Separate usb device handle from usb device. (deprecate)

chrome/browser/usb/usb_device_handle.h

Index: chrome/browser/usb/usb_device_handle.h
diff --git a/chrome/browser/usb/usb_device.h b/chrome/browser/usb/usb_device_handle.h
similarity index 83%
rename from chrome/browser/usb/usb_device.h
rename to chrome/browser/usb/usb_device_handle.h
index 0625e74cd02ca78a59cfe56438ec5ae0daeb448b..26698937534c2d70b54f5926ac5fe039bde7d1c2 100644
--- a/chrome/browser/usb/usb_device.h
+++ b/chrome/browser/usb/usb_device_handle.h
@@ -2,8 +2,8 @@
 // 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>
@@ -14,15 +14,9 @@
 #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;
 
@@ -48,7 +42,7 @@ 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 };
@@ -56,9 +50,11 @@ class UsbDevice : public base::RefCounted<UsbDevice> {
   // 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.
@@ -122,10 +118,10 @@ class UsbDevice : public base::RefCounted<UsbDevice> {
 
  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 {
@@ -138,8 +134,10 @@ class UsbDevice : public base::RefCounted<UsbDevice> {
     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
@@ -155,15 +153,24 @@ class UsbDevice : public base::RefCounted<UsbDevice> {
   // 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_