Changeset 39193 in vbox for trunk/src/VBox/HostDrivers/VBoxUSB

Timestamp:

Nov 3, 2011 5:05:12 PM (13 years ago)

Author:

vboxsync

Message:

usb/win: comments

File:

• trunk/src/VBox/HostDrivers/VBoxUSB/win/lib/VBoxUsbLib-win.cpp (modified) (1 diff)

trunk/src/VBox/HostDrivers/VBoxUSB/win/lib/VBoxUsbLib-win.cpp

@@ -1435 +1435 @@
 #else
                         /*
-                         * ??? Please explain this....
+                         * We can not use USB Mon for reliable device add/remove tracking
+                         * since once USB Mon is notified about PDO creation and/or IRP_MN_START_DEVICE,
+                         * the function device driver may still do some initialization, which might result in
+                         * notifying too early.
+                         * Instead we use WM_DEVICECHANGE + DBT_DEVNODES_CHANGED to make Windows notify us about
+                         * device arivals/removals.
+                         * Since WM_DEVICECHANGE is a window message, create a dedicated thread to be used for WndProc and stuff.
+                         * The thread would create a window, track windows messages and call usbLibOnDeviceChange on WM_DEVICECHANGE arrival.
+                         * See comments in usbLibOnDeviceChange function for detail about using the timer queue.
                          */
                         g_VBoxUsbGlobal.hTimerQueue = CreateTimerQueue();