // Checks how many events have been processed by the injector.
 148 void ExpectProcessedEvents(EventInjector* injector, int count) {
 149   EXPECT_EQ(injector->processed_events(), count);
 150 }
 151
 152 // Posts a task on the current message loop.
 153 void PostMessageLoopTask(const tracked_objects::Location& from_here,
 154                          const Closure& task) {
 155   MessageLoop::current()->PostTask(from_here, task);
 156 }
 157
 158 // Test fixture.
 159 class MessagePumpGLibTest : public testing::Test {
 160  public:
 161   MessagePumpGLibTest() : loop_(NULL), injector_(NULL) { }
 162
 163   // Overridden from testing::Test:
 164   void SetUp() override {
 165     loop_ = new MessageLoop(MessageLoop::TYPE_UI);
 166     injector_ = new EventInjector();
 167   }
 168   void TearDown() override {
 169     delete injector_;
 170     injector_ = NULL;
 171     delete loop_;
 172     loop_ = NULL;
 173   }
 174
 175   MessageLoop* loop() const { return loop_; }
 176   EventInjector* injector() const { return injector_; }
 177
 178  private:
 179   MessageLoop* loop_;
 180   EventInjector* injector_;
 181   DISALLOW_COPY_AND_ASSIGN(MessagePumpGLibTest);
 182 };
 183
 184 }  // namespace
 185
 186 TEST_F(MessagePumpGLibTest, TestQuit) {
 187   // Checks that Quit works and that the basic infrastructure is working.
 188
 189   // Quit from a task
 190   RunLoop().RunUntilIdle();
 191   EXPECT_EQ(0, injector()->processed_events());
 192
 193   injector()->Reset();
 194   // Quit from an event
 195   injector()->AddEvent(0, MessageLoop::QuitWhenIdleClosure());
 196   loop()->Run();
 197   EXPECT_EQ(1, injector()->processed_events());
 198 }
 199
 200 TEST_F(MessagePumpGLibTest, TestEventTaskInterleave) {
 201   // Checks that tasks posted by events are executed before the next event if
 202   // the posted task queue is empty.
 203   // MessageLoop doesn't make strong guarantees that it is the case, but the
 204   // current implementation ensures it and the tests below rely on it.
 205   // If changes cause this test to fail, it is reasonable to change it, but
 206   // TestWorkWhileWaitingForEvents and TestEventsWhileWaitingForWork have to be
 207   // changed accordingly, otherwise they can become flaky.
 208   injector()->AddEventAsTask(0, Bind(&DoNothing));
 209   Closure check_task =
 210       Bind(&ExpectProcessedEvents, Unretained(injector()), 2);
 211   Closure posted_task =
 212       Bind(&PostMessageLoopTask, FROM_HERE, check_task);
 213   injector()->AddEventAsTask(0, posted_task);
 214   injector()->AddEventAsTask(0, Bind(&DoNothing));
 215   injector()->AddEvent(0, MessageLoop::QuitWhenIdleClosure());
 216   loop()->Run();
 217   EXPECT_EQ(4, injector()->processed_events());
 218
 219   injector()->Reset();
 220   injector()->AddEventAsTask(0, Bind(&DoNothing));
 221   check_task =
 222       Bind(&ExpectProcessedEvents, Unretained(injector()), 2);
 223   posted_task = Bind(&PostMessageLoopTask, FROM_HERE, check_task);
 224   injector()->AddEventAsTask(0, posted_task);
 225   injector()->AddEventAsTask(10, Bind(&DoNothing));
 226   injector()->AddEvent(0, MessageLoop::QuitWhenIdleClosure());
 227   loop()->Run();
 228   EXPECT_EQ(4, injector()->processed_events());
 229 }
 230
 231 TEST_F(MessagePumpGLibTest, TestWorkWhileWaitingForEvents) {
 232   int task_count = 0;
 233   // Tests that we process tasks while waiting for new events.
 234   // The event queue is empty at first.
