J3/14-269
To:        J3
From:      Van Snyder
Subject:   F08/0105 (ASYNC + VALUE) revisited
Date: 2014 October 16
Reference: 10-007r1, 14-109r1, 14-192, 14-006Ar1

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NUMBER: F08/0105
TITLE: Is the ASYNCHRONOUS attribute allowed with the VALUE attribute?
KEYWORDS: ASYNCHRONOUS, VALUE
DEFECT TYPE: Interpretation
STATUS: J3 consideration in progress

QUESTION:

In the description of the VALUE attribute, [101:23-24] section
5.3.18p1, constraint C558 disallows the VOLATILE attribute with the
VALUE attribute:

  "C558 An entity with the VALUE attribute shall not have the
        ALLOCATABLE, INTENT (INOUT), INTENT (OUT), POINTER, or
        VOLATILE attributes."

But there is no prohibition of the ASYNCHRONOUS attribute with the
VALUE attribute.  Should this combination also be disallowed?

ANSWER:

No, the combination of VALUE and ASYNCHRONOUS attributes should not be
disallowed.  That is, the combination of VALUE and ASYNCHRONOUS
attributes should continue to be allowed.

A dummy argument with the VALUE attribute is not argument associated
with the corresponding actual argument.  Rather, it is associated with
an anonymous data object whose value is copied from the actual
argument before execution of the executable constructs of the
subprogram commences, and before expressions in the specification part
are evaluated.  Therefore, it can successfully take part in
asynchronous operations, independently of whether the corresponding
actual argument has or has not the ASYNCHRONOUS attribute.

There is no problem if a dummy argument has the VALUE attribute and
the corresponding actual argument has the ASYNCHRONOUS attribute,
independently of whether the dummy argument has the ASYNCHRONOUS
attribute.  Subclause 9.6.4.1, paragraph 6 [220:13-15], prohibits an
actual argument that is part of a pending input/output storage
sequence affector from being associated with a dummy argument that has
the VALUE attribute.

EDIT to 10-007r1:

None.

SUBMITTED BY: Stan Whitlock

HISTORY: 14-109    m203  F08/0105 submitted - disallow failed
         14-109r1  m203  try allow - passed by J3 meeting
         14-192    m204  Failed J3 letter ballot #30 14-146
         14-nnn    m205  Resubmitted with revised answer