INT 31H 0d02H: Serialize on Shared Memory

                                                    Compatibility: DPMI 1.0+ 
 Expects: AX    0d02H
          SI:DI handle of shared memory block as obtained via INT 31H 0d00H
          DX    option flags: bit 0: 0=suspend client until available
                                     1=return with error when unavailable
                              bit 1: 0=exclusive serialization requested
                                     1=shared serialization requested
                               2-15: reserved, must be 0
 Returns: CF    NC (clear) if successful; else AX = DPMI Error Code
    Info: This requests that access to a shared memory block be controlled
          (serialized).  This provides a means for multiple clients to
          access the block serially, avoiding simultaneous access.

       DX When bit 1 of DX is set, this call requests exclusive
          serialization, which effectively means "ownership for writing".
          Shared serialization can be considered as a way to gain "read-
          only access".

   Notes: ■ Use INT 31H 0d03H to release ownership.

          ■ A suspended client continues to receive interrupts and can use
            INT 31H 0d03H in an interrupt handler to cancel the

See Also: DPMI API
          INT 2fH: Multiplex Interrupt
          DOS Functions