Rework device removal to have a nice API

This enhances the device removal to create a well defined behaviour.

Primarily, it means that:
 * "device-removed" will only be called for closed devices
 * "removed" will be called only when no operation is active

Note that all actions will fail with FP_DEVICE_ERROR_REMOVED, *except*
for open which will only return this error if it failed.

Resolves: #330
This commit is contained in:
Benjamin Berg 2020-11-13 16:44:46 +01:00
parent 656bf3d175
commit b6dd522459
6 changed files with 205 additions and 9 deletions

View file

@ -86,6 +86,60 @@ is_driver_allowed (const gchar *driver)
return FALSE;
}
typedef struct
{
FpContext *context;
FpDevice *device;
} RemoveDeviceData;
static gboolean
remove_device_idle_cb (RemoveDeviceData *data)
{
FpContextPrivate *priv = fp_context_get_instance_private (data->context);
guint idx = 0;
g_return_val_if_fail (g_ptr_array_find (priv->devices, data->device, &idx), G_SOURCE_REMOVE);
g_signal_emit (data->context, signals[DEVICE_REMOVED_SIGNAL], 0, data->device);
g_ptr_array_remove_index_fast (priv->devices, idx);
g_free (data);
return G_SOURCE_REMOVE;
}
static void
remove_device (FpContext *context, FpDevice *device)
{
RemoveDeviceData *data;
data = g_new (RemoveDeviceData, 1);
data->context = context;
data->device = device;
g_idle_add ((GSourceFunc) remove_device_idle_cb, data);
}
static void
device_remove_on_notify_open_cb (FpContext *context, GParamSpec *pspec, FpDevice *device)
{
remove_device (context, device);
}
static void
device_removed_cb (FpContext *context, FpDevice *device)
{
gboolean open = FALSE;
g_object_get (device, "open", &open, NULL);
/* Wait for device close if the device is currently still open. */
if (open)
g_signal_connect_swapped (device, "notify::open", (GCallback) device_remove_on_notify_open_cb, context);
else
remove_device (context, device);
}
static void
async_device_init_done_cb (GObject *source_object, GAsyncResult *res, gpointer user_data)
{
@ -110,6 +164,9 @@ async_device_init_done_cb (GObject *source_object, GAsyncResult *res, gpointer u
}
g_ptr_array_add (priv->devices, device);
g_signal_connect_swapped (device, "removed", (GCallback) device_removed_cb, context);
g_signal_emit (context, signals[DEVICE_ADDED_SIGNAL], 0, device);
}
@ -189,12 +246,7 @@ usb_device_removed_cb (FpContext *self, GUsbDevice *device, GUsbContext *usb_ctx
continue;
if (fpi_device_get_usb_device (dev) == device)
{
g_signal_emit (self, signals[DEVICE_REMOVED_SIGNAL], 0, dev);
g_ptr_array_remove_index_fast (priv->devices, i);
return;
}
fpi_device_remove (dev);
}
}
@ -248,6 +300,10 @@ fp_context_class_init (FpContextClass *klass)
* @device: A #FpDevice
*
* This signal is emitted when a fingerprint reader is removed.
*
* It is guaranteed that the device has been closed before this signal
* is emitted. See the #FpDevice removed signal documentation for more
* information.
**/
signals[DEVICE_REMOVED_SIGNAL] = g_signal_new ("device-removed",
G_TYPE_FROM_CLASS (klass),

View file

@ -29,6 +29,7 @@ typedef struct
GUsbDevice *usb_device;
const gchar *virtual_env;
gboolean is_removed;
gboolean is_open;
gchar *device_id;

View file

@ -44,6 +44,7 @@ enum {
PROP_DEVICE_ID,
PROP_NAME,
PROP_OPEN,
PROP_REMOVED,
PROP_NR_ENROLL_STAGES,
PROP_SCAN_TYPE,
PROP_FINGER_STATUS,
@ -55,6 +56,13 @@ enum {
static GParamSpec *properties[N_PROPS];
enum {
REMOVED_SIGNAL,
N_SIGNALS
};
static guint signals[N_SIGNALS] = { 0, };
/**
* fp_device_retry_quark:
*
@ -204,6 +212,10 @@ fp_device_get_property (GObject *object,
g_value_set_boolean (value, priv->is_open);
break;
case PROP_REMOVED:
g_value_set_boolean (value, priv->is_removed);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
@ -351,6 +363,41 @@ fp_device_class_init (FpDeviceClass *klass)
"Whether the device is open or not", FALSE,
G_PARAM_STATIC_STRINGS | G_PARAM_READABLE);
properties[PROP_REMOVED] =
g_param_spec_boolean ("removed",
"Removed",
"Whether the device has been removed from the system", FALSE,
G_PARAM_STATIC_STRINGS | G_PARAM_READABLE);
/**
* FpDevice::removed:
* @device: the #FpDevice instance that emitted the signal
*
* This signal is emitted after the device has been removed and no operation
* is pending anymore.
*
* The API user is still required to close a removed device. The above
* guarantee means that the call to close the device can be made immediately
* from the signal handler.
*
* The close operation will return FP_DEVICE_ERROR_REMOVED, but the device
* will still be considered closed afterwards.
*
* The device will only be removed from the #FpContext after it has been
* closed by the API user.
**/
signals[REMOVED_SIGNAL] = g_signal_new ("removed",
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
0,
NULL,
NULL,
g_cclosure_marshal_VOID__VOID,
G_TYPE_NONE,
0);
/* Private properties */
/**
* FpDevice::fpi-environ: (skip)
*

