blob: e10bd16326702d74f2c9e9b990ce7bc501163521 [file] [log] [blame]
// Copyright 2016 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 <stdint.h>
#include <memory>
#include <vector>
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/lock.h"
#include "base/threading/thread.h"
#include "base/time/time.h"
#include "media/midi/midi_export.h"
#include "media/midi/midi_manager.h"
namespace midi {
class TaskService;
// Manages MidiManager backends. This class expects to be constructed and
// destructed on the browser main thread, but methods can be called on both
// the main thread and the I/O thread.
class MIDI_EXPORT MidiService final {
class MIDI_EXPORT ManagerFactory {
ManagerFactory() = default;
virtual ~ManagerFactory() = default;
virtual std::unique_ptr<MidiManager> Create(MidiService* service);
// Converts Web MIDI timestamp to base::TimeDelta delay for PostDelayedTask.
static base::TimeDelta TimestampToTimeDeltaDelay(base::TimeTicks timestamp);
// Customized ManagerFactory can be specified in the constructor for testing.
explicit MidiService(std::unique_ptr<ManagerFactory> factory);
// Called on the browser main thread to notify the I/O thread will stop and
// the instance will be destructed on the main thread soon.
void Shutdown();
// A client calls StartSession() to receive and send MIDI data.
void StartSession(MidiManagerClient* client);
// A client calls EndSession() to stop receiving MIDI data.
// Returns false if |client| did not start a session.
bool EndSession(MidiManagerClient* client);
// A client calls DispatchSendMidiData() to send MIDI data.
void DispatchSendMidiData(MidiManagerClient* client,
uint32_t port_index,
const std::vector<uint8_t>& data,
base::TimeTicks timestamp);
// Returns a SingleThreadTaskRunner reference to serve MidiManager. Each
// TaskRunner will be constructed on demand.
// MidiManager that supports the dynamic instantiation feature will use this
// method to post tasks that should not run on I/O. Since TaskRunners outlive
// MidiManager, each task should ensure that MidiManager that posted the task
// is still alive while accessing |this|. TaskRunners will be reused when
// another MidiManager is instantiated.
// TODO(toyoshim): Remove this interface.
scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunner(size_t runner_id);
// Obtains a TaskService that lives with MidiService.
TaskService* task_service() { return task_service_.get(); }
// ManagerFactory passed in the constructor.
std::unique_ptr<ManagerFactory> manager_factory_;
// Holds MidiManager instance. The MidiManager is constructed and destructed
// on the I/O thread, and all MidiManager methods should be called on the I/O
// thread.
std::unique_ptr<MidiManager> manager_;
// Holds TaskService instance.
std::unique_ptr<TaskService> task_service_;
// TaskRunner to destruct |manager_| on the right thread.
scoped_refptr<base::SingleThreadTaskRunner> manager_destructor_runner_;
// Protects all members above.
base::Lock lock_;
// Threads to host SingleThreadTaskRunners.
std::vector<std::unique_ptr<base::Thread>> threads_;
// Protects |threads_|.
base::Lock threads_lock_;
} // namespace midi