blob: 90def4e3a6ae2ebcac9e63b56ef86275f7c5eadb [file] [log] [blame]
// Copyright 2018 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 "base/base_export.h"
#include "base/task/task_scheduler/sequence.h"
#include "base/task/task_scheduler/task.h"
#include "base/task/task_traits.h"
namespace base {
namespace internal {
// Delegate interface for SchedulerParallelTaskRunner and
// SchedulerSequencedTaskRunner.
class BASE_EXPORT SchedulerTaskRunnerDelegate {
virtual ~SchedulerTaskRunnerDelegate();
// Returns true if a SchedulerTaskRunnerDelegate instance exists in the
// process. This is needed in case of unit tests wherein a TaskRunner
// outlives the TaskScheduler that created it.
static bool Exists();
// Invoked when a |task| is posted to the SchedulerParallelTaskRunner or
// SchedulerSequencedTaskRunner. The implementation must post |task| to
// |sequence| within the appropriate priority queue, depending on |sequence|
// traits. Returns true if task was successfully posted.
virtual bool PostTaskWithSequence(Task task,
scoped_refptr<Sequence> sequence) = 0;
// Invoked when RunsTasksInCurrentSequence() is called on a
// SchedulerParallelTaskRunner. Returns true if the worker pool used by the
// SchedulerParallelTaskRunner (as determined by |traits|) is running on
// this thread.
virtual bool IsRunningPoolWithTraits(const TaskTraits& traits) const = 0;
// Invoked when the priority of |sequence|'s TaskRunner is updated. The
// implementation must update |sequence|'s priority to |priority|, then place
// |sequence| in the correct priority-queue position within the appropriate
// worker pool.
virtual void UpdatePriority(scoped_refptr<Sequence> sequence,
TaskPriority priority) = 0;
} // namespace internal
} // namespace base