This is an old revision of the document!
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
DosSubFree
This call frees memory previously allocated by DosSubAlloc.
Syntax
DosSubFree (SegSelector, BlockOffset, Size)
Parameters
;SegSelector (SEL) - input : Data segment selector. ;BlockOffset (USHORT) - input : Memory block offset. The value specified must equal the BlockOffset returned on a previous DosSubAlloc call. ;Size (USHORT) - input : Size, in bytes, of the block to be freed.
Return Code
rc (USHORT) - return Return code descriptions are: * 0 NO_ERROR * 312 ERROR_DOSSUB_OVERLAP * 313 ERROR_DOSSUB_BADSIZE
Remarks
DosSubFree specifies the offset of a block of memory previously suballocated by a DosSubAlloc request. If the block specified overlaps memory in the segment that is not suballocated, an error is returned. Like DosSubAlloc, the size parameter must be a multiple of four bytes; otherwise, it is rounded up to a multiple of four bytes.
The allocated segment is freed by calling DosFreeSeg.
Example Code
C Binding
<PRE> #define INCL_DOSMEMMGR
USHORT rc = DosSubFree(SegSelector, BlockOffset, Size);
SEL SegSelector; /* Segment selector */ USHORT BlockOffset; /* Offset of memory block to free */ USHORT Size; /* Size of block in bytes */
USHORT rc; /* return code */ </PRE>
MASM Binding
<PRE> EXTRN DosSubFree:FAR INCL_DOSMEMMGR EQU 1
PUSH WORD SegSelector ;Segment selector PUSH WORD BlockOffset ;Offset of memory block to free PUSH WORD Size ;Size of block in bytes CALL DosSubFree
Returns WORD </PRE>
Note
Text based on http://www.edm2.com/index.php/DosSubFree