IBM AS/400 manual Problems when ILE CL Monitors for Notify and Status Messages

*-----------------------------------------------------------------

*Define the cancel handler. The parameter is a pointer to the

*'communication area', a message to be displayed.

	*-----------------------------------------------------------------
P CanHdlr		B
D CanHdlr		PI
D	pMsg		*
	*-----------------------------------------------------------------
	* Define a field based on the input pointer pMsg.
	*-----------------------------------------------------------------
D Msg		S	20A	BASED(pMsg)
	*-----------------------------------------------------------------

*Display the message set by the procedure that enabled the￿

*handler.

	*-----------------------------------------------------------------
C	'Cancel Hdlr 'DSPLY		Msg
P CanHdlr		E
Figure	118 (Part	4 of 4).	Enabling and Coding a Cancel Handler for a Subprocedure

The following is the output from program CANHDLR. Note that the *PSSR of procedure SubProc is called three times but the cancel handler is o because it was disabled before the third error.

DSPLY	Cancel Hdlr	Divide by zero
DSPLY	Subproc PSSR
DSPLY	Cancel Hdlr	String error
DSPLY	Subproc PSSR
DSPLY	Subproc PSSR
Figure	119. Output from CANHDLR program

Problems when ILE CL Monitors for Notify and Status Messages

If your ILE RPG procedure is called by an ILE CL procedure in th group, and the caller is monitoring for status or notify messages, th caller may get control prematurely because of a notify or status me ILE RPG procedure was trying to ignore.

For example, if the ILE RPG procedure writes a record to a printe actual printer file has a shorter record length that was declared dure, notify message CPF4906 is sent to the RPG procedure. The RPG e handling percolates this message which causes the default reply of message. This should allow the output operation to continue normally, an procedure should proceed to the next instruction.

However,

when the

ILE

CL

MONMSG

gets

control,

control passes

immediately

the

action

for

the MONMSG or the next statement

in

the

ILE

CL

proced

Note:

For

this

problem

to

occur,

the

procedure

monitoring

for

the

mes

not

have

to

be

the

immediate

caller

of

the

RPG

procedure.

This

problem

is

most

likely

to

occur

with

a

MONMSG

in

an

ILE

CL

caller,

also occur with other ILE languages

that

can

monitor

for

notify

and

sages, including

ILE

RPG using

ILE

condition

handlers

enabled

using

CEEHD

Chapter

12.

Handling

Exceptions247