IBM AS/400 manual Managing Dynamically-Allocated Storage, Name?, Enddo

Managing Dynamically-Allocated Storage

Note: Although the ALLOC operation code works only with the default heap REALLOC and DEALLOC operation codes work with both the default heap and user-created heaps.

Figure 52	shows	an	example		of how the		memory management operation codes
can be	used	to	build	a	linked	list	of names.
*-----------------------------------------------------------------								*
* Prototypes for subprocedures in this module								*
*-----------------------------------------------------------------								*
D AddName			PR
D	name_parm				40A
D Display			PR
D Free			PR
*-----------------------------------------------------------------								*
* Each element in the list contains a pointer to the								*
* name and a pointer to the next element								*
*-----------------------------------------------------------------								*
D elem			DS			BASED(elem@)
D	name@				*
D	next@				*
D	name_len				5U 0
D nameVal			S		40A	BASED(name@)
D elemSize			C			%SIZE(elem)
*-----------------------------------------------------------------								*
* The first element in the list is in static storage.								*
* The name field of this element is not set to a value.								*
*-----------------------------------------------------------------								*
D first			DS
D					*	INZ(*NULL)
D					*	INZ(*NULL)
D					5U 0 INZ(0)
*-----------------------------------------------------------------								*
* This is the pointer to the current element.								*
* When elem@ is set to the address of <first>, the list is								*
* empty.								*
*-----------------------------------------------------------------								*
D elem@			S		*	INZ(%ADDR(first))
*-----------------------------------------------------------------								*
* Put 5 elements in the list								*
*-----------------------------------------------------------------								*
C			DO		5
C	'Name?'		DSPLY			name		40
C			CALLP		AddName(name)
C			ENDDO
*-----------------------------------------------------------------								*
* Display the list and then free it.								*
*-----------------------------------------------------------------								*
C			CALLP		Display
C			CALLP		Free
C			EVAL		*INLR = '1'
Figure 52 (Part		1	of 5).	Memory Management - Build a Linked List of Names

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