content/renderer/scheduler/resource_dispatch_throttler_unittest.cc

   1 // Copyright 2014 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 "content/renderer/scheduler/resource_dispatch_throttler.h"
   6
   7 #include "base/memory/scoped_vector.h"
   8 #include "content/common/resource_messages.h"
   9 #include "content/test/fake_renderer_scheduler.h"
  10 #include "testing/gtest/include/gtest/gtest.h"
  11
  12 namespace content {
  13 namespace {
  14
  15 const uint32 kRequestsPerFlush = 4;
  16 const double kFlushPeriodSeconds = 1.f / 60;
  17 const int kRoutingId = 1;
  18
  19 typedef ScopedVector<IPC::Message> ScopedMessages;
  20
  21 int GetRequestId(const IPC::Message& msg) {
  22   int request_id = -1;
  23   switch (msg.type()) {
  24     case ResourceHostMsg_RequestResource::ID: {
  25       base::PickleIterator iter(msg);
  26       int routing_id = -1;
  27       if (!iter.ReadInt(&routing_id) || !iter.ReadInt(&request_id))
  28         NOTREACHED() << "Invalid id for resource request message.";
  29     } break;
  30
  31     case ResourceHostMsg_DidChangePriority::ID:
  32     case ResourceHostMsg_ReleaseDownloadedFile::ID:
  33     case ResourceHostMsg_CancelRequest::ID:
  34       if (!base::PickleIterator(msg).ReadInt(&request_id))
  35         NOTREACHED() << "Invalid id for resource message.";
  36       break;
  37
  38     default:
  39       NOTREACHED() << "Invalid message for resource throttling.";
  40       break;
  41   }
  42   return request_id;
  43 }
  44
  45 class RendererSchedulerForTest : public FakeRendererScheduler {
  46  public:
  47   RendererSchedulerForTest() : high_priority_work_anticipated_(false) {}
  48   ~RendererSchedulerForTest() override {}
  49
  50   // RendererScheduler implementation:
  51   bool IsHighPriorityWorkAnticipated() override {
  52     return high_priority_work_anticipated_;
  53   }
  54
  55   void set_high_priority_work_anticipated(bool anticipated) {
  56     high_priority_work_anticipated_ = anticipated;
  57   }
  58
  59  private:
  60   bool high_priority_work_anticipated_;
  61 };
  62
  63 }  // namespace
  64
  65 class ResourceDispatchThrottlerForTest : public ResourceDispatchThrottler {
  66  public:
  67   ResourceDispatchThrottlerForTest(IPC::Sender* sender,
  68                                    scheduler::RendererScheduler* scheduler)
  69       : ResourceDispatchThrottler(
  70             sender,
  71             scheduler,
  72             base::TimeDelta::FromSecondsD(kFlushPeriodSeconds),
  73             kRequestsPerFlush),
  74         flush_scheduled_(false) {}
  75   ~ResourceDispatchThrottlerForTest() override {}
  76
  77   void Advance(base::TimeDelta delta) { now_ += delta; }
  78
  79   bool RunScheduledFlush() {
  80     if (!flush_scheduled_)
  81       return false;
  82
  83     flush_scheduled_ = false;
  84     Flush();
  85     return true;
  86   }
  87
  88   bool flush_scheduled() const { return flush_scheduled_; }
  89
  90  private:
  91   // ResourceDispatchThrottler overrides:
