无法解除阻止boost asio受体

Question

I am trying to cancel a TCP acceptor by the programs keeps blocked in that line.

One thread waits for connections like this:

boost::system::error_code ec;
acceptor_ = new boost::asio::ip::tcp::acceptor(io_service_, boost::asio::ip::tcp::endpoint(boost::asio::ip::tcp::v4(), port));
acceptor_->accept(socket_, ec);  // socket_ is a boost::asio::ip::tcp:socket

The thread that must close the acceptor does:

boost::system::error_code ec;
acceptor_->close(ec);

Is there something I am missing? I am not using any async operation, so may I do something with the io_service object?

Answer 1

In short, you cannot cancel most of async operations using asio function and methods.

The problem is underlying accept , read etc are system calls. They cannot be interrupted using io_service::stop or cancel since accepting thread is blocked inside syscall, not asio event loop. They only can be interrupted by killing thread or sending a signal.

I'd prefer to make this acceptor asyncronous, so problem will gone. Also see this Q on SO about this