Initializing Monitors at Spooler Start-up

During its initialization, the spooler does the following for every port and language monitor it finds in the registry:

• Loads the monitor’s DLL.

• Calls the monitor’s InitializePrintMonitor function to obtain its function table. The table is returned as a set of function pointers in a MONITOREX structure. The monitor must initialize pointers to the routines listed in the must-implement section of The Print Monitor API, or the spooler fails the monitor’s creation.

• If the monitor is a port monitor or LMPM, the spooler calls the monitor’s EnumPorts function to obtain the list of ports available on the local machine for printing that this monitor supports.

• For every printer to be added, the spooler calls the associated monitor’s OpenPort or OpenPortEx function to acquire a port handle for every port that has been assigned to that printer.

Once initialization is complete, the spooler has a record of which print monitors and printers exist, and which ports are associated with each monitor and printer. Note that port setup is performed before printers are associated with ports.