[Spice-devel] [spice-gtk v2 10/13] win-usb-dev: maintain list of libusb devices
Christophe Fergeau
cfergeau at redhat.com
Thu Mar 21 13:19:42 UTC 2019
On Tue, Mar 19, 2019 at 07:56:05AM +0200, Yuri Benditovich wrote:
> Change internal device list to maintain libusb devices
> instead of GUdevDevice objects. Create temporary
> GUdevDevice object only for indication to usb-dev-manager.
>
> Signed-off-by: Yuri Benditovich <yuri.benditovich at daynix.com>
> ---
> src/win-usb-dev.c | 80 ++++++++++++++++++++++++++++++-----------------
> 1 file changed, 51 insertions(+), 29 deletions(-)
>
> diff --git a/src/win-usb-dev.c b/src/win-usb-dev.c
> index b3b2ed8..0b87e75 100644
> --- a/src/win-usb-dev.c
> +++ b/src/win-usb-dev.c
> @@ -95,7 +95,7 @@ static void g_udev_device_print_list(GList *l, const gchar *msg);
> #else
> static void g_udev_device_print_list(GList *l, const gchar *msg) {}
> #endif
> -static void g_udev_device_print(GUdevDevice *udev, const gchar *msg);
> +static void g_udev_device_print(libusb_device *dev, const gchar *msg);
>
> static gboolean g_udev_skip_search(libusb_device *dev);
>
> @@ -129,8 +129,6 @@ g_udev_client_list_devices(GUdevClient *self, GList **devs,
> gssize rc;
> libusb_device **lusb_list, **dev;
> GUdevClientPrivate *priv;
> - GUdevDeviceInfo *udevinfo;
> - GUdevDevice *udevice;
> ssize_t n;
>
> g_return_val_if_fail(G_UDEV_IS_CLIENT(self), -1);
> @@ -155,10 +153,7 @@ g_udev_client_list_devices(GUdevClient *self, GList **devs,
> if (g_udev_skip_search(*dev)) {
> continue;
> }
> - udevinfo = g_new0(GUdevDeviceInfo, 1);
> - get_usb_dev_info(*dev, udevinfo);
> - udevice = g_udev_device_new(udevinfo);
> - *devs = g_list_prepend(*devs, udevice);
> + *devs = g_list_prepend(*devs, libusb_ref_device(*dev));
> n++;
> }
> libusb_free_device_list(lusb_list, 1);
> @@ -166,11 +161,17 @@ g_udev_client_list_devices(GUdevClient *self, GList **devs,
> return n;
> }
>
> +static void unreference_libusb_device(gpointer data)
> +{
> + libusb_unref_device((libusb_device *)data);
> +}
> +
> static void g_udev_client_free_device_list(GList **devs)
> {
> g_return_if_fail(devs != NULL);
> if (*devs) {
> - g_list_free_full(*devs, g_object_unref);
> + /* avoiding casting of imported procedure to GDestroyNotify */
Maybe make this very explicit with something like this?
