File Descriptor Lists

Two separate file descriptor lists are maintained; destinations for inbound data and sources of outbound data. The data structure for storage of a file descriptor and its data for inclusion in either list is defined in Figure below.

Figure: C structure for File Descriptor List elements.

The independence of the file descriptor lists from the outbound data polling and message handler components provides for a flexible and versatile environment within which to expand functionality. In order to include new data types for transfer, all that is required is to define a new data type ID for both applications to correlate messages upon, open a file descriptor to the appropriate place to read or write the data, and include the file descriptor in the appropriate list.

• Inbound File Descriptors
• Outbound File Descriptors