bad executor exception using a timeout in the client

[Ban44n]

Hi,

We are using boost beast in a high performance manner, i.e. we need to be able to communicate >1000 transactions per second per connection. For our application it is crucial to use a timeout on the stream which is provided by your library.

We encounter a critical exception when a client has a timeout policy enabled (which sends ping/pong messages by the beast library) and when we stress the async_write function (see example client below) by sending messages all the time. The bug results in an unhandled exception:

terminate called after throwing an instance of 'boost::wrapexcept<boost::asio::bad_executor>'
  what():  bad executor
Aborted (core dumped)

Stack trace:

__GI_raise(int sig) (/build/glibc-KRRWSm/glibc-2.29/sysdeps/unix/sysv/linux/raise.c:50)
__GI_abort() (/build/glibc-KRRWSm/glibc-2.29/stdlib/abort.c:79)
[Unknown/Just-In-Time compiled code] (Unknown Source:0)
std::terminate() (Unknown Source:0)
__cxa_throw (Unknown Source:0)
boost::throw_exception<boost::asio::bad_executor>(const boost::asio::bad_executor & e) (/usr/local/include/boost/throw_exception.hpp:70)
boost::asio::executor::get_impl(const boost::asio::executor * const this) (/usr/local/include/boost/asio/executor.hpp:309)
boost::asio::executor::post<boost::asio::detail::work_dispatcher<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor> >, std::allocator<void> >(const boost::asio::executor * const this, boost::asio::detail::work_dispatcher<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> > >::idle_ping_op<boost::asio::executor> > && f, const std::allocator<void> & a) (/usr/local/include/boost/asio/impl/executor.hpp:358)
boost::asio::detail::initiate_post::operator()<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor>, boost::asio::executor const&>(const boost::asio::detail::initiate_post * const this, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor> && handler, const boost::asio::executor & ex) (/usr/local/include/boost/asio/impl/post.hpp:54)
boost::asio::async_result<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor>, void ()>::initiate<boost::asio::detail::initiate_post, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor>, boost::asio::executor const&>(boost::asio::detail::initiate_post&&, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor>&&, boost::asio::executor const&)(boost::asio::detail::initiate_post && initiation, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor> && token,  args#0) (/usr/local/include/boost/asio/async_result.hpp:82)
boost::asio::async_initiate<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor>, void (), boost::asio::detail::initiate_post, boost::asio::executor const&>(boost::asio::detail::initiate_post&&, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor>&, boost::asio::executor const&)(boost::asio::detail::initiate_post && initiation, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor> & token,  args#0) (/usr/local/include/boost/asio/async_result.hpp:257)
boost::asio::post<boost::asio::executor, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor> >(const boost::asio::executor & ex, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor> && token) (/usr/local/include/boost/asio/impl/post.hpp:74)
boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor>::operator()(boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::executor, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::executor> * const this, boost::beast::error_code ec, std::size_t bytes_transferred) (/usr/local/include/boost/beast/websocket/impl/ping.hpp:179)
....

It seems that op_idle_ping implementation in the beast library cannot find the strand to execute the ping operation and an exception is raised (see websocket/impl/ping.hpp:179, I am not sure though). It is our belief that the library should function perfectly fine when the async_write function is properly stressed like our example.

Version of Beast

#define BOOST_BEAST_VERSION 248
(using boost 1_70_00)

Steps necessary to reproduce the problem

We have adjusted the client websocket async c++ example to reproduce the bug. Basically we added the timeout function with ping enabled and we keep on sending the message on the stream in a proper way.