/* the unreference_libusb_device method is required as
* libusb_unref_device calling convention differs from glib's
* see 558c967ec
*/
> + g_list_free_full(*devs, unreference_libusb_device);
> *devs = NULL;
> }
> }
> @@ -246,9 +247,22 @@ static void g_udev_client_initable_iface_init(GInitableIface *iface)
> iface->init = g_udev_client_initable_init;
> }
>
> +static void g_udev_notify_device(GUdevClient *self, libusb_device *dev, gboolean add)
> +{
> + GUdevDeviceInfo *udevinfo;
> + GUdevDevice *udevice;
> + udevinfo = g_new0(GUdevDeviceInfo, 1);
> + if (get_usb_dev_info(dev, udevinfo)) {
> + udevice = g_udev_device_new(udevinfo);
> + g_signal_emit(self, signals[UEVENT_SIGNAL], 0, udevice, add);
> + } else {
> + g_free(udevinfo);
> + }
> +}
> +
> static void report_one_device(gpointer data, gpointer self)
> {
> - g_signal_emit(self, signals[UEVENT_SIGNAL], 0, data, TRUE);
> + g_udev_notify_device(self, data, TRUE);
> }
>
> void g_udev_client_report_devices(GUdevClient *self)
> @@ -388,18 +402,20 @@ static gboolean get_usb_dev_info(libusb_device *dev, GUdevDeviceInfo *udevinfo)
> }
>
> /* comparing bus:addr and vid:pid */
> -static gint gudev_devices_differ(gconstpointer a, gconstpointer b)
> +static gint compare_libusb_devices(gconstpointer a, gconstpointer b)
> {
> - GUdevDeviceInfo *ai, *bi;
> + libusb_device *a_dev = (libusb_device *)a;
> + libusb_device *b_dev = (libusb_device *)b;
> + struct libusb_device_descriptor a_desc, b_desc;
> gboolean same_bus, same_addr, same_vid, same_pid;
>
> - ai = G_UDEV_DEVICE(a)->priv->udevinfo;
> - bi = G_UDEV_DEVICE(b)->priv->udevinfo;
> + libusb_get_device_descriptor(a_dev, &a_desc);
> + libusb_get_device_descriptor(b_dev, &b_desc);
>
> - same_bus = (ai->bus == bi->bus);
> - same_addr = (ai->addr == bi->addr);
> - same_vid = (ai->vid == bi->vid);
> - same_pid = (ai->pid == bi->pid);
> + same_bus = (libusb_get_bus_number(a_dev) == libusb_get_bus_number(b_dev));
> + same_addr = (libusb_get_device_address(a_dev) == libusb_get_device_address(b_dev));
> + same_vid = (a_desc.idVendor == b_desc.idVendor);
> + same_pid = (a_desc.idProduct == b_desc.idProduct);
>
> return (same_bus && same_addr && same_vid && same_pid) ? 0 : -1;
> }
> @@ -412,10 +428,17 @@ static void notify_dev_state_change(GUdevClient *self,
> GList *dev;
>
> for (dev = g_list_first(old_list); dev != NULL; dev = g_list_next(dev)) {
> - if (g_list_find_custom(new_list, dev->data, gudev_devices_differ) == NULL) {
> - /* Found a device that changed its state */
> + GList *found = g_list_find_custom(new_list, dev->data, compare_libusb_devices);
> + if (found == NULL) {
> g_udev_device_print(dev->data, add ? "add" : "remove");
> - g_signal_emit(self, signals[UEVENT_SIGNAL], 0, dev->data, add);
> + g_udev_notify_device(self, dev->data, add);
> + } else if (add) {
> + /* keep old existing libusb_device in the new list, when
> + usb-dev-manager will maintain its own list of libusb_device,
> + these lists will be completely consistent */
> + libusb_device *temp = found->data;
> + found->data = dev->data;
> + dev->data = temp;
I'm still annoyed by this slightly complicated code in a method named notify_dev_state_change
(more on this below)
> }
> }
> }
> @@ -446,7 +469,8 @@ static void handle_dev_change(GUdevClient *self)
> /* Unregister devices that are not present anymore */
> notify_dev_state_change(self, priv->udev_list, now_devs, FALSE);
>
> - /* Register newly inserted devices */
> + /* report newly inserted devices and swap pointers to existing devices:
> + keep old pointers in now_devs list, keep new pointers in udev_list */
> notify_dev_state_change(self, now_devs, priv->udev_list, TRUE);
>
> /* keep most recent info: free previous list, and keep current list */
> g_udev_client_free_device_list(&priv->udev_list);
> priv->udev_list = now_devs;
Maybe these 2 lines + the code to replace new libusb_device pointers
with the old ones could be moved to a new
g_udev_client_update_device_list(self, now_devs);
helper?
Christophe
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