Fix async object lifetimes

src/asio_server_connection.h

@@ -41,15 +41,15 @@
 
 #include <memory>
 
-#include <boost/noncopyable.hpp>
 #include <boost/array.hpp>
+#include <boost/noncopyable.hpp>
 
 #include <nghttp2/asio_http2_server.h>
 
 #include "asio_server_http2_handler.h"
 #include "asio_server_serve_mux.h"
-#include "util.h"
 #include "template.h"
+#include "util.h"
 
 namespace nghttp2 {
 
@@ -69,13 +69,10 @@ public:
       const boost::posix_time::time_duration &tls_handshake_timeout,
       const boost::posix_time::time_duration &read_timeout,
       SocketArgs &&... args)
-      : socket_(std::forward<SocketArgs>(args)...),
-        mux_(mux),
+      : socket_(std::forward<SocketArgs>(args)...), mux_(mux),
         deadline_(socket_.get_io_service()),
         tls_handshake_timeout_(tls_handshake_timeout),
-        read_timeout_(read_timeout),
-        writing_(false),
-        stopped_(false) {}
+        read_timeout_(read_timeout), writing_(false), stopped_(false) {}
 
   /// Start the first asynchronous operation for the connection.
   void start() {
@@ -83,7 +80,13 @@ public:
 
     handler_ = std::make_shared<http2_handler>(
         socket_.get_io_service(), socket_.lowest_layer().remote_endpoint(ec),
-        [this]() { do_write(); }, mux_);
+        [ this, self = this->shared_from_this() ]() {
+          if (!std::weak_ptr<connection>{self}.lock()) {
+            return;
+          }
+          do_write();
+        },
+        mux_);
     if (handler_->start() != 0) {
       stop();
       return;
@@ -95,14 +98,22 @@ public:
 
   void start_tls_handshake_deadline() {
     deadline_.expires_from_now(tls_handshake_timeout_);
-    deadline_.async_wait(
-        std::bind(&connection::handle_deadline, this->shared_from_this()));
+    deadline_.async_wait([self = this->shared_from_this()](
+        const boost::system::error_code &) {
+      if (!std::weak_ptr<connection>{self}.lock())
+        return;
+      return self->handle_deadline();
+    });
   }
 
   void start_read_deadline() {
     deadline_.expires_from_now(read_timeout_);
-    deadline_.async_wait(
-        std::bind(&connection::handle_deadline, this->shared_from_this()));
+    deadline_.async_wait([self = this->shared_from_this()](
+        const boost::system::error_code &) {
+      if (!std::weak_ptr<connection>{self}.lock())
+        return;
+      return self->handle_deadline();
+    });
   }
 
   void handle_deadline() {
@@ -117,49 +128,51 @@ public:
       return;
     }
 
-    deadline_.async_wait(
-        std::bind(&connection::handle_deadline, this->shared_from_this()));
+    deadline_.async_wait([self = this->shared_from_this()](
+        const boost::system::error_code &) {
+      if (!std::weak_ptr<connection>{self}.lock())
+        return;
+      return self->handle_deadline();
+    });
   }
 
   void do_read() {
-    auto self = this->shared_from_this();
-
     deadline_.expires_from_now(read_timeout_);
 
-    socket_.async_read_some(
-        boost::asio::buffer(buffer_),
-        [this, self](const boost::system::error_code &e,
-                     std::size_t bytes_transferred) {
-          if (e) {
-            stop();
-            return;
-          }
+    socket_.async_read_some(boost::asio::buffer(buffer_), [
+      this, self = this->shared_from_this()
+    ](const boost::system::error_code &e, std::size_t bytes_transferred) {
+      if (!std::weak_ptr<connection>{self}.lock()) {
+        return;
+      }
+      if (e) {
+        stop();
+        return;
+      }
 
-          if (handler_->on_read(buffer_, bytes_transferred) != 0) {
-            stop();
-            return;
-          }
+      if (handler_->on_read(buffer_, bytes_transferred) != 0) {
+        stop();
+        return;
+      }
 
-          do_write();
+      do_write();
 
-          if (!writing_ && handler_->should_stop()) {
-            stop();
-            return;
-          }
+      if (!writing_ && handler_->should_stop()) {
+        stop();
+        return;
+      }
 
-          do_read();
+      do_read();
 
-          // If an error occurs then no new asynchronous operations are
-          // started. This means that all shared_ptr references to the
-          // connection object will disappear and the object will be
-          // destroyed automatically after this handler returns. The
-          // connection class's destructor closes the socket.
-        });
+      // If an error occurs then no new asynchronous operations are
+      // started. This means that all shared_ptr references to the
+      // connection object will disappear and the object will be
+      // destroyed automatically after this handler returns. The
+      // connection class's destructor closes the socket.
+    });
   }
 
   void do_write() {
-    auto self = this->shared_from_this();
-
     if (writing_) {
       return;
     }
@@ -187,18 +200,21 @@ public:
     // something, it does not expect timeout while doing it.
     deadline_.expires_from_now(read_timeout_);
 
-    boost::asio::async_write(
-        socket_, boost::asio::buffer(outbuf_, nwrite),
-        [this, self](const boost::system::error_code &e, std::size_t) {
-          if (e) {
-            stop();
-            return;
-          }
+    boost::asio::async_write(socket_, boost::asio::buffer(outbuf_, nwrite), [
+      this, self = this->shared_from_this()
+    ](const boost::system::error_code &e, std::size_t) {
+      if (!std::weak_ptr<connection>{self}.lock()) {
+        return;
+      }
+      if (e) {
+        stop();
+        return;
+      }
 
-          writing_ = false;
+      writing_ = false;
 
-          do_write();
-        });
+      do_write();
+    });
 
     // No new asynchronous operations are started. This means that all
     // shared_ptr references to the connection object will disappear and