USBIO Driver for Windows CE - Thesycon Systemsoftware ...

3 Programming Interface
After that, the buffer is put back to the pool and the main loop is started from the beginning.
3.1.5 CUsbIoWriter Class
The class CUsbIoWriter extends the CUsbIoThread class by a specific worker thread routine
that continuously sends write requests to the pipe. The thread’s main routine gets a buffer
from an internal buffer pool and calls the virtual member function ProcessBuffer to fill the
buffer with data. After that, the buffer is sent to the pipe using the Write() function of the
CUsbIoPipe class. After all buffers are submitted the routine waits for the first pending buffer
to complete. If a buffer is completed by the USBIO driver the buffer is put back to the pool and
the main loop is started from the beginning.
3.1.6 CUsbIoBuf Class
The helper class CUsbIoBuf is used as a descriptor for buffers that are processed by the class
CUsbIoPipe and derived classes. One instance of the CUsbIoBuf class has to be created
for each buffer. The CUsbIoBuf object stores context and status information that is needed to
process the buffer asynchronously.
The CUsbIoBuf class contains a link element (Next pointer). This may be used to build a chain of
linked buffer objects to hold them in a list. This way, the management of buffers can be simplified.
3.1.7 CUsbIoBufPool Class
The class CUsbIoBufPool is used to manage a pool of free buffers. It provides functions used
to allocate an initial number of buffers, to get a buffer from the pool, and to put a buffer back to
the pool.
3.1.8 CPnPNotificator Class
The class CPnPNotificator can be used to get plug and play notifications. To use the class
derive a handler class from CPnPNotifyHandler and overwrite the function HandlePnPMessage().
Pass a pointer to an instance of this class to the function call CPnPNotificator::Initialize().
3.2 Class Library Reference
CUsbIo class
This class implements the interface to the USBIO device driver. It contains only general
device-related functions that can be executed without a pipe context. Pipe specific functions are
implemented by the UsbIoPipe class.
24 USBIO Driver for Windows CE