cc: Separate raster and decode prepaint regions.

cc/tiles/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/tiles/tile_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 285 matching lines @@
   state->SetInteger("completed_count",
                     base::saturated_cast<int>(stats.completed_count));
   state->SetInteger("canceled_count",
                     base::saturated_cast<int>(stats.canceled_count));
   return std::move(state);
 }
 
 TileManager::TileManager(TileManagerClient* client,
                          scoped_refptr<base::SequencedTaskRunner> task_runner,
                          size_t scheduled_raster_task_limit,
-                         bool use_partial_raster)
+                         bool use_partial_raster,
+                         int max_preraster_distance_in_screen_pixels)
     : client_(client),
       task_runner_(std::move(task_runner)),
       resource_pool_(nullptr),
       tile_task_manager_(nullptr),
       scheduled_raster_task_limit_(scheduled_raster_task_limit),
       use_partial_raster_(use_partial_raster),
       use_gpu_rasterization_(false),
       all_tiles_that_need_to_be_rasterized_are_scheduled_(true),
       did_check_for_completed_tasks_since_last_schedule_tasks_(true),
       did_oom_on_last_assign_(false),
       more_tiles_need_prepare_check_notifier_(
           task_runner_.get(),
           base::Bind(&TileManager::CheckIfMoreTilesNeedToBePrepared,
                      base::Unretained(this))),
       signals_check_notifier_(task_runner_.get(),
                               base::Bind(&TileManager::CheckAndIssueSignals,
                                          base::Unretained(this))),
       has_scheduled_tile_tasks_(false),
       prepare_tiles_count_(0u),
       next_tile_id_(0u),
+      max_preraster_distance_in_screen_pixels_(
+          max_preraster_distance_in_screen_pixels),
       task_set_finished_weak_ptr_factory_(this) {}
 
 TileManager::~TileManager() {
   FinishTasksAndCleanUp();
 }
 
 void TileManager::FinishTasksAndCleanUp() {
   if (!tile_task_manager_)
     return;
 
@@ skipping 10 matching lines @@
   tile_task_manager_->CheckForCompletedTasks();
 
   FreeResourcesForReleasedTiles();
   CleanUpReleasedTiles();
 
   tile_task_manager_ = nullptr;
   resource_pool_ = nullptr;
   more_tiles_need_prepare_check_notifier_.Cancel();
   signals_check_notifier_.Cancel();
   task_set_finished_weak_ptr_factory_.InvalidateWeakPtrs();
+
+  for (auto& draw_image_pair : locked_images_)
+    image_decode_controller_->UnrefImage(draw_image_pair.first);
+  locked_images_.clear();
 }
 
 void TileManager::SetResources(ResourcePool* resource_pool,
                                ImageDecodeController* image_decode_controller,
                                TileTaskManager* tile_task_manager,
                                size_t scheduled_raster_task_limit,
                                bool use_gpu_rasterization) {
   DCHECK(!tile_task_manager_);
   DCHECK(tile_task_manager);
 
@@ skipping 90 matching lines @@
   // We need to call CheckForCompletedTasks() once in-between each call
   // to ScheduleTasks() to prevent canceled tasks from being scheduled.
   if (!did_check_for_completed_tasks_since_last_schedule_tasks_) {
     tile_task_manager_->CheckForCompletedTasks();
     did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
   }
 
   FreeResourcesForReleasedTiles();
   CleanUpReleasedTiles();
 
-  std::vector<PrioritizedTile> tiles_that_need_to_be_rasterized =
-      AssignGpuMemoryToTiles();
+  PrioritizedWorkToSchedule prioritized_work = AssignGpuMemoryToTiles();
 
   // Inform the client that will likely require a draw if the highest priority
   // tile that will be rasterized is required for draw.
   client_->SetIsLikelyToRequireADraw(
-      !tiles_that_need_to_be_rasterized.empty() &&
-      tiles_that_need_to_be_rasterized.front().tile()->required_for_draw());
+      !prioritized_work.tiles_to_raster.empty() &&
+      prioritized_work.tiles_to_raster.front().tile()->required_for_draw());
 
   // Schedule tile tasks.
-  ScheduleTasks(tiles_that_need_to_be_rasterized);
+  ScheduleTasks(prioritized_work);
 
   TRACE_EVENT_INSTANT1("cc", "DidPrepareTiles", TRACE_EVENT_SCOPE_THREAD,
                        "state", BasicStateAsValue());
   return true;
 }
 
 void TileManager::Flush() {
   TRACE_EVENT0("cc", "TileManager::Flush");
 
   if (!tile_task_manager_) {
@@ skipping 84 matching lines @@
     case ALLOW_PREPAINT_ONLY:
       return priority.priority_bin > TilePriority::SOON;
     case ALLOW_ANYTHING:
       return priority.distance_to_visible ==
              std::numeric_limits<float>::infinity();
   }
   NOTREACHED();
   return true;
 }
 
