This is a port of Python 2.2 to OS/2 using the EMX development tools
=========================================================================
What's new since the previous release
-------------------------------------
This release of the port incorporates the following changes from the
August 14, 2001 release of the Python 2.1.1 port:
- based on the Python v2.2 final release source.
Licenses and info about Python and EMX
--------------------------------------
Please read the file README.Python-2.2 included in this package for
information about Python 2.2. This file is the README file from the
Python 2.2 source distribution available via http://www.python.org/
and its mirrors. The file LICENCE.Python-2.2 is the text of the Licence
from the Python 2.2 source distribution.
Note that the EMX package that this package depends on is released under
the GNU General Public Licence. Please refer to the documentation
accompanying the EMX Runtime libraries for more information about the
implications of this. A copy of version 2 of the GPL is included as the
file COPYING.gpl2.
Readline and GDBM are covered by the GNU General Public Licence. I think
Eberhard Mattes' porting changes to BSD DB v1.85 are also GPL'ed (BSD DB
itself is BSD Licenced). ncurses and expat appear to be covered by MIT
style licences - please refer to the source distributions for more detail.
zlib is distributable under a very free license. GNU MP and GNU UFC are
under the GNU LGPL (see file COPYING.lib).
My patches to the Python-2.x source distributions, and any other packages
used in this port, are placed in the public domain.
This software is provided 'as-is', without any express or implied warranty.
In no event will the author be held liable for any damages arising from the
use of the software.
I do hope however that it proves useful to someone.
Other ports
-----------
There have been ports of previous versions of Python to OS/2.
The best known would be that by Jeff Rush, most recently of version
1.5.2. Jeff used IBM's Visual Age C++ (v3) for his ports, and his
patches have been included in the Python 2.2 source distribution.
Andrew Zabolotny implemented a port of Python v1.5.2 using the EMX
development tools. His patches against the Python v1.5.2 source
distribution have become the core of this port, and without his efforts
this port wouldn't exist. Andrew's port also appears to have been
compiled with his port of gcc 2.95.2 to EMX, which I have but have
chosen not to use for the binary distribution of this port (see item 21
of the "YOU HAVE BEEN WARNED" section below).
Previous Python port releases by me:-
- v2.0 on March 31, 2001;
- v2.0 on April 25, 2001 (cleanup release + Stackless variant);
- v2.1 on June 17, 2001;
- v2.0 (Stackless re-release) on June 18, 2001.
- v2.1.1 on August 5, 2001;
- v2.1.1 on August 12, 2001 (cleanup release);
- v2.1.1 (updated DLL) on August 14, 2001.
- v2.2b2 on December 8, 2001 (not uploaded to archive sites)
- v2.2c1 on December 16, 2001 (not uploaded to archive sites)
It is possible to have these earlier ports still usable after installing
this port - see the README.os2emx.multiple_versions file, contributed by
Dr David Mertz, for a suggested approach to achieving this.
Software requirements
---------------------
This package requires the EMX Runtime package, available from the
Hobbes (http://hobbes.nmsu.edu/) and LEO (http://archiv.leo.org/)
archives of OS/2 software. I have used EMX version 0.9d fix04 in
developing this port.
My development system is running OS/2 v4 with fixpack 12.
3rd party software which has been linked into dynamically loaded modules:
- ncurses (see http://dickey.his.com/ for more info, v5.2)
- GNU Readline (Kai Uwe Rommel's port available from Hobbes or LEO, v2.1)
- GNU GDBM (Kai Uwe Rommel's port available from Hobbes or LEO, v1.7.3)
- zlib (Hung-Chi Chu's port available from Hobbes or LEO, v1.1.3)
- expat (from ftp://ftp.jclark.com/pub/xml/, v1.2)
- GNU MP (Peter Meerwald's port available from LEO, v2.0.2)
- GNU UFC (Kai Uwe Rommel's port available from LEO, v2.0.4)
The zlib module requires the Z.DLL to be installed - see the Installation
section and item 12 of the "YOU HAVE BEEN WARNED" section for more
information.
About this port
---------------
I have attempted to make this port as complete and functional as I can,
notwithstanding the issues in the "YOU HAVE BEEN WARNED" section below.
Core components:
Python.exe is linked as an a.out executable, ie using EMX method E1
to compile & link the executable. This is so that fork() works (see
"YOU HAVE BEEN WARNED" item 2).
Python22.dll is created as a normal OMF DLL, with an OMF import
library and module definition file. There is also an a.out (.a) import
library to support linking the DLL to a.out executables.
This port has been built with complete support for multithreading.