//
// Copyright (c) 2016-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//

//------------------------------------------------------------------------------
//
// Example: WebSocket SSL client, asynchronous
//
//------------------------------------------------------------------------------

#include "certificates.hpp"

#include <boost/beast/core.hpp>
#include <boost/beast/ssl.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/beast/websocket/ssl.hpp>
#include <boost/asio/strand.hpp>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <memory>
#include <string>
#include <thread>

namespace beast = boost::beast;         // from <boost/beast.hpp>
namespace http = beast::http;           // from <boost/beast/http.hpp>
namespace websocket = beast::websocket; // from <boost/beast/websocket.hpp>
namespace net = boost::asio;            // from <boost/asio.hpp>
namespace ssl = boost::asio::ssl;       // from <boost/asio/ssl.hpp>
using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>

//------------------------------------------------------------------------------

// Report a failure
void fail(beast::error_code ec, char const *what)
{
  std::cerr << what << ": " << ec.message() << "\n";
}

// Sends a WebSocket message and prints the response
class session : public std::enable_shared_from_this<session>
{
  tcp::resolver resolver_;
  websocket::stream<
      beast::ssl_stream<beast::tcp_stream>>
      ws_;
  beast::flat_buffer buffer_;
  std::string host_;
  std::string text_;

public:
  // Resolver and socket require an io_context
  explicit session(net::io_context &ioc, ssl::context &ctx)
      : resolver_(net::make_strand(ioc)), ws_(net::make_strand(ioc), ctx)
  {
  }

  // Start the asynchronous operation
  void
  run(
      char const *host,
      char const *port,
      char const *text)
  {
    // Save these for later
    host_ = host;
    text_ = text;

    // Look up the domain name
    resolver_.async_resolve(
        host,
        port,
        beast::bind_front_handler(
            &session::on_resolve,
            shared_from_this()));
  }

  void
  on_resolve(
      beast::error_code ec,
      tcp::resolver::results_type results)
  {
    if (ec)
      return fail(ec, "resolve");

    // Set a timeout on the operation
    beast::get_lowest_layer(ws_).expires_after(std::chrono::seconds(30));

    // Make the connection on the IP address we get from a lookup
    beast::get_lowest_layer(ws_).async_connect(
        results,
        beast::bind_front_handler(
            &session::on_connect,
            shared_from_this()));
  }

  void
  on_connect(beast::error_code ec, tcp::resolver::results_type::endpoint_type)
  {
    if (ec)
      return fail(ec, "connect");

    // Set a timeout on the operation
    beast::get_lowest_layer(ws_).expires_after(std::chrono::seconds(30));

    // Perform the SSL handshake
    ws_.next_layer().async_handshake(
        ssl::stream_base::client,
        beast::bind_front_handler(
            &session::on_ssl_handshake,
            shared_from_this()));
  }

  void
  on_ssl_handshake(beast::error_code ec)
  {
    if (ec)
      return fail(ec, "ssl_handshake");

    // Turn off the timeout on the tcp_stream, because
    // the websocket stream has its own timeout system.
    beast::get_lowest_layer(ws_).expires_never();

    // Set timeout
    auto timeout = 3;
    beast::websocket::stream_base::timeout opt{
        std::chrono::seconds(timeout), // close timeout
        std::chrono::seconds(timeout), // idle timeout
        true};                         // pings enabled (results in weird bug)
    ws_.set_option(opt);

    // Perform the websocket handshake
    ws_.async_handshake(host_, "/",
                        beast::bind_front_handler(
                            &session::on_handshake,
                            shared_from_this()));
  }

  void
  on_handshake(beast::error_code ec)
  {
    if (ec)
      return fail(ec, "handshake");

    // Start writing to the stream
    ws_.async_write(
        net::buffer(text_),
        beast::bind_front_handler(
            &session::on_write,
            shared_from_this()));

    // Start reading from the stream
    ws_.async_read(
        buffer_,
        beast::bind_front_handler(
            &session::on_read,
            shared_from_this()));
  }

  void
  on_write(
      beast::error_code ec,
      std::size_t bytes_transferred)
  {
    boost::ignore_unused(bytes_transferred);

    if (ec)
      return fail(ec, "write");

