Does boost::shared_ptr close connection once destroyed?

Question

I have a small code snippet that uses Thrift for network communications.

int main() {
  while (true) {
    boost::shared_ptr<TTransport> socket(new TSocket("localhost", 9090));
    boost::shared_ptr<TTransport> transport(new TBufferedTransport(socket));
    boost::shared_ptr<TProtocol> protocol(new TBinaryProtocol(transport));

    CalculatorClient client(protocol);

    try {
      transport->open();

      client.ping();
      cout << "ping()" << endl;

      // following line is commented out intentionally
      //transport->close();
    } catch (TException& tx) {
      cout << "ERROR: " << tx.what() << endl;
    }
  }
}

My question is: Does boost::shared_ptr close connection once destroyed? If yes, then transport->close(); can be commented out without any problems, right?

Answer 1

Looking at the source, I don't see TTransport doing anything in its destructor. However, the destructor of TSocket (src), does call it's close() function.

Since the shared_ptr was created in the scope of your main function and no one else has asked for a pointer to the object in care of the shared_ptr, 'socket' will destruct after it goes out of scope.

TBufferedTransport does not appear to explictly declare a destructor, however, it does own a TSocket, which will got out of scope when TBufferedTransport destructs, thus the TSocket's destructor gets called.

TBufferedTransport::[rBuf_/wBuf_] are scoped_arrays so I don't think you need to worry about those either.