Modules:
As far as possible, extension modules have been made dynamically loadable
when the module is intended to be built this way. I haven't yet changed
the building of Python's standard modules over to using the DistUtils.
See "YOU HAVE BEEN WARNED" item 5 for notes about the fcntl module, and
"YOU HAVE BEEN WARNED" item 14 for notes about the pwd and grp modules.
Support for case sensitive module import semantics has been added to match
the Windows release. This can be deactivated by setting the PYTHONCASEOK
environment variable (the value doesn't matter) - see "YOU HAVE BEEN WARNED"
item 16.
Optional modules:
Where I've been able to locate the required 3rd party packages already
ported to OS/2, I've built and included them.
These include ncurses (_curses, _curses_panel), BSD DB (bsddb),
GNU GDBM (gdbm, dbm), zlib (zlib), GNU Readline (readline), expat
(pyexpat), GNU MP (mpz) and GNU UFC (crypt).
I have built these modules statically linked against the 3rd party
libraries, with the exception of zlib. Unfortunately my attempts to use
the dll version of GNU readline have been a dismal failure, in that when
the dynamically linked readline module is active other modules
immediately provoke a core dump when imported.
Only the BSD DB package (part of the BSD package distributed with EMX)
needed source modifications to be used for this port, pertaining to use
of errno with multithreading.
The other packages, except for ncurses and zlib, needed Makefile changes
for multithreading support but no source changes.
The _curses_panel module is a potential problem - see "YOU HAVE BEEN
WARNED" item 17.
Upstream source patches:
No updates to the Python 2.2 release have become available.
Eberhard Mattes' EMXFIX04 update to his EMX 0.9d tools suite includes
bug fixes for the BSD DB library. The bsddb module included in this
port incorporates these fixes.
Library and other distributed Python code:
The Python standard library lives in the Lib directory. All the standard
library code included with the Python 2.2 source distribution is included
in the binary archive, with the exception of the dos-8x3 and tkinter
subdirectories which have been omitted to reduce the size of the binary
archive - the dos-8x3 components are unnecessary duplicates and Tkinter
is not supported by this port (yet). All the plat-* subdirectories in the
source distribution have also been omitted, and a plat-os2emx directory
included.
The Tools and Demo directories contain a collection of Python scripts.
To reduce the size of the binary archive, the Demo/sgi, Demo/Tix,
Demo/tkinter, Tools/audiopy and Tools/IDLE subdirectories have been
omitted as not being supported by this port. The Misc directory has
also been omitted.
All subdirectories omitted from the binary archive can be reconstituted
from the Python 2.2 source distribution, if desired.
Support for building Python extensions:
The Config subdirectory contains the files describing the configuration
of the interpreter and the Makefile, import libraries for the Python DLL,
and the module definition file used to create the Python DLL. The
Include subdirectory contains all the standard Python header files
needed for building extensions.
As I don't have the Visual Age C++ compiler, I've made no attempt to
have this port support extensions built with that compiler.
Packaging
---------
This port is packaged into several archives:
- python-2.2-os2emx-bin-011224.zip (binaries, library modules)
- python-2.2-os2emx-src-011224.zip (source patches and makefiles)
Documentation for the Python language, as well as the Python 2.2
source distibution, can be obtained from the Python website
(http://www.python.org/) or the Python project pages at Sourceforge
(http://sf.net/projects/python/).
Installation
------------
Obtain and install, as per the included instructions, the EMX runtime
package.
If you wish to use the zlib module, you will need to obtain and install
the Z.DLL from Hung-Chi Chu's port of zlib v1.1.3 (zlib113.zip). See also
"YOU HAVE BEEN WARNED" item 12 below.
Unpack this archive, preserving the subdirectories, in the root directory
of the drive where you want Python to live.
Add the Python directory (eg C:\Python22) to the PATH and LIBPATH
variables in CONFIG.SYS.
You should then set the PYTHONHOME and PYTHONPATH environment variables
in CONFIG.SYS.
PYTHONHOME should be set to Python's top level directory. PYTHONPATH
should be set to the semicolon separated list of principal Python library
directories.
I use:
SET PYTHONHOME=F:/Python22
SET PYTHONPATH=F:/Python22/Lib;F:/Python22/Lib/plat-os2emx;
F:/Python22/Lib/lib-dynload;F:/Python22/Lib/site-packages
NOTE!: the PYTHONPATH setting above is linewrapped for this document - it
should all be on one line in CONFIG.SYS!
If you wish to use the curses module, you should set the TERM and TERMINFO
environment variables appropriately.
