public int SubmitNextRead()
{
// Pull from head of Completed list and push to end of Outstanding list
IsoTransferItem isoTransferItem = Completed.First.Value;
Completed.RemoveFirst();
Outstanding.AddLast(isoTransferItem);
// If managing a start frame manually, set it here and update the the frame counter for the next transfer.
SetNextFrameNumber(isoTransferItem);
// Prepare the OvlK handle to be submitted.
OvlPool.ReUse(isoTransferItem.Ovl);
// The data buffer was pinned earlier when it was allocated. Always pin managed memory before using it
// in an asynchronous function to keep the framework from tampering with it.
Usb.IsoReadPipe(PipeInfo.PipeId,
isoTransferItem.Buffer,
DataBufferSize,
isoTransferItem.Ovl,
isoTransferItem.Iso.Handle);
int errorCode = Marshal.GetLastWin32Error();
// 997 is ERROR_IO_PENDING. For async, this means so far so good.
// IE: The transfer is submitted but we won't know if a problem occurs until it is completed.
if (errorCode != ErrorCodes.IoPending)
{
return(errorCode);
}
TotalSubmittedCount++;
return(0);
}