    // Write again
    ws_.async_write(
        net::buffer(text_),
        beast::bind_front_handler(
            &session::on_write,
            shared_from_this()));
  }

  void
  on_read(
      beast::error_code ec,
      std::size_t bytes_transferred)
  {
    boost::ignore_unused(bytes_transferred);

    if (ec)
      return fail(ec, "read");

    // Clear buffer
    buffer_.clear();

    // Read again
    ws_.async_read(
        buffer_,
        beast::bind_front_handler(
            &session::on_read,
            shared_from_this()));
  }
};

//------------------------------------------------------------------------------

int main(int argc, char **argv)
{
  // Check command line arguments.
  if (argc != 4)
  {
    std::cerr << "Usage: websocket-client-async-ssl <host> <port> <text>\n"
              << "Example:\n"
              << "    websocket-client-async-ssl echo.websocket.org 443 \"Hello, world!\"\n";
    return EXIT_FAILURE;
  }
  auto const host = argv[1];
  auto const port = argv[2];
  auto const text = argv[3];

  // The io_context is required for all I/O
  boost::asio::io_context ioc;

  // The SSL context is required, and holds certificates
  ssl::context ctx{ssl::context::tlsv13};

  // Launch the asynchronous operation

  std::make_shared<session>(ioc, ctx)->run(host, port, text);

  ioc.run();

  return EXIT_SUCCESS;
}

All relevant compiler information

We are using ubuntu 19.04 and gnu compiler

g++ (Ubuntu 8.3.0-6ubuntu1) 8.3.0

The server can be anything, a quick running server in nodejs is for example (using the certificate and key of your example directory):

const WebSocket = require('ws');
const fs = require('fs');
const https = require('https');

let cert = `-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----`;

let key = `-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----`;

const server = https.createServer({
  key: key,
  cert: cert
});
const wss = new WebSocket.Server({ server });


wss.on('connection', function connection(ws) {
  ws.on('ping', () => {
    console.log('received ping');
  });
  ws.on('pong', () => {
    console.log('received pong');
  });
  ws.on('message', function incoming(message) {
    console.log('received: %s', message);
  });
});

// Start listen
server.listen(8080);

[vinniefalco]

Thank you for the detailed report. Moved-from executors are supposed to still be usable (according to boostorg/asio@e830f97) but it seems that a moved-from polymorphic executor is no longer usable:

https://github.com/boostorg/asio/blob/db6423c9b1bd5c5ff4f7ea391446c7ac593ce549/include/boost/asio/executor.hpp#L70

If possible, please try doing both of these things:

1. Change your copy of the asio source code for net::executor to perform a copy instead of a move on a move-construction. I think you can just delete or comment out the move constructor to achieve this. Then run the program to determine if the issue is still present (I suspect it won't be).

2. Change your code to use a strand instead of the polymorphic executor on the websocket stream, by changing your declaration to:

websocket::stream<beast::ssl_stream<beast::basic_stream<
    net::ip::tcp, net::strand<net::io_context::executor_type>>>>ws_;

Then run the program to determine if the issue is still present (I suspect it won't be).

I believe that either of these changes will resolve your issue. The information provided by attempting these changes will help support our case for a bug in asio.

[Ban44n]

Thanks for your quick reply!

I have commented out the move-constructor of net::executor inside my boost files, it seems to be working as I haven't received any error when running for 5 minutes. Did you already submit a bug report to asio?

Your second suggestion has my preference, since this is a fix in my own code instead of inside the boost asio header files. I do not always have write access to these files. Unfortunately when I change the stream template to use the strand executor as you suggest, it leads to a segfault (there is no segfault when the ping feature is disabled):

