cc: Add mailbox support to ResourceProvider write locks.

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 329 matching lines @@
 void TileManager::FinishTasksAndCleanUp() {
   if (!tile_task_manager_)
     return;
 
   global_state_ = GlobalStateThatImpactsTilePriority();
 
   // This cancels tasks if possible, finishes pending tasks, and release any
   // uninitialized resources.
   tile_task_manager_->Shutdown();
 
-  // Now that all tasks have been finished, we can clear any
-  // |orphan_tasks_|.
+  raster_buffer_provider_->Shutdown();
+
+  // Now that all tasks have been finished, we can clear any |orphan_tasks_|.
   orphan_tasks_.clear();
 
   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,
+                               RasterBufferProvider* raster_buffer_provider,
                                size_t scheduled_raster_task_limit,
                                bool use_gpu_rasterization) {
   DCHECK(!tile_task_manager_);
   DCHECK(tile_task_manager);
 
   use_gpu_rasterization_ = use_gpu_rasterization;
   scheduled_raster_task_limit_ = scheduled_raster_task_limit;
   resource_pool_ = resource_pool;
   image_decode_controller_ = image_decode_controller;
   tile_task_manager_ = tile_task_manager;
+  raster_buffer_provider_ = raster_buffer_provider;
 }
 
 void TileManager::Release(Tile* tile) {
   released_tiles_.push_back(tile);
 }
 
 void TileManager::FreeResourcesForReleasedTiles() {
   for (auto* tile : released_tiles_)
     FreeResourcesForTile(tile);
 }
@@ skipping 478 matching lines @@
       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);
 
+  // We must reduce the amount of unused resources before calling
+  // ScheduleTasks to prevent usage from rising above limits.
+  resource_pool_->ReduceResourceUsage();
+  image_decode_controller_->ReduceCacheUsage();
+
+  // Synchronize worker with compositor. If that fails do not schedule tasks.

[vmpstr, 2016/06/15 00:39:34]

Can you expand this comment a little bit to mention why we do this? It's a bit
awkward that we don't bother freeing up resources here (like locked images that
we locked above). I think they will still be properly freed up in Finish
function, but it'd be nice to explain that the goal here is to just prevent new
raster from happening.

[sunnyps, 2016/06/15 00:42:00]

Calling task->OnTaskCompleted will free up resources. I'll add a comment
explaining that we want to avoid new raster work.

[sunnyps, 2016/06/15 01:56:58]

Done.

+  if (!raster_buffer_provider_->OrderingBarrier()) {
+    // Cancel tasks to appease DCHECKs in TileTask dtor.
+    for (auto& node : graph_.nodes) {
+      TileTask* task = static_cast<TileTask*>(node.task);
+      task->state().DidCancel();
+      task->OnTaskCompleted();
+      task->DidComplete();
+    }
+    graph_.Reset();
+    required_for_activate_count = 0;
+    required_for_draw_count = 0;
+    all_count = 0;
+  }
+
   // 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);
   InsertNodeForTask(&graph_, all_done_task.get(),
                     TASK_CATEGORY_NONCONCURRENT_FOREGROUND,
                     kAllDoneTaskPriority, all_count);
 
-  // We must reduce the amount of unused resoruces before calling
-  // ScheduleTasks to prevent usage from rising above limits.
-  resource_pool_->ReduceResourceUsage();
-  image_decode_controller_->ReduceCacheUsage();
-
   // Schedule running of |raster_queue_|. This replaces any previously
   // scheduled tasks and effectively cancels all tasks not present
   // in |raster_queue_|.
   tile_task_manager_->ScheduleTasks(&graph_);
 
   // 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_tasks_.clear();
 