View file

@ -91,6 +91,7 @@ typedef enum {
* @FP_DEVICE_ERROR_DATA_NOT_FOUND: Requested print was not found on device
* @FP_DEVICE_ERROR_DATA_FULL: No space on device available for operation
* @FP_DEVICE_ERROR_DATA_DUPLICATE: Enrolling template duplicates storaged templates
* @FP_DEVICE_ERROR_REMOVED: The device has been removed.
*
* Error codes for device operations. More specific errors from other domains
* such as #G_IO_ERROR or #G_USB_DEVICE_ERROR may also be reported.
@ -106,6 +107,8 @@ typedef enum {
FP_DEVICE_ERROR_DATA_NOT_FOUND,
FP_DEVICE_ERROR_DATA_FULL,
FP_DEVICE_ERROR_DATA_DUPLICATE,
/* Leave some room to add more DATA related errors */
FP_DEVICE_ERROR_REMOVED = 0x100,
} FpDeviceError;
GQuark fp_device_retry_quark (void);

View file

@ -139,6 +139,10 @@ fpi_device_error_new (FpDeviceError error)
msg = "This finger has already enrolled, please try a different finger";
break;
case FP_DEVICE_ERROR_REMOVED:
msg = "This device has been removed from the system.";
break;
default:
g_warning ("Unsupported error, returning general error instead!");
error = FP_DEVICE_ERROR_GENERAL;
@ -576,6 +580,49 @@ fpi_device_get_cancellable (FpDevice *device)
return g_task_get_cancellable (priv->current_task);
}
static void
emit_removed_on_task_completed (FpDevice *device)
{
g_signal_emit_by_name (device, "removed");
}
/**
* fpi_device_remove:
* @device: The #FpDevice
*
* Called to signal to the #FpDevice that it has been unplugged (physically
* removed from the system).
*
* For USB devices, this API is called automatically by #FpContext.
*/
void
fpi_device_remove (FpDevice *device)
{
FpDevicePrivate *priv = fp_device_get_instance_private (device);
g_return_if_fail (FP_IS_DEVICE (device));
g_return_if_fail (!priv->is_removed);
priv->is_removed = TRUE;
g_object_notify (G_OBJECT (device), "removed");
/* If there is a pending action, we wait for it to fail, otherwise we
* immediately emit the "removed" signal. */
if (priv->current_task)
{
g_signal_connect_object (priv->current_task,
"notify::completed",
(GCallback) emit_removed_on_task_completed,
device,
G_CONNECT_SWAPPED);
}
else
{
g_signal_emit_by_name (device, "removed");
}
}
/**
* fpi_device_action_error:
* @device: The #FpDevice
@ -691,6 +738,7 @@ fp_device_task_return_in_idle_cb (gpointer user_data)
FpDeviceTaskReturnData *data = user_data;
FpDevicePrivate *priv = fp_device_get_instance_private (data->device);
g_autofree char *action_str = NULL;
FpiDeviceAction action;
g_autoptr(GTask) task = NULL;
@ -699,9 +747,24 @@ fp_device_task_return_in_idle_cb (gpointer user_data)
g_debug ("Completing action %s in idle!", action_str);
task = g_steal_pointer (&priv->current_task);
action = priv->current_action;
priv->current_action = FPI_DEVICE_ACTION_NONE;
priv->current_task_idle_return_source = NULL;
/* Return FP_DEVICE_ERROR_REMOVED if the device is removed,
* with the exception of a successful open, which is an odd corner case. */
if (priv->is_removed &&
((action != FPI_DEVICE_ACTION_OPEN) ||
(action == FPI_DEVICE_ACTION_OPEN && data->type == FP_DEVICE_TASK_RETURN_ERROR)))
{
g_task_return_error (task, fpi_device_error_new (FP_DEVICE_ERROR_REMOVED));
/* NOTE: The removed signal will be emitted from the GTask
* notify::completed if that is neccessary. */
return G_SOURCE_REMOVE;
}
switch (data->type)
{
case FP_DEVICE_TASK_RETURN_INT:
@ -713,16 +776,17 @@ fp_device_task_return_in_idle_cb (gpointer user_data)
break;
case FP_DEVICE_TASK_RETURN_OBJECT:
g_task_return_pointer (task, data->result, g_object_unref);
g_task_return_pointer (task, g_steal_pointer (&data->result),
g_object_unref);
break;
case FP_DEVICE_TASK_RETURN_PTR_ARRAY:
g_task_return_pointer (task, data->result,
g_task_return_pointer (task, g_steal_pointer (&data->result),
(GDestroyNotify) g_ptr_array_unref);
break;
case FP_DEVICE_TASK_RETURN_ERROR:
g_task_return_error (task, data->result);
g_task_return_error (task, g_steal_pointer (&data->result));
break;
default:
@ -735,6 +799,30 @@ fp_device_task_return_in_idle_cb (gpointer user_data)
static void
fpi_device_task_return_data_free (FpDeviceTaskReturnData *data)
{
if (data->result)
{
switch (data->type)
{
case FP_DEVICE_TASK_RETURN_INT:
case FP_DEVICE_TASK_RETURN_BOOL:
break;
case FP_DEVICE_TASK_RETURN_OBJECT:
g_clear_object ((GObject **) &data->result);
break;
case FP_DEVICE_TASK_RETURN_PTR_ARRAY:
g_clear_pointer ((GPtrArray **) &data->result, g_ptr_array_unref);
break;
case FP_DEVICE_TASK_RETURN_ERROR:
g_clear_error ((GError **) &data->result);
break;
default:
g_assert_not_reached ();
}
}
g_object_unref (data->device);
g_free (data);
}

View file

@ -202,6 +202,7 @@ void fpi_device_get_delete_data (FpDevice *device,
FpPrint **print);
GCancellable *fpi_device_get_cancellable (FpDevice *device);
void fpi_device_remove (FpDevice *device);
GSource * fpi_device_add_timeout (FpDevice *device,
gint interval,