Fix Resource Priorities and Scheduling (Chrome Side)

content/browser/loader/resource_scheduler_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/loader/resource_scheduler.h"
 
 #include "base/memory/scoped_vector.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/field_trial.h"
 #include "base/run_loop.h"
@@ skipping 366 matching lines @@
   EXPECT_TRUE(lowest->started());
   EXPECT_FALSE(lowest2->started());
   scheduler()->OnWillInsertBody(kChildId, kRouteId);
   EXPECT_TRUE(lowest2->started());
 }
 
 TEST_F(ResourceSchedulerTest, OneLowLoadsUntilBodyInsertedExceptSpdy) {
   http_server_properties_.SetSupportsSpdy(
       net::HostPortPair("spdyhost", 443), true);
   scoped_ptr<TestRequest> high(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> low(NewRequest("http://host/low", net::LOWEST));
+  scoped_ptr<TestRequest> low2(NewRequest("http://host/low", net::LOWEST));
   scoped_ptr<TestRequest> low_spdy(
       NewRequest("https://spdyhost/low", net::LOWEST));
-  scoped_ptr<TestRequest> low(NewRequest("http://host/low", net::LOWEST));
-  scoped_ptr<TestRequest> low2(NewRequest("http://host/low", net::LOWEST));
   EXPECT_TRUE(high->started());
   EXPECT_TRUE(low_spdy->started());
   EXPECT_TRUE(low->started());
   EXPECT_FALSE(low2->started());
   scheduler()->OnWillInsertBody(kChildId, kRouteId);
   high.reset();
   EXPECT_TRUE(low2->started());
 }
 
 TEST_F(ResourceSchedulerTest, NavigationResetsState) {
@@ skipping 299 matching lines @@
   EXPECT_TRUE(low1->started());
 
   low1.reset();
   scoped_ptr<TestRequest> low2_spdy(
       NewRequest("http://spdyhost2:8080/low", net::IDLE));
   // Reprioritize a request after we learn the server supports SPDY.
   EXPECT_TRUE(low2_spdy->started());
   http_server_properties_.SetSupportsSpdy(
       net::HostPortPair("spdyhost2", 8080), true);
   ChangeRequestPriority(low2_spdy.get(), net::LOWEST);
+  // Low priority in-flight requests on the SPDY connection are still considered
+  // delayable as far as the accounting goes and should still hold back the
+  // request on the non-spdy host.
   scoped_ptr<TestRequest> low2(NewRequest("http://host/low", net::LOWEST));
-  EXPECT_TRUE(low2->started());
+  EXPECT_FALSE(low2->started());
 }
 
 TEST_F(ResourceSchedulerTest, ThrottledClientCreation) {
   // TODO(aiolos): remove when throttling and coalescing have both landed
   scheduler()->SetThrottleOptionsForTesting(true /* should_throttle */,
                                           false /* should_coalesce */);
   EXPECT_TRUE(scheduler()->should_throttle());
   scheduler()->OnClientCreated(
       kBackgroundChildId2, kBackgroundRouteId2, false, false);
 
@@ skipping 1631 matching lines @@
   }
   scoped_ptr<TestRequest> lowest(NewRequestWithChildAndRoute(
       "http://host/lowest", net::LOWEST, kChildId2, kRouteId2));
   EXPECT_FALSE(lowest->started());
   scheduler_->OnClientDeleted(kChildId2, kRouteId2);
   high.reset();
   delayable_requests.clear();
   EXPECT_TRUE(lowest->started());
 }
 
