IBM AS/400 manual Exception Handling Overview, Each, boundary is controlreached boundary. A

Exception Handling Overview

¹

Optionally

recovering

from

the exception

by passing the exception inf

to a piece of code to

take

any

necessary

actions.

When a run-time error occurs, an

exception message is generated. An e

message

has

one

of

the following

types depending

on

the

error

which

*ESCAPE

Indicates

that

a severe error has been detected.

*STATUS

Describes

the

status

of

work

being done by a program.

*NOTIFY

Describes a condition requiring corrective action or reply from

program.

Function

Check

Indicates

that

one

of

the

three previous exceptions

occurred

not

handled.

Exception

messages

are

associated

with

call

stack

entries.

Each

call st

in

turn

associated

with

a

list

of

exception

handlers

defined

for tha

Call

Stack”

on page 129

for further discussion of a call stack.)

Figure 108

on

page 219

shows

a

call

stack

where an OPM program calls an

ILEprogram

consisting

of

several modules and therefore several procedure

to

this

figure

in

the

discussions

which

follow.

In general, when an exception occurs,

the handlers associated with the

entry

are

given

a

chance

to

handle

the

exception.

If

the

exception

any

of

the

handlers

on

the

list

then

it

is

considered

to

be

unhandle

the

following

default

actions

are

taken

for

the

unhandled

exception:

1.If the exception is a function check, the call stack entry is re stack.

2. The exception is moved (percolated) to the previous call stack entr

3. The exception handling process is restarted for this call stack ent

The action of allowing the previous call stack entry to handle								an	exc
referred		percolationto as	. Percolation continues until the exception is					handled
until	the	control	boundary is controlreachedboundary. A			is a call stack entry		for
which	the	immediately		preceding	call stack	entry is in	a or different		ac
is an	OPM	program.	In	Figure 108	on page 219	Procedure	P1 is the	contro

boundary.

218 ILE RPG for AS/400 Programmer's Guide