Mailman 3 November 2005 - Cplusplus-sig

solaris-intel sem deadlock problem... :-/
by Cameron Blackwood Nov. 10, 2005

Nov. 10, 2005

Any ideas welcome.... im out of ideas... :-/ Summary: -------- Semaphore code hangs when call from python module but not from c/c++. Kill me.... Background: ----------- Im working on a project that is a massive c++ piece of work that offers a single object with useful methods. Its a database and it starts 3 other processes and uses shared memory and semaphores to communicate. The c++ interface is the native one (and its kinda big at ~30M exe's). It has a C interface which creates a dll of c++ code and wraps each method call in a c function. There is a python wrapper that wraps the c interface. Problem: -------- It works fine on linux-x86, linux-ppc64 and we're just porting to solaris-intel but we've hit a problem. The startup code for the c++ object does some forking and sem work and it works fine for the c++ interface and the c interface but the python module just hangs in the semaphore semget loop. The constructor for the c++ object is called with the same args via python or c (so its not that). We're using boost for config passing, but the boost config values are the same. The c interface works (so its not the dll). It could be some solaris issue, but the c and c++ interfaces work fine... its just the python interface. :-( Has anyone got _any_ ideas? Or am I in for a big chunk of c++ semaphore debugging? :-/ (refer to kill me comment ;) cheers, cam -- / Cameron Blackwood korg at csse.unimelb.edu.au \ [ Research Programmer, Aditi Project +61 3 8344-1315 ] \ University of Melbourne /

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call policies
by Ricardo Kirkner Nov. 9, 2005

Nov. 9, 2005

Hello again: this time I have a question regarding call policies. I have a function that returns a double * which actually is an array of doubles. I am required to provide a policy for this functions, however I cannot find out which one would apply here (from how well I understand each posibility). Can anyone please enlighten me? Thank you Ricardo Kirkner

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Problem using the ptr() function
by Emmanuel Taurel Nov. 8, 2005

Nov. 8, 2005

Hello everybody, I am using Boost.python to interface a C++ set of classes. In one of my C+++ class, I am calling a method implemented in Python with the boost "call_method" call. This method has one parameter of our own data type and return a pointer to this type. I have installed converters for this type as it is adviced in the FAQ "How can I automatically convert my custom string type..." If I call my method like this MyType *ret = call_method<MyType *>(my_py_obj,"My_method", my_ptr) With my_ptr being a MyType *, it works. But if I call it like this MyType *ret = call_method<MyType *>(my_py_obj,"My_method", ptr(my_ptr)) to avoid a copy, I received a run time error complaining that "No Python class registered for C++..." Could someone explain me why it works in the first case and not in the second one. Many thanks in advance Emmanuel Taurel (etaurel(a)cells.es)

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boost.python error
by Ricardo Kirkner Nov. 7, 2005

Nov. 7, 2005

Hi: I just wrote a small wrapper for a class, using pyste (boost.python). I am just trying to figure out how this works, before I get on wrapping the whole real library. I did run pyste succesfully (which generated a .cpp file) , and I also did run bjam successfully, which generated the .so library. However, when I try to import the newly generated library in python, I get the following error: ImportError: ./opal.so: undefined symbol: _ZTVN5boost6python7objects21py_function_impl_baseE Can anyone tell me why is this error being produced (and how to fix it)? Does this mean that the .so didnt linked to the boost library? Thank you, Ricardo Kirkner

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boost package import error
by Marc Rossi Nov. 3, 2005

Nov. 3, 2005

I'm running into import problems trying to create a package that is similiar in layout to the one in the docs described here: http://www.boost.org/libs/python/doc/tutorial/doc/html/python/techniques.ht… So my package layout is as follows: xyzzy/ __init__.py research/ __init__.py _research.so stats.pyc My __init__.py file contains 2 lines: from stats import * from _research import * With the directory containing 'xyzzy' on my PYTHONPATH, the following occurs: Python 2.4.2 (#2, Nov 3 2005, 11:35:03) [GCC 3.2.3 20030502 (Red Hat Linux 3.2.3-52)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import frfr.research Traceback (most recent call last): File "<stdin>", line 1, in ? File "xyzzy/research/__init__.py", line 2, in ? from _research import * ImportError: No module named _research Running python with the -vv switch shows python does indeed look at _research.so but does not load it. However if I put the directory containing _research.so on my PYTHONPATH the following command is successful: >>> import _research Thanks for any help you can offer, Marc __________________________________ Yahoo! FareChase: Search multiple travel sites in one click. http://farechase.yahoo.com

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using boost.python to have access to boost::dynamic_bitset
by Øystein Lekang Nov. 3, 2005

