Graceful shutdown and joinable server

src/asio_io_service_pool.cc

@@ -35,8 +35,6 @@
 //
 #include "asio_io_service_pool.h"
 
-#include <future>
-
 namespace nghttp2 {
 
 namespace asio_http2 {
@@ -56,19 +54,23 @@ io_service_pool::io_service_pool(std::size_t pool_size) : next_io_service_(0) {
   }
 }
 
-void io_service_pool::run() {
+void io_service_pool::run(bool asynchronous) {
   // Create a pool of threads to run all of the io_services.
-  auto futs = std::vector<std::future<std::size_t>>();
-
   for (std::size_t i = 0; i < io_services_.size(); ++i) {
-    futs.push_back(std::async(std::launch::async,
+    futures_.push_back(std::async(std::launch::async,
                               (size_t (boost::asio::io_service::*)(void)) &
                                   boost::asio::io_service::run,
                               io_services_[i]));
   }
 
+  if (!asynchronous) {
+    join();
+  }
+}
+
+void io_service_pool::join() {
   // Wait for all threads in the pool to exit.
-  for (auto &fut : futs) {
+  for (auto &fut : futures_) {
     fut.get();
   }
 }

src/asio_io_service_pool.h

@@ -41,6 +41,7 @@
 
 #include <vector>
 #include <memory>
+#include <future>
 
 #include <boost/noncopyable.hpp>
 #include <boost/thread.hpp>
@@ -58,11 +59,14 @@ public:
   explicit io_service_pool(std::size_t pool_size);
 
   /// Run all io_service objects in the pool.
-  void run();
+  void run(bool asynchronous = false);
 
   /// Stop all io_service objects in the pool.
   void stop();
 
+  /// Join on all io_service objects in the pool.
+  void join();
+
   /// Get an io_service to use.
   boost::asio::io_service &get_io_service();
 
@@ -75,6 +79,9 @@ private:
 
   /// The next io_service to use for a connection.
   std::size_t next_io_service_;
+
+  /// Futures to all the io_service objects
+  std::vector<std::future<std::size_t>> futures_;
 };
 
 } // namespace asio_http2

src/asio_server.cc

@@ -50,7 +50,7 @@ boost::system::error_code
 server::listen_and_serve(boost::system::error_code &ec,
                          boost::asio::ssl::context *tls_context,
                          const std::string &address, const std::string &port,
-                         int backlog, serve_mux &mux) {
+                         int backlog, serve_mux &mux, bool asynchronous) {
   ec.clear();
 
   if (bind_and_listen(ec, address, port, backlog)) {
@@ -65,7 +65,7 @@ server::listen_and_serve(boost::system::error_code &ec,
     }
   }
 
-  io_service_pool_.run();
+  io_service_pool_.run(asynchronous);
 
   return ec;
 }
@@ -156,6 +156,16 @@ void server::start_accept(tcp::acceptor &acceptor, serve_mux &mux) {
   });
 }
 
+void server::stop()
+{
+  io_service_pool_.stop();
+}
+
+void server::join()
+{
+  io_service_pool_.join();
+}
+
 } // namespace server
 } // namespace asio_http2
 } // namespace nghttp2

src/asio_server.h

@@ -69,7 +69,9 @@ public:
   listen_and_serve(boost::system::error_code &ec,
                    boost::asio::ssl::context *tls_context,
                    const std::string &address, const std::string &port,
-                   int backlog, serve_mux &mux);
+                   int backlog, serve_mux &mux, bool asynchronous = false);
+  void join();
+  void stop();
 
 private:
   /// Initiate an asynchronous accept operation.

