Restrict to use of two transaction concurrently in ABAP program

Question

Hi,
We have requirement to restrict a user could not using two transaction
at the same time. how could i achieve this. Please throw some light on this.

Answer 1

Hi
--> create a lock object from SE11
Ex :  lock object name is EZLOCK
     -->Click on Create
     -->Give the table name
     --> Lock mode (Write, read, Exclusive not cumulative)
     --> Give the Lock parameters
-->save --> activate --> Then system will generate to function module
                      1. ENQUEUE_EZLOCK (for locking)
                      2. DEQUEUE_EZLOCK (For Unlocking)
--> you need to call these function module in respective areas
ex: In PAI of the screen call ENQUEUE F.M and in
    the exit perfroms use DEQUEUE F.M
Ex code to use the f.m's
*To avoid acces of multiple users at a time
  CALL FUNCTION 'ENQUEUE_EZCONIC'
    EXPORTING
      mode_zpicci    = 'E'
      zpicnum        = g_fffc
    EXCEPTIONS
      foreign_lock   = 1
      system_failure = 2
      OTHERS         = 3.
  IF sy-subrc <> 0.
    MESSAGE ID sy-msgid TYPE 'S' NUMBER sy-msgno
            WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.
    LEAVE TO SCREEN 1000.
  ENDIF.
*To unlock the trascation
    CALL FUNCTION 'DEQUEUE_EZCONIC'.
Thanks & Regards
Mallikharjuna Reddy