Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

◄Function Group►  ◄Overview►  ◄Changes►               ◄Up► ◄Next► ◄Previous►
────────────────────────────────────────────────────────────────────────────
 
#define INCL_DOSMEMMGR
 
USHORT DosReallocHuge(usNumSeg, usPartialSeg, sel)
USHORT usNumSeg;        /* number of 65,536-byte segments  */
USHORT usPartialSeg;    /* number of bytes in last segment */
SEL sel;                /* segment selector                */
 
The DosReallocHuge function reallocates a huge-memory block. This function
changes the size of the huge memory to the specified number of 65,536-byte
segments plus an additional segment of a specified size.
 
The DosReallocHuge function is a family API function.
 
Parameter     Description
────────────────────────────────────────────────────────────────────────────
 
usNumSeg      Specifies the number of 65,536-byte segments to allocate.
 
usPartialSeg  Specifies the number of bytes in the last segment. This number
              can be any value in the range 0 through 65,535. If this number
              is zero, no additional segment is allocated.
 
sel           Specifies the selector for the huge-memory block to be
              reallocated. The selector must have been created by using the
              DosAllocHuge function.
 
Return Value
 
The return value is zero if the function is successful. Otherwise, it is an
error value, which may be one of the following:
 
     ERROR_INVALID_PARAMETER
     ERROR_NOT_ENOUGH_MEMORY
 
Comments
 
The DosReallocHuge function does not change the shareable and discardable
attributes of the segments in the huge-memory block. If it was originally a
shareable or discardable block, it remains a shareable or discardable block.
However, if DosReallocHuge reallocates a discardable block, it also locks
the segments. The DosUnlockSeg function must be used to unlock the segments
and permit discarding.
 
The huge-memory block cannot be reallocated for a size larger than the
maximum specified by the usMaxNumSeg parameter in the original call to the
DosAllocHuge function.
 
Each segment in the huge-memory block has a unique selector. The selectors
are consecutive. The sel parameter specifies the value of the first
selector; the remaining selectors can be computed by adding the selector
offset to the first selector one or more times──that is, once for the second
selector, twice for the third, and so on. The selector offset is a multiple
of 2, as specified by the shift count retrieved by using the
DosGetHugeShift function. For example, if the shift count is 2, the selector
offset is 4 (1 << 2). If the selector offset is 4 and the first selector is
6, the second selector is 10, the third is 14, and so on.
 
Typically, DosReallocHuge can increase, not decrease, the size of shared
huge segments. If the shared segment is allocated by the DosAllocHuge
function, the segment can be decreased in size by setting the fsAttr
parameter to SEG_SIZEABLE.
 
DosReallocHuge can be issued from ring 2, but only ring-3 segments are
affected by this function.
 
Restrictions
 
In real mode, the following restriction applies to the DosReallocHuge
function:
 
♦  The usPartialSeg parameter is rounded up to the next paragraph (16-byte)
   value.
 
See Also
 
DosAllocHuge, DosFreeSeg, DosGetHugeShift, DosLockSeg, DosReallocSeg,
DosUnlockSeg
 
                                      ♦