boost::asio::detail::strand_executor_service::enqueue(const boost::asio::detail::strand_executor_service::implementation_type & impl, boost::asio::detail::scheduler_operation * op) (/usr/local/include/boost/asio/detail/impl/strand_executor_service.ipp:99)
boost::asio::detail::strand_executor_service::post<boost::asio::io_context::executor_type const, boost::asio::detail::work_dispatcher<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > >, std::allocator<void> >(const boost::asio::detail::strand_executor_service::implementation_type & impl, const boost::asio::io_context::executor_type & ex, boost::asio::detail::work_dispatcher<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > > && function, const std::allocator<void> & a) (/usr/local/include/boost/asio/detail/impl/strand_executor_service.hpp:147)
boost::asio::strand<boost::asio::io_context::executor_type>::post<boost::asio::detail::work_dispatcher<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > >, std::allocator<void> >(const boost::asio::strand<boost::asio::io_context::executor_type> * const this, boost::asio::detail::work_dispatcher<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > > && f, const std::allocator<void> & a) (/usr/local/include/boost/asio/strand.hpp:213)
boost::asio::detail::initiate_post::operator()<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >, boost::asio::strand<boost::asio::io_context::executor_type> const&>(const boost::asio::detail::initiate_post * const this, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > && handler, const boost::asio::strand<boost::asio::io_context::executor_type> & ex) (/usr/local/include/boost/asio/impl/post.hpp:54)
boost::asio::async_result<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >, void ()>::initiate<boost::asio::detail::initiate_post, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >, boost::asio::strand<boost::asio::io_context::executor_type> const&>(boost::asio::detail::initiate_post&&, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >&&, boost::asio::strand<boost::asio::io_context::executor_type> const&)(boost::asio::detail::initiate_post && initiation, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > && token,  args#0) (/usr/local/include/boost/asio/async_result.hpp:82)
boost::asio::async_initiate<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >, void (), boost::asio::detail::initiate_post, boost::asio::strand<boost::asio::io_context::executor_type> const&>(boost::asio::detail::initiate_post&&, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >&, boost::asio::strand<boost::asio::io_context::executor_type> const&)(boost::asio::detail::initiate_post && initiation, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > & token,  args#0) (/usr/local/include/boost/asio/async_result.hpp:257)
boost::asio::post<boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > >(const boost::asio::strand<boost::asio::io_context::executor_type> & ex, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > && token) (/usr/local/include/boost/asio/impl/post.hpp:74)
boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >::operator()(boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> > * const this, boost::beast::error_code ec, std::size_t bytes_transferred) (/usr/local/include/boost/beast/websocket/impl/ping.hpp:179)
boost::beast::saved_handler::impl<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >, std::allocator<void> >::invoke(boost::beast::saved_handler::impl<boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::idle_ping_op<boost::asio::strand<boost::asio::io_context::executor_type> >, std::allocator<void> > * const this) (/usr/local/include/boost/beast/core/impl/saved_handler.hpp:91)
boost::beast::saved_handler::maybe_invoke(boost::beast::saved_handler * const this) (/usr/local/include/boost/beast/core/impl/saved_handler.ipp:69)
boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1>::operator()(boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> * const this, boost::beast::error_code ec, std::size_t bytes_transferred, bool cont) (/usr/local/include/boost/beast/websocket/impl/write.hpp:429)
boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> >::operator()(boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > * const this, const boost::system::error_code & ec, std::size_t bytes_transferred, int start) (/usr/local/include/boost/asio/impl/write.hpp:338)
boost::beast::async_base<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> >, boost::asio::strand<boost::asio::io_context::executor_type>, std::allocator<void> >::complete_now<boost::system::error_code&, unsigned long&>(boost::beast::async_base<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> >, boost::asio::strand<boost::asio::io_context::executor_type>, std::allocator<void> > * const this,  args#0,  args#1) (/usr/local/include/boost/beast/core/async_base.hpp:377)
boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > >::operator()(boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > * const this, boost::system::error_code ec, std::size_t bytes_transferred) (/usr/local/include/boost/beast/core/impl/flat_stream.hpp:74)
boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>::call_handler<boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > >(const boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer> * const this, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > & handler, const boost::system::error_code & ec, const std::size_t & bytes_transferred) (/usr/local/include/boost/asio/ssl/detail/write_op.hpp:55)
boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > >::operator()(boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > * const this, boost::system::error_code ec, std::size_t bytes_transferred, int start) (/usr/local/include/boost/asio/ssl/detail/io.hpp:271)
boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > >::operator()(boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > > * const this, const boost::system::error_code & ec, std::size_t bytes_transferred, int start) (/usr/local/include/boost/asio/impl/write.hpp:338)
boost::beast::async_base<boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > >, boost::asio::strand<boost::asio::io_context::executor_type>, std::allocator<void> >::complete_now<boost::system::error_code&, unsigned long&>(boost::beast::async_base<boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > >, boost::asio::strand<boost::asio::io_context::executor_type>, std::allocator<void> > * const this,  args#0,  args#1) (/usr/local/include/boost/beast/core/async_base.hpp:377)
boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>::ops::transfer_op<false, boost::asio::const_buffers_1, boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > > >::operator()(boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>::ops::transfer_op<false, boost::asio::const_buffers_1, boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > > > * const this, boost::beast::error_code ec, std::size_t bytes_transferred) (/usr/local/include/boost/beast/core/impl/basic_stream.hpp:400)
boost::asio::detail::binder2<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>::ops::transfer_op<false, boost::asio::const_buffers_1, boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, true>::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > > >, boost::system::error_code, unsigned long>::operator()(boost::asio::detail::binder2<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> >::ops::transfer_op<false, boost::asio::const_buffers_1, boost::asio::detail::write_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::mutable_buffer, boost::asio::mutable_buffer const*, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy>, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffer>, boost::beast::flat_stream<boost::asio::ssl::stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::ops::write_op<boost::asio::detail::write_op<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type>, boost::beast::unlimited_rate_policy> >, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>, boost::beast::buffers_cat_view<boost::asio::mutable_buffer, boost::asio::mutable_buffers_1>::const_iterator, boost::asio::detail::transfer_all_t, boost::beast::websocket::stream<boost::beast::ssl_stream<boost::beast::basic_stream<boost::asio::ip::tcp, boost::asio::strand<boost::asio::io_context::executor_type> > > >::write_some_op<boost::beast::detail::bind_front_wrapper<void (session::*)(boost::system::error_code, unsigned long), std::shared_ptr<session> >, boost::asio::mutable_buffers_1> > > > > >, boost::system::error_code, unsigned long> * const this) (/usr/local/include/boost/asio/detail/bind_handler.hpp:164)
...

