Re-land: cc: Examine layers to determine if we're ready to activate.

This introduces a new mechanism for determining when
we're ready to activate the pending tree. The tile
priority is still used to determine when it's worth
waking up the compositor thread and evaluating if
we can activate. However, the actual check that
determines if we're ready to activate doesn't rely
on the state of scheduled raster tasks but is a
synchronous call on each layer.

The result is a pending tree activation mechanism that
is much easier to debug and validate for correctness,
while still providing the performance benefits of the
old mechanism by taking the "required to activate" field
of the tile priority into account when scheduling tasks.
 
BUG=375206
TEST=cc_unittests --gtest_filter=PictureLayerImplTest.AllTilesRequiredForActivationAreReadyToDraw

Review URL: https://codereview.chromium.org/287643004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@273040 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 90 insertions, 59 deletions

diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index 2b3e652..416c4e6 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -365,24 +365,25 @@ scoped_ptr<base::Value> RasterTaskCompletionStatsAsValue(
 // static
 scoped_ptr<TileManager> TileManager::Create(
     TileManagerClient* client,
+    base::SequencedTaskRunner* task_runner,
     ResourcePool* resource_pool,
     Rasterizer* rasterizer,
-    bool use_rasterize_on_demand,
     RenderingStatsInstrumentation* rendering_stats_instrumentation) {
   return make_scoped_ptr(new TileManager(client,
+                                         task_runner,
                                          resource_pool,
                                          rasterizer,
-                                         use_rasterize_on_demand,
                                          rendering_stats_instrumentation));
 }
 
 TileManager::TileManager(
     TileManagerClient* client,
+    base::SequencedTaskRunner* task_runner,
     ResourcePool* resource_pool,
     Rasterizer* rasterizer,
-    bool use_rasterize_on_demand,
     RenderingStatsInstrumentation* rendering_stats_instrumentation)
     : client_(client),
+      task_runner_(task_runner),
       resource_pool_(resource_pool),
       rasterizer_(rasterizer),
       prioritized_tiles_dirty_(false),
@@ -396,7 +397,8 @@ TileManager::TileManager(
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
       did_initialize_visible_tile_(false),
       did_check_for_completed_tasks_since_last_schedule_tasks_(true),
-      use_rasterize_on_demand_(use_rasterize_on_demand) {
+      check_if_ready_to_activate_pending_(false),
+      weak_ptr_factory_(this) {
   rasterizer_->SetClient(this);
 }
 
@@ -528,12 +530,14 @@ void TileManager::DidFinishRunningTasks() {
       // If we can't raster on demand, give up early (and don't activate).
       if (!allow_rasterize_on_demand)
         return;
-      if (use_rasterize_on_demand_)
-        tile_version.set_rasterize_on_demand();
+
+      tile_version.set_rasterize_on_demand();
+      client_->NotifyTileStateChanged(tile);
     }
   }
 
-  client_->NotifyReadyToActivate();
+  DCHECK(IsReadyToActivate());
+  ScheduleCheckIfReadyToActivate();
 }
 
 void TileManager::DidFinishRunningTasksRequiredForActivation() {
@@ -545,7 +549,7 @@ void TileManager::DidFinishRunningTasksRequiredForActivation() {
   if (!all_tiles_required_for_activation_have_memory_)
     return;
 
-  client_->NotifyReadyToActivate();
+  ScheduleCheckIfReadyToActivate();
 }
 
 void TileManager::GetTilesWithAssignedBins(PrioritizedTileSet* tiles) {
@@ -664,7 +668,7 @@ void TileManager::GetTilesWithAssignedBins(PrioritizedTileSet* tiles) {
     // can visit it.
     if (mts.bin == NEVER_BIN &&
         !mts.tile_versions[mts.raster_mode].raster_task_) {
-      FreeResourcesForTile(tile);
+      FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);
       continue;
     }
 
