FORTRAN Reference Manual

Statements
FORTRAN Reference Manual—528615-001
7-104
START BACKUP Statement
Examples
•
The following example specifies ENV OLD:
?ENV OLD
START BACKUP( CPU = 2, ERR = 400, OPTION = 16)
A START BACKUP statement with OPTION = 16 (only bit 11 is set) specifies the
following actions:
°
Maintain a permanent nowait read on $RECEIVE.
°
The primary process closes a file that it has just opened, if the backup process
cannot also open the file.
°
The primary process ABENDs if CHECKPOINT causes a “bad checkpoint
parameter” error.
°
A new backup is created immediately by the FORTRAN run-time system after
a takeover.
°
The backup process stops if a STOP command stops the primary process.
•
The following example specifies ENV COMMON.
?ENV COMMON
START BACKUP( CPU = 2, ERR = 400, OPTION = %1564)
If your program specifies ENV COMMON, OPTION = %1564 (all defined option
bits set to 1) specifies:
°
The START BACKUP statement checkpoints the extended stack when a
backup process is created.
°
FORTRAN does not maintain a permanent nowait read on $RECEIVE.
°
The primary process stops the backup process if the backup process cannot
successfully open a file just opened by the primary process.
°
FORTRAN returns an error code to the program if CHECKPOINT causes a
“bad checkpoint parameter” error.
°
A new backup is created immediately by the FORTRAN run-time library after a
takeover.
°
The backup becomes the new primary and creates a new backup if a STOP
TACL command stops the original primary.