base/message_loop/message_loop_proxy_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_loop_proxy.h"
   6
   7 #include "base/atomic_sequence_num.h"
   8 #include "base/bind.h"
   9 #include "base/debug/leak_annotations.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/synchronization/waitable_event.h"
  14 #include "base/threading/thread.h"
  15 #include "testing/gtest/include/gtest/gtest.h"
  16
  17 namespace base {
  18
  19 namespace {
  20
  21 class MessageLoopProxyTest : public testing::Test {
  22  public:
  23   MessageLoopProxyTest()
  24       : current_loop_(new MessageLoop()),
  25         task_thread_("task_thread"),
  26         thread_sync_(true, false) {
  27   }
  28
  29   void DeleteCurrentMessageLoop() {
  30     current_loop_.reset();
  31   }
  32
  33  protected:
  34   void SetUp() override {
  35     // Use SetUp() instead of the constructor to avoid posting a task to a
  36     // partialy constructed object.
  37     task_thread_.Start();
  38
  39     // Allow us to pause the |task_thread_|'s MessageLoop.
  40     task_thread_.message_loop()->PostTask(
  41         FROM_HERE,
  42         Bind(&MessageLoopProxyTest::BlockTaskThreadHelper, Unretained(this)));
  43   }
  44
  45   void TearDown() override {
  46     // Make sure the |task_thread_| is not blocked, and stop the thread
  47     // fully before destuction because its tasks may still depend on the
  48     // |thread_sync_| event.
  49     thread_sync_.Signal();
  50     task_thread_.Stop();
  51     DeleteCurrentMessageLoop();
  52   }
  53
  54   // Make LoopRecorder threadsafe so that there is defined behavior even if a
  55   // threading mistake sneaks into the PostTaskAndReplyRelay implementation.
  56   class LoopRecorder : public RefCountedThreadSafe<LoopRecorder> {
  57    public:
  58     LoopRecorder(MessageLoop** run_on, MessageLoop** deleted_on,
  59                  int* destruct_order)
  60         : run_on_(run_on),
  61           deleted_on_(deleted_on),
  62           destruct_order_(destruct_order) {
  63     }
  64
  65     void RecordRun() {
  66       *run_on_ = MessageLoop::current();
  67     }
  68
  69    private:
  70     friend class RefCountedThreadSafe<LoopRecorder>;
  71     ~LoopRecorder() {
  72       *deleted_on_ = MessageLoop::current();
  73       *destruct_order_ = g_order.GetNext();
  74     }
  75
  76     MessageLoop** run_on_;
  77     MessageLoop** deleted_on_;
  78     int* destruct_order_;
  79   };
  80
  81   static void RecordLoop(scoped_refptr<LoopRecorder> recorder) {
  82     recorder->RecordRun();
  83   }
  84
  85   static void RecordLoopAndQuit(scoped_refptr<LoopRecorder> recorder) {
  86     recorder->RecordRun();
  87     MessageLoop::current()->QuitWhenIdle();
  88   }
  89
  90   void UnblockTaskThread() {
  91     thread_sync_.Signal();
  92   }
  93
  94   void BlockTaskThreadHelper() {
  95     thread_sync_.Wait();
  96   }
  97
  98   static StaticAtomicSequenceNumber g_order;
  99
 100   scoped_ptr<MessageLoop> current_loop_;
 101   Thread task_thread_;
 102
 103  private:
 104   base::WaitableEvent thread_sync_;
 105 };
 106
 107 StaticAtomicSequenceNumber MessageLoopProxyTest::g_order;
 108
 109 TEST_F(MessageLoopProxyTest, PostTaskAndReply_Basic) {
 110   MessageLoop* task_run_on = NULL;
 111   MessageLoop* task_deleted_on = NULL;
 112   int task_delete_order = -1;
 113   MessageLoop* reply_run_on = NULL;
 114   MessageLoop* reply_deleted_on = NULL;
 115   int reply_delete_order = -1;
 116
 117   scoped_refptr<LoopRecorder> task_recoder =
 118       new LoopRecorder(&task_run_on, &task_deleted_on, &task_delete_order);
 119   scoped_refptr<LoopRecorder> reply_recoder =
 120       new LoopRecorder(&reply_run_on, &reply_deleted_on, &reply_delete_order);
 121
 122   ASSERT_TRUE(task_thread_.message_loop_proxy()->PostTaskAndReply(
 123       FROM_HERE,
 124       Bind(&RecordLoop, task_recoder),
 125       Bind(&RecordLoopAndQuit, reply_recoder)));
 126
 127   // Die if base::Bind doesn't retain a reference to the recorders.
 128   task_recoder = NULL;
 129   reply_recoder = NULL;
 130   ASSERT_FALSE(task_deleted_on);
 131   ASSERT_FALSE(reply_deleted_on);
 132
 133   UnblockTaskThread();
 134   current_loop_->Run();
 135
 136   EXPECT_EQ(task_thread_.message_loop(), task_run_on);
 137   EXPECT_EQ(current_loop_.get(), task_deleted_on);
 138   EXPECT_EQ(current_loop_.get(), reply_run_on);
 139   EXPECT_EQ(current_loop_.get(), reply_deleted_on);
 140   EXPECT_LT(task_delete_order, reply_delete_order);
 141 }
 142
 143 TEST_F(MessageLoopProxyTest, PostTaskAndReplyOnDeletedThreadDoesNotLeak) {
 144   MessageLoop* task_run_on = NULL;
 145   MessageLoop* task_deleted_on = NULL;
 146   int task_delete_order = -1;
 147   MessageLoop* reply_run_on = NULL;
 148   MessageLoop* reply_deleted_on = NULL;
 149   int reply_delete_order = -1;
 150
 151   scoped_refptr<LoopRecorder> task_recoder =
 152       new LoopRecorder(&task_run_on, &task_deleted_on, &task_delete_order);
 153   scoped_refptr<LoopRecorder> reply_recoder =
 154       new LoopRecorder(&reply_run_on, &reply_deleted_on, &reply_delete_order);
 155
 156   // Grab a MessageLoopProxy to a dead MessageLoop.
