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());
-
   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, tiles_.size());
   DCHECK_EQ(0u, bytes_releasable_);
   DCHECK_EQ(0u, resources_releasable_);
 }
 
 void TileManager::Release(Tile* tile) {
+  // Reset priority as tile is ref-counted and might still be used
+  // even though we no longer hold a reference to it here anymore.

[vmpstr, 2014/07/23 16:10:37]

This comment was meant to be for the picture layer tiling, I think. At this
point it's actually not correct. TileManager::Release means that the tile is
_not_ used anywhere anymore. That being said, I don't mind resetting it here (up
to reveman)

[reveman, 2014/07/23 16:26:54]

Yea, this doesn't make sense here.

[sohanjg, 2014/07/24 11:08:41]

Done.

+  tile->SetPriority(ACTIVE_TREE, TilePriority());
+  tile->SetPriority(PENDING_TREE, TilePriority());

[reveman, 2014/07/23 16:26:54]

Please try to reset these when dropping the ref from the picture layer tiling
instead. And keep the DCHECK you had here before. The above comment makes sense
in that context. I'd like to see what that looks like before we resort to
resetting the priority here.

[sohanjg, 2014/07/24 11:08:41]

Done.

+
   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();
+    FreeResourcesForTile(tile);
+  }
+}
 
-    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_);
+// TODO(sohanjg): Move it to UpdatePrioritizedTileSetIfNeeded to ensure
+// the prioritized set is rebuild.
+void TileManager::CleanUpReleasedTiles() {
+  std::vector<Tile*>::iterator it = released_tiles_.begin();
+  while (it != released_tiles_.end()) {
+    Tile* tile = *it;
+
+    if (tile->HasRasterTask()) {
+      ++it;
+      continue;
     }
 
+    DCHECK(!tile->HasResources());
     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;
+    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 13 matching lines @@
   AssignGpuMemoryToTiles(&prioritized_tiles_,
                          &tiles_that_need_to_be_rasterized);
 
   // |tiles_that_need_to_be_rasterized| will be empty when we reach a
   // steady memory state. Keep scheduling tasks until we reach this state.
   if (!tiles_that_need_to_be_rasterized.empty()) {
     ScheduleTasks(tiles_that_need_to_be_rasterized);
     return;
   }
 
+  FreeResourcesForReleasedTiles();
+
   resource_pool_->ReduceResourceUsage();
 
   // We don't reserve memory for required-for-activation tiles during
   // accelerated gestures, so we just postpone activation when we don't
   // have these tiles, and activate after the accelerated gesture.
   bool allow_rasterize_on_demand =
       global_state_.tree_priority != SMOOTHNESS_TAKES_PRIORITY;
 
   // Use on-demand raster for any required-for-activation tiles that have not
   // been been assigned memory after reaching a steady memory state. This
@@ skipping 567 matching lines @@
   if (task_it != pixel_ref_tasks.end())
     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(tiles_.find(tile_id) != tiles_.end());
 
-  Tile* tile = it->second;
+  Tile* tile = tiles_[tile_id];
   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;
@@ skipping 501 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