Nov. 3, 2005

I am in need of somthing like dynamic_bitset in python, and am currently searching for the best way to achieve this. So Im wondering how much work it would be to use boost.python to make dynamic_bitset accessable to python, and whether it can be done by me. (myself not beeing to versed in c++) I've had a brief look at swig, pyrex and pyinline, but thought that since boost.python also is a part of boost, it might be the way to go. -- Øystein Lekang

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Warning: non-POD class type passed through
by Raghavendra K . B Nov. 3, 2005

Nov. 3, 2005

Hi All, I am getting following Warning : non-POD class type passed through buf.Format(KKeyCreateTime, rate, noKeyPairCreations, keyCreateTime); ^ If any one has faced this problem , please let me know the solution .I badly need solution for this Thanks in Advance. Raghavendra K.B --------------------------------- Enjoy this Diwali with Y! India Click here

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help on quant finance code
by T Maisnam Nov. 3, 2005

Nov. 3, 2005

Hi Holger, I am currently studying a financial engineering course in sydney and am from an IT background. I came across your name in one of the bulletin boards. Can you please send me any links to financial program codes that I can look into. I am never worked in finance and i want to see some code implementation besides the abstract math concepts that I am studying now. cheers, Tony Maisnam __________________________________ Yahoo! Mail - PC Magazine Editors' Choice 2005 http://mail.yahoo.com

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new stl_iterator doesn't work with EDGs
by Ralf W. Grosse-Kunstleve Nov. 2, 2005

Nov. 2, 2005

The output below is an error message produced by Tru64 cxx 7.1, which is based on EDG 304. I got a similar error message with EDG 238 under IRIX. I guess it probably is the same for all EDGs in between. I'd be happy to try out ideas for fixes. We have EDG 238, 245 and 304 available. Cheers, Ralf BTW: I just checked in a patch to reorder the includes. Due to Python requirements, boost/python includes have to appear before any system includes. cxx -o boost/libs/python/test/stl_iterator.o -c -std strict_ansi -msg_display_number -msg_disable 186,450,1115,1133 -tlocal -DBOOST_DISABLE_THREADS -DNDEBUG -O2 -fast -DBOOST_PYTHON_MAX_BASES=2 -I/net/legless/scratch1/rwgk/hot/boost -I/usr/local_cci/Python-2.4.2_ticker_simple/include/python2.4 /net/legless/scratch1/rwgk/hot/boost/libs/python/test/stl_iterator.cpp cxx: Error: /net/legless/scratch1/rwgk/hot/boost/boost/iterator/iterator_facade.hpp, line 535: #265-D function "boost::python::stl_input_iterator<ValueT>::equal [with ValueT=int]" is inaccessible detected during: instantiation of "bool boost::iterator_core_access::equal(const Facade1 &, const Facade2 &, mpl_::true_) [with Facade1=boost::python::stl_input_iterator<int>, Facade2=boost::python::stl_input_iterator<int>]" at line 838 instantiation of "boost::detail::enable_if_interoperable<Derived1, Derived2, boost::mpl::apply2<boost::detail::always_bool2, Derived1, Derived2>::type>::type boost::operator!=(const boost::iterator_facade<Derived1, V1, TC1, R1, D1> &, const boost::iterator_facade<Derived2, V2, TC2, R2, D2> &) [with Derived1=boost::python::stl_input_iterator<int>, V1=int, TC1=std::input_iterator_tag, R1=int, D1=std::ptrdiff_t={signed long}, Derived2=boost::python::stl_input_iterator<int>, V2=int, TC2=std::input_iterator_tag, R2=int, D2=std::ptrdiff_t={signed long}]" at line 845 of "/usr/lib/cmplrs/cxx/V7.1-006/include/cxx/list" instantiation of "void std::list<T, Allocator>::_RWinsert_interval_dispatch(std::list<T, Allocator>::iterator, InputIterator, InputIterator, std::input_iterator_tag) [with T=int, Allocator=std::allocator<int>, InputIterator=boost::python::stl_input_iterator<int>]" at line 156 of "/usr/lib/cmplrs/cxx/V7.1-006/include/cxx/list.cc" instantiation of "void std::list<T, Allocator>::insert(std::list<T, Allocator>::iterator, InputIterator, InputIterator) [with T=int, Allocator=std::allocator<int>, InputIterator=boost::python::stl_input_iterator<int>]" return f1.equal(f2); --------------------^ cxx: Error: /net/legless/scratch1/rwgk/hot/boost/boost/iterator/iterator_facade.hpp, line 517: #265-D function "boost::python::stl_input_iterator<ValueT>::dereference [with ValueT=int]" is inaccessible detected during: instantiation of "Facade::reference boost::iterator_core_access::dereference(const Facade &) [with Facade=boost::python::stl_input_iterator<int>]" at line 635 instantiation of "boost::iterator_facade<Derived, Value, CategoryOrTraversal, Reference, Difference>::reference boost::iterator_facade<Derived, Value, CategoryOrTraversal, Reference, Difference>::operator*() const [with Derived=boost::python::stl_input_iterator<int>, Value=int, CategoryOrTraversal=std::input_iterator_tag, Reference=int, Difference=std::ptrdiff_t={signed long}]" at line 846 of "/usr/lib/cmplrs/cxx/V7.1-006/include/cxx/list" instantiation of "void std::list<T, Allocator>::_RWinsert_interval_dispatch(std::list<T, Allocator>::iterator, InputIterator, InputIterator, std::input_iterator_tag) [with T=int, Allocator=std::allocator<int>, InputIterator=boost::python::stl_input_iterator<int>]" at line 156 of "/usr/lib/cmplrs/cxx/V7.1-006/include/cxx/list.cc" instantiation of "void std::list<T, Allocator>::insert(std::list<T, Allocator>::iterator, InputIterator, InputIterator) [with T=int, Allocator=std::allocator<int>, InputIterator=boost::python::stl_input_iterator<int>]" return f.dereference(); -------------------^ cxx: Error: /net/legless/scratch1/rwgk/hot/boost/boost/iterator/iterator_facade.hpp, line 523: #265-D function "boost::python::stl_input_iterator<ValueT>::increment [with ValueT=int]" is inaccessible detected during: instantiation of "void boost::iterator_core_access::increment(Facade &) [with Facade=boost::python::stl_input_iterator<int>]" at line 665 instantiation of "Derived &boost::iterator_facade<Derived, Value, CategoryOrTraversal, Reference, Difference>::operator++() [with Derived=boost::python::stl_input_iterator<int>, Value=int, CategoryOrTraversal=std::input_iterator_tag, Reference=int, Difference=std::ptrdiff_t={signed long}]" at line 848 of "/usr/lib/cmplrs/cxx/V7.1-006/include/cxx/list" instantiation of "void std::list<T, Allocator>::_RWinsert_interval_dispatch(std::list<T, Allocator>::iterator, InputIterator, InputIterator, std::input_iterator_tag) [with T=int, Allocator=std::allocator<int>, InputIterator=boost::python::stl_input_iterator<int>]" at line 156 of "/usr/lib/cmplrs/cxx/V7.1-006/include/cxx/list.cc" instantiation of "void std::list<T, Allocator>::insert(std::list<T, Allocator>::iterator, InputIterator, InputIterator) [with T=int, Allocator=std::allocator<int>, InputIterator=boost::python::stl_input_iterator<int>]" f.increment(); ------------^ cxx: Info: 3 errors detected in the compilation of "/net/legless/scratch1/rwgk/hot/boost/libs/python/test/stl_iterator.cpp". scons: *** [boost/libs/python/test/stl_iterator.o] Error 1 __________________________________ Yahoo! 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Re: [C++-sig] how to handle bare references with a shared_ptr HeldType
by Gregory Price Nov. 1, 2005

