Windows: Free all WinUSB handles when closing a device

* libusbK (as of v3.0.7.0) will fail after 32 opens because
  resources from claimed interfaces are not freed by simply
  closing just the device handle
* Closes #16

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>

diff --git a/libusb/os/windows_usb.c b/libusb/os/windows_usb.c
index add2b37..3add9e1 100644 (file)
--- a/libusb/os/windows_usb.c
+++ b/libusb/os/windows_usb.c
@@ -2803,14 +2803,40 @@ static void winusbx_close(int sub_api, struct libusb_device_handle *dev_handle)
        if (!WinUSBX[sub_api].initialized)
                return;
 
-       for (i = 0; i < USB_MAXINTERFACES; i++) {
-               if (priv->usb_interface[i].apib->id == USB_API_WINUSBX) {
-                       file_handle = handle_priv->interface_handle[i].dev_handle;
-                       if ( (file_handle != 0) && (file_handle != INVALID_HANDLE_VALUE)) {
-                               CloseHandle(file_handle);
+       if (priv->apib->id == USB_API_COMPOSITE) {
+               // If this is a composite device, just free and close all WinUSB-like
+               // interfaces directly (each is independent and not associated with another)
+               for (i = 0; i < USB_MAXINTERFACES; i++) {
+                       if (priv->usb_interface[i].apib->id == USB_API_WINUSBX) {
+                               handle = handle_priv->interface_handle[i].api_handle;
+                               if ((handle != 0) && (handle != INVALID_HANDLE_VALUE)) {
+                                       WinUSBX[sub_api].Free(handle);
+                               }
+                               handle = handle_priv->interface_handle[i].dev_handle;
+                               if ((handle != 0) && (handle != INVALID_HANDLE_VALUE)) {
+                                       CloseHandle(handle);
+                               }
                        }
                }
        }
+       else {
+               // If this is a WinUSB device, free all interfaces above interface 0,
+               // then free and close interface 0 last
+               for (i = 1; i < USB_MAXINTERFACES; i++) {
+                       handle = handle_priv->interface_handle[i].api_handle;
+                       if ((handle != 0) && (handle != INVALID_HANDLE_VALUE)) {
+                               WinUSBX[sub_api].Free(handle);
+                       }
+               }
+               handle = handle_priv->interface_handle[0].api_handle;
+               if ((handle != 0) && (handle != INVALID_HANDLE_VALUE)) {
+                       WinUSBX[sub_api].Free(handle);
+               }
+               handle = handle_priv->interface_handle[0].dev_handle;
+               if ((handle != 0) && (handle != INVALID_HANDLE_VALUE)) {
+                       CloseHandle(handle);
+               }
+       }
 }
 
 static int winusbx_configure_endpoints(int sub_api, struct libusb_device_handle *dev_handle, int iface)