Separate usb device handle from usb device. (deprecate)

chrome/browser/usb/usb_device_handle.h

 // Copyright (c) 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.
 
-#ifndef CHROME_BROWSER_USB_USB_DEVICE_H_
-#define CHROME_BROWSER_USB_USB_DEVICE_H_
+#ifndef CHROME_BROWSER_USB_USB_DEVICE_HANDLE_H_
+#define CHROME_BROWSER_USB_USB_DEVICE_HANDLE_H_
 
 #include <map>
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/usb/usb_interface.h"
 #include "net/base/completion_callback.h"
 #include "net/base/io_buffer.h"
 
-struct libusb_device;
-struct libusb_device_handle;
-struct libusb_iso_packet_descriptor;
-struct libusb_transfer;
-
-typedef libusb_device* PlatformUsbDevice;
-typedef libusb_device_handle* PlatformUsbDeviceHandle;
-typedef libusb_iso_packet_descriptor* PlatformUsbIsoPacketDescriptor;
-typedef libusb_transfer* PlatformUsbTransferHandle;
+typedef struct libusb_device_handle* PlatformUsbDeviceHandle;
+typedef struct libusb_iso_packet_descriptor* PlatformUsbIsoPacketDescriptor;
+typedef struct libusb_transfer* PlatformUsbTransferHandle;
 
 class UsbService;
 
 namespace net {
 class IOBuffer;
 }  // namespace net
 
 enum UsbTransferStatus {
   USB_TRANSFER_COMPLETED = 0,
   USB_TRANSFER_ERROR,
   USB_TRANSFER_TIMEOUT,
   USB_TRANSFER_CANCELLED,
   USB_TRANSFER_STALLED,
   USB_TRANSFER_DISCONNECT,
   USB_TRANSFER_OVERFLOW,
   USB_TRANSFER_LENGTH_SHORT,
 };
 
 typedef base::Callback<void(UsbTransferStatus, scoped_refptr<net::IOBuffer>,
     size_t)> UsbTransferCallback;
 typedef base::Callback<void(bool)> UsbInterfaceCallback;
 
 // A UsbDevice wraps the platform's underlying representation of what a USB
 // device actually is, and provides accessors for performing many of the
 // standard USB operations.
-class UsbDevice : public base::RefCounted<UsbDevice> {
+class UsbDeviceHandle : public base::RefCountedThreadSafe<UsbDeviceHandle> {
  public:
   enum TransferRequestType { STANDARD, CLASS, VENDOR, RESERVED };
   enum TransferRecipient { DEVICE, INTERFACE, ENDPOINT, OTHER };
 
   // Usually you will not want to directly create a UsbDevice, favoring to let
   // the UsbService take care of the logistics of getting a platform device
   // handle and handling events for it.
-  UsbDevice(UsbService* service, PlatformUsbDeviceHandle handle);
+  UsbDeviceHandle(UsbService* service, int device,
+                  PlatformUsbDeviceHandle handle);
 
   PlatformUsbDeviceHandle handle() { return handle_; }
+  int device() { return device_; }
 
   // Close the USB device and release the underlying platform device. |callback|
   // is invoked after the device has been closed.
   virtual void Close(const base::Callback<void()>& callback);
 
   virtual void ListInterfaces(UsbConfigDescriptor* config,
                               const UsbInterfaceCallback& callback);
 
   virtual void ClaimInterface(const int interface_number,
                               const UsbInterfaceCallback& callback);
@@ skipping 43 matching lines @@
   virtual void ResetDevice(const base::Callback<void(bool)>& callback);
 
   // Normal code should not call this function. It is called by the platform's
   // callback mechanism in such a way that it cannot be made private. Invokes
   // the callbacks associated with a given transfer, and removes it from the
   // in-flight transfer set.
   void TransferComplete(PlatformUsbTransferHandle transfer);
 
  protected:
   // This constructor variant is for use in testing only.
-  UsbDevice();
+  UsbDeviceHandle();
 
-  friend class base::RefCounted<UsbDevice>;
-  virtual ~UsbDevice();
+  friend class base::RefCountedThreadSafe<UsbDeviceHandle>;
+  virtual ~UsbDeviceHandle();
 
  private:
   struct Transfer {
     Transfer();
     ~Transfer();
 
     UsbTransferType transfer_type;
     scoped_refptr<net::IOBuffer> buffer;
     size_t length;
     UsbTransferCallback callback;
   };
 
-  // Checks that the device has not yet been closed.
-  void CheckDevice();
+  friend class UsbDevice;
+
+  // This only called from UsbDevice, thus always from FILE thread.
+  void InternalClose();
 
   // Submits a transfer and starts tracking it. Retains the buffer and copies
   // the completion callback until the transfer finishes, whereupon it invokes
   // the callback then releases the buffer.
   void SubmitTransfer(PlatformUsbTransferHandle handle,
                       UsbTransferType transfer_type,
                       net::IOBuffer* buffer,
                       const size_t length,
                       const UsbTransferCallback& callback);
 
   // The UsbService isn't referenced here to prevent a dependency cycle between
   // the service and the devices. Since a service owns every device, and is
   // responsible for its destruction, there is no case where a UsbDevice can
   // have outlived its originating UsbService.
   UsbService* const service_;
+  int const device_;
+
+  // Lock the handle for the race condition of InternalClose and
+  // TransferComplete.
+  base::Lock handle_lock_;
   PlatformUsbDeviceHandle handle_;
 
   // transfers_ tracks all in-flight transfers associated with this device,
   // allowing the device to retain the buffer and callback associated with a
-  // transfer until such time that it completes. It is protected by lock_.
-  base::Lock lock_;
+  // transfer until such time that it completes. It is protected by
+  // transfer_lock_.
+  //
+  // If both locks are used, the locking order must be first handle_lock_, then
+  // transfer_lock_.
+  base::Lock transfer_lock_;
   std::map<PlatformUsbTransferHandle, Transfer> transfers_;
 
-  DISALLOW_COPY_AND_ASSIGN(UsbDevice);
+  DISALLOW_COPY_AND_ASSIGN(UsbDeviceHandle);
 };
 
-#endif  // CHROME_BROWSER_USB_USB_DEVICE_H_
+#endif  // CHROME_BROWSER_USB_USB_DEVICE_HANDLE_H_