cc: Always check for completed raster tasks before scheduling more 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 140 matching lines @@
       raster_worker_pool_(raster_worker_pool.Pass()),
       prioritized_tiles_dirty_(false),
       all_tiles_that_need_to_be_rasterized_have_memory_(true),
       all_tiles_required_for_activation_have_memory_(true),
       memory_required_bytes_(0),
       memory_nice_to_have_bytes_(0),
       bytes_releasable_(0),
       resources_releasable_(0),
       ever_exceeded_memory_budget_(false),
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
-      did_initialize_visible_tile_(false) {
+      did_initialize_visible_tile_(false),
+      did_check_for_completed_tasks_since_last_schedule_tasks_(true) {
   raster_worker_pool_->SetClient(this);
 }
 
 TileManager::~TileManager() {
   // Reset global state and manage. This should cause
   // our memory usage to drop to zero.
   global_state_ = GlobalStateThatImpactsTilePriority();
 
   DCHECK_EQ(0u, tiles_.size());
 
-  TileVector empty;
-  ScheduleTasks(empty);
+  RasterWorkerPool::RasterTask::Queue empty;
+  raster_worker_pool_->ScheduleTasks(&empty);
 
   // This should finish all pending tasks and release any uninitialized
   // resources.
   raster_worker_pool_->Shutdown();
   raster_worker_pool_->CheckForCompletedTasks();
 
   DCHECK_EQ(0u, bytes_releasable_);
   DCHECK_EQ(0u, resources_releasable_);
 }
 
@@ skipping 51 matching lines @@
 
 void TileManager::DidFinishRunningTasks() {
   TRACE_EVENT0("cc", "TileManager::DidFinishRunningTasks");
 
   // When OOM, keep re-assigning memory until we reach a steady state
   // where top-priority tiles are initialized.
   if (all_tiles_that_need_to_be_rasterized_have_memory_)
     return;
 
   raster_worker_pool_->CheckForCompletedTasks();
+  did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
 
   TileVector tiles_that_need_to_be_rasterized;
   AssignGpuMemoryToTiles(GetPrioritizedTileSet(),
                          &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;
@@ skipping 135 matching lines @@
                                   : mts.bin;
 
     // Insert the tile into a priority set.
     tiles->InsertTile(tile, priority_bin);
   }
 }
 
 void TileManager::ManageTiles() {
   TRACE_EVENT0("cc", "TileManager::ManageTiles");
 
+  // 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_) {
+    raster_worker_pool_->CheckForCompletedTasks();
+    did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
+  }
+
   TileVector tiles_that_need_to_be_rasterized;
   AssignGpuMemoryToTiles(GetPrioritizedTileSet(),
                          &tiles_that_need_to_be_rasterized);
 
   // Finally, schedule rasterizer tasks.
   ScheduleTasks(tiles_that_need_to_be_rasterized);
 
   TRACE_EVENT_INSTANT1(
       "cc", "DidManage", TRACE_EVENT_SCOPE_THREAD,
       "state", TracedValue::FromValue(BasicStateAsValue().release()));
 
   TRACE_COUNTER_ID1("cc", "unused_memory_bytes", this,
                     resource_pool_->total_memory_usage_bytes() -
                     resource_pool_->acquired_memory_usage_bytes());
 }
 
 bool TileManager::UpdateVisibleTiles() {
   TRACE_EVENT0("cc", "TileManager::UpdateVisibleTiles");
 
   raster_worker_pool_->CheckForCompletedTasks();
+  did_check_for_completed_tasks_since_last_schedule_tasks_ = true;
 
   TRACE_EVENT_INSTANT1(
       "cc", "DidUpdateVisibleTiles", TRACE_EVENT_SCOPE_THREAD,
       "stats", TracedValue::FromValue(
           RasterTaskCompletionStatsAsValue(
               update_visible_tiles_stats_).release()));
   update_visible_tiles_stats_ = RasterTaskCompletionStats();
 
   bool did_initialize_visible_tile = did_initialize_visible_tile_;
   did_initialize_visible_tile_ = false;
@@ skipping 237 matching lines @@
       FreeResourceForTile(tile, static_cast<RasterMode>(mode));
   }
 }
 
 void TileManager::ScheduleTasks(
     const TileVector& tiles_that_need_to_be_rasterized) {
   TRACE_EVENT1("cc", "TileManager::ScheduleTasks",
                "count", tiles_that_need_to_be_rasterized.size());
   RasterWorkerPool::RasterTask::Queue tasks;
 
+  DCHECK(did_check_for_completed_tasks_since_last_schedule_tasks_);
+
   // Build a new task queue containing all task currently needed. Tasks
   // are added in order of priority, highest priority task first.
   for (TileVector::const_iterator it = tiles_that_need_to_be_rasterized.begin();
        it != tiles_that_need_to_be_rasterized.end();
        ++it) {
     Tile* tile = *it;
     ManagedTileState& mts = tile->managed_state();
     ManagedTileState::TileVersion& tile_version =
         mts.tile_versions[mts.raster_mode];
 
     DCHECK(tile_version.requires_resource());
     DCHECK(!tile_version.resource_);
 
     if (tile_version.raster_task_.is_null())
       tile_version.raster_task_ = CreateRasterTask(tile);
 
     tasks.Append(tile_version.raster_task_, tile->required_for_activation());
   }
 
   // We must reduce the amount of unused resoruces before calling
   // ScheduleTasks to prevent usage from rising above limits.
   resource_pool_->ReduceResourceUsage();
 
   // Schedule running of |tasks|. This replaces any previously
   // scheduled tasks and effectively cancels all tasks not present
   // in |tasks|.
   raster_worker_pool_->ScheduleTasks(&tasks);
+
+  did_check_for_completed_tasks_since_last_schedule_tasks_ = false;
 }
 
 RasterWorkerPool::Task TileManager::CreateImageDecodeTask(
     Tile* tile, skia::LazyPixelRef* pixel_ref) {
   return RasterWorkerPool::CreateImageDecodeTask(
       pixel_ref,
       tile->layer_id(),
       rendering_stats_instrumentation_,
       base::Bind(&TileManager::OnImageDecodeTaskCompleted,
                  base::Unretained(this),
@@ skipping 116 matching lines @@
     bytes_releasable_ += tile->bytes_consumed_if_allocated();
     ++resources_releasable_;
   }
 
   FreeUnusedResourcesForTile(tile);
   if (tile->priority(ACTIVE_TREE).distance_to_visible_in_pixels == 0)
     did_initialize_visible_tile_ = true;
 }
 
 }  // namespace cc