cc: Do not cleanup tiles with raster tasks.

cc/resources/tile_manager.cc

 // Copyright 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 "cc/resources/tile_manager.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
@@ skipping 371 matching lines @@
           base::Bind(&TileManager::CheckIfReadyToActivate,
                      base::Unretained(this))) {
   rasterizer_->SetClient(this);
 }
 
 TileManager::~TileManager() {
   // Reset global state and manage. This should cause
   // our memory usage to drop to zero.
   global_state_ = GlobalStateThatImpactsTilePriority();
 
-  CleanUpReleasedTiles();
-  DCHECK_EQ(0u, tiles_.size());

[reveman, 2014/07/11 17:06:36]

why remove this DCHECK? this is very useful. please keep it.

[sohanjg, 2014/07/12 11:41:59]

Done.

-
   RasterTaskQueue empty;
   rasterizer_->ScheduleTasks(&empty);
-  orphan_raster_tasks_.clear();
 
   // This should finish all pending tasks and release any uninitialized
   // resources.
   rasterizer_->Shutdown();
   rasterizer_->CheckForCompletedTasks();
 
+  FreeResourcesForReleasedTiles();
+  CleanUpReleasedTiles();
+
   DCHECK_EQ(0u, bytes_releasable_);
   DCHECK_EQ(0u, resources_releasable_);
 }
 
 void TileManager::Release(Tile* tile) {
   prioritized_tiles_dirty_ = true;
   released_tiles_.push_back(tile);
 }
 
 void TileManager::DidChangeTilePriority(Tile* tile) {
   prioritized_tiles_dirty_ = true;
 }
 
 bool TileManager::ShouldForceTasksRequiredForActivationToComplete() const {
   return global_state_.tree_priority != SMOOTHNESS_TAKES_PRIORITY;
 }
 
-void TileManager::CleanUpReleasedTiles() {
+void TileManager::FreeResourcesForReleasedTiles() {
   for (std::vector<Tile*>::iterator it = released_tiles_.begin();
        it != released_tiles_.end();
        ++it) {
     Tile* tile = *it;
-    ManagedTileState& mts = tile->managed_state();
+    for (int mode = 0; mode < NUM_RASTER_MODES; ++mode)
+      FreeResourceForTile(tile, static_cast<RasterMode>(mode));
+  }
+}
 
+bool TileManager::TileHasRasterTask(Tile* tile) {
+  DCHECK(tile);

[reveman, 2014/07/11 17:06:36]

I don't think this DCHECK is useful. please remove it.

[sohanjg, 2014/07/12 11:41:59]

Done.

+  ManagedTileState& mts = tile->managed_state();
+  bool tile_has_raster_task = false;

[reveman, 2014/07/11 17:06:36]

you don't need this variable

[sohanjg, 2014/07/12 11:41:58]

Done.

     for (int mode = 0; mode < NUM_RASTER_MODES; ++mode) {
-      FreeResourceForTile(tile, static_cast<RasterMode>(mode));
-      orphan_raster_tasks_.push_back(mts.tile_versions[mode].raster_task_);
+      if (mts.tile_versions[mode].raster_task_)
+        tile_has_raster_task = true;

[reveman, 2014/07/11 17:06:36]

no need to iterate through all modes. just "return true" here instead.

[sohanjg, 2014/07/12 11:41:58]

Done.

+    }
+    return tile_has_raster_task;

[reveman, 2014/07/11 17:06:36]

and just "return false" here.

[sohanjg, 2014/07/12 11:41:59]

Done.

+}
+
+void TileManager::CleanUpReleasedTiles() {
+  std::vector<Tile*>::iterator it = released_tiles_.begin();
+  while (it != released_tiles_.end()) {
+    Tile* tile = *it;
+    if (TileHasRasterTask(tile)) {

[reveman, 2014/07/11 17:06:36]

nit: I'd add a blank line before "if (TileHasR.." to separate that chunk of code
a bit. looks like "Tile* tile = *it;" is only useful for this check right now..

