Fix crash on firing timer when object is gone already

1 files changed, 15 insertions, 6 deletions

diff --git a/whiteboard.cpp b/whiteboard.cpp
index 2c8a47b..88f4f3b 100644
--- a/whiteboard.cpp
+++ b/whiteboard.cpp
@@ -104,6 +104,13 @@ public:
  {
  }
 
+ ~session()
+ {
+  if (m_stats_timer)
+   m_stats_timer->cancel();
+  m_stats_timer = nullptr;
+ }
+
  void do_read_handshake()
  {
   // Set a decorator to change the Server of the handshake
@@ -273,13 +280,15 @@ public:
 
  void stats_callback(const boost::system::error_code&)
  {
-  auto data{std::make_shared<std::string>(stats_xml())};
-  auto buffer{std::make_shared<boost::asio::const_buffer>(data->data(), data->size())};
-  m_ws->async_write(*buffer, boost::asio::bind_executor(m_ws->next_layer().get_executor(),
-                                                        boost::beast::bind_front_handler(&session::on_write_stats, shared_from_this(), data, buffer)));
+  if (m_stats_timer) {
+   auto data{std::make_shared<std::string>(stats_xml())};
+   auto buffer{std::make_shared<boost::asio::const_buffer>(data->data(), data->size())};
+   m_ws->async_write(*buffer, boost::asio::bind_executor(m_ws->next_layer().get_executor(),
+                                                         boost::beast::bind_front_handler(&session::on_write_stats, shared_from_this(), data, buffer)));
 
-  m_stats_timer->expires_at(m_stats_timer->expires_at() + boost::asio::chrono::seconds(5));
-  m_stats_timer->async_wait(boost::beast::bind_front_handler(&session::stats_callback, this));
+   m_stats_timer->expires_at(m_stats_timer->expires_at() + boost::asio::chrono::seconds(5));
+   m_stats_timer->async_wait(boost::beast::bind_front_handler(&session::stats_callback, this));
+  }
  }
 
  void setup_stats_timer()