Fixes to support Asio changes (API Change):

This adjusts Beast's interfaces and implementation to match
the changes in Boost.Asio.

example/websocket/server/async-ssl/websocket_server_async_ssl.cpp

@@ -48,13 +48,13 @@ fail(beast::error_code ec, char const* what)
 // Echoes back all received WebSocket messages
 class session : public std::enable_shared_from_this<session>
 {
-    websocket::stream<beast::ssl_stream<
-        beast::tcp_stream<net::io_context::strand>>> ws_;
+    websocket::stream<
+        beast::ssl_stream<beast::tcp_stream>> ws_;
     beast::multi_buffer buffer_;
 
 public:
     // Take ownership of the socket
-    session(tcp::socket socket, ssl::context& ctx)
+    session(tcp::socket&& socket, ssl::context& ctx)
         : ws_(std::move(socket), ctx)
     {
     }
@@ -172,16 +172,20 @@ public:
 // 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_;
+    tcp::socket socket_;
 
 public:
     listener(
         net::io_context& ioc,
         ssl::context& ctx,
         tcp::endpoint endpoint)
-        : ctx_(ctx)
-        , acceptor_(ioc)
+        : ioc_(ioc)
+        , ctx_(ctx)
+        , acceptor_(beast::make_strand(ioc))
+        , socket_(beast::make_strand(ioc))
     {
         beast::error_code ec;
 
@@ -232,13 +236,14 @@ public:
     do_accept()
     {
         acceptor_.async_accept(
+            socket_,
             beast::bind_front_handler(
                 &listener::on_accept,
                 shared_from_this()));
     }
 
     void
-    on_accept(beast::error_code ec, tcp::socket socket)
+    on_accept(beast::error_code ec)
     {
         if(ec)
         {
@@ -247,9 +252,12 @@ public:
         else
         {
             // Create the session and run it
-            std::make_shared<session>(std::move(socket), ctx_)->run();
+            std::make_shared<session>(std::move(socket_), ctx_)->run();
         }
 
+        // Make sure each session gets its own strand
+        socket_ = tcp::socket(beast::make_strand(ioc_));
+
         // Accept another connection
         do_accept();
     }

example/websocket/server/async/websocket_server_async.cpp

@@ -43,13 +43,13 @@ fail(beast::error_code ec, char const* what)
 // Echoes back all received WebSocket messages
 class session : public std::enable_shared_from_this<session>
 {
-    websocket::stream<beast::tcp_stream<net::io_context::strand>> ws_;
+    websocket::stream<beast::tcp_stream> ws_;
     beast::multi_buffer buffer_;
 
 public:
     // Take ownership of the socket
     explicit
-    session(tcp::socket socket)
+    session(tcp::socket&& socket)
         : ws_(std::move(socket))
     {
     }
@@ -146,13 +146,17 @@ public:
 // Accepts incoming connections and launches the sessions
 class listener : public std::enable_shared_from_this<listener>
 {
+    net::io_context& ioc_;
     tcp::acceptor acceptor_;
+    tcp::socket socket_;
 
 public:
     listener(
         net::io_context& ioc,
         tcp::endpoint endpoint)
-        : acceptor_(ioc)
+        : ioc_(ioc)
+        , acceptor_(ioc)
+        , socket_(beast::make_strand(ioc_))
     {
         beast::error_code ec;
 
@@ -203,13 +207,14 @@ public:
     do_accept()
     {
         acceptor_.async_accept(
+            socket_,
             beast::bind_front_handler(
                 &listener::on_accept,
                 shared_from_this()));
     }
 
     void
-    on_accept(beast::error_code ec, tcp::socket socket)
+    on_accept(beast::error_code ec)
     {
         if(ec)
         {
@@ -218,9 +223,12 @@ public:
         else
         {
             // Create the session and run it
-            std::make_shared<session>(std::move(socket))->run();
+            std::make_shared<session>(std::move(socket_))->run();
         }
 
