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Installing a Class

There are three distinct modes of operation with class drivers:

Local

The class driver is a part of the user's program. This is independent of whether the user uses DSPACK server or not. The driver must be linked with the user's program and DSPACK should be informed with a ds_install call.

Stand-Alone

In the client-server operation the class methods may be a separate process. In this mode this process should be started once and then called whenever there is a message to it's object. This is achieved by installing the interface driver in the user's program. The process containing methods is started by the interface driver when INIT message is received. Afterwards the interface driver may communicate with the methods process in any way it wants to - DSPACK provides an easy way of communication with ids_wait and ds_update calls which allow a client to wait for an object to become available.

EXEC

In the client-server operation the program containing methods may be started every time a message is sent to an object of it's class. The program executes the method requested and exits. This mode requires no installation and no driver. The program must assume that all needed objects are in the server's memory, it connects to the server and fulfils the request. See EXEC driver description for details.

call ds_install(iclass,driver)

iclass

Integer - class number. At present class numbers are assigned manually. Each class should have a unique number between 1000 and 32000. Classes from 1 to 999 are reserved for DSPACK internal drivers.

driver

Driver entry point - must be declared external.

In Local or Stand-Alone mode this call installs a class driver.