This section explains regarding ISA's, the configuration of ISAPI extensions. However, ISAPI filters are not supported by COBOL ISAPI Subroutines. For more information on ISAPI Subroutines, see the books and IIS manuals.
An ISAPI extension must be a DLL that exports the following three functions. Each individual function runs as a multi-threaded function.
This function is called once when an application DLL is loaded. The HttpExtensionProc function noted below is executed only after this function is terminated.
Application called for each request. This function is used to receive data sent from the WWW Browser and to send HTML documents to the WWW Browser and is provided as an interface to IIS.
This function is called when the application DLL is unloaded.
Figure 1.1 How each export function is called