@@ -853,7 +857,7 @@ void TileManager::AssignGpuMemoryToTiles(
 
     // If the tile is not needed, free it up.
     if (mts.bin == NEVER_BIN) {
-      FreeResourcesForTile(tile);
+      FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(tile);
       continue;
     }
 
@@ -895,14 +899,19 @@ void TileManager::AssignGpuMemoryToTiles(
 
     // Tile is OOM.
     if (tile_bytes > tile_bytes_left || tile_resources > resources_left) {
+      bool was_ready_to_draw = tile->IsReadyToDraw();
+
       FreeResourcesForTile(tile);
 
       // This tile was already on screen and now its resources have been
       // released. In order to prevent checkerboarding, set this tile as
       // rasterize on demand immediately.
-      if (mts.visible_and_ready_to_draw && use_rasterize_on_demand_)
+      if (mts.visible_and_ready_to_draw)
         tile_version.set_rasterize_on_demand();
 
+      if (was_ready_to_draw)
+        client_->NotifyTileStateChanged(tile);
+
       oomed_soft = true;
       if (tile_uses_hard_limit) {
         oomed_hard = true;
@@ -997,6 +1006,14 @@ void TileManager::FreeUnusedResourcesForTile(Tile* tile) {
   }
 }
 
+void TileManager::FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(
+    Tile* tile) {
+  bool was_ready_to_draw = tile->IsReadyToDraw();
+  FreeResourcesForTile(tile);
+  if (was_ready_to_draw)
+    client_->NotifyTileStateChanged(tile);
+}
+
 void TileManager::ScheduleTasks(
     const TileVector& tiles_that_need_to_be_rasterized) {
   TRACE_EVENT1("cc",
@@ -1189,11 +1206,11 @@ void TileManager::OnRasterTaskCompleted(
     ++resources_releasable_;
   }
 
-  client_->NotifyTileInitialized(tile);
-
   FreeUnusedResourcesForTile(tile);
   if (tile->priority(ACTIVE_TREE).distance_to_visible == 0.f)
     did_initialize_visible_tile_ = true;
+
+  client_->NotifyTileStateChanged(tile);
 }
 
 scoped_refptr<Tile> TileManager::CreateTile(PicturePileImpl* picture_pile,
@@ -1627,4 +1644,38 @@ void TileManager::SetRasterizerForTesting(Rasterizer* rasterizer) {
   rasterizer_->SetClient(this);
 }
 
+bool TileManager::IsReadyToActivate() const {
+  for (std::vector<PictureLayerImpl*>::const_iterator it = layers_.begin();
+       it != layers_.end();
+       ++it) {
+    if (!(*it)->AllTilesRequiredForActivationAreReadyToDraw())
+      return false;
+  }
+
+  return true;
+}
+
+void TileManager::ScheduleCheckIfReadyToActivate() {
+  if (check_if_ready_to_activate_pending_)
+    return;
+
+  task_runner_->PostTask(FROM_HERE,
+                         base::Bind(&TileManager::CheckIfReadyToActivate,
+                                    weak_ptr_factory_.GetWeakPtr()));
+  check_if_ready_to_activate_pending_ = true;
+}
+
+void TileManager::CheckIfReadyToActivate() {
+  TRACE_EVENT0("cc", "TileManager::CheckIfReadyToActivate");
+
+  DCHECK(check_if_ready_to_activate_pending_);
+  check_if_ready_to_activate_pending_ = false;
+
+  rasterizer_->CheckForCompletedTasks();
+  did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
+
+  if (IsReadyToActivate())
+    client_->NotifyReadyToActivate();
+}
+
 }  // namespace cc
diff --git a/cc/resources/tile_manager.h b/cc/resources/tile_manager.h
index cdc7d1e..0881e6f 100644
--- a/cc/resources/tile_manager.h
+++ b/cc/resources/tile_manager.h
@@ -30,8 +30,15 @@ class ResourceProvider;
 
