Shutdown cleanly on SIGINT

src/main.cpp

@@ -1,9 +1,19 @@
 #include <xmpp/xmpp_component.hpp>
 #include <network/poller.hpp>
 #include <config/config.hpp>
+#include <logger/logger.hpp>
 
 #include <iostream>
 #include <memory>
+#include <atomic>
+
+#include <signal.h>
+
+// A flag set by the SIGINT signal handler.
+volatile std::atomic<bool> stop(false);
+// A flag indicating that we are wanting to exit the process. i.e: if this
+// flag is set and all connections are closed, we can exit properly.
+static bool exiting = false;
 
 /**
  * Provide an helpful message to help the user write a minimal working
@@ -20,6 +30,11 @@ int config_help(const std::string& missing_option)
   return 1;
 }
 
+static void sigint_handler(int, siginfo_t*, void*)
+{
+  stop = true;
+}
+
 int main(int ac, char** av)
 {
   if (ac > 1)
@@ -44,8 +59,40 @@ int main(int ac, char** av)
 
   Poller p;
   p.add_socket_handler(xmpp_component);
-  xmpp_component->start();
-  while (p.poll())
-    ;
+  if (!xmpp_component->start())
+  {
+    log_info("Exiting");
+    return -1;
+  }
+
+  // Install the signals used to exit the process cleanly, or reload the
+  // config
+  sigset_t mask;
+  sigemptyset(&mask);
+  struct sigaction on_sig;
+  on_sig.sa_sigaction = &sigint_handler;
+  on_sig.sa_mask = mask;
+  // we want to catch that signal only once.
+  // Sending SIGINT again will "force" an exit
+  on_sig.sa_flags = SA_RESETHAND;
+  sigaction(SIGINT, &on_sig, nullptr);
+  sigaction(SIGTERM, &on_sig, nullptr);
+
+  const std::chrono::milliseconds timeout(-1);
+  while (p.poll(timeout) != -1 || !exiting)
+  {
+    if (stop)
+    {
+      log_info("Signal received, exiting...");
+      exiting = true;
+      stop = false;
+      xmpp_component->shutdown();
+    }
+    // If the only existing connection is the one to the XMPP component:
+    // close the XMPP stream.
+    if (exiting && p.size() == 1 && xmpp_component->is_document_open())
+      xmpp_component->close_document();
+  }
+  log_info("All connection cleanely closed, have a nice day.");
   return 0;
 }