SwNtfy Fn 0002H: Switcher Is Suspending Your Session

  Expect: AX    0002H
          BX    ID of the session that is about to be suspended
          ES:DI addr of switcher's service-entry address
  Return: AX    0000H if OK to suspend, as far as you're concerned
                0001H if you object to the switch
    Info: Task switchers first call SwNtfyFn 0001H to see if a session
          switch is OK, then they call this fn directly before suspending
          your session.  This is the last chance for your application to
          prevent the switch.  When called, interrupts are disabled you
          should NOT use any DOS fns.

       BX will contain the session ID of the session that is about to be
          switched out.  Global TSRs may wish to take special actions for
          each session.

    ES:SI will contain the task switcher's service entry address.  Use this
          address if you need to call service fns such as SwSrvcFn 0001H
          (test memory region) to determine how you feel about being
          switched out.

  Return: AX=0000H if you have no objection to being switched out. If any
          task returns a non-zero value, the session will not be switched
          out and all tasks may receive SwNtfyFn 0004H (session is active).

See Also: Switcher Services and Notifications
          INT 2fH 4bxxH (switcher functions)