Nov. 1, 2005

Hans Meine wrote: > Hmm. What about return_internal_reference (which I am using a lot)? > AFAICS, the C++ A object will not be deleted as long as B is not deleted, > because of the shared ptr. OTOH, during the lifetime of the A python > wrapper, B will not get deleted because of the custodian-ward relationship > initialized via return_internal_reference. Does that make sense? I agree with the second half of that -- return_internal_reference will keep the B instance alive as long as the wrapped A instance exists. But now say the wrapped A instance dies; the HeldType=shared_ptr<A> instance will think it's the only shared_ptr for that A instance, and will delete it. Now the shared_ptr<A> inside the B instance is dangling. I've lost as soon as I let Boost.Python create a new shared_ptr<A> from the bare A& -- the only way to avoid a dangling pointer then is to ensure that the A instance never dies at all. Is there a way to tell Boost.Python not to make a shared_ptr for this return value -- to override the HeldType just for this function's return value? Alternatively, to tell Boost.Python always to leave bare A references as they are? Or perhaps there's a simpler solution that I'm missing. Thanks, Greg ============================================================================================= Email transmissions can not be guaranteed to be secure or error-free, as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of email transmission. In addition, the information contained in this email message is intended only for use of the individual or entity named above. If the reader of this message is not the intended recipient, or the employee or agent responsible to deliver it to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication, disclosure of the parties to it, or any action taken or omitted to be taken in reliance on it, is strictly prohibited, and may be unlawful. If you are not the intended recipient please delete this email message. ==============================================================================================

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