+TEST_F(ResourceSchedulerTest, DefaultLayoutBlockingPriority) {
+  const int kEnablePriorityIncrease = 0;
+  ASSERT_TRUE(InitializeFieldTrials(
+      base::StringPrintf("ResourcePriorities/LayoutBlocking_000%d0_0_1_10/",
+                         kEnablePriorityIncrease)));
+  InitializeScheduler();
+  scoped_ptr<TestRequest> high(
+      NewRequest("http://hosthigh/high", net::HIGHEST));
+  scoped_ptr<TestRequest> high2(
+      NewRequest("http://hosthigh/high", net::HIGHEST));
+  scoped_ptr<TestRequest> medium(
+      NewRequest("http://hostmedium/medium", net::MEDIUM));
+  scoped_ptr<TestRequest> medium2(
+      NewRequest("http://hostmedium/medium", net::MEDIUM));
+  scoped_ptr<TestRequest> low(NewRequest("http://hostlow/low", net::LOW));
+  scoped_ptr<TestRequest> low2(NewRequest("http://hostlow/low", net::LOW));
+  scoped_ptr<TestRequest> lowest(NewRequest("http://hostlowest/lowest", net::LOWEST));
+  scoped_ptr<TestRequest> lowest2(
+      NewRequest("http://hostlowest/lowest", net::LOWEST));
+  EXPECT_TRUE(high->started());
+  EXPECT_TRUE(high2->started());
+  EXPECT_TRUE(medium->started());
+  EXPECT_TRUE(medium2->started());
+  EXPECT_TRUE(low->started());
+  EXPECT_TRUE(low2->started());
+  EXPECT_TRUE(lowest->started());
+  EXPECT_FALSE(lowest2->started());
+  lowest.reset();
+  EXPECT_TRUE(lowest2->started());
+}
+
+TEST_F(ResourceSchedulerTest, IncreaseLayoutBlockingPriority) {
+  // Changes the level of priorities that are allowed during layout-blocking
+  // from net::LOWEST to net::LOW.
+  const int kEnablePriorityIncrease = 1;
+  ASSERT_TRUE(InitializeFieldTrials(
+      base::StringPrintf("ResourcePriorities/LayoutBlocking_000%d0_0_1_10/",
+                         kEnablePriorityIncrease)));
+  InitializeScheduler();
+  scoped_ptr<TestRequest> high(
+      NewRequest("http://hosthigh/high", net::HIGHEST));
+  scoped_ptr<TestRequest> high2(
+      NewRequest("http://hosthigh/high", net::HIGHEST));
+  scoped_ptr<TestRequest> medium(
+      NewRequest("http://hostmedium/medium", net::MEDIUM));
+  scoped_ptr<TestRequest> medium2(
+      NewRequest("http://hostmedium/medium", net::MEDIUM));
+  scoped_ptr<TestRequest> low(NewRequest("http://hostlow/low", net::LOW));
+  scoped_ptr<TestRequest> low2(NewRequest("http://hostlow/low", net::LOW));
+  scoped_ptr<TestRequest> lowest(NewRequest("http://hostlowest/lowest", net::LOWEST));
+  scoped_ptr<TestRequest> lowest2(
+      NewRequest("http://hostlowest/lowest", net::LOWEST));
+  EXPECT_TRUE(high->started());
+  EXPECT_TRUE(high2->started());
+  EXPECT_TRUE(medium->started());
+  EXPECT_TRUE(medium2->started());
+  EXPECT_TRUE(low->started());
+  EXPECT_FALSE(low2->started());
+  EXPECT_FALSE(lowest->started());
+  EXPECT_FALSE(lowest2->started());
+  low.reset();
+  EXPECT_TRUE(low2->started());
+  EXPECT_FALSE(lowest->started());
+  EXPECT_FALSE(lowest2->started());
+  low2.reset();
+  EXPECT_TRUE(lowest->started());
+  EXPECT_FALSE(lowest2->started());
+  lowest.reset();
+  EXPECT_TRUE(lowest2->started());
+}
+
+TEST_F(ResourceSchedulerTest, UseLayoutBlockingThresholdOne) {
+  // Prevents anly low priority requests from starting while more than
+  // N high priority requests are pending (before body).
+  const int kLayoutBlockingThreshold = 1;
+  ASSERT_TRUE(InitializeFieldTrials(
+      base::StringPrintf("ResourcePriorities/LayoutBlocking_00001_%d_1_10/",
+                         kLayoutBlockingThreshold)));
+  InitializeScheduler();
+  scoped_ptr<TestRequest> high(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> high2(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> low(NewRequest("http://host/low", net::LOWEST));
+  scoped_ptr<TestRequest> low2(NewRequest("http://host/low", net::LOWEST));
+  EXPECT_TRUE(high->started());
+  EXPECT_TRUE(high2->started());
+  EXPECT_FALSE(low->started());
+  EXPECT_FALSE(low2->started());
+  high.reset();
+  EXPECT_TRUE(low->started());
+  EXPECT_FALSE(low2->started());
+  high2.reset();
+  scheduler()->OnWillInsertBody(kChildId, kRouteId);
+  EXPECT_TRUE(low2->started());
+}
+
+TEST_F(ResourceSchedulerTest, UseLayoutBlockingThresholdTwo) {
+  // Prevents anly low priority requests from starting while more than