-std::vector<PrioritizedTile> TileManager::AssignGpuMemoryToTiles() {
+TileManager::PrioritizedWorkToSchedule TileManager::AssignGpuMemoryToTiles() {
   TRACE_EVENT_BEGIN0("cc", "TileManager::AssignGpuMemoryToTiles");
 
   DCHECK(resource_pool_);
   DCHECK(tile_task_manager_);
 
   // Maintain the list of released resources that can potentially be re-used
   // or deleted. If this operation becomes expensive too, only do this after
   // some resource(s) was returned. Note that in that case, one also need to
   // invalidate when releasing some resource from the pool.
   resource_pool_->CheckBusyResources();
 
   // Now give memory out to the tiles until we're out, and build
   // the needs-to-be-rasterized queue.
   unsigned schedule_priority = 1u;
   all_tiles_that_need_to_be_rasterized_are_scheduled_ = true;
   bool had_enough_memory_to_schedule_tiles_needed_now = true;
 
   MemoryUsage hard_memory_limit(global_state_.hard_memory_limit_in_bytes,
                                 global_state_.num_resources_limit);
   MemoryUsage soft_memory_limit(global_state_.soft_memory_limit_in_bytes,
                                 global_state_.num_resources_limit);
   MemoryUsage memory_usage(resource_pool_->memory_usage_bytes(),
                            resource_pool_->resource_count());
 
   std::unique_ptr<RasterTilePriorityQueue> raster_priority_queue(
       client_->BuildRasterQueue(global_state_.tree_priority,
                                 RasterTilePriorityQueue::Type::ALL));
   std::unique_ptr<EvictionTilePriorityQueue> eviction_priority_queue;
-  std::vector<PrioritizedTile> tiles_that_need_to_be_rasterized;
+  PrioritizedWorkToSchedule work_to_schedule;
   for (; !raster_priority_queue->IsEmpty(); raster_priority_queue->Pop()) {
     const PrioritizedTile& prioritized_tile = raster_priority_queue->Top();
     Tile* tile = prioritized_tile.tile();
     TilePriority priority = prioritized_tile.priority();
 
     if (TilePriorityViolatesMemoryPolicy(priority)) {
       TRACE_EVENT_INSTANT0(
           "cc", "TileManager::AssignGpuMemory tile violates memory policy",
           TRACE_EVENT_SCOPE_THREAD);
       break;
@@ skipping 12 matching lines @@
       if (is_solid_color) {
         tile->draw_info().set_solid_color(color);
         tile->draw_info().set_was_ever_ready_to_draw();
         if (!tile_is_needed_now)
           tile->draw_info().set_was_a_prepaint_tile();
         client_->NotifyTileStateChanged(tile);
         continue;
       }
     }
 
+    // Prepaint tiles that are far away are only processed for images.
+    if (!tile->required_for_activation() && !tile->required_for_draw() &&

[ericrk, 2016/05/24 23:42:34]

Just to make sure - low resolution tiles are not required for activation/draw,
so they may be ignored if they're outside the preraster distance. I'd assume
this is fine, but given that you had to check for activation/draw, I wonder if
there are some cases where this might cause problems?

Also, where do we skip images for low resolution tiles - probably fine, but want
to make sure we skip them in the predecode path as well.

[vmpstr, 2016/06/07 20:43:55]

Yeah, LOW_RESOLUTION tiles are neither required for draw or activation. The if
check ensures that if it _is_ required then it is rasterized always. So, low
resolution tiles would be skipped by this same check. I can add explicit code
not to add those tiles into tiles_to_process_for_images if you'd like. I don't
think it matters too much and low res tiles also don't have images enabled
anyway.

+        priority.distance_to_visible >
+            max_preraster_distance_in_screen_pixels_) {
+      work_to_schedule.tiles_to_process_for_images.push_back(prioritized_tile);
+      continue;
+    }
+
     // We won't be able to schedule this tile, so break out early.
-    if (tiles_that_need_to_be_rasterized.size() >=
+    if (work_to_schedule.tiles_to_raster.size() >=
         scheduled_raster_task_limit_) {
       all_tiles_that_need_to_be_rasterized_are_scheduled_ = false;
       break;
     }
 
     tile->scheduled_priority_ = schedule_priority++;
 
     DCHECK(tile->draw_info().mode() == TileDrawInfo::OOM_MODE ||
            !tile->draw_info().IsReadyToDraw());
 
