[ns] Packet::copy() issue with ns2.33

[Swaroop Shere]

Hi guys,
      I found the solution to the problem. While debugging further, I found out that the virtual destructor ~AppData() was being called. Then I realized that I was instantiating the object of class PQR as follows:
PQR pkt(arguments);
whereas, the instantiation should have been
PQR* pkt = new PQR(arguments);
The former method resulted in pkt variable going out of scope at the end of the instantiating function, whereas, it does not happen in the latter method.

regards,
Swaroop

--- On Mon, 1/6/09, Swaroop Shere <swaroopshere at yahoo.co.in> wrote:

From: Swaroop Shere <swaroopshere at yahoo.co.in>
Subject: [ns] Packet::copy() issue with ns2.33
To: "ns-users" <ns-users at ISI.EDU>
Date: Monday, 1 June, 2009, 8:43 PM



From: swaroopshere at yahoo.co.in <swaroopshere at yahoo.co.in>
Subject: Packet::copy() issue with ns2.33
To: "ns-users" <ns-users at ISI.EDU>
Date: Monday, 1 June, 2009, 1:22 PM

Hi,
    I am writing a new protocol in NS2 and using application level data packets by extending AppData. So I have class ABC:: public AppData and class PQR::public ABC. I have defined the size() and copy() methods for both, and also defined the constants in packet.h in enum AppDataType.

Now, when I run the simulation, I get an error that says...
-----------------------------------------------------------------------
pure virtual method called
terminate called without an active exception
-----------------------------------------------------------------------
Upon debugging, I found out that this error comes when it executes 
Packet::copy(), specifically the statement
p->data_ = data_-> copy()

here, data_->copy() happens to be a pure virtual function, which is why I am
 getting the error, but I am wondering what is the cause.. I have defined the proper copy() functions for new AppData types...

It would be great if someone points me out my mistake.. If someone wants more information about my code, I would be happy to share it ...

thank you,

regards,
Swaroop





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