Subject: C436 JGSI Review
Resent-Date: Thu, 30 Sep 1999 23:17:37 -0400
Resent-From: Geoffrey Fox <gcf@npac.syr.edu>
Resent-To: p_gcf@npac.syr.edu
Date: Fri, 17 Sep 1999 15:50:36 -0400 (EDT)
From: Bryan Carpenter <dbc@npac.syr.edu>
To: gcf@npac.syr.edu (Geoffrey Fox)
CC: dbc@npac.syr.edu (Bryan Carpenter)

Javia: A Java Interface to the Virtual Interface Architecture
Chi-Chao Chang and Thorsten von Eicken

a)Overall Recommendation

Clear and well-organized paper.  Minor corrections and comments
below.

b)Words suitable for authors

Section 2.1, last sentence in para 2

  "The architecture also supports for interrupt-driven reception"
                                  ^^^
Typo?

Section 3.1.1

Something has gone wrong with the line-numbering in the interface code.
Lines 7 and 8 (referred to in the subsequent text) are missing.

Same section, the authors write:

  "To post a Java byte array transmission, Javia-I gets a free ticket
  from the ring [...] to receive [...] Javia-I obtains the ticket that
  corresponds to the head of the VI queue"

I'd like to know what this looks like in user code for the `sendPost',
`revPost' cases.  Are necessary entry-points missing from the API
given above?

Section 4

In Sun's JDK, using standard JNI, I'm not aware there is any mechanism
to allocate an array in native code, then view it as a Java array (which
is what the authors do here).  Can the authors comment on this?

Section 5.1

In the example code, what is `r' (= n/p, perhaps)?
I don't think `redDoubleArray' has been defined earlier.

Paragraph prior to 5.1.1, authors state:

  "performance [...] using Marmot is about 70 Mflops for 64x64 matrices,
   and 45 Mflops for 256x256 matrices (compared to JDK 1.2's 55Mflops and
   Jview's 37Mflops for same size matrices)"

*Which* size for JDK/Jview---64x64 or 256x256?

Section 5.2, first para.
A citation label "[CCH+96]" appears.  It isn't defined in the bibliography.

Same section para 4, last sentence:

   "Java *knows* whether the GC is copying after [...]"

I didn't understand this sentence.  It might be worth adding some brief
explanation of how copying garbage collectors work, for the uninitiated.

Section 6, first para:

  "This re-direction incurs on level of indirection [...]"
                            ^^
Typo?

c)Words for me if necessary

None.