This category includes the following APIs:
Alert APIs provide a system for notifying network service programs and applications of network events. They are used with the ALERT.H and NETCONS.H header files.
An event is a particular instance of a process or state of hardware defined by either an application or the LAN Server software. LAN Server sends out an alert, in the form of a message or the resetting of a semaphore, when certain events occur. Other programs, network services, or internal network components use the NetAlertRaise API to raise an alert, notifying various applications or users when a particular type of event occurs.
The ALERT.H header file defines the following classes of events for the alerts that are sent out:
Other classes of alerts can be defined for network applications as needed. For example, if an application routinely writes large amounts of data to a disk drive, running the risk of filling the disk, the user might want the event of no free disk space to trigger an alert that notifies the application to pause or end the process slowing the system.
An application or network service, known as a client, registers to be notified of an event (or class of events) by calling the NetAlertStart API. Each registration adds an entry to an alert table.
A client can receive alert messages through one of two delivery mechanisms:
A client can be registered for one type of event, or it can be registered for several types by calling the NetAlertStart API a number of times.
To discontinue alerts for a registered client, use the NetAlertStop API to remove that entry in the alert table for the particular class of event.
To change the internal size of the alert table (thus allowing more alerts to be defined), a user or application must change the numalert component in the IBMLAN.INI file, and then restart the requester (by using the NET STOP RDR /Y and NET START RDR commands).