@@ skipping 57 matching lines @@
       decode_tasks.push_back(task);
 
     if (need_to_unref_when_finished)
       ++it;
     else
       it = images.erase(it);
   }
 
   bool supports_concurrent_execution = !use_gpu_rasterization_;
   std::unique_ptr<RasterBuffer> raster_buffer =
-      tile_task_manager_->GetRasterBufferProvider()->AcquireBufferForRaster(
+      raster_buffer_provider_->AcquireBufferForRaster(
           resource, resource_content_id, tile->invalidated_id());
   return make_scoped_refptr(new RasterTaskImpl(
       this, tile, resource, prioritized_tile.raster_source(), playback_settings,
       prioritized_tile.priority().resolution, prepare_tiles_count_,
       std::move(raster_buffer), &decode_tasks, supports_concurrent_execution));
 }
 
 void TileManager::OnRasterTaskCompleted(
     std::unique_ptr<RasterBuffer> raster_buffer,
     Tile* tile,
     Resource* resource,
     bool was_canceled) {
   DCHECK(tile);
   DCHECK(tiles_.find(tile->id()) != tiles_.end());
-  tile_task_manager_->GetRasterBufferProvider()->ReleaseBufferForRaster(
-      std::move(raster_buffer));
+  raster_buffer_provider_->ReleaseBufferForRaster(std::move(raster_buffer));
 
   TileDrawInfo& draw_info = tile->draw_info();
   DCHECK(tile->raster_task_.get());
   orphan_tasks_.push_back(tile->raster_task_);
   tile->raster_task_ = nullptr;
 
   // Unref all the images.
   auto images_it = scheduled_draw_images_.find(tile->id());
   const std::vector<DrawImage>& images = images_it->second;
   for (const auto& image : images)
@@ skipping 35 matching lines @@
 
   tiles_[tile->id()] = tile.get();
   return tile;
 }
 
 void TileManager::SetTileTaskManagerForTesting(
     TileTaskManager* tile_task_manager) {
   tile_task_manager_ = tile_task_manager;
 }
 
+void TileManager::SetRasterBufferProviderForTesting(
+    RasterBufferProvider* raster_buffer_provider) {
+  raster_buffer_provider_ = raster_buffer_provider;
+}
+
 bool TileManager::AreRequiredTilesReadyToDraw(
     RasterTilePriorityQueue::Type type) const {
   std::unique_ptr<RasterTilePriorityQueue> raster_priority_queue(
       client_->BuildRasterQueue(global_state_.tree_priority, type));
   // It is insufficient to check whether the raster queue we constructed is
   // empty. The reason for this is that there are situations (rasterize on
   // demand) when the tile both needs raster and it's ready to draw. Hence, we
   // have to iterate the queue to check whether the required tiles are ready to
   // draw.
   for (; !raster_priority_queue->IsEmpty(); raster_priority_queue->Pop()) {
@@ skipping 149 matching lines @@
     Tile* tile = queue->Top().tile();
     if (tile->draw_info().IsReadyToDraw())
       continue;
     tile->draw_info().set_oom();
     client_->NotifyTileStateChanged(tile);
   }
   return true;
 }
 
 ResourceFormat TileManager::DetermineResourceFormat(const Tile* tile) const {
-  return tile_task_manager_->GetRasterBufferProvider()->GetResourceFormat(
+  return raster_buffer_provider_->GetResourceFormat(!tile->is_opaque());
+}
+
+bool TileManager::DetermineResourceRequiresSwizzle(const Tile* tile) const {
+  return raster_buffer_provider_->GetResourceRequiresSwizzle(
       !tile->is_opaque());
 }
 
-bool TileManager::DetermineResourceRequiresSwizzle(const Tile* tile) const {
-  return tile_task_manager_->GetRasterBufferProvider()
-      ->GetResourceRequiresSwizzle(!tile->is_opaque());
-}
-
 std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
 TileManager::ScheduledTasksStateAsValue() const {
   std::unique_ptr<base::trace_event::TracedValue> state(
       new base::trace_event::TracedValue());
   state->BeginDictionary("tasks_pending");
   state->SetBoolean("ready_to_activate", signals_.ready_to_activate);
   state->SetBoolean("ready_to_draw", signals_.ready_to_draw);
   state->SetBoolean("all_tile_tasks_completed",
                     signals_.all_tile_tasks_completed);
   state->EndDictionary();
@@ skipping 84 matching lines @@
   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