  92   base::TimeTicks Now() const override { return now_; }
  93   void ScheduleFlush() override { flush_scheduled_ = true; }
  94
  95   base::TimeTicks now_;
  96   bool flush_scheduled_;
  97 };
  98
  99 class ResourceDispatchThrottlerTest : public testing::Test, public IPC::Sender {
 100  public:
 101   ResourceDispatchThrottlerTest() : last_request_id_(0) {
 102     throttler_.reset(new ResourceDispatchThrottlerForTest(this, &scheduler_));
 103   }
 104   ~ResourceDispatchThrottlerTest() override {}
 105
 106   // IPC::Sender implementation:
 107   bool Send(IPC::Message* msg) override {
 108     sent_messages_.push_back(msg);
 109     return true;
 110   }
 111
 112  protected:
 113   void SetHighPriorityWorkAnticipated(bool anticipated) {
 114     scheduler_.set_high_priority_work_anticipated(anticipated);
 115   }
 116
 117   void Advance(base::TimeDelta delta) { throttler_->Advance(delta); }
 118
 119   bool RunScheduledFlush() { return throttler_->RunScheduledFlush(); }
 120
 121   bool FlushScheduled() { return throttler_->flush_scheduled(); }
 122
 123   bool RequestResource() {
 124     ResourceHostMsg_Request request;
 125     request.download_to_file = true;
 126     return throttler_->Send(new ResourceHostMsg_RequestResource(
 127         kRoutingId, ++last_request_id_, request));
 128   }
 129
 130   bool RequestResourceSync() {
 131     SyncLoadResult result;
 132     return throttler_->Send(new ResourceHostMsg_SyncLoad(
 133         kRoutingId, ++last_request_id_, ResourceHostMsg_Request(), &result));
 134   }
 135
 136   void RequestResourcesUntilThrottled() {
 137     SetHighPriorityWorkAnticipated(true);
 138     GetAndResetSentMessageCount();
 139     RequestResource();
 140     while (GetAndResetSentMessageCount())
 141       RequestResource();
 142   }
 143
 144   bool UpdateRequestPriority(int request_id, net::RequestPriority priority) {
 145     return throttler_->Send(
 146         new ResourceHostMsg_DidChangePriority(request_id, priority, 0));
 147   }
 148
 149   bool ReleaseDownloadedFile(int request_id) {
 150     return throttler_->Send(
 151         new ResourceHostMsg_ReleaseDownloadedFile(request_id));
 152   }
 153
 154   bool CancelRequest(int request_id) {
 155     return throttler_->Send(new ResourceHostMsg_CancelRequest(request_id));
 156   }
 157
 158   size_t GetAndResetSentMessageCount() {
 159     size_t sent_message_count = sent_messages_.size();
 160     sent_messages_.clear();
 161     return sent_message_count;
 162   }
 163
 164   const IPC::Message* LastSentMessage() const {
 165     return sent_messages_.empty() ? nullptr : sent_messages_.back();
 166   }
 167
 168   int LastSentRequestId() const {
 169     const IPC::Message* msg = LastSentMessage();
 170     if (!msg)
 171       return -1;
 172
 173     int routing_id = -1;
 174     int request_id = -1;
 175     base::PickleIterator iter(*msg);
 176     CHECK(IPC::ReadParam(msg, &iter, &routing_id));
 177     CHECK(IPC::ReadParam(msg, &iter, &request_id));
 178     return request_id;
 179   }
 180
 181   int last_request_id() const { return last_request_id_; }
