XAllowDeviceEvents - release queued events
#include <X11/extensions/XInput.h>
int XAllowDeviceEvents( Display *display,
                        XDevice *device,
                        int event_mode,
                        Time time);
display
       Specifies the connection to the X server.
device
       Specifies the device from which events are to be
       allowed.
event_mode
       Specifies the event mode. You can pass AsyncThisDevice,
       SyncThisDevice, ReplayThisDevice, AsyncOtherDevices,
       SyncAll, or AsyncAll.
time
       Specifies the time. You can pass either a timestamp or
       CurrentTime.
The XAllowDeviceEvents function releases some queued events if the client has
  caused a device to freeze. It has no effect if the specified time is earlier
  than the last-grab time of the most recent active grab for the client and
  device, or if the specified time is later than the current X server time.
The following describes the processing that occurs depending on
    what constant you pass to the event_mode argument.
  •AsyncThisDevice - If the specified
  device is frozen by the client, event processing for that device continues as
  usual. If the device is frozen multiple times by the client on behalf of
  multiple separate grabs, AsyncThisDevice thaws for all. AsyncThisDevice has no
  effect if the specified device is not frozen by the client, but the device
  need not be grabbed by the client.
  •SyncThisDevice - If the specified device
  is frozen and actively grabbed by the client, event processing for that device
  continues normally until the next key or button event is reported to the
  client. At this time, the specified device again appears to freeze. However,
  if the reported event causes the grab to be released, the specified device
  does not freeze. SyncThisDevice has no effect if the specified device is not
  frozen by the client or is not grabbed by the client.
  •ReplayThisDevice - If the specified
  device is actively grabbed by the client and is frozen as the result of an
  event having been sent to the client (either from the activation of a
  GrabDeviceButton or from a previous AllowDeviceEvents with mode
  SyncThisDevice, but not from a GrabDevice), the grab is released and that
  event is completely reprocessed. This time, however, the request ignores any
  passive grabs at or above (toward the root) that the grab-window of the grab
  just released. The request has no effect if the specified device is not
  grabbed by the client or if it is not frozen as the result of an event.
  •AsyncOtherDevices - If the remaining
  devices are frozen by the client, event processing for them continues as
  usual. If the other devices are frozen multiple times by the client on behalf
  of multiple grabs, AsyncOtherDevices "thaws" for all.
  AsyncOtherDevices has no effect if the devices are not frozen by the
  client.
  •SyncAll - If all devices are frozen by
  the client, event processing (for all devices) continues normally until the
  next button or key event is reported to the client for a grabbed device, at
  which time all devices again appear to freeze. However, if the reported event
  causes the grab to be released, then the devices do not freeze. If any device
  is still grabbed, then a subsequent event for it will still cause all devices
  to freeze. SyncAll has no effect unless all devices are frozen by the client.
  If any device is frozen twice by the client on behalf of two separate grabs,
  SyncAll thaws for both. A subsequent freeze for SyncAll will only freeze each
  device once.
  •AsyncAll - If all devices are frozen by
  the client, event processing for all devices continues normally. If any device
  is frozen multiple times by the client on behalf of multiple separate grabs,
  AsyncAll thaws for all. AsyncAll has no effect unless all devices are frozen
  by the client.
AsyncThisDevice, SyncThisDevice, and ReplayThisDevice have no
    effect on the processing of events from the remaining devices.
    AsyncOtherDevices has no effect on the processing of events from the
    specified device. When the event_mode is SyncAll or AsyncAll, the device
    parameter is ignored.
It is possible for several grabs of different devices by the same
    or different clients to be active simultaneously. If a device is frozen on
    behalf of any grab, no event processing is performed for the device. It is
    possible for a single device to be frozen because of several grabs. In this
    case, the freeze must be released on behalf of each grab before events can
    again be processed.
XAllowDeviceEvents can generate a BadDevice or BadValue error.
 
BadDevice
       An invalid device was specified. The specified device
       does not exist or has not been opened by this client via
       XOpenInputDevice. This error may also occur if the
       specified device is the X keyboard or X pointer device.
  
 
BadValue
       An invalid mode was specified on the request.