boost::asio::io_service.post() background thread memory usage

I want to run boost::asio::io_service.run() in a background thread. So when I need it post() func into. This is main func: int main(int /*argc*/, char** /*argv*/) { std::string message = "hello"; logg = new logger_client(filename,ip,13666); logg->start(); while (true) logg->add_string(message); return 0; } And some relevant funcs from logger_client: std::auto_ptr<boost::asio::io_service::work> work; logger_client::logger_client(std::string& filename,std::string& ip, uint16_t port) : work(new boost::asio::io_service::work(io_service)) { } void logger_client::start() { ios_thread = new boost::thread(boost::bind(&io_service.run,&io_service)); } void print_nothing() { printf("%sn","lie"); } void logger_client::add_string(std::string& message) { io_service.post(boost::bind(print_nothing)); //io_service.post(strand->wrap(boost::bind(&logger_client::add_string_imp,this,message))); //io_service.run(); } When i run this, my program eats 2Gb less than a minute. If i remove endless work and change to this: void logger_client::add_string(std::string& message) { io_service.post(boost::bind(print_nothing)); //io_service.post(strand->wrap(boost::bind(&logger_client::add_string_imp,this,message))); io_service.run(); } Program works just fine. But I don't want to invoke async operations on this (main) thread. What am i doing wrong? UPDATE I added sleep(1sec) in while(true) loop and memory is no longer growing. But this is not a solution. Because if I call run() after post() (i.e. use main thread for processing handles) and even add five more threads with while(true) loops memory is not growing. So why main thread is so much better than newly created? I also tried thread pool for io_service::run - did not help.