cc: Rasterize cheap tiles immediately

cc/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/tile_manager.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
@@ skipping 176 matching lines @@
     bool use_cheapness_estimator)
     : client_(client),
       resource_pool_(ResourcePool::Create(resource_provider)),
       raster_worker_pool_(RasterWorkerPool::Create(this, num_raster_threads)),
       manage_tiles_pending_(false),
       manage_tiles_call_count_(0),
       bytes_pending_set_pixels_(0),
       has_performed_uploads_since_last_flush_(false),
       ever_exceeded_memory_budget_(false),
       record_rendering_stats_(false),
-      use_cheapness_estimator_(use_cheapness_estimator) {
+      use_cheapness_estimator_(use_cheapness_estimator),
+      allow_cheap_tasks_(true),
+      did_schedule_cheap_tasks_(false) {
   for (int i = 0; i < NUM_STATES; ++i) {
     for (int j = 0; j < NUM_TREES; ++j) {
       for (int k = 0; k < NUM_BINS; ++k)
         raster_state_count_[i][j][k] = 0;
     }
   }
 }
 
 TileManager::~TileManager() {
   // Reset global state and manage. This should cause
@@ skipping 239 matching lines @@
     managed_tile_state.can_be_freed = true;
     managed_tile_state.can_use_gpu_memory = false;
     FreeResourcesForTile(tile);
 
     bytes_pending_set_pixels_ -= tile->bytes_consumed_if_allocated();
     DidTileRasterStateChange(tile, IDLE_STATE);
     tiles_with_pending_set_pixels_.pop();
   }
 }
 
+void TileManager::DidCompleteFrame() {
+  allow_cheap_tasks_ = true;
+  did_schedule_cheap_tasks_ = false;
+}
+
 void TileManager::GetMemoryStats(
     size_t* memoryRequiredBytes,
     size_t* memoryNiceToHaveBytes,
     size_t* memoryUsedBytes) const {
   *memoryRequiredBytes = 0;
   *memoryNiceToHaveBytes = 0;
   *memoryUsedBytes = 0;
   for (size_t i = 0; i < live_or_allocated_tiles_.size(); i++) {
     const Tile* tile = live_or_allocated_tiles_[i];
     const ManagedTileState& mts = tile->managed_state();
@@ skipping 177 matching lines @@
       tiles_that_need_to_be_rasterized_.end());
 }
 
 void TileManager::FreeResourcesForTile(Tile* tile) {
   ManagedTileState& managed_tile_state = tile->managed_state();
   DCHECK(managed_tile_state.can_be_freed);
   if (managed_tile_state.resource)
     resource_pool_->ReleaseResource(managed_tile_state.resource.Pass());
 }
 
-bool TileManager::CanDispatchRasterTask(Tile* tile) {
+bool TileManager::CanDispatchRasterTask(Tile* tile) const {
   if (raster_worker_pool_->IsBusy())
     return false;
   size_t new_bytes_pending = bytes_pending_set_pixels_;
   new_bytes_pending += tile->bytes_consumed_if_allocated();
   return new_bytes_pending <= kMaxPendingUploadBytes &&
          tiles_with_pending_set_pixels_.size() < kMaxPendingUploads;
 }
 
 void TileManager::DispatchMoreTasks() {
   // Because tiles in the image decoding list have higher priorities, we
   // need to process those tiles first before we start to handle the tiles
   // in the need_to_be_rasterized queue.
   for(TileList::iterator it = tiles_with_image_decoding_tasks_.begin();
       it != tiles_with_image_decoding_tasks_.end(); ) {
     DispatchImageDecodeTasksForTile(*it);
     ManagedTileState& managed_state = (*it)->managed_state();
     if (managed_state.pending_pixel_refs.empty()) {
       if (!CanDispatchRasterTask(*it))
-        return;
+        break;

[reveman, 2013/02/19 18:05:23]

hm, this makes us enter the loop below in cases where we didn't before. is that
ok? I think we should probably avoid that in this patch unless there's a good
reason for it.

