internal static ErrorCode SyncTransfer(UsbTransfer transferContext,
IntPtr buffer,
int offset,
int length,
int timeout,
int isoPacketSize,
out int transferLength)
{
if (ReferenceEquals(transferContext, null))
{
throw new NullReferenceException("Invalid transfer context.");
}
if (offset < 0)
{
throw new ArgumentException("must be >=0", "offset");
}
if (isoPacketSize == 0 && transferContext.EndpointBase.Type == EndpointType.Isochronous)
{
Info.UsbEndpointInfo endpointInfo = transferContext.EndpointBase.EndpointInfo;
if (endpointInfo != null)
{
isoPacketSize = endpointInfo.Descriptor.MaxPacketSize;
}
}
lock (transferContext.mTransferLOCK)
{
transferLength = 0;
int transferred;
ErrorCode ec;
transferContext.Fill(buffer, offset, length, timeout, isoPacketSize);
while (true)
{
ec = transferContext.Submit();
if (ec != ErrorCode.Success)
{
return(ec);
}
ec = transferContext.Wait(out transferred);
if (ec != ErrorCode.Success)
{
return(ec);
}
transferLength += transferred;
if ((ec != ErrorCode.None || transferred != UsbEndpointBase.MaxReadWrite) ||
!transferContext.IncrementTransfer(transferred))
{
break;
}
}
return(ec);
}
}
/// <summary>
/// Creates, fills and submits an asynchronous <see cref="UsbTransfer"/> context.
/// </summary>
/// <remarks>
/// <note type="tip">This is a non-blocking asynchronous transfer function. This function returns immediately after the context is created and submitted.</note>
/// </remarks>
/// <param name="buffer">A caller-allocated buffer for the data that is transferred.</param>
/// <param name="offset">Position in buffer that transferring begins.</param>
/// <param name="length">Number of bytes, starting from thr offset parameter to transfer.</param>
/// <param name="timeout">Maximum time to wait for the transfer to complete.</param>
/// <param name="transferContext">On <see cref="ErrorCode.Success"/>, a new transfer context.</param>
/// <returns><see cref="ErrorCode.Success"/> if the transfer context was created and <see cref="UsbTransfer.Submit"/> succeeded.</returns>
/// <seealso cref="SubmitAsyncTransfer(object,int,int,int,out LibUsbDotNet.Main.UsbTransfer)"/>
/// <seealso cref="NewAsyncTransfer"/>
public virtual ErrorCode SubmitAsyncTransfer(IntPtr buffer, int offset, int length, int timeout, out UsbTransfer transferContext)
{
transferContext = CreateTransferContext();
transferContext.Fill(buffer, offset, length, timeout);
ErrorCode ec = transferContext.Submit();
if (ec != ErrorCode.None)
{
transferContext.Dispose();
transferContext = null;
UsbError.Error(ec, 0, "SubmitAsyncTransfer Failed", this);
}
return(ec);
}