If you don't already have ncurses installed, I have included a copy of the
EMX subset of the Terminfo database included with the ncurses-5.2 source
distribution. This can be used by setting the TERMINFO environment variable
to the path of the Terminfo subdirectory below the Python home directory.
On my system this looks like:
SET TERMINFO=F:/Python22/Terminfo
For the TERM environment variable, I would try one of the following:
SET TERM=ansi
SET TERM=os2
SET TERM=window
You will have to reboot your system for these changes to CONFIG.SYS to take
effect.
If you wish to compile all the included Python library modules to bytecode,
you can change into the Python home directory and run the COMPILEALL.CMD
batch file.
You can execute the regression tests included with the Python 2.2 source
distribution by changing to the Python 2.2 home directory and executing the
REGRTEST.CMD batch file. The following tests are known to fail at this
time:
- test_longexp (see "YOU HAVE BEEN WARNED" item 1);
- test_mhlib (I don't know of any port of MH to OS/2);
- test_pwd (see "YOU HAVE BEEN WARNED" item 14, probably a bug in my code);
- test_grp (as per test_pwd);
- test_strftime (see "YOU HAVE BEEN WARNED" item 20);
- test_socketserver (fork() related, see "YOU HAVE BEEN WARNED" item 2).
YOU HAVE BEEN WARNED!!
----------------------
I know about a number of nasties in this port.
1. EMX's malloc() and/or the underlying OS/2 VM system aren't particularly
comfortable with Python's use of heap memory. The test_longexp regression
test exhausts the available swap space on a machine with 64MB of RAM with
150MB of available swap space.
Using a crudely instrumented wrapper around malloc()/realloc()/free(), the
heap memory usage of the expression at the core of the test
(eval('[' + '2,' * NUMREPS + ']')) is as follows (approximately):
NUMREPS = 1 => 300k
NUMREPS = 10000 => 22MB
NUMREPS = 20500 => 59MB
I don't even have enough memory to try for NUMREPS = 25000 :-(, let alone
the NUMREPS = 65580 in test_longexp! I do have a report that the test
succeeds in the presence of sufficient memory (~200MB RAM).
During the course of running the test routine, the Python parser
allocates lots of 21 byte memory chunks, each of which is actually
a 64 byte allocation. There are a smaller number of 3 byte allocations
which consume 12 bytes each. Consequently, more than 3 times as much
memory is allocated than is actually used.
The Python Object Allocator code (PyMalloc) was introduced in Python 2.1
for Python's core to be able to wrap the malloc() system to deal with
problems with "unfriendly" malloc() behaviour, such as this. Unfortunately
for the OS/2 port, it is only supported for the allocation of memory for
objects, whereas my research into this problem indicates it is the parser
which is source of this particular malloc() frenzy.
I have attempted using PyMalloc to manage all of Python's memory
allocation. While this works fine (modulo the socket regression test
failing in the absence of a socket.pyc), it is a significant performance
hit - the time to run the regression test blows out from ~3.5 minutes to
~5.75 minutes on my system.
I therefore don't plan to pursue this any further for the time being.
Be aware that certain types of expressions could well bring your system
to its knees as a result of this issue. I have modified the longexp test
to report failure to highlight this.
2. Eberhard Mattes, author of EMX, writes in his documentation that fork()
is very inefficient in the OS/2 environment. It also requires that the
executable be linked in a.out format rather than OMF. Use the os.exec
and/or the os.spawn family of functions where possible.
{3. Issue resolved...}
4. In the absence of GNU Readline, terminating the interpreter requires a
control-Z (^Z) followed by a carriage return. Jeff Rush documented this
problem in his Python 1.5.2 port. With Readline, a control-D (^D) works
as per the standard Unix environment.
5. EMX only has a partial implementation of fcntl(). The fcntl module
in this port supports what EMX supports. If fcntl is important to you,
please review the EMX C Library Reference (included in .INF format in the
EMXVIEW.ZIP archive as part of the complete EMX development tools suite).
Because of other side-effects I have modified the test_fcntl.py test
script to deactivate the exercising of the missing functionality.
6. The BSD DB module is linked against DB v1.85. This version is widely
known to have bugs, although some patches have become available (and are
incorporated into the included bsddb module). Unless you have problems
with software licenses which would rule out GDBM (and the dbm module
because it is linked against the GDBM library) or need it for file format
compatibility, you may be better off deleting it and relying on GDBM. I
haven't looked at porting the version of the module supporting the later
SleepyCat releases of BSD DB, which would also require a port of the
SleepyCat DB package.