 182
 183   ScopedMessages sent_messages_;
 184
 185  private:
 186   scoped_ptr<ResourceDispatchThrottlerForTest> throttler_;
 187   RendererSchedulerForTest scheduler_;
 188   int last_request_id_;
 189   bool flush_scheduled_;
 190
 191   DISALLOW_COPY_AND_ASSIGN(ResourceDispatchThrottlerTest);
 192 };
 193
 194 TEST_F(ResourceDispatchThrottlerTest, NotThrottledByDefault) {
 195   SetHighPriorityWorkAnticipated(false);
 196   for (size_t i = 0; i < kRequestsPerFlush * 2; ++i) {
 197     RequestResource();
 198     EXPECT_EQ(i + 1, sent_messages_.size());
 199   }
 200 }
 201
 202 TEST_F(ResourceDispatchThrottlerTest, NotThrottledIfSendLimitNotReached) {
 203   SetHighPriorityWorkAnticipated(true);
 204   for (size_t i = 0; i < kRequestsPerFlush; ++i) {
 205     RequestResource();
 206     EXPECT_EQ(i + 1, sent_messages_.size());
 207   }
 208 }
 209
 210 TEST_F(ResourceDispatchThrottlerTest, ThrottledWhenHighPriorityWork) {
 211   SetHighPriorityWorkAnticipated(true);
 212   for (size_t i = 0; i < kRequestsPerFlush; ++i)
 213     RequestResource();
 214   ASSERT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 215
 216   RequestResource();
 217   EXPECT_EQ(0U, sent_messages_.size());
 218
 219   EXPECT_TRUE(RunScheduledFlush());
 220   EXPECT_EQ(1U, sent_messages_.size());
 221 }
 222
 223 TEST_F(ResourceDispatchThrottlerTest,
 224        ThrottledWhenDeferredMessageQueueNonEmpty) {
 225   SetHighPriorityWorkAnticipated(true);
 226   for (size_t i = 0; i < kRequestsPerFlush; ++i)
 227     RequestResource();
 228   ASSERT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 229
 230   RequestResource();
 231   EXPECT_EQ(0U, sent_messages_.size());
 232   SetHighPriorityWorkAnticipated(false);
 233   RequestResource();
 234   EXPECT_EQ(0U, sent_messages_.size());
 235
 236   EXPECT_TRUE(RunScheduledFlush());
 237   EXPECT_EQ(2U, sent_messages_.size());
 238 }
 239
 240 TEST_F(ResourceDispatchThrottlerTest, NotThrottledIfSufficientTimePassed) {
 241   SetHighPriorityWorkAnticipated(true);
 242
 243   for (size_t i = 0; i < kRequestsPerFlush * 2; ++i) {
 244     Advance(base::TimeDelta::FromSecondsD(kFlushPeriodSeconds * 2));
 245     RequestResource();
 246     EXPECT_EQ(1U, GetAndResetSentMessageCount());
 247     EXPECT_FALSE(FlushScheduled());
 248   }
 249 }
 250
 251 TEST_F(ResourceDispatchThrottlerTest, NotThrottledIfSyncMessage) {
 252   SetHighPriorityWorkAnticipated(true);
 253
 254   RequestResourceSync();
 255   EXPECT_EQ(1U, GetAndResetSentMessageCount());
 256
 257   // Saturate the queue.
 258   for (size_t i = 0; i < kRequestsPerFlush * 2; ++i)
 259     RequestResource();
 260   ASSERT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 261
 262   // Synchronous messages should flush any previously throttled messages.
 263   RequestResourceSync();
 264   EXPECT_EQ(1U + kRequestsPerFlush, GetAndResetSentMessageCount());
 265   RequestResourceSync();
 266   EXPECT_EQ(1U, GetAndResetSentMessageCount());
 267
 268   // Previously throttled messages should already have been flushed.
