Log of /branches/ROBW_XPLATFORM/bruce/py_src
Directory Listing
Revision
668 -
Directory Listing
Modified
Sat Mar 25 13:27:27 2006 UTC
(16 years, 3 months ago)
by
robwdcock
+ finally figured out why the tests failed when the python extension libs were
no longer sym links. The original setup for python extension modules was to
have sym links in the esys/* directories named, for example escriptcpp.so.
These would link to the actual libraries libescriptcpp.so. The lib*.so would
link to each other. When you replaced the symlink with a copy of the lib*.so
but renamed without the lib you would then get problems. In particular,
py_tests would suddenly start failing.
The problem appears (I've not been able to find documentary evidence to this
case) to be that when, for example, you import bruce, brucecpp.so imports
lib/libescriptcpp.so (which intialises escript python bits), bruce then
imports escriptcpp.so (which also initialised escript python bits).
Whether that is exactly correct or not is of interest but the important bit
is you appear to get two versions. After thinking about this for a bit and
reviewing a bunch of other examples of working python modules I noticed a
pattern. NONE of the other examples ever included more than the python
wrapper code in the python extension library. Instead they just link to
the pure C++ library. This would avoid the duplicate load.
So, I've refactored the code. If you consider escript the pattern in now:
lib/libescript.so - which has all of escript EXCEPT the python escriptcpp.cpp
esys/escript/escriptcpp.so - which has ONLY the escriptcpp.cpp and links to
lib/libescript.so
Run the tests and low and behold they all pass again.
Q: Why doesn't this problem occur with sym links?
A: My guess is that python and the dynamic linker take a look at the actual
absolute python of libraries to determine if its a "different" library.
I did fine some discussions that seem to suggest this.
Q: Why can't you just set LD_LIBRARY_PATH==PYTHONPATH and stick all the
libs in that directory?
A: I (in fact we, Peter Hornby was there) tried. With the renaming of the
python module so it doesn't have a lib prefix you get problems with
getting the shared libraries to be looked up in LD_LIBRARY_PATH. Do
the opposite and use lib on the python modules and you have problems
with windows which doesn't prepend the lib. Various combination
in between were also tried but you end up in a catch 22 situation so far
as I could tell
Please if you know more about the ins and outs of python and shared
libraries let me know if this isn't true. I'd really like to know if my
guesses are correct. In any event, the fix is more consistent with the
patterns I've seen
Phew! this was a long log message, glad it is on a branch!
Revision
667 -
Directory Listing
Modified
Fri Mar 24 13:25:00 2006 UTC
(16 years, 3 months ago)
by
robwdcock
+ OUCH ARGHH
+ Okay the wizzy linkHack doesn't work. Not sure why but py_tests fail
when the shared library is on the link line directly (without a -l)
+ Unfortunately we can't figure out how to use -l without it prepending
a lib prefix. Hence all the shareable objects in python now need to be
called libblah.so (and lib will need to be prepended on windows!!!!).
This is not the python way and its very annoying. Why do we have this
problem? Because the C++ shared libraries link with each other.
Revision
651 -
Directory Listing
Modified
Fri Mar 24 06:44:23 2006 UTC
(16 years, 3 months ago)
by
robwdcock
+Python file now compile and install into pyinstall directory
Revision
622 -
Directory Listing
Modified
Wed Mar 22 14:00:08 2006 UTC
(16 years, 3 months ago)
by
robwdcock
Creating a private branch so I can test and verify cross-platform build
Revision
352 -
Directory Listing
Modified
Wed Dec 14 02:21:37 2005 UTC
(16 years, 6 months ago)
by
jgs
Original Path:
trunk/bruce/py_src
turns out Install() targets should also be made Default()
targets if you want them to actually reliably work!
Revision
288 -
Directory Listing
Modified
Fri Dec 2 01:55:04 2005 UTC
(16 years, 7 months ago)
by
jgs
Original Path:
trunk/bruce/py_src
now automatically build unit tests as required based on dependencies
between unit tests and libraries
Revision
268 -
Directory Listing
Modified
Wed Nov 30 01:39:47 2005 UTC
(16 years, 7 months ago)
by
jgs
Original Path:
trunk/bruce/py_src
setup scons configuration to make and install python code
Revision
155 -
Directory Listing
Modified
Wed Nov 9 02:02:19 2005 UTC
(16 years, 7 months ago)
by
jgs
Original Path:
trunk/bruce/py_src
move all directories from trunk/esys2 into trunk and remove esys2
