Re: Help with Glade (Annex E) on Windows

On Jan 29, 6:29 am, "Dr. Adrian Wrigley"
<a...@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Sun, 28 Jan 2007 17:00:19 -0800, Gene wrote:
Is there someone who can help with Glade setup on Windows? Have tried
both Academic and free GPL versions. Gnatdist builds clean with MSYS
(current version .10). The bank example works fine. Two of the prime
number finding examples work fine. Two hang after partial output.
Recursive calls seem to cause this. The Adacore folks are looking at
it.

Which version? I had the serious problems below with GPL 2005, GPL 2006
on x86 Linux. GNAT 3.15p + glade was more usable.

My view only. Not officially endorsed!

GNAL GPL 2006 + glade appears to have a number of serious faults.
If you are using glade for professional purposes, you are strongly advised
to use a commercially supported Annex E implementation for your compiler.
Contact AdaCore at s...@xxxxxxxxxxx (or visithttp://www.adacore.com/).

The problems with this version are believed to be:

1) Deadlock when making RCI call from within RCI call
Examples such as Eratho/Spiral will hang during execution.

You should architect your software to avoid chains of
remote calls to avoid this bug.

2) Intermittent deadlock when making simultaneous RCI calls on a partition
using dynamic subprogram binding though Remote Access to
Class Wide types (RACW). This occurs with multiple
tasks or partitions making dynamic remote calls at the same time.
It is believed this also occurs with remote subprogram access types.
The problem does not seem to occur when the target of the remote call is
in the same partition as the boot server and program "main" procedure.

If possible avoid dynamic binding to remote calls. If not possible,
put all the dynamically bound units into the main partition
("procedure MainProc is in partition MainPartition" in .cfg file)

3) Failure of MultiPro test case to build in the examples directory.

4) Problem with dependencies - gnatdist sometimes fails to rebuild when necessar
y.
Certain partition configurations can result in out of date builds
after source code modifications.

This bug can be avoided by deleting the old executables before
invoking gnatdist.

5) Returning SUCCESS return code from gnatdist when compiles fail.
This cause problems in compilation scripts, since a build may
complete when errors remain undetected.

You will need to be careful to watch for errors during build.

6) Failure of "abort" after task calls RCI unit - including timed abort
with a select statement, as well as simple task abort statements.

You should avoid using any abort statements to stop a task
which has executed any remote calls.

7) gnatdist does not pass -m options (such as -m32 for 32-bit build
on amd64 system) to the compiler, even after -cargs option.

If building 32-bit and 64-bit code, you are recommended to install
two versions of the compiler, or use dchroot with a 32-bit environment.

8) Package variables of controlled types are not finalized until
after the partition communication system is shut down when
a partition is terminating. This prevents the finalization routines
from making any remote accesses to clean up as a package terminates.
It is unclear whether this is an error.

You should avoid making remote calls in finalization code which
may be invoked during partition shutdown.

9) Killing a distributed program and restarting it immediately may
not work as expected, but produce an error (return code 137).
Invoking the program a second time will work. Seems to be something
to do with the IP port not clearing in time.

Error is:
raised SYSTEM.GARLIC.COMMUNICATION_ERROR : Do_Listen: tcp bind error

Solution is to check for this error in a script and retry once.
Alternatively, waiting ten seconds after killing a program usually works.

10) Shared Passive units crash if values declared are of types with initial valu
es.

11) Shared Passive units crash if protected types are used in them.

Protected access to Shared Passive data may be achieved by placing
the protected type in a Remote Call Interface unit instead.

12) Shared Passive units do not seem to detect version mismatches
between the persistent data and the executing code.

Users should manually delete the Shared Passive unit data files
before running new versions with incompatible data representation.

13) Shared Passive units may crash if the data stored is too large(?)
Test cases have failed with 20kB of SP data. Cause is unclear.

14) Shared Passive units do not initialise data. This can lead to
program failure, even when the uninitialised data are not used.
This problem may be caused by attempts to transmit invalid data.

Take care to initialise *all* data as early as possible in execution.

These problems are also thought to affect GNAT GPL 2006 glade.
The version of glade supplied with GNAT 3.15p avoids problems (1), (6).

It *is* possible to build reliable code with this release of glade,
provided that the program is designed to avoid the above problems.
Depending on your requirements, this may involve significant
changes to the application architecture.

It may also be possible to avoid some of these problems by
rebuilding your GNAT system with the "setjmp/longjmp" exception
model (use --RTS=sjlj options), in place of the default option
of zero cost exceptions.

Notes by Adrian Wrigley (amtw at linuxchip.demon.co.uk)
23 October 2006.
--
Adrian

Thanks very much. Extremely helpful. I was trying GPL 2006, both
free and academic versions.

Today I rolled back to 3.15p, and everything started working
immediately, at least with the synchrnous RCI part of the Annex we
need. GPL 2006 seems to be totally unusable on Windows.

If anyone needs help with the Win32 3.15p configuration, write me.

.

Relevant Pages

  • Re: Help with Glade (Annex E) on Windows
    ... I had the serious problems below with GPL 2005, ... remote calls to avoid this bug. ... Intermittent deadlock when making simultaneous RCI calls on a partition ... Shared Passive units crash if protected types are used in them. ...
    (comp.lang.ada)
  • Misc.
    ... MINIX itself due to differences in assembly language. ... Comment on GPL: The GPL license states that aggregating GPL'ed ... As to NTFS partition management, ...
    (comp.os.minix)