7. The readline module has been linked against ncurses rather than the
termcap library supplied with EMX.
{8. Workaround implemented}
9. I have configured this port to use "/" as the preferred path separator
character, rather than "\" ('\\'), in line with the convention supported
by EMX. Backslashes are still supported of course, and still appear in
unexpected places due to outside sources that don't get normalised.
10. While the DistUtils components are now functional, other
packaging/binary handling tools and utilities such as those included in
the Demo and Tools directories - freeze in particular - are unlikely to
work. If you do get them going, I'd like to know about your success.
11. I haven't set out to support the [BEGIN|END]LIBPATH functionality
supported by one of the earlier ports (Rush's??). If it works let me know.
12. There appear to be several versions of Z.DLL floating around - the one
I have is 45061 bytes and dated January 22, 1999. I have a report that
another version causes SYS3175s when the zlib module is imported.
14. As a result of the limitations imposed by EMX's library routines, the
standard extension module pwd only synthesises a simple passwd database,
and the grp module cannot be supported at all.
I have written substitutes, in Python naturally, which can process real
passwd and group files for those applications (such as MailMan) that
require more than EMX emulates. I have placed pwd.py and grp.py in
Lib/plat-os2emx, which is usually before Lib/lib-dynload (which contains
pwd.pyd) in the PYTHONPATH. If you have become attached to what pwd.pyd
supports, you can put Lib/lib-dynload before Lib/plat-os2emx in PYTHONPATH
or delete/rename pwd.py & grp.py.
pwd.py & grp.py support locating their data files by looking in the
environment for them in the following sequence:
pwd.py: $ETC_PASSWD (%ETC_PASSWD%)
$ETC/passwd (%ETC%/passwd)
$PYTHONHOME/Etc/passwd (%PYTHONHOME%/Etc/passwd)
grp.py: $ETC_GROUP (%ETC_GROUP%)
$ETC/group (%ETC%/group)
$PYTHONHOME/Etc/group (%PYTHONHOME%/Etc/group)
Both modules support using either the ":" character (Unix standard) or
";" (OS/2, DOS, Windows standard) field separator character, and pwd.py
implements the following drive letter conversions for the home_directory and
shell fields (for the ":" separator only):
$x -> x:
x; -> x:
Example versions of passwd and group are in the Etc subdirectory. Note
that as of this release, this code fails the regression test. I'm looking
into why, and hope to have this fixed.
15. As of Python 2.1, termios support has mutated. There is no longer a
platform specific TERMIOS.py containing the symbolic constants - these
now live in the termios module. EMX's termios routines don't support all
of the functionality now exposed by the termios module - refer to the EMX
documentation to find out what is supported.
16. The case sensitive import semantics introduced in Python 2.1 for other
case insensitive but case preserving file/operating systems (Windows etc),
have been incorporated into this port, and are active by default. Setting
the PYTHONCASEOK environment variable (to any value) reverts to the
previous (case insensitive) semantics.
17. Because I am statically linking ncurses, the _curses_panel
module has potential problems arising from separate library data areas.
To avoid this, I have configured the _curses_.pyd (imported as
"_curses_panel") to import the ncurses symbols it needs from _curses.pyd.
As a result the _curses module must be imported before the _curses_panel
module. As far as I can tell, the modules in the curses package do this.
If you have problems attempting to use the _curses_panel support please
let me know, and I'll look into an alternative solution.
18. I tried enabling the Python Object Allocator (PYMALLOC) code. While
the port built this way passes the regression test, the Numpy extension
(I tested v19.0.0) as built with with the port's DistUtils code doesn't
work. Specifically, attempting to "import Numeric" provokes a core dump.
Supposedly Numpy v20.1.0 contains a fix for this, but for reason outlined
in item 1 above, PYMALLOC is not enabled in this release.
19. sys.platform now reports "os2emx" instead of "os2". os.name still
reports "os2". This change was to make it easier to distinguish between
the VAC++ build (being maintained by Michael Muller) and the EMX build
(this port), principally for DistUtils.
20. it appears that the %W substitution in the EMX strftime() routine has
an off-by-one bug. strftime was listed as passing the regression tests
in previous releases, but this fact appears to have been an oversight in
the regression test suite. To fix this really requires a portable
strftime routine - I'm looking into using one from FreeBSD, but its not
ready yet.
21. previous releases of my Python ports have used the GCC optimisations
"-O2 -fomit-frame-pointer". After experimenting with various optimisation
settings, including deactivating assert()ions, I have concluded that "-O2"
appears the best compromise for GCC 2.8.1 on my hardware. Curiously,
deactivating assert() (via defining NDEBUG) _negatively_ impacts
performance, allbeit only slightly, so I've chosen to leave the assert()s
active.