The stack trace shows that again the segfault is produced by the same ping code (ping.hpp:179) that tries to queue something on the strand.

[vinniefalco]

Your second suggestion has my preference

Yes of course, but the temporary change to asio has produced useful data :) I am investigating...

[djarek]

I'm having trouble reproducing this issue in 19.04, tip of develop, using websocket-server-async-ssl as the server and your snippet as the client. Tried both debug and release builds with no luck. Any hints?

[vinniefalco]

@Ban44n Questions:

1. are you using the exact 1.70 distribution?
2. what compiler flags are you using (e.g. optimization level)
3. what are the command line parameters used to launch the client

Thanks

[stenreijers]

@vinniefalco

1. are you using the exact 1.70 distribution?

Yes, boost version.hpp says:
#define BOOST_VERSION 107000
#define BOOST_LIB_VERSION "1_70"

2. what compiler flags are you using (e.g. optimization level)

No special flags:
g++ test.cpp -lpthread -lcrypto -lssl

or for debugging:
g++ test.cpp -lpthread -lcrypto -lssl -g

We are using:
Ubuntu:
Distributor ID: Ubuntu
Description: Ubuntu 19.04
Release: 19.04
Codename: disco
g++ (Ubuntu 8.3.0-6ubuntu1) 8.3.0

3. what are the command line parameters used to launch the client

./client localhost 8080 "test"

@djarek Indeed it does not throw the exception when using the websocket-async-server example out of the box for some unknown reason. We do however randomly see this exception happening in our own beast server implementation. In this implementation, we have used limits on the stream like the simple ratelimiter and we have set a timeout policy. I will try to isolate what parameters in our server code server trigger this bahaviour.

