Re: [boost] shared_ptr question

21 Jun 2005


      Martin Bonner wrote:
...
----Original Message----
From: H. van Niekerk [mailto:h.v.niekerk@hccnet.nl]
Sent: 20 June 2005 19:22
To: boost@lists.boost.org
Subject: [boost] shared_ptr question
...
Hi,
I'm rather new to shared_ptr and I'm not very experienced in
programmer 
with C++ but have to do it anyway.
My problem is this: I have 3 .cpp files, e.g. Master.cpp, Client.cpp
and Satellite.cpp.
Originally, Master.cpp is the only .cpp file, and uses auto_ptr to
enable writing and reading from an interface. Like this:
{
   ....
   auto_ptr<FtInterface> fti (ftGetIfFromFactory(device,
                                                     connection)); 
   fti->getIfInfo(ii);
   IfOutputs out; // to set interface outputs (ctor clears
                  // everything to 0) 
   IfInputs inp;  // to be read from interface
   fti->writeAndReadAllData(out, inp);
   ...
}
This works well with every action taking place in this file. Now, as
said I have those 3 .cpp files. Master.cpp sends an argument to
Client.cpp and Client.cpp sends it to Satellite.cpp. Satellite.cpp
reads 
from the interface, and sends it back via Client.cpp to Master.cpp. I
can't use auto_ptr with this and from the Boost-documentation I can't
figure out exactly how to use shared_ptr for this. Can somebody please
help me out?
I hope I explained my problem clear enough.
I'm afraid you didn't.  Could you write some sample (pseudo-) code just
using raw C pointers and not worrying about memory leaks?  Then we can
probably work out how to rewrite using smart pointers.
Incidentally, I don't think the presence of three .cpp files is directly
relevent.  I suspect that the relevent factor is that you have three
*functions*, and your problem is passing the data between them.
Thank you for your response. I hope the code below explains more:

Master.cpp
{
	Client c;
	c.readFromSatellite(input);
	cout << "input = " << input << endl;
}

Client.cpp
{
	Satellite s;

	readFromSatellite(input)
	{
		s.readFromInterface(input);
		return input;
	}
}

Satellite.cpp
{
	readFromInterface(input)
	{
		// Here the actual reading is done
		fti->writeAndReadAllData(output, input);
		return input;
	}
}