+        // Make sure each session gets its own strand
+        socket_ = tcp::socket(beast::make_strand(ioc_));
+
         // Accept another connection
         do_accept();
     }

example/websocket/server/chat-multi/http_session.hpp

@@ -21,7 +21,7 @@
 */
 class http_session : public boost::enable_shared_from_this<http_session>
 {
-    beast::tcp_stream<net::io_context::strand> stream_;
+    beast::tcp_stream stream_;
     beast::flat_buffer buffer_;
     boost::shared_ptr<shared_state> state_;
     http::request<http::string_body> req_;

example/websocket/server/chat-multi/listener.cpp

@@ -16,7 +16,9 @@ listener(
     net::io_context& ioc,
     tcp::endpoint endpoint,
     boost::shared_ptr<shared_state> const& state)
-    : acceptor_(ioc)
+    : ioc_(ioc)
+    , acceptor_(ioc)
+    , socket_(beast::make_strand(ioc))
     , state_(state)
 {
     beast::error_code ec;
@@ -61,6 +63,7 @@ run()
 {
     // Start accepting a connection
     acceptor_.async_accept(
+        socket_,
         beast::bind_front_handler(
             &listener::on_accept,
             shared_from_this()));
@@ -80,18 +83,22 @@ fail(beast::error_code ec, char const* what)
 // Handle a connection
 void
 listener::
-on_accept(beast::error_code ec, tcp::socket socket)
+on_accept(beast::error_code ec)
 {
     if(ec)
         return fail(ec, "accept");
     else
         // Launch a new session for this connection
         boost::make_shared<http_session>(
-            std::move(socket),
+            std::move(socket_),
             state_)->run();
 
+    // Make sure each session gets its own strand
+    socket_ = tcp::socket(beast::make_strand(ioc_));
+
     // Accept another connection
     acceptor_.async_accept(
+        socket_,
         beast::bind_front_handler(
             &listener::on_accept,
             shared_from_this()));

example/websocket/server/chat-multi/listener.hpp

@@ -22,11 +22,13 @@ class shared_state;
 // Accepts incoming connections and launches the sessions
 class listener : public boost::enable_shared_from_this<listener>
 {
+    net::io_context& ioc_;
     tcp::acceptor acceptor_;
+    tcp::socket socket_;
     boost::shared_ptr<shared_state> state_;
 
     void fail(beast::error_code ec, char const* what);
-    void on_accept(beast::error_code ec, tcp::socket socket);
+    void on_accept(beast::error_code ec);
 
 public:
     listener(

example/websocket/server/chat-multi/websocket_session.cpp

@@ -83,17 +83,22 @@ void
 websocket_session::
 send(boost::shared_ptr<std::string const> const& ss)
 {
-    // Get on the strand if we aren't already,
-    // otherwise we will concurrently access
-    // objects which are not thread-safe.
-    if(! ws_.get_executor().running_in_this_thread())
-        return net::post(
-            ws_.get_executor(),
-            beast::bind_front_handler(
-                &websocket_session::send,
-                shared_from_this(),
-                ss));
+    // Post our work to the strand, this ensures
+    // that the members of `this` will not be
+    // accessed concurrently.
 
+    net::post(
+        ws_.get_executor(),
+        beast::bind_front_handler(
+            &websocket_session::on_send,
+            shared_from_this(),
+            ss));
+}
+
+void
+websocket_session::
+on_send(boost::shared_ptr<std::string const> const& ss)
+{
     // Always add to queue
     queue_.push_back(ss);
 

example/websocket/server/chat-multi/websocket_session.hpp

@@ -27,7 +27,7 @@ class shared_state;
 class websocket_session : public boost::enable_shared_from_this<websocket_session>
 {
     beast::flat_buffer buffer_;
-    websocket::stream<beast::tcp_stream<net::io_context::strand>> ws_;
+    websocket::stream<beast::tcp_stream> ws_;
     boost::shared_ptr<shared_state> state_;
     std::vector<boost::shared_ptr<std::string const>> queue_;
 
@@ -50,6 +50,10 @@ public:
     // Send a message
     void
     send(boost::shared_ptr<std::string const> const& ss);
+
+private:
+    void
+    on_send(boost::shared_ptr<std::string const> const& ss);
 };
 
 template<class Body, class Allocator>

example/websocket/server/coro-ssl/websocket_server_coro_ssl.cpp

@@ -38,11 +38,6 @@ using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>
 
 //------------------------------------------------------------------------------
 
-// The type of websocket stream to use
-// Stackful coroutines are already stranded.
-using ws_type = websocket::stream<beast::ssl_stream<
-    beast::tcp_stream<net::io_context::executor_type>>>;
-
 // Report a failure
 void
 fail(beast::error_code ec, char const* what)
@@ -53,7 +48,8 @@ fail(beast::error_code ec, char const* what)
 // Echoes back all received WebSocket messages
 void
 do_session(
-    ws_type& ws,
+    websocket::stream<
+        beast::ssl_stream<beast::tcp_stream>>& ws,
     net::yield_context yield)
 {
     beast::error_code ec;
@@ -153,10 +149,11 @@ do_listen(
             fail(ec, "accept");
         else
             net::spawn(
-                acceptor.get_executor().context(),
+                acceptor.get_executor(),
                 std::bind(
                     &do_session,
-                    ws_type(std::move(socket), ctx),
+                    websocket::stream<beast::ssl_stream<
+                        beast::tcp_stream>>(std::move(socket), ctx),
                     std::placeholders::_1));
     }
 }