 235   for (int i = 0; i < 10; ++i) {
 236     loop()->PostTask(FROM_HERE, Bind(&IncrementInt, &task_count));
 237   }
 238   // After all the previous tasks have executed, enqueue an event that will
 239   // quit.
 240   loop()->PostTask(
 241       FROM_HERE,
 242       Bind(&EventInjector::AddEvent, Unretained(injector()), 0,
 243                  MessageLoop::QuitWhenIdleClosure()));
 244   loop()->Run();
 245   ASSERT_EQ(10, task_count);
 246   EXPECT_EQ(1, injector()->processed_events());
 247
 248   // Tests that we process delayed tasks while waiting for new events.
 249   injector()->Reset();
 250   task_count = 0;
 251   for (int i = 0; i < 10; ++i) {
 252     loop()->PostDelayedTask(
 253         FROM_HERE,
 254         Bind(&IncrementInt, &task_count),
 255         TimeDelta::FromMilliseconds(10*i));
 256   }
 257   // After all the previous tasks have executed, enqueue an event that will
 258   // quit.
 259   // This relies on the fact that delayed tasks are executed in delay order.
 260   // That is verified in message_loop_unittest.cc.
 261   loop()->PostDelayedTask(
 262       FROM_HERE,
 263       Bind(&EventInjector::AddEvent, Unretained(injector()), 10,
 264                  MessageLoop::QuitWhenIdleClosure()),
 265       TimeDelta::FromMilliseconds(150));
 266   loop()->Run();
 267   ASSERT_EQ(10, task_count);
 268   EXPECT_EQ(1, injector()->processed_events());
 269 }
 270
 271 TEST_F(MessagePumpGLibTest, TestEventsWhileWaitingForWork) {
 272   // Tests that we process events while waiting for work.
 273   // The event queue is empty at first.
 274   for (int i = 0; i < 10; ++i) {
 275     injector()->AddDummyEvent(0);
 276   }
 277   // After all the events have been processed, post a task that will check that
 278   // the events have been processed (note: the task executes after the event
 279   // that posted it has been handled, so we expect 11 at that point).
 280   Closure check_task =
 281       Bind(&ExpectProcessedEvents, Unretained(injector()), 11);
 282   Closure posted_task =
 283       Bind(&PostMessageLoopTask, FROM_HERE, check_task);
 284   injector()->AddEventAsTask(10, posted_task);
 285
 286   // And then quit (relies on the condition tested by TestEventTaskInterleave).
 287   injector()->AddEvent(10, MessageLoop::QuitWhenIdleClosure());
 288   loop()->Run();
 289
 290   EXPECT_EQ(12, injector()->processed_events());
 291 }
 292
 293 namespace {
 294
 295 // This class is a helper for the concurrent events / posted tasks test below.
 296 // It will quit the main loop once enough tasks and events have been processed,
 297 // while making sure there is always work to do and events in the queue.
 298 class ConcurrentHelper : public RefCounted<ConcurrentHelper>  {
 299  public:
 300   explicit ConcurrentHelper(EventInjector* injector)
 301       : injector_(injector),
 302         event_count_(kStartingEventCount),
 303         task_count_(kStartingTaskCount) {
 304   }
 305
 306   void FromTask() {
 307     if (task_count_ > 0) {
 308       --task_count_;
 309     }
 310     if (task_count_ == 0 && event_count_ == 0) {
 311         MessageLoop::current()->QuitWhenIdle();
 312     } else {
 313       MessageLoop::current()->PostTask(
 314           FROM_HERE, Bind(&ConcurrentHelper::FromTask, this));
 315     }
 316   }
 317
 318   void FromEvent() {
 319     if (event_count_ > 0) {
 320       --event_count_;
 321     }
 322     if (task_count_ == 0 && event_count_ == 0) {
 323         MessageLoop::current()->QuitWhenIdle();
 324     } else {
 325       injector_->AddEventAsTask(
 326           0, Bind(&ConcurrentHelper::FromEvent, this));
 327     }
 328   }
 329
 330   int event_count() const { return event_count_; }
 331   int task_count() const { return task_count_; }
 332
 333  private:
 334   friend class RefCounted<ConcurrentHelper>;
 335
 336   ~ConcurrentHelper() {}
 337
 338   static const int kStartingEventCount = 20;
 339   static const int kStartingTaskCount = 20;
 340
 341   EventInjector* injector_;
 342   int event_count_;
 343   int task_count_;
 344 };
 345
 346 }  // namespace
 347
 348 TEST_F(MessagePumpGLibTest, TestConcurrentEventPostedTask) {
 349   // Tests that posted tasks don't starve events, nor the opposite.