@@ skipping 24 matching lines @@
     // If we couldn't fit the tile into our current memory limit, then we're
     // done.
     if (!memory_usage_is_within_limit) {
       if (tile_is_needed_now)
         had_enough_memory_to_schedule_tiles_needed_now = false;
       all_tiles_that_need_to_be_rasterized_are_scheduled_ = false;
       break;
     }
 
     memory_usage += memory_required_by_tile_to_be_scheduled;
-    tiles_that_need_to_be_rasterized.push_back(prioritized_tile);
+    work_to_schedule.tiles_to_raster.push_back(prioritized_tile);
 
     // Since we scheduled the tile, set whether it was a prepaint or not
     // assuming that the tile will successfully finish running. We don't have
     // priority information at the time the tile completes, so it should be done
     // here.
     if (!tile_is_needed_now)
       tile->draw_info().set_was_a_prepaint_tile();
   }
 
   // Note that we should try and further reduce memory in case the above loop
@@ skipping 11 matching lines @@
   memory_stats_from_last_assign_.total_bytes_used = memory_usage.memory_bytes();
   DCHECK_GE(memory_stats_from_last_assign_.total_bytes_used, 0);
   memory_stats_from_last_assign_.had_enough_memory =
       had_enough_memory_to_schedule_tiles_needed_now;
 
   TRACE_EVENT_END2("cc", "TileManager::AssignGpuMemoryToTiles",
                    "all_tiles_that_need_to_be_rasterized_are_scheduled",
                    all_tiles_that_need_to_be_rasterized_are_scheduled_,
                    "had_enough_memory_to_schedule_tiles_needed_now",
                    had_enough_memory_to_schedule_tiles_needed_now);
-  return tiles_that_need_to_be_rasterized;
+  return work_to_schedule;
 }
 
 void TileManager::FreeResourcesForTile(Tile* tile) {
   TileDrawInfo& draw_info = tile->draw_info();
   if (draw_info.resource_) {
     resource_pool_->ReleaseResource(draw_info.resource_, tile->id());
     draw_info.resource_ = nullptr;
   }
 }
 
 void TileManager::FreeResourcesForTileAndNotifyClientIfTileWasReadyToDraw(
     Tile* tile) {
   bool was_ready_to_draw = tile->draw_info().IsReadyToDraw();
   FreeResourcesForTile(tile);
   if (was_ready_to_draw)
     client_->NotifyTileStateChanged(tile);
 }
 
 void TileManager::ScheduleTasks(
-    const std::vector<PrioritizedTile>& tiles_that_need_to_be_rasterized) {
+    const PrioritizedWorkToSchedule& work_to_schedule) {
+  const std::vector<PrioritizedTile>& tiles_that_need_to_be_rasterized =
+      work_to_schedule.tiles_to_raster;
   TRACE_EVENT1("cc", "TileManager::ScheduleTasks", "count",
                tiles_that_need_to_be_rasterized.size());
 
   DCHECK(did_check_for_completed_tasks_since_last_schedule_tasks_);
 
   if (!has_scheduled_tile_tasks_) {
     TRACE_EVENT_ASYNC_BEGIN0("cc", "ScheduledTasks", this);
   }
 
   // Cancel existing OnTaskSetFinished callbacks.
@@ skipping 52 matching lines @@
     // A tile should use a foreground task cateogry if it is either blocking
     // future compositing (required for draw or required for activation), or if
     // it has a priority bin of NOW for another reason (low resolution tiles).
     bool use_foreground_category =
         tile->required_for_draw() || tile->required_for_activation() ||
         prioritized_tile.priority().priority_bin == TilePriority::NOW;
     InsertNodesForRasterTask(&graph_, task, task->dependencies(), priority++,
                              use_foreground_category);
   }
 
