File and Record Locking

Certain versions of RM/COBOL contain some software errors in the way in which locks for files and records are handled. These errors do not occur in Visual COBOL.

The errors fixed when upgrading to Visual COBOL are:

  • Indexed files do not detect or acquire locks if they are opened for output. This is regardless of whether you specify the WITH LOCK phrase
  • Relative and sequential files cannot be locked exclusively
  • Files which are opened for input can detect record locks, although the RM/COBOL documentation states that they cannot. When the RM directive is set in Visual COBOL, record locks can still be detected by files opened for input
  • The first record in a sequential file opened for input-output is locked whenever any other record in that file is locked