cc: Remove memory state from tile management

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 <string>
 
 #include "base/bind.h"
@@ skipping 289 matching lines @@
   if (!client_->ShouldForceTileUploadsRequiredForActivationToComplete())
     return;
 
   TileSet initialized_tiles;
   for (TileSet::iterator it =
            tiles_that_need_to_be_initialized_for_activation_.begin();
        it != tiles_that_need_to_be_initialized_for_activation_.end();
        ++it) {
     Tile* tile = *it;
     if (!tile->managed_state().raster_task.is_null() &&
-        tile->tile_version().memory_state_ == USING_UNRELEASABLE_MEMORY &&
         !tile->tile_version().forced_upload_) {
       if (!raster_worker_pool_->ForceUploadToComplete(
               tile->managed_state().raster_task))
         continue;
 
       // Setting |forced_upload_| to true makes this tile ready to draw.
       tile->tile_version().forced_upload_ = true;
       initialized_tiles.insert(tile);
     }
   }
@@ skipping 20 matching lines @@
     const Tile* tile = *it;
     if (!tile->tile_version().requires_resource())
       continue;
 
     const ManagedTileState& mts = tile->managed_state();
     size_t tile_bytes = tile->bytes_consumed_if_allocated();
     if (mts.gpu_memmgr_stats_bin == NOW_BIN)
       *memory_required_bytes += tile_bytes;
     if (mts.gpu_memmgr_stats_bin != NEVER_BIN)
       *memory_nice_to_have_bytes += tile_bytes;
-    if (tile->tile_version().memory_state_ != NOT_ALLOWED_TO_USE_MEMORY)
+    if (!tile->managed_state().raster_task.is_null())

[reveman, 2013/06/03 14:11:34]

This is not the same. raster_task is only set while tile is being initialized.

[vmpstr, 2013/06/03 17:08:26]

Done.

       *memory_used_bytes += tile_bytes;
   }
 }
 
 scoped_ptr<base::Value> TileManager::BasicStateAsValue() const {
   scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
   state->SetInteger("tile_count", tiles_.size());
   state->Set("global_state", global_state_.AsValue().release());
   state->Set("memory_requirements", GetMemoryRequirementsAsValue().release());
   return state.PassAs<base::Value>();
@@ skipping 44 matching lines @@
   tiles_that_need_to_be_initialized_for_activation_.clear();
 
   // By clearing the tiles_that_need_to_be_rasterized_ vector list
   // above we move all tiles currently waiting for raster to idle state.
   // Some memory cannot be released. We figure out how much in this
   // loop.
   for (TileVector::const_iterator it = tiles_.begin();
        it != tiles_.end();
        ++it) {
     const Tile* tile = *it;
-    if (tile->tile_version().memory_state_ == USING_UNRELEASABLE_MEMORY)
+    if (!tile->managed_state().raster_task.is_null())

[reveman, 2013/06/03 14:11:34]

It's a bit weird that we examine |raster_task| to determine available memory.
Maybe we should compute bytes_allocatable as the sum of all releasable memory +
max(0, memory_limit_in_bytes - resource_pool_->memory_usage_bytes()).

[vmpstr, 2013/06/03 17:08:26]

Done.

       unreleasable_bytes += tile->bytes_consumed_if_allocated();
   }
 
   // Global state's memory limit can decrease, causing
   // it to be less than unreleasable_bytes
   size_t bytes_allocatable =
       global_state_.memory_limit_in_bytes > unreleasable_bytes ?
       global_state_.memory_limit_in_bytes - unreleasable_bytes :
       0;
   size_t bytes_that_exceeded_memory_budget_in_now_bin = 0;
   size_t bytes_left = bytes_allocatable;
   size_t bytes_oom_in_now_bin_on_pending_tree = 0;
   TileVector tiles_requiring_memory_but_oomed;
   bool higher_priority_tile_oomed = false;
   for (TileVector::iterator it = tiles_.begin();
        it != tiles_.end();
        ++it) {
     Tile* tile = *it;
     ManagedTileState& mts = tile->managed_state();
     ManagedTileState::TileVersion& tile_version = tile->tile_version();
 
     // If this tile doesn't need a resource, then nothing to do.
     if (!tile_version.requires_resource())
       continue;
 
     size_t tile_bytes = tile->bytes_consumed_if_allocated();
     // Memory is already reserved for tile with unreleasable memory
     // so adding it to |tiles_that_need_to_be_rasterized_| doesn't
     // affect bytes_allocatable.
-    if (tile_version.memory_state_ == USING_UNRELEASABLE_MEMORY)
+    if (!mts.raster_task.is_null())
       tile_bytes = 0;

[reveman, 2013/06/03 14:11:34]

Maybe we should reverse this. Make tile_bytes=0 by default and increase it based
on the needs for the tile. ie. maintaining a resource requires
tile->bytes_consumed_if_allocated(), creating a RasterTask for tile requires
another tile->bytes_consumed_if_allocated(). Wdyt?

Comment above needs to be updated anyhow. We shouldn't refer to unreleasable
memory anymore.

[vmpstr, 2013/06/03 17:08:26]

Done.

