DosGetShrSeg

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This call accesses a shared memory segment previously allocated by another process.

Syntax

DosGetShrSeg (Name, Selector)

Parameters

Name (PSZ) - input 
Address of the name string associated with the shared memory segment to be accessed. The name is an ASCIIZ string in the format of an OS/2 filename in a subdirectory called \SHAREMEM\, for example, \SHAREMEM\PUBLIC.DAT.
Selector (PSEL) - output 
Address of the selector for the shared memory segment.

Return Code

rc (USHORT) - return
Return code descriptions are:
  • 0 NO_ERROR
  • 2 ERROR_FILE_NOT_FOUND
  • 4 ERROR_TOO_MANY_OPEN_FILES
  • 123 ERROR_INVALID_NAME

Remarks

DosGetShrSeg provides access to a named shared segment allocated by another process with DosAllocShrSeg. The selector returned by DosGetShrSeg is the same as the one returned by the DosAllocShrSeg call.

A usage count is maintained for a named shared segment. Issuing DosGetShrSeg increments the count, and issuing DosFreeSeg decrements the count. When the usage count equals zero, the named shared segment is deallocated. Once the segment has been deallocated, it must be reinitialized by a call to DosAllocShrSeg.

To access shared memory that is allocated by another process with DosAllocSeg and DosAllocHuge requests, a process issues DosGetSeg.

Bindings

C

#define INCL_DOSMEMMGR

USHORT  rc = DosGetShrSeg(Name, Selector);

PSZ     Name;          /* Name string */
PSEL    Selector;      /* Selector of shared segment */

USHORT  rc;            /* return code /*

MASM

EXTRN  DosGetShrSeg:FAR
INCL_DOSMEMMGR      EQU 1

PUSH@  ASCIIZ  Name          ;Name string
PUSH@  WORD    Selector      ;Selector of shared segment (returned)
CALL   DosGetShrSeg

Returns WORD