+  const std::vector<PrioritizedTile>& tiles_to_process_for_images =
+      work_to_schedule.tiles_to_process_for_images;
+  std::vector<std::pair<DrawImage, scoped_refptr<TileTask>>> new_locked_images;
+  for (const PrioritizedTile& prioritized_tile : tiles_to_process_for_images) {
+    Tile* tile = prioritized_tile.tile();
+
+    std::vector<DrawImage> images;
+    prioritized_tile.raster_source()->GetDiscardableImagesInRect(
+        tile->enclosing_layer_rect(), tile->contents_scale(), &images);
+    ImageDecodeController::TracingInfo tracing_info(
+        prepare_tiles_count_, prioritized_tile.priority().priority_bin);
+    for (DrawImage& draw_image : images) {
+      scoped_refptr<TileTask> task;
+      bool need_to_unref_when_finished =
+          image_decode_controller_->GetTaskForImageAndRef(draw_image,
+                                                          tracing_info, &task);
+      // We only care about images that need to be locked (ie they need to be
+      // unreffed later).
+      if (!need_to_unref_when_finished)
+        continue;
+      new_locked_images.emplace_back(draw_image, task);
+
+      // If there's no actual task associated with this image, then we're done.
+      if (!task)
+        continue;
+
+      auto decode_it = std::find_if(graph_.nodes.begin(), graph_.nodes.end(),
+                                    [&task](const TaskGraph::Node& node) {
+                                      return node.task == task.get();
+                                    });
+      // If this task is already in the graph, then we don't have to insert it.
+      if (decode_it != graph_.nodes.end())
+        continue;
+
+      InsertNodeForDecodeTask(&graph_, task.get(), false, priority++);
+      all_count++;
+      graph_.edges.push_back(TaskGraph::Edge(task.get(), all_done_task.get()));
+    }
+  }
+
+  for (auto& draw_image_pair : locked_images_)
+    image_decode_controller_->UnrefImage(draw_image_pair.first);
+  // The old locked images have to stay around until past the ScheduleTasks call
+  // below, so we do a swap instead of a move.
+  locked_images_.swap(new_locked_images);
+
   // Insert nodes for our task completion tasks. We enqueue these using
   // NONCONCURRENT_FOREGROUND category this is the highest prioirty category and
   // we'd like to run these tasks as soon as possible.
   InsertNodeForTask(&graph_, required_for_activation_done_task.get(),
                     TASK_CATEGORY_NONCONCURRENT_FOREGROUND,
                     kRequiredForActivationDoneTaskPriority,
                     required_for_activate_count);
   InsertNodeForTask(&graph_, required_for_draw_done_task.get(),
                     TASK_CATEGORY_NONCONCURRENT_FOREGROUND,
                     kRequiredForDrawDoneTaskPriority, required_for_draw_count);
@@ skipping 233 matching lines @@
     }
   }
 }
 
 void TileManager::CheckIfMoreTilesNeedToBePrepared() {
   tile_task_manager_->CheckForCompletedTasks();
   did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
 
   // When OOM, keep re-assigning memory until we reach a steady state
   // where top-priority tiles are initialized.
-  std::vector<PrioritizedTile> tiles_that_need_to_be_rasterized =
-      AssignGpuMemoryToTiles();
+  PrioritizedWorkToSchedule work_to_schedule = AssignGpuMemoryToTiles();
 
   // Inform the client that will likely require a draw if the highest priority
   // tile that will be rasterized is required for draw.
   client_->SetIsLikelyToRequireADraw(
-      !tiles_that_need_to_be_rasterized.empty() &&
-      tiles_that_need_to_be_rasterized.front().tile()->required_for_draw());
+      !work_to_schedule.tiles_to_raster.empty() &&
+      work_to_schedule.tiles_to_raster.front().tile()->required_for_draw());
 
   // |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);
+  if (!work_to_schedule.tiles_to_raster.empty()) {
+    ScheduleTasks(work_to_schedule);
     return;
   }
 
+  // If we're not in SMOOTHNESS_TAKES_PRIORITY  mode, we should unlock all
+  // images since we're technically going idle here at least for this frame.
+  if (global_state_.tree_priority != SMOOTHNESS_TAKES_PRIORITY) {
+    for (auto& draw_image_pair : locked_images_)
+      image_decode_controller_->UnrefImage(draw_image_pair.first);
+    locked_images_.clear();
+  }
+
   FreeResourcesForReleasedTiles();
 
   resource_pool_->ReduceResourceUsage();
   image_decode_controller_->ReduceCacheUsage();
 
   signals_.all_tile_tasks_completed = true;
   signals_check_notifier_.Schedule();
 
   // We don't reserve memory for required-for-activation tiles during
   // accelerated gestures, so we just postpone activation when we don't
@@ skipping 148 matching lines @@
 
 void TileManager::Signals::reset() {
   ready_to_activate = false;
   did_notify_ready_to_activate = false;
   ready_to_draw = false;
   did_notify_ready_to_draw = false;
   all_tile_tasks_completed = false;
   did_notify_all_tile_tasks_completed = false;
 }
 
+TileManager::PrioritizedWorkToSchedule::PrioritizedWorkToSchedule() = default;
+TileManager::PrioritizedWorkToSchedule::PrioritizedWorkToSchedule(
+    PrioritizedWorkToSchedule&& other) = default;
+TileManager::PrioritizedWorkToSchedule::~PrioritizedWorkToSchedule() = default;
+
 }  // namespace cc