TaskGraphRunner refactor

content/renderer/raster_worker_pool.h

Index: content/renderer/raster_worker_pool.h
diff --git a/content/renderer/raster_worker_pool.h b/content/renderer/raster_worker_pool.h
index b8b4f358f2f2497dd9d5a6ad4f3a9efdab696386..547eeb8609fae6f23e48216f7a570bc872c14027 100644
--- a/content/renderer/raster_worker_pool.h
+++ b/content/renderer/raster_worker_pool.h
@@ -9,9 +9,11 @@
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_vector.h"
 #include "base/sequenced_task_runner.h"
+#include "base/synchronization/condition_variable.h"
 #include "base/task_runner.h"
 #include "base/threading/simple_thread.h"
 #include "cc/raster/task_graph_runner.h"
+#include "cc/raster/task_graph_work_queue.h"
 #include "content/common/content_export.h"
 
 namespace content {
@@ -24,10 +26,9 @@ namespace content {
 // parallel with other instances of sequenced task runners.
 // It's also possible to get the underlying TaskGraphRunner to schedule a graph
 // of tasks with their dependencies.
-// TODO(reveman): make TaskGraphRunner an abstract interface and have this
-// WorkerPool class implement it.
 class CONTENT_EXPORT RasterWorkerPool
     : public base::TaskRunner,
+      public cc::TaskGraphRunner,
       public base::DelegateSimpleThread::Delegate {
  public:
   RasterWorkerPool();
@@ -38,9 +39,18 @@ class CONTENT_EXPORT RasterWorkerPool
                        base::TimeDelta delay) override;
   bool RunsTasksOnCurrentThread() const override;
 
+  // Overridden from cc::TaskGraphRunner:
+  cc::NamespaceToken GetNamespaceToken() override;
+  void ScheduleTasks(cc::NamespaceToken token, cc::TaskGraph* graph) override;
+  void WaitForTasksToFinishRunning(cc::NamespaceToken token) override;
+  void CollectCompletedTasks(cc::NamespaceToken token,
+                             cc::Task::Vector* completed_tasks) override;
+
   // Overridden from base::DelegateSimpleThread::Delegate:
   void Run() override;
 
+  void FlushForTesting();
+
   // Spawn |num_threads| number of threads and start running work on the
   // worker threads.
   void Start(int num_threads,
@@ -52,7 +62,7 @@ class CONTENT_EXPORT RasterWorkerPool
   // terminated.
   void Shutdown();
 
-  cc::TaskGraphRunner* GetTaskGraphRunner() { return &task_graph_runner_; }
+  cc::TaskGraphRunner* GetTaskGraphRunner() { return this; }
 
   // Create a new sequenced task graph runner.
   scoped_refptr<base::SequencedTaskRunner> CreateSequencedTaskRunner();
@@ -64,6 +74,10 @@ class CONTENT_EXPORT RasterWorkerPool
   class RasterWorkerPoolSequencedTaskRunner;
   friend class RasterWorkerPoolSequencedTaskRunner;
 
+  // Run next task. Caller must acquire |lock_| prior to calling this function
+  // and make sure at least one task is ready to run.
+  void RunTaskWithLockAcquired();
+
   // Simple Task for the TaskGraphRunner that wraps a closure.
   // This class is used to schedule TaskRunner tasks on the
   // |task_graph_runner_|.
@@ -83,13 +97,19 @@ class CONTENT_EXPORT RasterWorkerPool
     DISALLOW_COPY_AND_ASSIGN(ClosureTask);
   };
 
+  void ScheduleTasksWithLockAcquired(cc::NamespaceToken token,
+                                     cc::TaskGraph* graph);
+  void CollectCompletedTasksWithLockAcquired(cc::NamespaceToken token,
+                                             cc::Task::Vector* completed_tasks);
+
   // The actual threads where work is done.
   ScopedVector<base::DelegateSimpleThread> threads_;
-  cc::TaskGraphRunner task_graph_runner_;
 
   // Lock to exclusively access all the following members that are used to
-  // implement the TaskRunner interfaces.
+  // implement the TaskRunner and TaskGraphRunner interfaces.
   base::Lock lock_;
+  // Stores the tasks to be run, sorted by priority.
+  cc::TaskGraphWorkQueue work_queue_;
   // Namespace used to schedule tasks in the task graph runner.
   cc::NamespaceToken namespace_token_;
   // List of tasks currently queued up for execution.
@@ -99,6 +119,14 @@ class CONTENT_EXPORT RasterWorkerPool
   // Cached vector to avoid allocation when getting the list of complete
   // tasks.
   cc::Task::Vector completed_tasks_;
+  // Condition variable that is waited on by Run() until new tasks are ready to
+  // run or shutdown starts.
+  base::ConditionVariable has_ready_to_run_tasks_cv_;
+  // Condition variable that is waited on by origin threads until a namespace
+  // has finished running all associated tasks.
+  base::ConditionVariable has_namespaces_with_finished_running_tasks_cv_;
+  // Set during shutdown. Tells Run() to return when no more tasks are pending.
+  bool shutdown_;
 };
 
 }  // namespace content