src/asio_server_http2.cc

@@ -54,15 +54,17 @@ http2 &http2::operator=(http2 &&other) noexcept {
 
 boost::system::error_code http2::listen_and_serve(boost::system::error_code &ec,
                                                   const std::string &address,
-                                                  const std::string &port) {
-  return impl_->listen_and_serve(ec, nullptr, address, port);
+                                                  const std::string &port,
+                                                  bool asynchronous) {
+  return impl_->listen_and_serve(ec, nullptr, address, port, asynchronous);
 }
 
 boost::system::error_code
 http2::listen_and_serve(boost::system::error_code &ec,
                         boost::asio::ssl::context &tls_context,
-                        const std::string &address, const std::string &port) {
-  return impl_->listen_and_serve(ec, &tls_context, address, port);
+                        const std::string &address, const std::string &port,
+                        bool asynchronous) {
+  return impl_->listen_and_serve(ec, &tls_context, address, port, asynchronous);
 }
 
 void http2::num_threads(size_t num_threads) { impl_->num_threads(num_threads); }
@@ -73,6 +75,16 @@ bool http2::handle(std::string pattern, request_cb cb) {
   return impl_->handle(std::move(pattern), std::move(cb));
 }
 
+void http2::stop()
+{
+  impl_->stop();
+}
+
+void http2::join()
+{
+  return impl_->join();
+}
+
 } // namespace server
 
 } // namespace asio_http2

src/asio_server_http2_impl.cc

@@ -41,9 +41,9 @@ http2_impl::http2_impl() : num_threads_(1), backlog_(-1) {}
 
 boost::system::error_code http2_impl::listen_and_serve(
     boost::system::error_code &ec, boost::asio::ssl::context *tls_context,
-    const std::string &address, const std::string &port) {
-  return server(num_threads_)
-      .listen_and_serve(ec, tls_context, address, port, backlog_, mux_);
+    const std::string &address, const std::string &port, bool asynchronous) {
+  server_.reset(new server(num_threads_));
+  return server_->listen_and_serve(ec, tls_context, address, port, backlog_, mux_, asynchronous);
 }
 
 void http2_impl::num_threads(size_t num_threads) { num_threads_ = num_threads; }
@@ -54,6 +54,15 @@ bool http2_impl::handle(std::string pattern, request_cb cb) {
   return mux_.handle(std::move(pattern), std::move(cb));
 }
 
+void http2_impl::stop() {
+  return server_->stop();
+}
+
+void http2_impl::join()
+{
+  return server_->join();
+}
+
 } // namespace server
 
 } // namespace asio_http2

src/asio_server_http2_impl.h

@@ -45,10 +45,13 @@ public:
   boost::system::error_code
   listen_and_serve(boost::system::error_code &ec,
                    boost::asio::ssl::context *tls_context,
-                   const std::string &address, const std::string &port);
+                   const std::string &address, const std::string &port,
+                   bool asynchronous);
   void num_threads(size_t num_threads);
   void backlog(int backlog);
   bool handle(std::string pattern, request_cb cb);
+  void stop();
+  void join();
 
 private:
   std::unique_ptr<server> server_;

src/includes/nghttp2/asio_http2_server.h

@@ -139,14 +139,16 @@ public:
   // incoming requests in cleartext TCP connection.
   boost::system::error_code listen_and_serve(boost::system::error_code &ec,
                                              const std::string &address,
-                                             const std::string &port);
+                                             const std::string &port,
+                                             bool asynchronous = false);
 
   // Starts listening connection on given address and port and serves
   // incoming requests in SSL/TLS encrypted connection.
   boost::system::error_code
   listen_and_serve(boost::system::error_code &ec,
                    boost::asio::ssl::context &tls_context,
-                   const std::string &address, const std::string &port);
+                   const std::string &address, const std::string &port,
+                   bool asynchronous = false);
 
   // Registers request handler |cb| with path pattern |pattern|.  This
   // function will fail and returns false if same pattern has been
@@ -187,6 +189,12 @@ public:
   // connections.
   void backlog(int backlog);
 
+  // Gracefully stop http2 server
+  void stop();
+
+  // Join on http2 server and wait for it to fully stop
+  void join();
+
 private:
   std::unique_ptr<http2_impl> impl_;
 };