example/websocket/server/coro/websocket_server_coro.cpp

@@ -33,11 +33,6 @@ using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>
 
 //------------------------------------------------------------------------------
 
-// The type of websocket stream to use
-// Stackful coroutines are already stranded.
-using ws_type = websocket::stream<
-    beast::tcp_stream<net::io_context::executor_type>>;
-
 // Report a failure
 void
 fail(beast::error_code ec, char const* what)
@@ -47,7 +42,9 @@ fail(beast::error_code ec, char const* what)
 
 // Echoes back all received WebSocket messages
 void
-do_session(ws_type& ws, net::yield_context yield)
+do_session(
+    websocket::stream<beast::tcp_stream>& ws,
+    net::yield_context yield)
 {
     beast::error_code ec;
 
@@ -133,10 +130,11 @@ do_listen(
             fail(ec, "accept");
         else
             net::spawn(
-                acceptor.get_executor().context(),
+                acceptor.get_executor(),
                 std::bind(
                     &do_session,
-                    ws_type(std::move(socket)),
+                    websocket::stream<
+                        beast::tcp_stream>(std::move(socket)),
                     std::placeholders::_1));
     }
 }
@@ -157,7 +155,7 @@ int main(int argc, char* argv[])
     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};
+    net::io_context ioc(threads);
 
     // Spawn a listening port
     net::spawn(ioc,

example/websocket/server/fast/websocket_server_fast.cpp

@@ -78,13 +78,8 @@ setup_stream(websocket::stream<NextLayer>& ws)
 
 //------------------------------------------------------------------------------
 
-// The type of websocket stream to use
-// Stackful coroutines are already stranded.
-using ws_type = websocket::stream<
-    beast::tcp_stream<net::io_context::executor_type>>;
-
 void
-do_sync_session(ws_type& ws)
+do_sync_session(websocket::stream<beast::tcp_stream>& ws)
 {
     beast::error_code ec;
 
@@ -135,7 +130,8 @@ do_sync_listen(
 
         std::thread(std::bind(
             &do_sync_session,
-            ws_type(std::move(socket)))).detach();
+            websocket::stream<beast::tcp_stream>(
+                std::move(socket)))).detach();
     }
 }
 
@@ -144,13 +140,13 @@ do_sync_listen(
 // Echoes back all received WebSocket messages
 class async_session : public std::enable_shared_from_this<async_session>
 {
-    websocket::stream<beast::tcp_stream<net::io_context::strand>> ws_;
+    websocket::stream<beast::tcp_stream> ws_;
     beast::multi_buffer buffer_;
 
 public:
     // Take ownership of the socket
     explicit
-    async_session(tcp::socket socket)
+    async_session(tcp::socket&& socket)
         : ws_(std::move(socket))
     {
         setup_stream(ws_);
@@ -160,6 +156,11 @@ public:
     void
     run()
     {
+        // Set suggested timeout settings for the websocket
+        ws_.set_option(
+            websocket::stream_base::suggested_settings(
+                websocket::role_type::server));
+
         // Set a decorator to change the Server of the handshake
         ws_.set_option(websocket::stream_base::decorator(
             [](websocket::response_type& res)
@@ -240,13 +241,17 @@ public:
 // Accepts incoming connections and launches the sessions
 class async_listener : public std::enable_shared_from_this<async_listener>
 {
+    net::io_context& ioc_;
     tcp::acceptor acceptor_;
+    tcp::socket socket_;
 
 public:
     async_listener(
         net::io_context& ioc,
         tcp::endpoint endpoint)
-        : acceptor_(ioc)
+        : ioc_(ioc)
+        , acceptor_(beast::make_strand(ioc))
+        , socket_(beast::make_strand(ioc))
     {
         beast::error_code ec;
 
