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XEROX
BUSINESS SYSTEMS
System Development Division
December 2, 1977 XEROX SDD ARCHIVES
I have read and understood
To: Mesa Language Working Group Pages_________ To _________
Reviewer Date
From: Dick Sweet
{I of Pages
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Ref .,t.1UJIf~; (;
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 obi
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.