 269   RunScheduledFlush();
 270   EXPECT_EQ(0U, GetAndResetSentMessageCount());
 271 }
 272
 273 TEST_F(ResourceDispatchThrottlerTest, MultipleFlushes) {
 274   SetHighPriorityWorkAnticipated(true);
 275   for (size_t i = 0; i < kRequestsPerFlush * 4; ++i)
 276     RequestResource();
 277   ASSERT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 278
 279   for (size_t i = 0; i < 3; ++i) {
 280     SCOPED_TRACE(i);
 281     EXPECT_TRUE(RunScheduledFlush());
 282     EXPECT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 283   }
 284
 285   EXPECT_FALSE(FlushScheduled());
 286   EXPECT_EQ(0U, sent_messages_.size());
 287 }
 288
 289 TEST_F(ResourceDispatchThrottlerTest, MultipleFlushesWhileReceiving) {
 290   SetHighPriorityWorkAnticipated(true);
 291   for (size_t i = 0; i < kRequestsPerFlush * 4; ++i)
 292     RequestResource();
 293   ASSERT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 294
 295   for (size_t i = 0; i < 3; ++i) {
 296     SCOPED_TRACE(i);
 297     EXPECT_TRUE(RunScheduledFlush());
 298     EXPECT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 299     for (size_t j = 0; j < kRequestsPerFlush; ++j)
 300       RequestResource();
 301     EXPECT_EQ(0U, sent_messages_.size());
 302   }
 303
 304   for (size_t i = 0; i < 3; ++i) {
 305     EXPECT_TRUE(RunScheduledFlush());
 306     EXPECT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 307   }
 308
 309   EXPECT_FALSE(FlushScheduled());
 310   EXPECT_EQ(0U, sent_messages_.size());
 311 }
 312
 313 TEST_F(ResourceDispatchThrottlerTest, NonRequestsNeverTriggerThrottling) {
 314   RequestResource();
 315   ASSERT_EQ(1U, GetAndResetSentMessageCount());
 316
 317   for (size_t i = 0; i < kRequestsPerFlush * 3; ++i)
 318     UpdateRequestPriority(last_request_id(), net::HIGHEST);
 319   EXPECT_EQ(kRequestsPerFlush * 3, sent_messages_.size());
 320
 321   RequestResource();
 322   EXPECT_EQ(1U + kRequestsPerFlush * 3, GetAndResetSentMessageCount());
 323 }
 324
 325 TEST_F(ResourceDispatchThrottlerTest, NonRequestsDeferredWhenThrottling) {
 326   RequestResource();
 327   ASSERT_EQ(1U, GetAndResetSentMessageCount());
 328
 329   RequestResourcesUntilThrottled();
 330   UpdateRequestPriority(last_request_id(), net::HIGHEST);
 331   ReleaseDownloadedFile(last_request_id());
 332   CancelRequest(last_request_id());
 333
 334   EXPECT_TRUE(RunScheduledFlush());
 335   EXPECT_EQ(4U, GetAndResetSentMessageCount());
 336   EXPECT_FALSE(FlushScheduled());
 337 }
 338
 339 TEST_F(ResourceDispatchThrottlerTest, MessageOrderingPreservedWhenThrottling) {
 340   SetHighPriorityWorkAnticipated(true);
 341   for (size_t i = 0; i < kRequestsPerFlush; ++i)
 342     RequestResource();
 343   ASSERT_EQ(kRequestsPerFlush, GetAndResetSentMessageCount());
 344
 345   for (size_t i = 0; i < kRequestsPerFlush; ++i) {
 346     RequestResource();
 347     UpdateRequestPriority(last_request_id(), net::HIGHEST);
 348     CancelRequest(last_request_id() - 1);
 349   }
 350   ASSERT_EQ(0U, sent_messages_.size());
 351
 352   EXPECT_TRUE(RunScheduledFlush());
 353   ASSERT_EQ(kRequestsPerFlush * 3, sent_messages_.size());
 354   for (size_t i = 0; i < sent_messages_.size(); i += 3) {
 355     SCOPED_TRACE(i);
 356     const auto& request_msg = *sent_messages_[i];
 357     const auto& priority_msg = *sent_messages_[i + 1];
 358     const auto& cancel_msg = *sent_messages_[i + 2];
 359
 360     EXPECT_EQ(request_msg.type(), ResourceHostMsg_RequestResource::ID);
 361     EXPECT_EQ(priority_msg.type(), ResourceHostMsg_DidChangePriority::ID);
 362     EXPECT_EQ(cancel_msg.type(), ResourceHostMsg_CancelRequest::ID);
 363
 364     EXPECT_EQ(GetRequestId(request_msg), GetRequestId(priority_msg));
 365     EXPECT_EQ(GetRequestId(request_msg) - 1, GetRequestId(cancel_msg));
 366   }
 367   EXPECT_FALSE(FlushScheduled());
 368 }
 369
 370 }  // namespace content