If you want to see the bug directly happening, try use the nodejs example that I passed. This uses a widely used websocket implementation that also obeys the spec and passes all autobahn tests. I have just run this on another machine and it directly throws the error on the client.

Like I said, we do also see it happening with the beast server implementation but we have used many flags on the stream. I will investigate and report back.

[stenreijers]

@djarek @vinniefalco

I found out why the async-server example does not reproduce the exception on the client side: the server example echos all messages directly back to the client and therefore the idle_timeout timer on the client never triggers. The error can be easily reproduced by putting the server-example in read-only mode.

The full async server example code that allows to reproduce the bug on the client is

//
// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//

//------------------------------------------------------------------------------
//
// Example: WebSocket SSL server, asynchronous
//
//------------------------------------------------------------------------------

#include "server_certificate.hpp"

#include <boost/beast/core.hpp>
#include <boost/beast/ssl.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/beast/websocket/ssl.hpp>
#include <boost/asio/strand.hpp>
#include <algorithm>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <memory>
#include <string>
#include <thread>
#include <vector>

namespace beast = boost::beast;         // from <boost/beast.hpp>
namespace http = beast::http;           // from <boost/beast/http.hpp>
namespace websocket = beast::websocket; // from <boost/beast/websocket.hpp>
namespace net = boost::asio;            // from <boost/asio.hpp>
namespace ssl = boost::asio::ssl;       // from <boost/asio/ssl.hpp>
using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>

//------------------------------------------------------------------------------

// Report a failure
void fail(beast::error_code ec, char const *what)
{
  std::cerr << what << ": " << ec.message() << "\n";
}

// Echoes back all received WebSocket messages
class session : public std::enable_shared_from_this<session>
{
  websocket::stream<
      beast::ssl_stream<beast::tcp_stream>>
      ws_;
  beast::flat_buffer buffer_;

public:
  // Take ownership of the socket
  session(tcp::socket &&socket, ssl::context &ctx)
      : ws_(std::move(socket), ctx)
  {
  }

  // Start the asynchronous operation
  void
  run()
  {
    // Set the timeout.
    beast::get_lowest_layer(ws_).expires_after(std::chrono::seconds(30));

    // Perform the SSL handshake
    ws_.next_layer().async_handshake(
        ssl::stream_base::server,
        beast::bind_front_handler(
            &session::on_handshake,
            shared_from_this()));
  }

  void
  on_handshake(beast::error_code ec)
  {
    if (ec)
      return fail(ec, "handshake");

    // Turn off the timeout on the tcp_stream, because
    // the websocket stream has its own timeout system.
    beast::get_lowest_layer(ws_).expires_never();

    // Set suggested timeout settings for the websocket
    ws_.set_option(
        websocket::stream_base::timeout::suggested(
            beast::role_type::server));

    // Set a decorator to change the Server of the handshake
    ws_.set_option(websocket::stream_base::decorator(
        [](websocket::response_type &res) {
          res.set(http::field::server,
                  std::string(BOOST_BEAST_VERSION_STRING) +
                      " websocket-server-async-ssl");
        }));

    // Accept the websocket handshake
    ws_.async_accept(
        beast::bind_front_handler(
            &session::on_accept,
            shared_from_this()));
  }

  void
  on_accept(beast::error_code ec)
  {
    if (ec)
      return fail(ec, "accept");

    // Read a message
    do_read();
  }

  void
  do_read()
  {
    // Read a message into our buffer
    ws_.async_read(
        buffer_,
        beast::bind_front_handler(
            &session::on_read,
            shared_from_this()));
  }

  void
  on_read(
      beast::error_code ec,
      std::size_t bytes_transferred)
  {
    boost::ignore_unused(bytes_transferred);

