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====== DosSubSet ======

This call is used to initialize a segment or to reset a reallocated segment for suballocation.

===== Syntax =====
<code c>
DosSubSet (SegSelector, Flags, Size)
</code>

===== Parameters =====

  * SegSelector ([[SEL]]) - input : Target data segment selector.
  * Flags ([[USHORT]]) - input :

  0 = Increasing the size of a segment already initialized.
  1 = Initializing a segment.

  * Size ([[USHORT]]) - input : Segment size in bytes.

===== Return Code =====
rc ([[USHORT]]) - return

Return code descriptions are:

  * 0          NO_ERROR
  * 310        ERROR_DOSSUB_SHRINK
  * 313        ERROR_DOSSUB_BADSIZE
  * 314        ERROR_DOSSUB_BADFLAG

===== Remarks =====

To initialize a segment for suballocation, issue DosSubSet before issuing [[DosSubAlloc]] and set Flags = 1. The segment must have been allocated with [[DosAllocSeg]] or [[DosAllocShrSeg]].

If a segment allocated by a [[DosAllocSeg]] call has already been set for suballocation, and a call to [[[DosSubAlloc]] returns ERROR_DOSSUB_NOMEM, the segment's size can be increased by a call to [[DosReallocSeg]]. After reallocation, the segment must be reset by a DosSubSet. Failure to reset the segment after changing its size can yield unpredictable results.

The size parameter should be a multiple of four bytes, or it is rounded up to a multiple of four. Note in DosSubSet, a size parameter of 0 indicates the segment is 64KB, while in [[DosSubAlloc]] and [[DosSubFree]], a size parameter of 0 is an error. Other than this special case of 0 meaning 64KB, the minimum size that can be set is 12 bytes. 

===== Example Code =====

==== C Binding ====

<code c>
#define INCL_DOSMEMMGR

USHORT  rc = DosSubSet(SegSelector, Flags, Size);

SEL              SegSelector;   /* Segment selector */
USHORT           Flags;         /* Parameter flags */
USHORT           Size;          /* Size of a block */

USHORT           rc;            /* return code */
</code>

==== MASM Binding ====

<code asm>
EXTRN  DosSubSet:FAR
INCL_DOSMEMMGR      EQU 1

PUSH   WORD    SegSelector   ;Segment selector
PUSH   WORD    Flags         ;Parameter flags
PUSH   WORD    Size          ;Size of a segment
CALL   DosSubSet

</code>

Returns WORD

===== Note =====

Text based on http://www.edm2.com/index.php/DosSubSet

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