SIGNAL()

The SIGNAL() function raises a cross-process application signal.

Format

SIGNAL(user.no)

where

user.no

evaluates to the QM number of the process to be signalled.

The SIGNAL() function provides a simple way to notify another QM process of a condition such as a request for a phantom to terminate. It returns True if the process identified by user.no is logged in.

Example

OK = SIGNAL(SERVER.USER)

This statement raises a cross-process application signal in the QM process with the user number in SERVER.USER.

The signalled process detects this signal using the SYSTEM() function with key 1062 (SYS$SIGNAMMED) which will also clear it. For example, a phantom server process might have a main loop as below:

LOOP

...processing...

UNTIL SYSTEM(1062)

SLEEP 5

REPEAT