    // This indicates that the session was closed
    if (ec == websocket::error::closed)
      return;

    if (ec)
      return fail(ec, "read");

    // Clear the buffer
    buffer_.consume(buffer_.size());

    // Read again
    return do_read();
  }
};

//------------------------------------------------------------------------------

// Accepts incoming connections and launches the sessions
class listener : public std::enable_shared_from_this<listener>
{
  net::io_context &ioc_;
  ssl::context &ctx_;
  tcp::acceptor acceptor_;

public:
  listener(
      net::io_context &ioc,
      ssl::context &ctx,
      tcp::endpoint endpoint)
      : ioc_(ioc), ctx_(ctx), acceptor_(net::make_strand(ioc))
  {
    beast::error_code ec;

    // Open the acceptor
    acceptor_.open(endpoint.protocol(), ec);
    if (ec)
    {
      fail(ec, "open");
      return;
    }

    // Allow address reuse
    acceptor_.set_option(net::socket_base::reuse_address(true), ec);
    if (ec)
    {
      fail(ec, "set_option");
      return;
    }

    // Bind to the server address
    acceptor_.bind(endpoint, ec);
    if (ec)
    {
      fail(ec, "bind");
      return;
    }

    // Start listening for connections
    acceptor_.listen(
        net::socket_base::max_listen_connections, ec);
    if (ec)
    {
      fail(ec, "listen");
      return;
    }
  }

  // Start accepting incoming connections
  void
  run()
  {
    do_accept();
  }

private:
  void
  do_accept()
  {
    // The new connection gets its own strand
    acceptor_.async_accept(
        net::make_strand(ioc_),
        beast::bind_front_handler(
            &listener::on_accept,
            shared_from_this()));
  }

  void
  on_accept(beast::error_code ec, tcp::socket socket)
  {
    if (ec)
    {
      fail(ec, "accept");
    }
    else
    {
      // Create the session and run it
      std::make_shared<session>(std::move(socket), ctx_)->run();
    }

    // Accept another connection
    do_accept();
  }
};

//------------------------------------------------------------------------------

int main(int argc, char *argv[])
{
  // Check command line arguments.
  if (argc != 4)
  {
    std::cerr << "Usage: websocket-server-async-ssl <address> <port> <threads>\n"
              << "Example:\n"
              << "    websocket-server-async-ssl 0.0.0.0 8080 1\n";
    return EXIT_FAILURE;
  }
  auto const address = net::ip::make_address(argv[1]);
  auto const port = static_cast<unsigned short>(std::atoi(argv[2]));
  auto const threads = std::max<int>(1, std::atoi(argv[3]));

  // The io_context is required for all I/O
  net::io_context ioc{threads};

  // The SSL context is required, and holds certificates
  ssl::context ctx{ssl::context::tlsv13};

  // This holds the self-signed certificate used by the server
  load_server_certificate(ctx);

  // Create and launch a listening port
  std::make_shared<listener>(ioc, ctx, tcp::endpoint{address, port})->run();

  // Run the I/O service on the requested number of threads
  std::vector<std::thread> v;
  v.reserve(threads - 1);
  for (auto i = threads - 1; i > 0; --i)
    v.emplace_back(
        [&ioc] {
          ioc.run();
        });
  ioc.run();

  return EXIT_SUCCESS;
}

[djarek]

The issue is here: https://github.com/boostorg/beast/blob/develop/include/boost/beast/websocket/impl/ping.hpp#L179
this->get() should be get_executor() instead, because this->get() returns a reference to an executor in this which is moved-from in post().

[vinniefalco]

I believe that version 248-hf1 fixes it, please try it if possible. We added a unit test which reproduces the problem exactly. Thank you for your very detailed report which made this easy to track down and fix!
https://github.com/vinniefalco/beast/tree/v248-hf1