On 2/19/07, Roman Yakovenko <roman.yakovenko@gmail.com> wrote:
On 2/19/07, Gustavo Carneiro <gjcarneiro@gmail.com> wrote:
>   Even with the name mangling problem, something was not right:
> gjc@nazgul:python$  python test-schedule.py
> Traceback (most recent call last):
>   File "test-schedule.py ", line 11, in <module>
>     Simulator.Schedule_fbf096d706be19b392c1e3fbcd3bf544(t1,
> ev)
> Boost.Python.ArgumentError: Python argument types in
> Simulator.Schedule_fbf096d706be19b392c1e3fbcd3bf544(Time,
> MyEvent)
> did not match C++ signature:
>     Schedule_fbf096d706be19b392c1e3fbcd3bf544(ns3::Time
> time, std::auto_ptr<ns3::EventImpl> event)
>   Then I saw something I missed in the unit test, and added this code:
>     EventImpl = mb.class_('EventImpl')
>     EventImpl.held_type = 'std::auto_ptr< %s >' % EventImpl.decl_string
>   (EventImpl is the type of the argument that is subject to the ownership
> transfer)
>   But with the above changes the code doesn't compile (errors below).  The
> generated source contains:
>     bp::class_< EventImpl_wrapper, std::auto_ptr< ::ns3::EventImpl >,
> boost::noncopyable >( "EventImpl" )    
>         .def( bp::init< >() )    
>   The error comes from the ".def( bp::init< >() )" line.  Manually removing
> the "std::auto_ptr< ::ns3::EventImpl >" part from the first line solves the
> compilation error.
>    Any hints?

1. change "std::auto_ptr< ::ns3::EventImpl >" to
    "std::auto_ptr< EventImpl_wrapper >" and add next line to your code:

ei = mb.class _( 'EventImpl' )
    "boost::python::implicitly_convertible< std::auto_ptr< EventImpl_wrapper >, std::auto_ptr< ::ns3::EventImpl > >();"
   , False )

This should help.

  Thanks, Roman!  I helped.

2. If not, please create small standalone test case, which reproduce the problem.
    I will take a look on it.

  Unfortunately after all this effort I am still experiencing similar memory errors as before.  I don't understand why because, as far as I can tell, Py++ generated the boost code according to the boost FAQ advice.  In this code, if I uncomment the 'del ev' line I get a memory error and segfault:

from ns3 import *

class MyEvent(EventImpl):

    def Notify(self):
        print "Notify!"

ev = MyEvent()
Simulator.Schedule(Seconds(1), ev) # takes ownership of ev
#del ev
Simulator.Run () # calls ev.Notify and then destroys it; memory error here

  Here's what valgrind reports:

==9790== Invalid read of size 4
==9790==    at 0x4B6E960: (within /usr/lib/libboost_python-gcc-mt-1_33_1.so.1.33.1)
==9790==    by 0x8097F18: (within /usr/bin/python2.5)
==9790==    by 0x8062CED: (within /usr/bin/python2.5)
==9790==    by 0x4ABE032: boost::python::api::object_base::~object_base() (object_core.hpp:436)
==9790==    by 0x4ABE080: boost::python::api::object::~object() (object_core.hpp:294)
==9790==    by 0x4ABE176: boost::python::override::~override() (override.hpp:88)
==9790==    by 0x4ADFC4F: EventImpl_wrapper::Notify() (ns3.cpp:32)
==9790==    by 0x4AF9CF5: ns3::EventImpl::Invoke() (event-impl.cc :39)
==9790==    by 0x4B005DE: ns3::SimulatorPrivate::ProcessOneEvent() (simulator.cc:138)
==9790==    by 0x4B0061E: ns3::SimulatorPrivate::Run() (simulator.cc:168)
==9790==  Address 0x497D838 is 0 bytes inside a block of size 12 free'd
==9790==    at 0x4020F9A: free (vg_replace_malloc.c:233)
==9790==    by 0x4B6E766: boost::python::instance_holder::deallocate(_object*, void*) (in /usr/lib/libboost_python-gcc-mt-1_33_1.so.1.33.1)
==9790==    by 0x4B6E97F: (within /usr/lib/libboost_python-gcc-mt-1_33_1.so.1.33.1)
==9790==    by 0x8097F18: (within /usr/bin/python2.5)
==9790==    by 0x8086418: PyDict_DelItem (in /usr/bin/python2.5)
==9790==    by 0x8061656: PyObject_DelItem (in /usr/bin/python2.5)
==9790==    by 0x80C27F9: PyEval_EvalFrameEx (in /usr/bin/python2.5)
==9790==    by 0x80C60F4: PyEval_EvalCodeEx (in /usr/bin/python2.5)
==9790==    by 0x80C6166: PyEval_EvalCode (in /usr/bin/python2.5)
==9790==    by 0x80E590B: PyRun_FileExFlags (in /usr/bin/python2.5)

  I think I'll try to make a small example to reproduce this...

Gustavo J. A. M. Carneiro
"The universe is always one step beyond logic."