@@ -297,13 +302,14 @@ public:
     do_accept()
     {
         acceptor_.async_accept(
+            socket_,
             beast::bind_front_handler(
                 &async_listener::on_accept,
                 shared_from_this()));
     }
 
     void
-    on_accept(beast::error_code ec, tcp::socket socket)
+    on_accept(beast::error_code ec)
     {
         if(ec)
         {
@@ -312,9 +318,12 @@ public:
         else
         {
             // Create the async_session and run it
-            std::make_shared<async_session>(std::move(socket))->run();
+            std::make_shared<async_session>(std::move(socket_))->run();
         }
 
+        // Make sure each session gets its own strand
+        socket_ = tcp::socket(beast::make_strand(ioc_));
+
         // Accept another connection
         do_accept();
     }
@@ -323,12 +332,19 @@ public:
 //------------------------------------------------------------------------------
 
 void
-do_coro_session(ws_type& ws, net::yield_context yield)
+do_coro_session(
+    websocket::stream<beast::tcp_stream>& ws,
+    net::yield_context yield)
 {
     beast::error_code ec;
 
     setup_stream(ws);
 
+    // Set suggested timeout settings for the websocket
+    ws.set_option(
+        websocket::stream_base::suggested_settings(
+            websocket::role_type::server));
+
     // Set a decorator to change the Server of the handshake
     ws.set_option(websocket::stream_base::decorator(
         [](websocket::response_type& res)
@@ -395,10 +411,11 @@ do_coro_listen(
         }
 
         net::spawn(
-            acceptor.get_executor().context(),
+            acceptor.get_executor(),
             std::bind(
                 &do_coro_session,
-                ws_type(std::move(socket)),
+                websocket::stream<
+                    beast::tcp_stream>(std::move(socket)),
                 std::placeholders::_1));
     }
 }

example/websocket/server/stackless-ssl/websocket_server_stackless_ssl.cpp

@@ -51,8 +51,7 @@ class session
     : public net::coroutine
     , public std::enable_shared_from_this<session>
 {
-    websocket::stream<beast::ssl_stream<
-        beast::tcp_stream<net::io_context::strand>>> ws_;
+    websocket::stream<beast::ssl_stream<beast::tcp_stream>> ws_;
     beast::multi_buffer buffer_;
 
 public:
@@ -166,6 +165,7 @@ class listener
     : public net::coroutine
     , public std::enable_shared_from_this<listener>
 {
+    net::io_context& ioc_;
     ssl::context& ctx_;
     tcp::acceptor acceptor_;
     tcp::socket socket_;
@@ -175,7 +175,8 @@ public:
         net::io_context& ioc,
         ssl::context& ctx,
         tcp::endpoint endpoint)
-        : ctx_(ctx)
+        : ioc_(ioc)
+        , ctx_(ctx)
         , acceptor_(ioc)
         , socket_(ioc)
     {
@@ -247,6 +248,9 @@ public:
                     // Create the session and run it
                     std::make_shared<session>(std::move(socket_), ctx_)->run();
                 }
+
+                // Make sure each session gets its own strand
+                socket_ = tcp::socket(beast::make_strand(ioc_));
             }
         }
     }

example/websocket/server/stackless/websocket_server_stackless.cpp

@@ -46,8 +46,7 @@ class session
     : public net::coroutine
     , public std::enable_shared_from_this<session>
 {
-    websocket::stream<
-        beast::tcp_stream<net::io_context::strand>> ws_;
+    websocket::stream<beast::tcp_stream> ws_;
     beast::multi_buffer buffer_;
 
 public:
@@ -143,6 +142,7 @@ class listener
     : public net::coroutine
     , public std::enable_shared_from_this<listener>
 {
+    net::io_context& ioc_;
     tcp::acceptor acceptor_;
     tcp::socket socket_;
 
@@ -150,8 +150,9 @@ public:
     listener(
         net::io_context& ioc,
         tcp::endpoint endpoint)
-        : acceptor_(ioc)
-        , socket_(ioc)
+        : ioc_(ioc)
+        , acceptor_(beast::make_strand(ioc))
+        , socket_(beast::make_strand(ioc))
     {
         beast::error_code ec;
 
@@ -221,6 +222,9 @@ public:
                     // Create the session and run it
                     std::make_shared<session>(std::move(socket_))->run();
                 }
+
+                // Make sure each session gets its own strand
+                socket_ = tcp::socket(beast::make_strand(ioc_));
             }
         }
     }