internal PenContext(IPimcContext pimcContext, IntPtr hwnd,
PenContexts contexts, bool supportInRange, bool isIntegrated,
int id, IntPtr commHandle, int tabletDeviceId)
{
_contexts = contexts;
_pimcContext = new SecurityCriticalDataClass<IPimcContext>(pimcContext);
_id = id;
_tabletDeviceId = tabletDeviceId;
_commHandle = new SecurityCriticalData<IntPtr>(commHandle);
_hwnd = new SecurityCriticalData<IntPtr>(hwnd);
_supportInRange = supportInRange;
_isIntegrated = isIntegrated;
}
internal PenContext(IPimcContext pimcContext, IntPtr hwnd,
PenContexts contexts, bool supportInRange, bool isIntegrated,
int id, IntPtr commHandle, int tabletDeviceId)
{
_contexts = contexts;
_pimcContext = new SecurityCriticalDataClass <IPimcContext>(pimcContext);
_id = id;
_tabletDeviceId = tabletDeviceId;
_commHandle = new SecurityCriticalData <IntPtr>(commHandle);
_hwnd = new SecurityCriticalData <IntPtr>(hwnd);
_supportInRange = supportInRange;
_isIntegrated = isIntegrated;
UpdateScreenMeasurementsPending = false;
}
internal void Disable(bool shutdownWorkerThread)
{
// DDVSO:202023
// There was a prior assumption here that this would always be called under Dispatcher.DisableProcessing.
// This assumption has not been valid for some time, leading to re-entrancy.
if (_penThreadPenContext != null)
{
if (_penThreadPenContext.RemovePenContext(this))
{
// DDVSO:202023
// It is possible that calling ReleaseComObject throws. We do not expect the
// COM object to be invalid here, but releasing can lead to a message pumped
// wait. Re-entrancy can occur that will release the COM object prior to
// the wait resolving. This results in an exception down the line when
// returning from the re-entrant call.
//
// To fix this, store a local, null out the member, and then release the local.
// Any re-entrant call will find the member variable already null and skip the
// release.
IPimcContext context = _pimcContext?.Value;
_pimcContext = null;
if (context != null)
{
Marshal.ReleaseComObject(context); // Make sure we release the COM Object so wisptis doesn't send messages to it anymore
}
// Check if we need to shut down our pen thread.
if (shutdownWorkerThread)
{
// DDVSO:202023
// A re-entrant call might find us with a null penThreadContext so we
// need to guard the call to Dispose against a null even though we already
// have a check above.
_penThreadPenContext?.Dispose();
}
_penThreadPenContext = null; // Can't free this ref until we can remove this context or else we won't see the stylus OutOfRange.
}
}
}