[Sami, 2013/02/19 22:24:38]

You're right. We only need to make sure the allow_cheap_tasks_ flag is properly
reset and we can do it in a simpler way.

       DispatchOneRasterTask(*it);
       tiles_with_image_decoding_tasks_.erase(it++);
     } else {
       ++it;
     }
   }
 
   // Process all tiles in the need_to_be_rasterized queue. If a tile has
   // image decoding tasks, put it to the back of the image decoding list.
   while (!tiles_that_need_to_be_rasterized_.empty()) {
     Tile* tile = tiles_that_need_to_be_rasterized_.back();
     DispatchImageDecodeTasksForTile(tile);
     ManagedTileState& managed_state = tile->managed_state();
     if (!managed_state.pending_pixel_refs.empty()) {
       tiles_with_image_decoding_tasks_.push_back(tile);
     } else {
       if (!CanDispatchRasterTask(tile))
-        return;
+        break;
       DispatchOneRasterTask(tile);
     }
     tiles_that_need_to_be_rasterized_.pop_back();
   }
+
+  if (did_schedule_cheap_tasks_)
+    allow_cheap_tasks_ = false;
 }
 
 void TileManager::GatherPixelRefsForTile(Tile* tile) {
   TRACE_EVENT0("cc", "TileManager::GatherPixelRefsForTile");
   ManagedTileState& managed_state = tile->managed_state();
   if (managed_state.need_to_gather_pixel_refs) {
     base::TimeTicks gather_begin_time;
     if (record_rendering_stats_)
       gather_begin_time = base::TimeTicks::HighResNow();
     tile->picture_pile()->GatherPixelRefs(
@@ skipping 35 matching lines @@
 
 void TileManager::DispatchOneImageDecodeTask(
     scoped_refptr<Tile> tile, skia::LazyPixelRef* pixel_ref) {
   TRACE_EVENT0("cc", "TileManager::DispatchOneImageDecodeTask");
   uint32_t pixel_ref_id = pixel_ref->getGenerationID();
   DCHECK(pending_decode_tasks_.end() ==
       pending_decode_tasks_.find(pixel_ref_id));
   pending_decode_tasks_[pixel_ref_id] = pixel_ref;
 
   raster_worker_pool_->PostTaskAndReply(
-      base::Bind(&TileManager::RunImageDecodeTask, pixel_ref),
+      base::Bind(&TileManager::PerformImageDecode, pixel_ref),
       base::Bind(&TileManager::OnImageDecodeTaskCompleted,
                  base::Unretained(this),
                  tile,
                  pixel_ref_id));
 }
 
 void TileManager::OnImageDecodeTaskCompleted(
     scoped_refptr<Tile> tile, uint32_t pixel_ref_id) {
   TRACE_EVENT0("cc", "TileManager::OnImageDecodeTaskCompleted");
   pending_decode_tasks_.erase(pixel_ref_id);
@@ skipping 25 matching lines @@
 
   DidTileRasterStateChange(tile, RASTER_STATE);
   return resource.Pass();
 }
 
 void TileManager::DispatchOneRasterTask(scoped_refptr<Tile> tile) {
   TRACE_EVENT0("cc", "TileManager::DispatchOneRasterTask");
   scoped_ptr<ResourcePool::Resource> resource = PrepareTileForRaster(tile);
   ResourceProvider::ResourceId resource_id = resource->id();
 