[sohanjg, 2014/07/12 11:41:59]

Done.

+      ++it;
+      continue;
     }
 
     DCHECK(tiles_.find(tile->id()) != tiles_.end());
     tiles_.erase(tile->id());
 
     LayerCountMap::iterator layer_it =
         used_layer_counts_.find(tile->layer_id());
     DCHECK_GT(layer_it->second, 0);
     if (--layer_it->second == 0) {
       used_layer_counts_.erase(layer_it);
       image_decode_tasks_.erase(tile->layer_id());
     }
 
     delete tile;

[reveman, 2014/07/11 17:06:36]

please add a DCHECK(!tile->HasResources()) here somewhere

[sohanjg, 2014/07/12 11:41:58]

Done.

+    it = released_tiles_.erase(it);
   }
-
-  released_tiles_.clear();
 }
 
 void TileManager::UpdatePrioritizedTileSetIfNeeded() {
   if (!prioritized_tiles_dirty_)
     return;
 
+  FreeResourcesForReleasedTiles();
   CleanUpReleasedTiles();
 
   prioritized_tiles_.Clear();
   GetTilesWithAssignedBins(&prioritized_tiles_);
   prioritized_tiles_dirty_ = false;
 }
 
 void TileManager::DidFinishRunningTasks() {
   TRACE_EVENT0("cc", "TileManager::DidFinishRunningTasks");
 
@@ skipping 499 matching lines @@
 
   // We must reduce the amount of unused resoruces before calling
   // ScheduleTasks to prevent usage from rising above limits.
   resource_pool_->ReduceResourceUsage();
 
   // Schedule running of |raster_tasks_|. This replaces any previously
   // scheduled tasks and effectively cancels all tasks not present
   // in |raster_tasks_|.
   rasterizer_->ScheduleTasks(&raster_queue_);
 
-  // It's now safe to clean up orphan tasks as raster worker pool is not
-  // allowed to keep around unreferenced raster tasks after ScheduleTasks() has
-  // been called.
-  orphan_raster_tasks_.clear();
-
   did_check_for_completed_tasks_since_last_schedule_tasks_ = false;
 }
 
 scoped_refptr<ImageDecodeTask> TileManager::CreateImageDecodeTask(
     Tile* tile,
     SkPixelRef* pixel_ref) {
   return make_scoped_refptr(new ImageDecodeTaskImpl(
       pixel_ref,
       tile->layer_id(),
       rendering_stats_instrumentation_,
@@ skipping 74 matching lines @@
     pixel_ref_tasks.erase(task_it);
 }
 
 void TileManager::OnRasterTaskCompleted(
     Tile::Id tile_id,
     scoped_ptr<ScopedResource> resource,
     RasterMode raster_mode,
     const PicturePileImpl::Analysis& analysis,
     bool was_canceled) {
   TileMap::iterator it = tiles_.find(tile_id);
-  if (it == tiles_.end()) {
-    ++update_visible_tiles_stats_.canceled_count;
-    resource_pool_->ReleaseResource(resource.Pass());
-    return;
-  }
+  DCHECK(it != tiles_.end());
 
   Tile* tile = it->second;
   ManagedTileState& mts = tile->managed_state();
   ManagedTileState::TileVersion& tile_version = mts.tile_versions[raster_mode];
   DCHECK(tile_version.raster_task_);
-  orphan_raster_tasks_.push_back(tile_version.raster_task_);
   tile_version.raster_task_ = NULL;
 
   if (was_canceled) {
     ++update_visible_tiles_stats_.canceled_count;
     resource_pool_->ReleaseResource(resource.Pass());
     return;
   }
 
   ++update_visible_tiles_stats_.completed_count;
 
@@ skipping 483 matching lines @@
   TRACE_EVENT0("cc", "TileManager::CheckIfReadyToActivate");
 
   rasterizer_->CheckForCompletedTasks();
   did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
 
   if (IsReadyToActivate())
     client_->NotifyReadyToActivate();
 }
 
 }  // namespace cc