COBOL Manual for TNS and TNS/R Programs

Procedure Division Verbs
HP COBOL Manual for TNS and TNS/R Programs—522555-006
9-33
CANCEL
If a called program that does not have the INITIAL attribute opens an internal file,
the file remains open until either:
°
The called program closes the file.
°
The calling program cancels the called program.
°
The process terminates.
•
PERFORM Statements Resume Their Initial State (Inactive)
•
GO TO Statements Modified by ALTER Statements Resume Their Initial Forms
Each GO TO statement that was modified by an ALTER statement is restored to
the form specified in the source program.
•
When Not to Use CANCEL
°
On programs compiled with the NOCANCEL directive
The NOCANCEL directive prevents the compiler from generating code that
initializes the program the first time the program is called after being canceled
by a CANCEL statement.
°
On programs that are still executing, including the main program
If you cancel the main program of the run unit or a called program that has not
returned control to its calling program, the run unit terminates abnormally with
a failure message.
°
On routines written in languages other than COBOL and called with X/Open
CALL statement
Applying a CANCEL statement to a routine written in a language other than
COBOL that was called with an X/Open CALL statement terminates the run
unit.
°
Within programs that are to run as process pairs
If the primary process of a process pair executes a CANCEL statement, the
backup process can become invalid.