 157   scoped_refptr<MessageLoopProxy> task_loop_proxy =
 158       task_thread_.message_loop_proxy();
 159   UnblockTaskThread();
 160   task_thread_.Stop();
 161
 162   ASSERT_FALSE(task_loop_proxy->PostTaskAndReply(
 163       FROM_HERE,
 164       Bind(&RecordLoop, task_recoder),
 165       Bind(&RecordLoopAndQuit, reply_recoder)));
 166
 167   // The relay should have properly deleted its resources leaving us as the only
 168   // reference.
 169   EXPECT_EQ(task_delete_order, reply_delete_order);
 170   ASSERT_TRUE(task_recoder->HasOneRef());
 171   ASSERT_TRUE(reply_recoder->HasOneRef());
 172
 173   // Nothing should have run though.
 174   EXPECT_FALSE(task_run_on);
 175   EXPECT_FALSE(reply_run_on);
 176 }
 177
 178 TEST_F(MessageLoopProxyTest, PostTaskAndReply_SameLoop) {
 179   MessageLoop* task_run_on = NULL;
 180   MessageLoop* task_deleted_on = NULL;
 181   int task_delete_order = -1;
 182   MessageLoop* reply_run_on = NULL;
 183   MessageLoop* reply_deleted_on = NULL;
 184   int reply_delete_order = -1;
 185
 186   scoped_refptr<LoopRecorder> task_recoder =
 187       new LoopRecorder(&task_run_on, &task_deleted_on, &task_delete_order);
 188   scoped_refptr<LoopRecorder> reply_recoder =
 189       new LoopRecorder(&reply_run_on, &reply_deleted_on, &reply_delete_order);
 190
 191   // Enqueue the relay.
 192   ASSERT_TRUE(current_loop_->message_loop_proxy()->PostTaskAndReply(
 193       FROM_HERE,
 194       Bind(&RecordLoop, task_recoder),
 195       Bind(&RecordLoopAndQuit, reply_recoder)));
 196
 197   // Die if base::Bind doesn't retain a reference to the recorders.
 198   task_recoder = NULL;
 199   reply_recoder = NULL;
 200   ASSERT_FALSE(task_deleted_on);
 201   ASSERT_FALSE(reply_deleted_on);
 202
 203   current_loop_->Run();
 204
 205   EXPECT_EQ(current_loop_.get(), task_run_on);
 206   EXPECT_EQ(current_loop_.get(), task_deleted_on);
 207   EXPECT_EQ(current_loop_.get(), reply_run_on);
 208   EXPECT_EQ(current_loop_.get(), reply_deleted_on);
 209   EXPECT_LT(task_delete_order, reply_delete_order);
 210 }
 211
 212 TEST_F(MessageLoopProxyTest, PostTaskAndReply_DeadReplyLoopDoesNotDelete) {
 213   // Annotate the scope as having memory leaks to suppress heapchecker reports.
 214   ANNOTATE_SCOPED_MEMORY_LEAK;
 215   MessageLoop* task_run_on = NULL;
 216   MessageLoop* task_deleted_on = NULL;
 217   int task_delete_order = -1;
 218   MessageLoop* reply_run_on = NULL;
 219   MessageLoop* reply_deleted_on = NULL;
 220   int reply_delete_order = -1;
 221
 222   scoped_refptr<LoopRecorder> task_recoder =
 223       new LoopRecorder(&task_run_on, &task_deleted_on, &task_delete_order);
 224   scoped_refptr<LoopRecorder> reply_recoder =
 225       new LoopRecorder(&reply_run_on, &reply_deleted_on, &reply_delete_order);
 226
 227   // Enqueue the relay.
 228   task_thread_.message_loop_proxy()->PostTaskAndReply(
 229       FROM_HERE,
 230       Bind(&RecordLoop, task_recoder),
 231       Bind(&RecordLoopAndQuit, reply_recoder));
 232
 233   // Die if base::Bind doesn't retain a reference to the recorders.
 234   task_recoder = NULL;
 235   reply_recoder = NULL;
 236   ASSERT_FALSE(task_deleted_on);
 237   ASSERT_FALSE(reply_deleted_on);
 238
 239   UnblockTaskThread();
 240
 241   // Mercilessly whack the current loop before |reply| gets to run.
 242   current_loop_.reset();
 243
 244   // This should ensure the relay has been run.  We need to record the
 245   // MessageLoop pointer before stopping the thread because Thread::Stop() will
 246   // NULL out its own pointer.
 247   MessageLoop* task_loop = task_thread_.message_loop();
 248   task_thread_.Stop();
 249
 250   EXPECT_EQ(task_loop, task_run_on);
 251   ASSERT_FALSE(task_deleted_on);
 252   EXPECT_FALSE(reply_run_on);
 253   ASSERT_FALSE(reply_deleted_on);
 254   EXPECT_EQ(task_delete_order, reply_delete_order);
 255
 256   // The PostTaskAndReplyRelay is leaked here.  Even if we had a reference to
 257   // it, we cannot just delete it because PostTaskAndReplyRelay's destructor
 258   // checks that MessageLoop::current() is the the same as when the
 259   // PostTaskAndReplyRelay object was constructed.  However, this loop must have
 260   // aleady been deleted in order to perform this test.  See
 261   // http://crbug.com/86301.
 262 }
 263
 264 }  // namespace
 265
 266 }  // namespace base