Re: Segfault in _this()

[Johan Cronje <jcronje dsp sun ac za>]

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On Friday 01 August 2003 01:47, Bowie Owens wrote:
> Hi Johan,
>
> As for where to look, please try and determine which memory reference
> caused the seg. fault. Was the rootPOA pointer null? Was the method
> invoked on a null pointer (null this pointer)? Was the object the method
> was invoked on deleted prior to the method call? Was the seg. fault
> inside one the calls to activate_object or servant_to_id?
>

This is the new generated _this() method that 1.3.6 gives me (-cpp-skels.cpp 
file). I have added the cout statements for debugging purposes.

1 ::sdr_corba::sdr_subcontroller_ptr POA_sdr_corba::sdr_subcontroller::_this()
2 {
3    cout << "blah\n";
4    PortableServer::POA_var rootPOA = _default_POA ();
5    cout << "blah 1\n";
6    CORBA::Object_var object = rootPOA->servant_to_reference (this);
7    cout << "blah 2\n";
8    return ::_orbitcpp::stub::sdr_corba::sdr_subcontroller::_orbitcpp_wrap
9    (object->_orbitcpp_cobj (), true);
10 }

Now, the program segfaults between blah1 and blah2, indicating an error in
line 6. The output of gdb is as follows:

(gdb) run
Starting program: /home/jcronje/SDR/devel/corbasdr/sdr_corba
[New Thread 16384 (LWP 29450)]
ORB_init
orb->resolve_initial_references
_narrow
rootPOA->the_POAManager
mgr->activate
POA_sdr_corba_sdr_subcontroller__init (Called by 
::POA_sdr_corba::sdr_subcontroller::sdr_subcontroller)
servant created
Test Class 
blah
blah 1

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 16384 (LWP 29450)]
0x4006d346 in ORBit_POA_activate_object () from /usr/lib/libORBit-2.so.0

Does this mean that my rootPOA pointer is null? If so, how do I fix it?

Also find attached my main server implementation file, sdr_corba.cpp.

Any help or direction will be greatly appreciated.

Thank you

Johan
- -- 

- ---------------------------------------------------------------
"There is beauty in simplicity"		-- Johan Cronje
- ---------------------------------------------------------------
Johan Cronje
Digital Signal Processing / Telecommunications Group
Electrical and Electronic Engineering Department
University of Stellenbosch
http://www.dsp.sun.ac.za/~jcronje
GNUPG Key: http://www.dsp.sun.ac.za/~jcronje/jcronje.asc
- ---------------------------------------------------------------

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/** $Id$
 * @file sdr_corba.cpp
 * @brief SDR CORBA ORBit Implementation
 * @author Johan Cronjé
 * @date 29/05/2003 14:53
 */

#include <string>
#include "sdr_corba.h"
#include "sdr_corba-cpp.h"
#include "sdr_corba_impl.h"
#include <iostream>
#include <linc/linc.h>

using namespace std;
using namespace POA_sdr_corba;
using namespace _orbitcpp;
using namespace sdr_corba;
//using namespace sdr_base_classes;

void POA_sdr_corba_sdr_subcontroller__init(PortableServer_Servant     servant,
                                           CORBA_Environment *        ev)
{
   cout << "POA_sdr_corba_sdr_subcontroller__init" <<
    " (Called by ::POA_sdr_corba::sdr_subcontroller::sdr_subcontroller)\n";
}

void POA_sdr_corba_sdr_subcontroller__fini(PortableServer_Servant     servant,
                                           CORBA_Environment *        ev)
{
   cout << "Sukkel jy lekker? fini\n";
}

sdr_corba_attributes_list* 
sdr_corba_sdr_subcontroller_return_attributes(sdr_corba_sdr_subcontroller _obj,
                                              CORBA_Environment * ev)
{
   cout << "Sukkel jy lekker? 34 - 39\n";
}

CORBA_float 
sdr_corba_sdr_subcontroller_return_attribute_value(sdr_corba_sdr_subcontroller _obj,
                                                   const CORBA_char * attrib_c,
                                                   CORBA_Environment * ev)
{
   cout << "Sukkel jy lekker? 41-47\n";
}

void sdr_corba_sdr_subcontroller_change_attribute_value(sdr_corba_sdr_subcontroller _obj,
                                                        const CORBA_char * attribute_name,
                                                        const CORBA_char * attribute_value,
                                                        CORBA_Environment * ev)
       {
         cout << "Sukkel jy lekker? 49-55\n";
       }

sdr_corba_component_name
sdr_corba_sdr_subcontroller_return_component_name(sdr_corba_sdr_subcontroller _obj,
                                                  CORBA_Environment* ev)
{
   cout << "Sukkel jy lekker? 57-62\n";
}


int main (int argc, char* argv[])
{
   // Initialize the CORBA orb
   CORBA::ORB_var orb = CORBA::ORB_init (argc, argv);

   cout << "ORB_init\n";
   // Get the root POA
   CORBA::Object_var pfobj = orb->resolve_initial_references("RootPOA");
   cout << "orb->resolve_initial_references\n";   
   PortableServer::POA_var rootPOA =
        PortableServer::POA::_narrow(pfobj);
   cout << "_narrow\n";
   // Activate the root POA's manager
   PortableServer::POAManager_var mgr = rootPOA->the_POAManager();
   cout << "rootPOA->the_POAManager\n";   
   mgr->activate();
   cout << "mgr->activate\n";
   // Create a Servant and explicitly create a CORBA object
   sdr_corba::sdr_corba_impl servant;
   cout << "servant created\n";  
   cout << servant.return_component_name() << endl;
   CORBA::Object_var object = servant._this(); 
   cout << "object = servant._this\n";
   // Here we get the IOR for the Hello server object.
   // Our "client" will use the IOR to find the object to connect to 
   CORBA::String_var ref = orb->object_to_string( object );

   // print out the IOR
   cout << ref << endl;
 
   // run the server event loop
   orb->run();

}