+  bool is_cheap = use_cheapness_estimator_ && allow_cheap_tasks_ &&
+      tile->picture_pile()->IsCheapInRect(tile->content_rect_,
+                                          tile->contents_scale());
   raster_worker_pool_->PostRasterTaskAndReply(
       tile->picture_pile(),
+      is_cheap,
       base::Bind(&TileManager::PerformRaster,
                  resource_pool_->resource_provider()->mapPixelBuffer(
                      resource_id),
                  tile->content_rect_,
                  tile->contents_scale(),
                  use_cheapness_estimator_,
                  GetRasterTaskMetadata(tile->managed_state())),
       base::Bind(&TileManager::OnRasterTaskCompleted,
                  base::Unretained(this),
                  tile,
                  base::Passed(&resource),
                  manage_tiles_call_count_));
-}
-
-void TileManager::PerformOneRaster(Tile* tile) {
-  scoped_ptr<ResourcePool::Resource> resource = PrepareTileForRaster(tile);
-  ResourceProvider::ResourceId resource_id = resource->id();
-
-  PerformRaster(resource_pool_->resource_provider()->mapPixelBuffer(
-                    resource_id),
-                tile->content_rect_,
-                tile->contents_scale(),
-                use_cheapness_estimator_,
-                GetRasterTaskMetadata(tile->managed_state()),
-                tile->picture_pile(),
-                &rendering_stats_);
-
-  OnRasterCompleted(tile, resource.Pass(), manage_tiles_call_count_);
+  did_schedule_cheap_tasks_ |= is_cheap;
 }
 
 void TileManager::OnRasterCompleted(
     scoped_refptr<Tile> tile,
     scoped_ptr<ResourcePool::Resource> resource,
     int manage_tiles_call_count_when_dispatched) {
   TRACE_EVENT0("cc", "TileManager::OnRasterCompleted");
 
   // Release raster resources.
   resource_pool_->resource_provider()->unmapPixelBuffer(resource->id());
@@ skipping 123 matching lines @@
     if (raster_task_metadata.is_tile_in_pending_tree_now_bin)
       stats->totalRasterizeTimeForNowBinsOnPendingTree += duration;
 
     UMA_HISTOGRAM_CUSTOM_COUNTS("Renderer4.PictureRasterTimeMS",
                                 duration.InMilliseconds(),
                                 0,
                                 10,
                                 10);
 
     if (use_cheapness_estimator) {
-      bool is_predicted_cheap = picture_pile->IsCheapInRect (rect, contents_scale);
+      bool is_predicted_cheap = picture_pile->IsCheapInRect(rect, contents_scale);

[reveman, 2013/02/19 18:05:23]

nit: make this line <= 80 characters long

[Sami, 2013/02/19 22:24:38]

Whoops, done.

       bool is_actually_cheap = duration.InMillisecondsF() <= 1.0f;
       RecordCheapnessPredictorResults(is_predicted_cheap, is_actually_cheap);
     }
   }
 }
 
 // static
 void TileManager::RecordCheapnessPredictorResults(bool is_predicted_cheap,
                                                   bool is_actually_cheap) {
   if (is_predicted_cheap && !is_actually_cheap)
     UMA_HISTOGRAM_BOOLEAN("Renderer4.CheapPredictorBadlyWrong", true);
   else if (!is_predicted_cheap && is_actually_cheap)
     UMA_HISTOGRAM_BOOLEAN("Renderer4.CheapPredictorSafelyWrong", true);
 
   UMA_HISTOGRAM_BOOLEAN("Renderer4.CheapPredictorAccuracy",
                         is_predicted_cheap == is_actually_cheap);
 }
 
 // static
-void TileManager::RunImageDecodeTask(skia::LazyPixelRef* pixel_ref,
+void TileManager::PerformImageDecode(skia::LazyPixelRef* pixel_ref,
                                      RenderingStats* stats) {
-  TRACE_EVENT0("cc", "TileManager::RunImageDecodeTask");
+  TRACE_EVENT0("cc", "TileManager::PerformImageDecode");
   base::TimeTicks decode_begin_time;
   if (stats)
     decode_begin_time = base::TimeTicks::HighResNow();
   pixel_ref->Decode();
   if (stats) {
     stats->totalDeferredImageDecodeCount++;
     stats->totalDeferredImageDecodeTime +=
         base::TimeTicks::HighResNow() - decode_begin_time;
   }
 }
 
 }  // namespace cc