@node __dpmi_allocate_shared_memory, dpmi
@subheading Syntax

@smallexample
#include <dpmi.h>

int __dpmi_allocate_shared_memory(__dpmi_shminfo *info);
@end smallexample

@subheading Description

Please refer to @ref{DPMI Specification} for details on DPMI
function call operation.  Also see @ref{DPMI Overview} for general
information.

DPMI function AX = 0x0d00 (DPMI 1.0 only).  Not supported by CWSDPMI and
Windows.

This function allocates a shared memory block that can be accessed from
different virtual machines.  Fill the required length in
@code{@var{info}->size_requested}.  The function fills the rest of the
structure: allocated length in @code{@var{info}->size}, block handle in
@code{@var{info}->handle}, linear address in @code{@var{info}->address},
and the selector:offset of an @sc{asciiz} block name (up to 128 bytes
long) in @code{@var{info}->name_selector} and
@code{@var{info}->name_offset}, respectively.

The access to the shared memory block can be serialized by calling
the @code{__dpmi_serialize_on_shared_memory} function
(@pxref{__dpmi_serialize_on_shared_memory}).

@subheading Return Value

-1 on error, else zero.

@subheading Portability

@portability !ansi, !posix