 class CC_EXPORT TileManagerClient {
  public:
+  // Called when all tiles marked as required for activation are ready to draw.
   virtual void NotifyReadyToActivate() = 0;
-  virtual void NotifyTileInitialized(const Tile* tile) = 0;
+
+  // Called when the visible representation of a tile might have changed. Some
+  // examples are:
+  // - Tile version initialized.
+  // - Tile resources freed.
+  // - Tile marked for on-demand raster.
+  virtual void NotifyTileStateChanged(const Tile* tile) = 0;
 
  protected:
   virtual ~TileManagerClient() {}
@@ -154,9 +161,9 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   static scoped_ptr<TileManager> Create(
       TileManagerClient* client,
+      base::SequencedTaskRunner* task_runner,
       ResourcePool* resource_pool,
       Rasterizer* rasterizer,
-      bool use_rasterize_on_demand,
       RenderingStatsInstrumentation* rendering_stats_instrumentation);
   virtual ~TileManager();
 
@@ -228,9 +235,9 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
  protected:
   TileManager(TileManagerClient* client,
+              base::SequencedTaskRunner* task_runner,
               ResourcePool* resource_pool,
               Rasterizer* rasterizer,
-              bool use_rasterize_on_demand,
               RenderingStatsInstrumentation* rendering_stats_instrumentation);
 
   // Methods called by Tile
@@ -276,6 +283,7 @@ class CC_EXPORT TileManager : public RasterizerClient,
   void FreeResourceForTile(Tile* tile, RasterMode mode);
   void FreeResourcesForTile(Tile* tile);
   void FreeUnusedResourcesForTile(Tile* tile);
+  void FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(Tile* tile);
   scoped_refptr<ImageDecodeTask> CreateImageDecodeTask(Tile* tile,
                                                        SkPixelRef* pixel_ref);
   scoped_refptr<RasterTask> CreateRasterTask(Tile* tile);
@@ -283,7 +291,12 @@ class CC_EXPORT TileManager : public RasterizerClient,
   void UpdatePrioritizedTileSetIfNeeded();
   void CleanUpLayers();
 
+  bool IsReadyToActivate() const;
+  void ScheduleCheckIfReadyToActivate();
+  void CheckIfReadyToActivate();
+
   TileManagerClient* client_;
+  scoped_refptr<base::SequencedTaskRunner> task_runner_;
   ResourcePool* resource_pool_;
   Rasterizer* rasterizer_;
   GlobalStateThatImpactsTilePriority global_state_;
@@ -323,8 +336,6 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   std::vector<Tile*> released_tiles_;
 
-  bool use_rasterize_on_demand_;
-
   ResourceFormat resource_format_;
 
   // Queue used when scheduling raster tasks.
@@ -334,6 +345,10 @@ class CC_EXPORT TileManager : public RasterizerClient,
 
   std::vector<PictureLayerImpl*> layers_;
 
+  bool check_if_ready_to_activate_pending_;
+
+  base::WeakPtrFactory<TileManager> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(TileManager);
 };
 
diff --git a/cc/resources/tile_manager_perftest.cc b/cc/resources/tile_manager_perftest.cc
index 22e7c66..c7fa68f 100644
--- a/cc/resources/tile_manager_perftest.cc
+++ b/cc/resources/tile_manager_perftest.cc
@@ -293,7 +293,7 @@ class TileManagerPerfTest : public testing::Test, public TileManagerClient {
 
   // TileManagerClient implementation.
   virtual void NotifyReadyToActivate() OVERRIDE { ready_to_activate_ = true; }
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE {}
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE {}
 
