DosSMRegisterDD

Legacy Function Warning
It is recommended to use a newer replacement for this function.
Replacement:
Remarks:	This page list the older version of the function for reference.

Allows a device driver to register itself with the Session Manager.

Syntax

 DosSMRegisterDD

    (RegisterData)

Parameters

RegisterData (PREGISTERDATA) - input

Address of the structure containing the RegisterData necessary for this call.

Length (USHORT) : Length of the data structure in bytes including Length itself. Length is 8 for OS/2 version 1.2.

Notification (USHORT) : Bit map that informs the session manager when to issue the notification IOCTL to the device driver. The bits of this word are defined as follows:

Bit            Description
15-4         Reserved and must be set to zero. 
3            Session termination notification. Action = 8 
2            Post-Session restore notification. Action = 4 
1            Post-Session save notification. Action = 2 
0            Pre-Session save notification. Action = 1 

Action is the unsigned integer in the Action field of the notification IOCTL. This tells the device driver what is happening. Notice that the integers correspond to bits 0 to 3 being set.

DDName (ULONG) : Address of the device name, as an ASCIIZ string (ie. SCREEN$, KBD$, etc.).

Return Code

rc (USHORT) - return

Return code descriptions are:

• 418 ERROR_SMG_INVALID_CALL
• 461 ERROR_SMG_INVALID_DATA_LENGTH
• 515 ERROR_SMG_TOO_MANY_DDS
• 516 ERROR_SMG_INVALID_NOTIFICATION

Remarks

The Session Manger calls the registered device driver during a session switch, based on the specific form of notifications required.

The notification IOCTL passed to the device driver has the following format:

Size    Definition 

WORD    DevIOCtl packet length, including the length itself 
WORD    Screen switch notification type 
WORD    Incoming session number 
WORD    Outgoing session number. 

The device driver passes a bit map that informs the session manager when the device driver needs to be called. The possible phases are:

• Before a session save
• After a session save (before a restore)
• After a session restore
• After a session termination.

The device drivers must issue this API only during their initialization phase. After the session manager has been initialized, it rejects all further calls to this API, returning ERROR_SMG_INVALID_CALL.

Example Code

C Binding

#define INCL_DOSFILEMGR

USHORT  rc = DosSMRegisterDD(RegisterData);

PREGISTERDATA RegisterData;          /* Data packet  */

USHORT           rc;            /* return code */

MASM Binding

EXTRN  DosSMRegisterDD:FAR
INCL_DOSFILEMGR     EQU 1

PUSH@  OTHER RegisterData        ;Data packet
CALL   DosSMRegisterDD

Returns WORD