Consistent shutdown when plugin_startup() fails.

include/appbase/application_instance.hpp

@@ -41,6 +41,11 @@ class plugin : public abstract_plugin {
  static_cast<Impl*>(this)->plugin_requires([&](auto& plug) { plug.startup(); });
  app().plugin_started(this); // add to `running_plugins` before so it will be shutdown if we throw in `plugin_startup()`
  static_cast<Impl*>(this)->plugin_startup();
+ if (app().is_quiting()) {
+ // some plugins, instead of throwing an exception when failing to start, call app().quit().
+ // throw exception to ensure no more plugin gets initialized, and all running plugins receive `plugin_shutdown()`
+ throw std::runtime_error("plugin " + name() + " quit during startup");
+ }
  }
  assert(_state == started); // if initial state was not initialized, final state cannot be started
  }

tests/basic_test.cpp

@@ -28,6 +28,7 @@ class pluginA : public appbase::plugin<pluginA>
  ("dbsize", bpo::value<uint64_t>()->default_value( 8*1024 ), "Minimum size MB of database shared memory file")
  ("replay", "clear db and replay all blocks" )
  ("throw_during_startup", "throw an exception in plugin_startup()" )
+ ("quit_during_startup", "calls app().quit() plugin_startup()" )
  ("log", "log messages" );
  }
 
@@ -36,6 +37,7 @@ class pluginA : public appbase::plugin<pluginA>
  replay_ = !!options.count("replay");
  log_ = !!options.count("log");
  throw_during_startup_ = !!options.count("throw_during_startup");
+ quit_during_startup_ = !!options.count("quit_during_startup");
  dbsize_ = options.at("dbsize").as<uint64_t>();
  log("initialize pluginA");
  }
@@ -44,6 +46,8 @@ class pluginA : public appbase::plugin<pluginA>
  log("starting pluginA");
  if (throw_during_startup_)
  do_throw("throwing as requested");
+ if (quit_during_startup_)
+ appbase::app().quit();
  }
 
  void plugin_shutdown() {
@@ -67,6 +71,7 @@ class pluginA : public appbase::plugin<pluginA>
  bool readonly_ {false};
  bool replay_ {false};
  bool throw_during_startup_ {false};
+ bool quit_during_startup_ {false};
  bool log_ {false};
  uint64_t dbsize_ {0};
  uint32_t* shutdown_counter { nullptr };
@@ -368,6 +373,37 @@ BOOST_AUTO_TEST_CASE(exception_in_startup)
  app_thread.join();
 }
 
+// -----------------------------------------------------------------------------
+// Here we make sure that if a plugin calls app().quit() during `plugin_startup()`
+// plugin_shutdown is called for that plugin
+// -----------------------------------------------------------------------------
+BOOST_AUTO_TEST_CASE(quit_in_startup)
+{
+ appbase::application::register_plugin<pluginB>();
+
+ appbase::scoped_app app;
+
+ const char* argv[] = { bu::framework::current_test_case().p_name->c_str(),
+ "--plugin", "pluginA", "--log", "--quit_during_startup",
+ "--plugin", "pluginB", "--log2" };
+
+ BOOST_CHECK(app->initialize<pluginB>(sizeof(argv) / sizeof(char*), const_cast<char**>(argv)));
+
+ std::thread app_thread( [&]() {
+ auto& pA = app->get_plugin<pluginA>();
+ uint32_t shutdown_counter(0);
+ pA.set_shutdown_counter(shutdown_counter);
+
+ try {
+ app->startup();
+ } catch(const std::exception& e ) {
+ std::cout << "exception during startup (as expected): " << e.what() << "\n";
+ }
+ BOOST_CHECK(shutdown_counter == 1); // check that plugin_shutdown() was executed for pA
+ } );
+
+ app_thread.join();
+}
 
 // -----------------------------------------------------------------------------
 // Make sure that queue is emptied when `app->quit()` is called, and that the