I did try using Andrew Zabolotny's (p)gcc 2.95.2 compiler, and in
general concluded that it produced larger objects that ran slower
than Mattes' gcc 2.8.1 compiler.
Pystone ratings varied from just over 2000/s (no optimisation at all)
to just under 3300/s (gcc 2.8.1, -O2) on my K6/2-300 system, for
100,000 iterations per run (rather than the default 10000).
As a result of the optimisation change, the Python DLL is about 10%
smaller than in the 2.1 release, and many of the dynamically loadable
modules are smaller too.
[2001/08/12]
22. As of this release, os.spawnv() and os.spawnve() now expose EMX's
library routines rather than use the emulation in os.py.
In order to make use of some of the features this makes available in
the OS/2 environment, you should peruse the relevant EMX documentation
(EMXLIB.INF in the EMXVIEW.ZIP archive accompanying the EMX archives
on Hobbes or LEO). Be aware that I have exposed all the "mode" options
supported by EMX, but there are combinations that either cannot be
practically used by/in Python or have the potential to compromise your
system's stability.
23. pythonpm.exe in previous releases was just python.exe with the
WINDOWAPI linker option set in the pythonpm.def file. In practice,
this turns out to do nothing useful.
I have written a replacement which wraps the Python DLL in a genuine
Presentation Manager application. This version actually runs the
Python interpreter in a separate thread from the PM shell, in order
that PythonPM has a functioning message queue as good PM apps should.
In its current state, PythonPM's window is hidden. It can be displayed,
although it will have no content as nothing is ever written to the
window. Only the "hide" button is available. Although the code
has support for shutting PythonPM down when the Python interpreter is
still busy (via the "control" menu), this is not well tested and given
comments I've come across in EMX documentation suggesting that the
thread killing operation has problems I would suggest caution in
relying on this capability.
PythonPM processes commandline parameters normally. The standard input,
output and error streams are only useful if redirected, as PythonPM's
window is not a console in any form and so cannot accept or display
anything. This means that the -i option is ineffective.
Because the Python thread doesn't create its own message queue, creating
PM Windows and performing most PM operations is not possible from within
this thread. How this will affect supporting PM extensions (such as
Tkinter using a PM port of Tcl/Tk, or wxPython using the PM port of
WxWindows) is still being researched.
Note that os.fork() _DOES_NOT_WORK_ in PythonPM - SYS3175s are the result
of trying. os.spawnv() _does_ work. PythonPM passes all regression tests
that the standard Python interpreter (python.exe) passes, with the exception
of test_fork1 and test_socket which both attempt to use os.fork().
I very much want feedback on the performance, behaviour and utility of
PythonPM. I would like to add a PM console capability to it, but that
will be a non-trivial effort. I may be able to leverage the code in
Illya Vaes' Tcl/Tk port, which would make it easier.
[2001/08/14]
24. os.chdir() now uses EMX's _chdir2(), which supports changing
both drive and directory at once. Similarly, os.getcwd() now uses
EMX's _getcwd() which returns drive as well as path.
[2001/12/08] - 2.2 Beta 2
25. pyconfig.h (previously known as config.h) is now located in the
Include subdirectory with all other include files.
[2001/12/16] - 2.2 Release Candidate 1
[2001/12/08] - 2.2 Final
... probably other issues that I've not encountered, or don't remember :-(
If you encounter other difficulties with this port, which can be
characterised as peculiar to this port rather than to the Python release,
I would like to hear about them. However I cannot promise to be able to do
anything to resolve such problems. See the Contact section below...
To do...
--------
In no particular order of apparent importance or likelihood...
- support Tkinter and/or alternative GUI (wxWindows??)
Credits
-------
In addition to people identified above, I'd like to thank:
- the BDFL, Guido van Rossum, and crew for Python;
- Dr David Mertz, for trying out a pre-release of this port;
- the Python-list/comp.lang.python community;
- John Poltorak, for input about pwd/grp.
Contact
-------
Constructive feedback, negative or positive, about this port is welcome
and should be addressed to me at the e-mail addresses below.
I intend creating a private mailing list for announcements of fixes &
updates to this port. If you wish to receive such e-mail announcments,
please send me an e-mail requesting that you be added to this list.
Andrew MacIntyre
E-mail: andymac at bullseye dot apana dot org dot au, or
andymac at pcug dot org dot au
Web: http://www.andymac.org/
24 December, 2001.