+  // N high priority requests are pending (before body).
+  const int kLayoutBlockingThreshold = 2;
+  ASSERT_TRUE(InitializeFieldTrials(
+      base::StringPrintf("ResourcePriorities/LayoutBlockingTwo_00001_%d_1_10/",
+                         kLayoutBlockingThreshold)));
+  InitializeScheduler();
+  scoped_ptr<TestRequest> high(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> high2(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> high3(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> low(NewRequest("http://host/low", net::LOWEST));
+  scoped_ptr<TestRequest> low2(NewRequest("http://host/low", net::LOWEST));
+  EXPECT_TRUE(high->started());
+  EXPECT_TRUE(high2->started());
+  EXPECT_TRUE(high3->started());
+  EXPECT_FALSE(low->started());
+  EXPECT_FALSE(low2->started());
+  high.reset();
+  EXPECT_TRUE(low->started());
+  EXPECT_FALSE(low2->started());
+  high2.reset();
+  high3.reset();
+  scheduler()->OnWillInsertBody(kChildId, kRouteId);
+  EXPECT_TRUE(low2->started());
+}
+
+TEST_F(ResourceSchedulerTest, IncreaseLowLoadsUntilBodyInserted) {
+  const int kMaxNumDelayableWhileLayoutBlocking = 2;
+  ASSERT_TRUE(InitializeFieldTrials(
+      base::StringPrintf("ResourcePriorities/IncreaseLow_00000_0_%d_10/",
+                         kMaxNumDelayableWhileLayoutBlocking)));
+  InitializeScheduler();
+  scoped_ptr<TestRequest> high(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> low(NewRequest("http://host/low", net::LOWEST));
+  scoped_ptr<TestRequest> low2(NewRequest("http://host/low", net::LOWEST));
+  scoped_ptr<TestRequest> low3(NewRequest("http://host/low", net::LOWEST));
+  EXPECT_TRUE(high->started());
+  EXPECT_TRUE(low->started());
+  EXPECT_TRUE(low2->started());
+  EXPECT_FALSE(low3->started());
+  high.reset();
+  scheduler()->OnWillInsertBody(kChildId, kRouteId);
+  EXPECT_TRUE(low3->started());
+}
+
+TEST_F(ResourceSchedulerTest, IncreaseLowLoadsUntilBodyInsertedLayoutBlocking) {
+  const int kLayoutBlockingThreshold = 1;
+  const int kMaxNumDelayableWhileLayoutBlocking = 2;
+  ASSERT_TRUE(InitializeFieldTrials(
+      base::StringPrintf("ResourcePriorities/IncreaseLow_00001_%d_%d_10/",
+                         kLayoutBlockingThreshold,
+                         kMaxNumDelayableWhileLayoutBlocking)));
+  InitializeScheduler();
+  scoped_ptr<TestRequest> high(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> high2(NewRequest("http://host/high", net::HIGHEST));
+  scoped_ptr<TestRequest> low(NewRequest("http://host/low", net::LOWEST));
+  scoped_ptr<TestRequest> low2(NewRequest("http://host/low", net::LOWEST));
+  scoped_ptr<TestRequest> low3(NewRequest("http://host/low", net::LOWEST));
+  EXPECT_TRUE(high->started());
+  EXPECT_TRUE(high2->started());
+  EXPECT_FALSE(low->started());
+  EXPECT_FALSE(low2->started());
+  EXPECT_FALSE(low3->started());
+  high.reset();
+  EXPECT_TRUE(low->started());
+  EXPECT_TRUE(low2->started());
+  EXPECT_FALSE(low3->started());
+  high2.reset();
+  scheduler()->OnWillInsertBody(kChildId, kRouteId);
+  EXPECT_TRUE(low3->started());
+}
+
+TEST_F(ResourceSchedulerTest, IncreaseMaxNumDelayableRequestsPerClient) {
+  const int kMaxNumDelayableRequestsPerClient = 25;
+  ASSERT_TRUE(InitializeFieldTrials(
+      base::StringPrintf("ResourcePriorities/IncreaseDelayable_00000_0_1_%d/",
+                         kMaxNumDelayableRequestsPerClient)));
+  InitializeScheduler();
+
+  // We only load low priority resources if there's a body.
+  scheduler()->OnWillInsertBody(kChildId, kRouteId);
+
+  // Queue requests from different hosts until we reach the total limit.
+  ScopedVector<TestRequest> lows_differenthosts;
+  for (int i = 0; i < kMaxNumDelayableRequestsPerClient; ++i) {
+    string url = "http://host" + base::IntToString(i) + "/low";
+    lows_differenthosts.push_back(NewRequest(url.c_str(), net::LOWEST));
+    EXPECT_TRUE(lows_differenthosts[i]->started());
+  }
+
+  scoped_ptr<TestRequest> last_differenthost(NewRequest("http://host_new/last",
+                                                        net::LOWEST));
+  EXPECT_FALSE(last_differenthost->started());
+}
+
 }  // unnamed namespace
 
 }  // namespace content