QTcpSocket - memory allocation problem

[dreac]

Thanks, but ... sorry, I don't get it. I can't see anything wrong with this. Could you please point out what's causing a memory leak here?

This is executed every time a client calls connectToHost(). Thus if only 1 client connects, then I will get only 1 instance of serversocket. The socket descriptor is passed to the tcp socket who then emits the signal readyRead() whenever data is coming in. The signal is connected to my method readBlockData() which reads the data from the stream, and thus should free the buffer.

I set a breakpoint at these lines to check how often a ServerSocket is instantiated, and it was only once as expected.

Or did I miss anything else here.

[tbscope]

ServerSocket *socket = new ServerSocket(this);

ServerSocket *socket = new ServerSocket(this);

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This creates a local variable called socket which points to a memory location.

Two important facts:
1. local means that the variable will be deleted at the end of the scope, in this case the } bracket of the function.
2. Since it is a pointer, the memory allocated will not be freed at the end of the scope.

This has a consequence:
The allocated memory still exists, but you can't access it anymore (the socket variable).

What you need to do:
Manage all your pointers.
If there isn't a parent/child relationship where the parent frees all the child allocations, or in the case the lifetime of the parent is too long (as in the parent exists for the duration the program is being run), then you need to explicitly free the resources yourself.

Thus:
In your case, just before the scope of the function ends, you should delete the memory allocated. This, of course, will make your program not work anymore like you expect it.

Thus:
You should really define your pointers at class level so they are accessible everywhere in the class for the lifetime of an object based on that class.