 350   // We use the helper class above. We keep both event and posted task queues
 351   // full, the helper verifies that both tasks and events get processed.
 352   // If that is not the case, either event_count_ or task_count_ will not get
 353   // to 0, and MessageLoop::QuitWhenIdle() will never be called.
 354   scoped_refptr<ConcurrentHelper> helper = new ConcurrentHelper(injector());
 355
 356   // Add 2 events to the queue to make sure it is always full (when we remove
 357   // the event before processing it).
 358   injector()->AddEventAsTask(
 359       0, Bind(&ConcurrentHelper::FromEvent, helper.get()));
 360   injector()->AddEventAsTask(
 361       0, Bind(&ConcurrentHelper::FromEvent, helper.get()));
 362
 363   // Similarly post 2 tasks.
 364   loop()->PostTask(
 365       FROM_HERE, Bind(&ConcurrentHelper::FromTask, helper.get()));
 366   loop()->PostTask(
 367       FROM_HERE, Bind(&ConcurrentHelper::FromTask, helper.get()));
 368
 369   loop()->Run();
 370   EXPECT_EQ(0, helper->event_count());
 371   EXPECT_EQ(0, helper->task_count());
 372 }
 373
 374 namespace {
 375
 376 void AddEventsAndDrainGLib(EventInjector* injector) {
 377   // Add a couple of dummy events
 378   injector->AddDummyEvent(0);
 379   injector->AddDummyEvent(0);
 380   // Then add an event that will quit the main loop.
 381   injector->AddEvent(0, MessageLoop::QuitWhenIdleClosure());
 382
 383   // Post a couple of dummy tasks
 384   MessageLoop::current()->PostTask(FROM_HERE, Bind(&DoNothing));
 385   MessageLoop::current()->PostTask(FROM_HERE, Bind(&DoNothing));
 386
 387   // Drain the events
 388   while (g_main_context_pending(NULL)) {
 389     g_main_context_iteration(NULL, FALSE);
 390   }
 391 }
 392
 393 }  // namespace
 394
 395 TEST_F(MessagePumpGLibTest, TestDrainingGLib) {
 396   // Tests that draining events using GLib works.
 397   loop()->PostTask(
 398       FROM_HERE,
 399       Bind(&AddEventsAndDrainGLib, Unretained(injector())));
 400   loop()->Run();
 401
 402   EXPECT_EQ(3, injector()->processed_events());
 403 }
 404
 405 namespace {
 406
 407 // Helper class that lets us run the GLib message loop.
 408 class GLibLoopRunner : public RefCounted<GLibLoopRunner> {
 409  public:
 410   GLibLoopRunner() : quit_(false) { }
 411
 412   void RunGLib() {
 413     while (!quit_) {
 414       g_main_context_iteration(NULL, TRUE);
 415     }
 416   }
 417
 418   void RunLoop() {
 419     while (!quit_) {
 420       g_main_context_iteration(NULL, TRUE);
 421     }
 422   }
 423
 424   void Quit() {
 425     quit_ = true;
 426   }
 427
 428   void Reset() {
 429     quit_ = false;
 430   }
 431
 432  private:
 433   friend class RefCounted<GLibLoopRunner>;
 434
 435   ~GLibLoopRunner() {}
 436
 437   bool quit_;
 438 };
 439
 440 void TestGLibLoopInternal(EventInjector* injector) {
 441   // Allow tasks to be processed from 'native' event loops.
