| // Copyright 2014 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. |
| |
| #ifndef DEVICE_USB_USB_SERVICE_H_ |
| #define DEVICE_USB_USB_SERVICE_H_ |
| |
| #include <memory> |
| #include <string> |
| #include <unordered_map> |
| #include <unordered_set> |
| #include <vector> |
| |
| #include "base/bind_helpers.h" |
| #include "base/logging.h" |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/observer_list.h" |
| #include "base/sequenced_task_runner.h" |
| #include "base/single_thread_task_runner.h" |
| #include "base/threading/non_thread_safe.h" |
| |
| namespace device { |
| |
| class UsbDevice; |
| |
| // The USB service handles creating and managing an event handler thread that is |
| // used to manage and dispatch USB events. It is also responsible for device |
| // discovery on the system, which allows it to re-use device handles to prevent |
| // competition for the same USB device. |
| class UsbService : public base::NonThreadSafe { |
| public: |
| using GetDevicesCallback = |
| base::Callback<void(const std::vector<scoped_refptr<UsbDevice>>&)>; |
| |
| class Observer { |
| public: |
| virtual ~Observer(); |
| |
| // These events are delivered from the thread on which the UsbService object |
| // was created. |
| virtual void OnDeviceAdded(scoped_refptr<UsbDevice> device); |
| virtual void OnDeviceRemoved(scoped_refptr<UsbDevice> device); |
| // For observers that need to process device removal after others have run. |
| // Should not depend on any other service's knowledge of connected devices. |
| virtual void OnDeviceRemovedCleanup(scoped_refptr<UsbDevice> device); |
| |
| // Notifies the observer that the UsbService it depends on is shutting down. |
| virtual void WillDestroyUsbService(); |
| }; |
| |
| // The file task runner reference is used for blocking I/O operations. |
| // Returns nullptr when initialization fails. |
| static std::unique_ptr<UsbService> Create( |
| scoped_refptr<base::SequencedTaskRunner> blocking_task_runner); |
| |
| virtual ~UsbService(); |
| |
| scoped_refptr<UsbDevice> GetDevice(const std::string& guid); |
| |
| // Shuts down the UsbService. Must be called before destroying the UsbService |
| // when tasks can still be posted to the |blocking_task_runner| provided to |
| // Create(). |
| virtual void Shutdown(); |
| |
| // Enumerates available devices. |
| virtual void GetDevices(const GetDevicesCallback& callback); |
| |
| void AddObserver(Observer* observer); |
| void RemoveObserver(Observer* observer); |
| |
| // Methods to add and remove devices for testing purposes. Only a device added |
| // by this method can be removed by RemoveDeviceForTesting(). |
| void AddDeviceForTesting(scoped_refptr<UsbDevice> device); |
| void RemoveDeviceForTesting(const std::string& device_guid); |
| void GetTestDevices(std::vector<scoped_refptr<UsbDevice>>* devices); |
| |
| protected: |
| UsbService(scoped_refptr<base::SequencedTaskRunner> blocking_task_runner); |
| |
| void NotifyDeviceAdded(scoped_refptr<UsbDevice> device); |
| void NotifyDeviceRemoved(scoped_refptr<UsbDevice> device); |
| |
| const scoped_refptr<base::SingleThreadTaskRunner>& task_runner() const { |
| return task_runner_; |
| } |
| |
| const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner() const { |
| return blocking_task_runner_; |
| } |
| |
| std::unordered_map<std::string, scoped_refptr<UsbDevice>>& devices() { |
| return devices_; |
| } |
| |
| private: |
| scoped_refptr<base::SingleThreadTaskRunner> task_runner_; |
| scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_; |
| std::unordered_map<std::string, scoped_refptr<UsbDevice>> devices_; |
| std::unordered_set<std::string> testing_devices_; |
| base::ObserverList<Observer, true> observer_list_; |
| |
| #if DCHECK_IS_ON() |
| bool did_shutdown_ = false; |
| #endif |
| |
| DISALLOW_COPY_AND_ASSIGN(UsbService); |
| }; |
| |
| } // namespace device |
| |
| #endif // DEVICE_USB_USB_SERVICE_H_ |