XEROX
BUSINESS SYSTEMS
System Development Division
December 2, 1977

To:Mesa Language Working Group

From:Dick Sweet

Subject:Mesa Language Working Group minutes

The Language Working Group met on 23 November, 1977.

The discussion of object style monitors continued. A new type of procedure was proposed. An INTERNAL PROCEDURE is a non-entry one that is called only when the monitor lock is held. For object style monitors, each INTERNAL procedure must begin with the same obj parameter as must each ENTRY procedure.

WAIT, NOTIFY, and BROADCAST are allowed only from within an ENTRY or an INTERNAL procedure. Is this also true for non object style?

A new type, LOCK, will exist with only one public field, priority. Thus we no longer need MONITORED RECORDs, only ones with a LOCK in them. Likewise, CONDITION types have a private field, timeout.

The discussion of long pointers began. One question was what sort of flavors of the monitor stuff to do for various shaped pointers. There were 3 options.

1. Only LONG POINTER forms.

2. Short flavors for some or all.

3. Routines could take either. If they are done with a minimal stack, the interpreter could use the stack size to determine whether the arguments are long or short.