 442   MessageLoop::current()->SetNestableTasksAllowed(true);
 443   scoped_refptr<GLibLoopRunner> runner = new GLibLoopRunner();
 444
 445   int task_count = 0;
 446   // Add a couple of dummy events
 447   injector->AddDummyEvent(0);
 448   injector->AddDummyEvent(0);
 449   // Post a couple of dummy tasks
 450   MessageLoop::current()->PostTask(
 451       FROM_HERE, Bind(&IncrementInt, &task_count));
 452   MessageLoop::current()->PostTask(
 453       FROM_HERE, Bind(&IncrementInt, &task_count));
 454   // Delayed events
 455   injector->AddDummyEvent(10);
 456   injector->AddDummyEvent(10);
 457   // Delayed work
 458   MessageLoop::current()->PostDelayedTask(
 459       FROM_HERE,
 460       Bind(&IncrementInt, &task_count),
 461       TimeDelta::FromMilliseconds(30));
 462   MessageLoop::current()->PostDelayedTask(
 463       FROM_HERE,
 464       Bind(&GLibLoopRunner::Quit, runner.get()),
 465       TimeDelta::FromMilliseconds(40));
 466
 467   // Run a nested, straight GLib message loop.
 468   runner->RunGLib();
 469
 470   ASSERT_EQ(3, task_count);
 471   EXPECT_EQ(4, injector->processed_events());
 472   MessageLoop::current()->QuitWhenIdle();
 473 }
 474
 475 void TestGtkLoopInternal(EventInjector* injector) {
 476   // Allow tasks to be processed from 'native' event loops.
 477   MessageLoop::current()->SetNestableTasksAllowed(true);
 478   scoped_refptr<GLibLoopRunner> runner = new GLibLoopRunner();
 479
 480   int task_count = 0;
 481   // Add a couple of dummy events
 482   injector->AddDummyEvent(0);
 483   injector->AddDummyEvent(0);
 484   // Post a couple of dummy tasks
 485   MessageLoop::current()->PostTask(
 486       FROM_HERE, Bind(&IncrementInt, &task_count));
 487   MessageLoop::current()->PostTask(
 488       FROM_HERE, Bind(&IncrementInt, &task_count));
 489   // Delayed events
 490   injector->AddDummyEvent(10);
 491   injector->AddDummyEvent(10);
 492   // Delayed work
 493   MessageLoop::current()->PostDelayedTask(
 494       FROM_HERE,
 495       Bind(&IncrementInt, &task_count),
 496       TimeDelta::FromMilliseconds(30));
 497   MessageLoop::current()->PostDelayedTask(
 498       FROM_HERE,
 499       Bind(&GLibLoopRunner::Quit, runner.get()),
 500       TimeDelta::FromMilliseconds(40));
 501
 502   // Run a nested, straight Gtk message loop.
 503   runner->RunLoop();
 504
 505   ASSERT_EQ(3, task_count);
 506   EXPECT_EQ(4, injector->processed_events());
 507   MessageLoop::current()->QuitWhenIdle();
 508 }
 509
 510 }  // namespace
 511
 512 TEST_F(MessagePumpGLibTest, TestGLibLoop) {
 513   // Tests that events and posted tasks are correctly executed if the message
 514   // loop is not run by MessageLoop::Run() but by a straight GLib loop.
 515   // Note that in this case we don't make strong guarantees about niceness
 516   // between events and posted tasks.
 517   loop()->PostTask(
 518       FROM_HERE,
 519       Bind(&TestGLibLoopInternal, Unretained(injector())));
 520   loop()->Run();
 521 }
 522
 523 TEST_F(MessagePumpGLibTest, TestGtkLoop) {
 524   // Tests that events and posted tasks are correctly executed if the message
 525   // loop is not run by MessageLoop::Run() but by a straight Gtk loop.
 526   // Note that in this case we don't make strong guarantees about niceness
 527   // between events and posted tasks.
 528   loop()->PostTask(
 529       FROM_HERE,
 530       Bind(&TestGtkLoopInternal, Unretained(injector())));
 531   loop()->Run();
 532 }
 533
 534 }  // namespace base