Compatibility: DPMI 1.0+

Expects: AX    0d00H

ES:DI (or ES:EDI) address of 28-byte info structure (see below)

Returns: CF    NC (clear) if successful; else AX = DPMI Error Code

ES:DI (or ES:EDI) structure updated

Info: This allocates a named block of memory that may be shared by DPMI

clients.  This may be used for interprocess communication.

DS:(E)DI this selector:offset must point to a 28-byte local structure

defined as follows:

Offset Size Contents

+0      4  lReqSize     desired size of block, in bytes

+4      4  lActualSize  actual size allocated (returned)

+8      4  lHandle      handle for the allocation (returned)

+0cH     4  lLinAddr     linear addr of allocation (returned)

+10H     6  p48szName    48-bit address of ASCIIZ  name for

the shared block.  First 4 bytes are

the offset; the last 2 are selector.

+16H     2  wRes1        reserved

+18H     4  lRes2        reserved; must be 0

28               size of this structure

On entry, you must fill in lReqSize and set p48szName to a 48-bit

address of an ASCIIZ string that names the block.  The host

fills-in lAllocSize, lHandle, and lLinAddr.

For 16-bit clients, the high word of p48szName must be 0000H.

Note:   The second and subsequent client to use this fn with the same

ASCIIZ name, will be returned info about the initial

allocation.  For such subsequent "allocations", the lReqSize

field is ignored.  Be sure to check the lActualSize field on

return.

  The first client to allocate a named block will find that the

first 16-bytes are 0.  It can gain exclusive ownership via

INT 31H 0d02H, and store some non-zero values so that

subsequent clients can tell that it has been initialized.

  0-length allocations are explicitly supported and can be used

as a way to implement semaphores (see INT 31H 0d02H, for

instance).

  All of your shared memory allocations and serializations are

freed by the host automatically when you terminate.

See Also: DPMI API

INT 2fH: Multiplex Interrupt

DOS Functions

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