Re: [Boost-users] How can I free memory allocated when deserializing with boost::archive::text_iarchive

Subject: Re: [Boost-users] How can I free memory allocated when deserializing with boost::archive::text_iarchive
From: Jeff Flinn (Jeffrey.Flinn_at_[hidden])
Date: 2013-02-05 08:11:03

A general comment on using this mailing list is to reply directly to the 
message, and to put the library in question in square brackets such as 
[serialization].

On 2/4/2013 9:29 PM, Adlai Shawareb wrote:
> Thanks for your reply. Here is a code sample:
>
>              std::istringstream istr;
> 	<* put data into istr here *>
>              boost::archive::text_iarchive ia(istr_);
>
>              Message* p_temp;
>              ia &  p_temp;
>              mpBaseIncomingMessage = p_temp;	// mpBaseIncomingMessage is of type (Message *)
>
>             mpIncomingMessage = static_cast<SystemMessage*>(mpBaseIncomingMessage);	// mpIncomingMessage is a pointer to a class derived from Message
>             mObjectCallbackMap.process(mpIncomingMessage->mEvent);	// execute a callback for this event
>             delete mpIncomingMessage;		// delete the allocated memory
>
> We then see a crash on either the " mObjectCallbackMap.process..." line or the " delete mpIncomingMessage", but only when certain actions are taken by the system.
>
> Any thoughts would be greatly appreciated.

Serialization library is designed to work with symmetrically 
serialized/de-serialized data. How are you serializing the Message*?

You can save yourself lots of time by using boost::polymorphic_downcast 
in situations like your usage of static_cast above to ensure you 
actually have a base pointer pointing to the derived type you think you 
have.

Also creating a standalone minimal example demonstrating the problem 
usually helps you detect where things have gone awry.

Jeff