Subject: SC22 N2438 - Disposition of Comments on PDAM1 to IS 13719-1 (PCTE)

From: "william c. rinehuls" <[email-masked]>
Date: Thu, 13 Mar 1997 13:02:28 -0500 (EST)

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ISO/IEC JTC 1/SC22
Programming languages, their environments and system software interfaces
Secretariat:  U.S.A.  (ANSI)

ISO/IEC JTC 1/SC22
N2438

March 1997

TITLE:             Disposition of Comments Report on Proposed Draft
                   Amendment 1 (PDAM1): Fine-Grain Object Extensions
                   to ISO/IEC 13719-1: Information Technology - 
                   Portable Common Tool Environment (PCTE), Part 1:
                   Abstract Specification

SOURCE:            Secretariat, ISO/IEC JTC 1/SC22

WORK ITEM:         JTC 1.22.47.3

STATUS:            N/A

CROSS REFERENCE:   SC22 N2175, N2326

DOCUMENT TYPE:     Disposition of Comments Report

ACTION:            To SC22 Member Bodies for information.

Address reply to:
ISO/IEC JTC 1/SC22 Secretariat
William C. Rinehuls
8457 Rushing Creek Court
Springfield, VA 22153 USA
Tel:  +1 (703) 912-9680
Fax:  +1 (703) 912-2973
email:  [email-masked]

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                         Disposition of comments
          on PDAM1 to ISO/IEC 13719-1 PDAM ballot (SC22 N2175)

One substantive comment was received, accompanying a positive vote
from the UK:

Clause F.4 (Concurrency and integrity control) does not make sufficiently 
clear the relation between locks on fine-grain objects and locks on their
clusters.  In particular:

 - Is the translation of a lock on a fine-grain object to one on the 
cluster transparent to the application? - presumably yes.

 - Is a lock on a cluster equivalent to locks on all the fine-grain  
objects in the cluster? - presumably yes.

 - Can LOCK_SET_OBJECT and LOCK_UNSET_OBJECT be used on fine-grain 
>objects? - presumably yes.

 - If 2 locks are acquired to different fine-grain objects in a cluster
via LOCK_SET_OBJECT and the first is then released via LOCK_UNSET_OBJECT,
does the second still hold or not? - presumably not.

The response from WG22 is as follows.

The translation of a lock on a fine-grain object to one on the cluster 
is not really transparent because no "locked_by" link is created
between the locked fine-grain object and the enclosing activity.  Such a
link is created at the level of the cluster object when the first lock on
any object of the cluster (including the cluster itself is requested by
the activity.  Note that this is a direct consequence of the definition of 
locks on fine-grain objects.

Locking a cluster object is equivalent to locking any object of the
cluster.

The operations LOCK_SET_OBJECT and LOCK_UNSET_OBJECT can be used on 
fine-grain objects.  Therefore, if LOCK_SET_OBJECT and
LOCK_UNSET_OBJECT are applied successively to two different objects of a
cluster, th whole cluster and all the objects of the cluster are
successively locked and then unlocked.

The following note will be added to the end of F.2.as a result of this 
comment:

NOTE.  LOCK_SET_OBJECT and LOCK_UNSET_OBJECT can be used on fine-grain 
objects, but their effects are to lock and unlock (respectively) the 
whole cluster and all its fine-grain objects.

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