To: J3                                                     J3/19-240
From: Malcolm Cohen
Subject: FORM TEAM and failed images
Date: 2019-October-15
Reference: 19-181

1. Introduction

Paper 19-181 contains five purported interpretation requests glommed into
a single paper. This paper discusses the first of them.


2. The alleged problem

From 19-181:
    18-007r1, 11.6.9 p6 says
        "If execution of a FORM TEAM statement assigns the value
         STAT_FAILED_IMAGE to the stat-variable, the effect is the same as
         for the successful execution of FORM TEAM except for the value
         assigned to stat-variable."
    How can this be the case?  11.6.11 says:
        "If a STAT= specifier appears in a sync-stat in an image control
         statement, the stat-variable is assigned the value zero if
         execution of the statement is successful."
...
    In 11.6.9 FORM TEAM statement p6 add
        "on a team consisting of the active images of the team" before
         "except" to make the sentence read
             "If execution of a FORM TEAM statement assigns the value
              STAT_FAILED_IMAGE to the stat-variable, the effect is the
              same as for the successful execution of FORM TEAM on a team
              consisting of the active images of the team except for the
              value assigned to stat-variable."


3. Response from /INTERP

The complaint has no merit.

(a) The comment about 11.6.11 is pointless: 11.6.9p6 explicitly excludes
    the assignment of the value zero to stat-variable.

(b) The effect of a successful execution of FORM TEAM is explicitly stated
    in p2 to create new teams for the active images. Reference is made
    throughout p2-p5 which detail the effects to the "executing image",
    a term that excludes failed images by definition, as they have "ceased
    to participate in program execution", or the term "active images".

    This whole subclause has been carefully written to use these terms so
    that the failed images case has a very straightforward interpretation.

    Furthermore, /INTERP disagrees that the
        "effect is the same as for the successful execution of FORM TEAM on
         [a completely different team from the one actually current]"
    Such a successful execution would produce a different subteam/parent
    relationship tree.

    Thus the edit appears to be both wrong and unnecessary.

Therefore, /INTERP politely declines to accept this as an interpretation
request at this time.

Instead, /HPC subgroup is requested to double-check the rest of 11.6.9 to
confirm that it all makes sense, and has the desired semantics, in the
presence of failed images.

If /HPC subgroup find a problem here, /INTERP will reconsider and process
accordingly.


4. Response from the Editor

I see no ambiguity or contradiction here. I do note that
    "the successful execution of FORM TEAM"
could be rewritten to
    "successful execution of the FORM TEAM statement,"
but this is very minor wordsmithing.

I recall someone suggesting, in p2, the second sentence
    "The value of team-number shall be positive."
could be written to apply only to the active teams, but since team-number
does not even exist on failed images seeing as how they are not executing
anything, let alone this FORM TEAM statement, it is hard to see how it
can be misinterpreted.

Any other suggestions for wording improvements from /HPC will be considered
by the editor for the next revision.

===END===