[omniORB] The Simple example not working :0)

[Bjorn R. Jensen]

Hi there,

 There is a problem in your implementation of the Item servant,
where you return a char * to the orb runtime. The orb runtime
expects a char * to memory allocated using CORBA::string_alloc.
The orb runtime also assumes ownership of the string handed to
it, and will free it using CORBA::string_free, when it is done
marshalling it. In your case it would be easiest, if you used
return CORBA::string_dup(d_name). You are basically corrupting
the heap.

Yours sincerely,

Bjorn

On Thu, 10 Oct 2002 16:19:07 -0500, "Laurent JOIGNY"
<ljoigny@houston.westerngeco.slb.com> said:
> Hi,
> 
> I am a new user of omniORB and I tried to run a simple example
> of a time server. All goes well until I decide to add some spicy
> stuff like sequence.
> 
> First of all my problem was at the compilation stage, when I try to
> assign an element of a vector to an element of my sequence.
> It seems that the _this() operation was enough to solve the problem,
> but at the execution stage my server stop in this portion of code.
> 
> If somebody has an idea, I would be glad to hear it.
> 
> I read some of other issues on the list archive but I didn't find my
> answer. Any way I thing that a bigger example of omniORB use, with
> sequence,
> should be present in the product archive.
> 
> Server Execution:
> -----------------
> Get ORB reference
> Get the POA reference
> Create and activate the TimeImpl object
> Start the POA manager
> Stringify the TimeImpl reference
> Running ORB...
> 
> Begin get_items
> itemList size = 3
> New sequence created
> Copy an item
> 
> Client Execution:
> ------------------
> Starting the server
> Get ORB reference
> Destringify the Object reference
> Get a Time object from the reference
> Use the time service
> Time in GreenWich is 21:13:17
> Get a list of item and display it
> ERROR IN THE CLIENT
> 
> 
> IDL:
> -----
> module TIDL {
> 	interface Item {
> 		attribute string name;
> 	};
> 	typedef sequence<Item> ItemSeq;
> 	struct TimeOfDay {
> 		short hour;
> 		short minute;
> 		short second;
> 	};
> 	interface Time {
> 		TimeOfDay get_gmt();
> 		ItemSeq get_items();
> 	};
> };
> 
> Servant code: timeImpl.cc
> -------------------------
> using namespace TIDL;
> 
> class ItemImpl : public POA_TIDL::Item,
> 	public PortableServer::RefCountServantBase
> {
> public :
> 	ItemImpl(char *n) { strcpy(d_name, n); };
> 	virtual char *name() { return d_name; };
> 	virtual void name(const char *n) { strcpy(d_name, n); };
> 
> 	char d_name[50];
> };
> 
> class TimeImpl : public POA_TIDL::Time,
> 	public PortableServer::RefCountServantBase
> {
> public :
> 	virtual TimeOfDay get_gmt();
> 	virtual ItemSeq*  get_items();
> 
> 	vector<ItemImpl> itemList;
> };
> 
> TimeOfDay TimeImpl::get_gmt()
> {
>      TimeOfDay tod;
>      ... etc ..
>      return tod;
> }
> 
> ItemSeq*  TimeImpl::get_items()
> {
> 	cerr<<"Begin get_items"<<endl;
> 	int len = itemList.size();
> 	cerr<<"itemList size = "<<len<<endl;
> 	ItemSeq* seq = new ItemSeq(len);
> 	cerr<<"New sequence created"<<endl;
> 
> 	for (int i=0; i<len; i++)
> 	{
> 		cerr<<"Copy an item"<<endl;
> 		(*seq)[i] = itemList[i]._this();   // FIXE ME !!
> 	}
> 
> 	cerr<<"End get_items"<<endl;
> 	return seq;
> }
> 
> Server code: timeImpl.cc
> ------------------------
> int main(int argc, char * argv[])
> {
> 	... etc...
> 	TimeImpl *mytime = new TimeImpl();
> 
> 	ItemImpl item = ItemImpl("A");
> 	mytime->itemList.push_back( item );
> 	item.name("simple");	
> 	mytime->itemList.push_back( item );
> 	item.name("test");
> 	mytime->itemList.push_back( item );
> 	
> 	PortableServer::ObjectId_var mytimeid = poa->activate_object(mytime);
> 
> 	Time_var mytimeref = mytime->_this();
> 	mytime->_remove_ref();
> 
> 	... etc ...
> }
> 
> Client code:
> ------------
> int main(int argc, char * argv[])
> {
> 	... etc ...
> 	cerr<<"Get a Time object from the reference"<<endl;
> 	Time_var tm = Time::_narrow(obj);
> 	if (CORBA::is_nil(tm)) {
> 		cerr<<"Argument is not a Time reference"<<endl;
> 		throw 0;
> 	}
> 
> 	// Get time
> 	cerr<<"Use the time service"<<endl;
> 	TimeOfDay tod = tm->get_gmt();
> 	... etc ...
> 	
> 	cout<<"Get a list of item and display it "<<endl;
> 	ItemSeq *seq = tm->get_items();
> 	cout<<"List taken"<<endl;
> 	int len2 = seq->length();
> 	for (int i=0; i<len2; i++)
> 	{
> 		cout<<(*seq)[i]<<" ";
> 	}
> 
> 	... etc ...
> }
> 
> 
> --
> Laurent JOIGNY
> WesternGeco / Schlumberger / Houston
> phone : (+1) 713 689 6646
> 
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