 
     // If the tile is not needed, free it up.
     if (mts.is_in_never_bin_on_both_trees()) {
-      if (tile_version.memory_state_ != USING_UNRELEASABLE_MEMORY) {
-        FreeResourcesForTile(tile);
-        tile_version.memory_state_ = NOT_ALLOWED_TO_USE_MEMORY;
-      }
+      FreeResourcesForTile(tile);
       continue;
     }
 
     // Tile is OOM.
     if (tile_bytes > bytes_left) {
       tile->tile_version().set_rasterize_on_demand();
       if (mts.tree_bin[PENDING_TREE] == NOW_BIN) {
         tiles_requiring_memory_but_oomed.push_back(tile);
         bytes_oom_in_now_bin_on_pending_tree += tile_bytes;
       }
@@ skipping 22 matching lines @@
   }
 
   // In OOM situation, we iterate tiles_, remove the memory for active tree
   // and not the now bin. And give them to bytes_oom_in_now_bin_on_pending_tree
   if (!tiles_requiring_memory_but_oomed.empty()) {
     size_t bytes_freed = 0;
     for (TileVector::iterator it = tiles_.begin(); it != tiles_.end(); ++it) {
       Tile* tile = *it;
       ManagedTileState& mts = tile->managed_state();
       ManagedTileState::TileVersion& tile_version = tile->tile_version();
-      if ((tile_version.memory_state_ == CAN_USE_MEMORY ||
-           tile_version.memory_state_ == USING_RELEASABLE_MEMORY) &&
+      if (tile_version.resource_ &&
           mts.tree_bin[PENDING_TREE] == NEVER_BIN &&
           mts.tree_bin[ACTIVE_TREE] != NOW_BIN) {
         DCHECK(!tile->required_for_activation());
         FreeResourcesForTile(tile);
         tile_version.set_rasterize_on_demand();
         bytes_freed += tile->bytes_consumed_if_allocated();
         TileVector::iterator it = std::find(
                 tiles_that_need_to_be_rasterized_.begin(),
                 tiles_that_need_to_be_rasterized_.end(),
                 tile);
@@ skipping 29 matching lines @@
   memory_stats_from_last_assign_.total_budget_in_bytes =
       global_state_.memory_limit_in_bytes;
   memory_stats_from_last_assign_.bytes_allocated =
       bytes_allocatable - bytes_left;
   memory_stats_from_last_assign_.bytes_unreleasable = unreleasable_bytes;
   memory_stats_from_last_assign_.bytes_over =
       bytes_that_exceeded_memory_budget_in_now_bin;
 }
 
 void TileManager::FreeResourcesForTile(Tile* tile) {
-  DCHECK_NE(USING_UNRELEASABLE_MEMORY, tile->tile_version().memory_state_);
   if (tile->tile_version().resource_) {
     resource_pool_->ReleaseResource(
         tile->tile_version().resource_.Pass());
   }
-  tile->tile_version().memory_state_ = NOT_ALLOWED_TO_USE_MEMORY;
 }
 
 void TileManager::ScheduleTasks() {
   TRACE_EVENT0("cc", "TileManager::ScheduleTasks");
   RasterWorkerPool::RasterTask::Queue tasks;
 
   // Build a new task queue containing all task currently needed. Tasks
   // are added in order of priority, highest priority task first.
   for (TileVector::iterator it = tiles_that_need_to_be_rasterized_.begin();
        it != tiles_that_need_to_be_rasterized_.end();
@@ skipping 56 matching lines @@
 
 RasterWorkerPool::RasterTask TileManager::CreateRasterTask(Tile* tile) {
   TRACE_EVENT0("cc", "TileManager::CreateRasterTask");
 
   scoped_ptr<ResourcePool::Resource> resource =
       resource_pool_->AcquireResource(
           tile->tile_size_.size(),
           tile->tile_version().resource_format_);
   const Resource* const_resource = resource.get();
 
-  DCHECK_EQ(CAN_USE_MEMORY, tile->tile_version().memory_state_);
-  tile->tile_version().memory_state_ = USING_UNRELEASABLE_MEMORY;
   tile->tile_version().resource_id_ = resource->id();
 
   PicturePileImpl::Analysis* analysis = new PicturePileImpl::Analysis;
 
   // Create and queue all image decode tasks that this tile depends on.
   RasterWorkerPool::Task::Set decode_tasks;
   for (PicturePileImpl::PixelRefIterator iter(tile->content_rect(),
                                               tile->contents_scale(),
                                               tile->picture_pile());
        iter; ++iter) {
@@ skipping 50 matching lines @@
     scoped_ptr<ResourcePool::Resource> resource,
     PicturePileImpl::Analysis* analysis,
     bool was_canceled) {
   TRACE_EVENT1("cc", "TileManager::OnRasterTaskCompleted",
                "was_canceled", was_canceled);
 
   ManagedTileState& mts = tile->managed_state();
   DCHECK(!mts.raster_task.is_null());
   mts.raster_task.Reset();
 
-  // Tile resources can't be freed until task has completed.
-  DCHECK_EQ(USING_UNRELEASABLE_MEMORY, tile->tile_version().memory_state_);
-
   if (was_canceled) {
-    tile->tile_version().memory_state_ = CAN_USE_MEMORY;
     resource_pool_->ReleaseResource(resource.Pass());
     return;
   }
 
   mts.picture_pile_analysis = *analysis;
   mts.picture_pile_analyzed = true;
 
   if (analysis->is_solid_color) {
     tile->tile_version().set_solid_color(analysis->solid_color);
     resource_pool_->ReleaseResource(resource.Pass());
   } else {
-    tile->tile_version().memory_state_ = USING_RELEASABLE_MEMORY;
     tile->tile_version().resource_ = resource.Pass();
   }
 
   DidFinishTileInitialization(tile);
 }
 
 void TileManager::DidFinishTileInitialization(Tile* tile) {
   if (tile->priority(ACTIVE_TREE).distance_to_visible_in_pixels == 0)
     did_initialize_visible_tile_ = true;
   if (tile->required_for_activation()) {
@@ skipping 114 matching lines @@
         100000,
         100);
   } else {
     picture_pile->RasterToBitmap(&canvas, rect, contents_scale, NULL);
   }
 
   return true;
 }
 
 }  // namespace cc