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This is part of Family API which allow to create dual-os version of program runs under OS/2 and DOS
Note: This is legacy API call. It is recommended to use 32-bit equivalent
DosSubAlloc
This call suballocates portions of a segment allocated by DosAllocSeg or DosAllocShrSeg, and initialized by DosSubSet.
Syntax
DosSubAlloc (SegSelector, BlockOffset, Size)
Parameters
;SegSelector (SEL) - input : Data segment selector that allocates the memory. ;BlockOffset (PUSHORT) - output : Address of the allocated block offset. ;Size (USHORT) - input : Memory block size requested in bytes.
Return Code
rc (USHORT) - return Return code descriptions are: * 0 NO_ERROR * 311 ERROR_DOSSUB_NOMEM * 313 ERROR_DOSSUB_BADSIZE
Remarks
Before a segment allocated by DosAllocSeg or DosAllocShrSeg can be suballocated, it must first be initialized for suballocation by a call to DosSubSet.
Allocation size must be a multiple of four bytes. Otherwise, it is rounded up to a multiple of four bytes. The maximum value for the size parameter is the size that was set with DosSubSet minus 8. Note that no paragraph (16-byte) alignment is required; all requests are serviced on a byte alignment basis.
A suballocated block of memory in a suballocated segment is freed by a call to DosSubFree.
Example Code
C Binding
<PRE> #define INCL_DOSMEMMGR
USHORT rc = DosSubAlloc(SegSelector, BlockOffset, Size);
SEL SegSelector; /* Segment selector */ PUSHORT BlockOffset; /* Block Offset (returned) */ USHORT Size; /* Size of requested block */
USHORT rc; /* return code */ </PRE>
MASM Binding
<PRE> EXTRN DosSubAlloc:FAR INCL_DOSMEMMGR EQU 1
PUSH WORD SegSelector ;Segment selector PUSH@ WORD BlockOffset ;Block Offset (returned) PUSH WORD Size ;Size of requested block CALL DosSubAlloc
Returns WORD </PRE>
Note
Text based on http://www.edm2.com/index.php/DosSubAlloc