   TileManager* tile_manager() { return host_impl_.tile_manager(); }
 
diff --git a/cc/resources/tile_manager_unittest.cc b/cc/resources/tile_manager_unittest.cc
index 5a1837f..ce54d38 100644
--- a/cc/resources/tile_manager_unittest.cc
+++ b/cc/resources/tile_manager_unittest.cc
@@ -32,8 +32,7 @@ class TileManagerTest : public testing::TestWithParam<bool>,
 
   void Initialize(int max_tiles,
                   TileMemoryLimitPolicy memory_limit_policy,
-                  TreePriority tree_priority,
-                  bool allow_on_demand_raster = true) {
+                  TreePriority tree_priority) {
     output_surface_ = FakeOutputSurface::Create3d();
     CHECK(output_surface_->BindToClient(&output_surface_client_));
 
@@ -43,8 +42,8 @@ class TileManagerTest : public testing::TestWithParam<bool>,
         false);
     resource_pool_ = ResourcePool::Create(
         resource_provider_.get(), GL_TEXTURE_2D, RGBA_8888);
-    tile_manager_ = make_scoped_ptr(new FakeTileManager(
-        this, resource_pool_.get(), allow_on_demand_raster));
+    tile_manager_ =
+        make_scoped_ptr(new FakeTileManager(this, resource_pool_.get()));
 
     memory_limit_policy_ = memory_limit_policy;
     max_tiles_ = max_tiles;
@@ -85,7 +84,7 @@ class TileManagerTest : public testing::TestWithParam<bool>,
 
   // TileManagerClient implementation.
   virtual void NotifyReadyToActivate() OVERRIDE { ready_to_activate_ = true; }
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE {}
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE {}
 
   TileVector CreateTilesWithSize(int count,
                                  TilePriority active_priority,
@@ -614,40 +613,6 @@ TEST_P(TileManagerTest, RespectMemoryLimit) {
   EXPECT_LE(memory_allocated_bytes, global_state_.hard_memory_limit_in_bytes);
 }
 
-TEST_P(TileManagerTest, AllowRasterizeOnDemand) {
-  // Not enough memory to initialize tiles required for activation.
-  Initialize(0, ALLOW_ANYTHING, SAME_PRIORITY_FOR_BOTH_TREES);
-  TileVector tiles =
-      CreateTiles(2, TilePriority(), TilePriorityRequiredForActivation());
-
-  tile_manager()->AssignMemoryToTiles(global_state_);
-
-  // This should make required tiles ready to draw by marking them as
-  // required tiles for on-demand raster.
-  tile_manager()->DidFinishRunningTasksForTesting();
-
-  EXPECT_TRUE(ready_to_activate());
-  for (TileVector::iterator it = tiles.begin(); it != tiles.end(); ++it)
-    EXPECT_TRUE((*it)->IsReadyToDraw());
-}
-
-TEST_P(TileManagerTest, PreventRasterizeOnDemand) {
-  // Not enough memory to initialize tiles required for activation.
-  Initialize(0, ALLOW_ANYTHING, SAME_PRIORITY_FOR_BOTH_TREES, false);
-  TileVector tiles =
-      CreateTiles(2, TilePriority(), TilePriorityRequiredForActivation());
-
-  tile_manager()->AssignMemoryToTiles(global_state_);
-
-  // This should make required tiles ready to draw by marking them as
-  // required tiles for on-demand raster.
-  tile_manager()->DidFinishRunningTasksForTesting();
-
-  EXPECT_TRUE(ready_to_activate());
-  for (TileVector::iterator it = tiles.begin(); it != tiles.end(); ++it)
-    EXPECT_FALSE((*it)->IsReadyToDraw());
-}
-
 // If true, the max tile limit should be applied as bytes; if false,
 // as num_resources_limit.
 INSTANTIATE_TEST_CASE_P(TileManagerTests,
@@ -754,7 +719,7 @@ class TileManagerTileIteratorTest : public testing::Test,
 
   // TileManagerClient implementation.
   virtual void NotifyReadyToActivate() OVERRIDE { ready_to_activate_ = true; }
-  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE {}
+  virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE {}
 
   TileManager* tile_manager() { return host_impl_.tile_manager(); }