/sys$common/syshlp/helplib.hlb System Services, $START TRANS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Starts a new transaction.

    Format

      SYS$START_TRANS  [efn] ,[flags] ,iosb [,[astadr] ,[astprm]

                       ,[tid] ,[timout] ,[acmode]]

    C Prototype

      int sys$start_trans  (unsigned int efn, unsigned int flags,

                           struct _iosb *iosb,...);

    Arguments

 efn

    OpenVMS usage:ef_number
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Number of the event flag that is set when the service completes.
    If this argument is omitted, event flag 0 is set.

 flags

    OpenVMS usage:mask_longword
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    Flags specifying options for the service. The flags argument is
    a longword bit mask in which each bit corresponds to an option
    flag. The $DDTMDEF macro defines symbolic names for these option
    flags. All undefined bits must be 0. If this argument is omitted,
    no flags are set.

    The flags currently defined are shown in the following table:

    Flag                 Description

    DDTM$M_NONDEFAULT    Set this flag if you do not want the new
                         transaction to be the default transaction of
                         the calling process.

                         If this flag is clear, the new transaction
                         becomes the default transaction of the
                         calling process. An error is returned if
                         this flag is clear and the calling process
                         already has a default transaction.

    DDTM$M_PROCESS       Set this flag if you do not want the DECdtm
                         transaction manager to try to abort the
                         transaction if the current image terminates.

                         If this flag is clear, when the current
                         image terminates (normally or abnormally),
                         the DECdtm transaction manager will abort
                         the transaction if it has not already
                         committed.

                         An error is returned if this flag is set and
                         the caller is in user mode.

    DDTM$M_SYNC          Set this flag to specify that successful
                         synchronous completion is to be indicated
                         by returning SS$_SYNCH. When SS$_SYNCH is
                         returned, the AST routine is not called, the
                         event flag is not set, and the I/O status
                         block is not filled in.

 iosb

    OpenVMS usage:io_status_block
    type:         quadword (unsigned)
    access:       write only
    mechanism:    by reference
    I/O status block in which the completion status of the service is
    returned as a condition value.

    Refer to the OpenVMS System Services Reference Manual to view the
    I/O status block diagram.

 astadr

    OpenVMS usage:ast_procedure
    type:         procedure value
    access:       call without stack unwinding
    mechanism:    by reference
    AST routine that is executed when the service completes. The
    astadr argument is the address of this routine. This routine is
    executed in the access mode of the caller.

 astprm

    OpenVMS usage:user_arg
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    AST parameter that is passed to the AST routine specified by the
    astadr argument.

 tid

    OpenVMS usage:transaction_id
    type:         octaword (unsigned)
    access:       write only
    mechanism:    by reference
    Address of an octaword in which the service returns the
    identifier of the new transaction.

 timout

    OpenVMS usage:date_time
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by reference
    Timeout for the new transaction. This is the time at which the
    DECdtm transaction manager is to abort the transaction if the
    transaction has not already committed.

    The time value is a binary number, in units of 100 nanoseconds.

    A positive time value specifies an offset from the system base
    time. The system base time is 00:00 hours November 17, 1858.

    A negative time value specifies an offset from the current time
    to some time in the future.

    The transaction is aborted at the next timer interval if you
    specify either a zero time value or any time in the past.

    If this argument is omitted, the new transaction has no timeout.

 acmode

    OpenVMS usage:access_mode
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value
    The least privileged access mode that the calling process must
    be in to end the transaction by calling $END_TRANS. Note that the
    calling process can end the transaction by calling $ABORT_TRANS
    from any access mode.

    The access mode that the calling process must be in to end the
    transaction by calling $END_TRANS is whichever is the least
    privileged of the following:

    o  The access mode of the caller

    o  The access mode specified by the acmode argument

    If the acmode argument is omitted, it defaults to the access mode
    of the caller.