allow to specify how many times we can try to connect to the database at startup

add config options:
db_startup_connection_max_attempts - default 0 (infinite)
db_startup_connection_attempt_delay - delay in seconds between attempts (default 5)

BREAKING CHANGE: WINIX_PLUGIN_INIT plugin message requires to set result status,
you have to set the result status to true (env.res) if your
plugin was initialized correctly, otherwise winix will not start

winixd/core/app.cpp

@@ -178,7 +178,7 @@ Log & App::GetMainLog()
 
 
 
-void App::InitPlugins()
+void App::LoadPlugins()
 {
 	plugin.LoadPlugins(config.plugins_dir, config.plugin_file);
 }
@@ -350,8 +350,26 @@ bool App::TryToMakeDatabaseMigration()
 }
 
 
+bool App::InitializePlugins()
+{
+	PluginRes plugin_res = plugin.Call((Session*)0, WINIX_PLUGIN_INIT);
+
+	if( plugin_res.res_false > 0 )
+	{
+		log << log1 << "App: " << plugin_res.res_false << " plugin(s) cannot initialize itself, exiting" << logend;
+		return false;
+	}
+
+	return true;
+}
+
+
 bool App::Init()
 {
+	// load plugins before loading sessions - session_manager.LoadSessions()
+	// because some of the plugins can init its own sessions dates
+	LoadPlugins();
+
 	if( !config.db_conn_string.empty() )
 		postgresql_connector.set_conn_param(config.db_conn_string);
 	else
@@ -359,7 +377,11 @@ bool App::Init()
 
 	postgresql_connector.set_logger(log);
 	postgresql_connector.set_log_queries(config.log_db_query);
-	postgresql_connector.wait_for_connection();
+
+	if( !postgresql_connector.wait_for_connection(config.db_startup_connection_max_attempts, config.db_startup_connection_attempt_delay) )
+	{
+		return false;
+	}
 
 	model_connector.set_flat_connector(json_connector);
 	model_connector.set_db_connector(postgresql_connector);
@@ -378,6 +400,7 @@ bool App::Init()
 	model_connector.set_winix_time_zones(&system.time_zones);
 	model_connector.set_winix_pattern_cacher(&TemplatesFunctions::pattern_cacher);
 
+	// CHECKME this will call WINIX_MAKE_DATABASE_MIGRATION, but WINIX_PLUGIN_INIT was not called yet, it is correct?
 	if( !TryToMakeDatabaseMigration() )
 		return false;
 
@@ -387,13 +410,17 @@ bool App::Init()
 	else
 		db_conn.SetConnParam(config.db_host, config.db_hostaddr, config.db_port, config.db_database, config.db_user, config.db_pass);
 
-	db_conn.WaitForConnection();
+	if( !db_conn.WaitForConnection(config.db_startup_connection_max_attempts, config.db_startup_connection_attempt_delay) )
+		return false;
+
 	db.LogQueries(config.log_db_query);
 
 	cur.request->Clear();
 	compress.set_dependency(&winix_base);
 	compress.Init();
-	system.Init();
+
+	if( !system.Init() )
+		return false;
 
 	functions.Init();
 	templates.Init(); // init templates after functions are created
@@ -414,9 +441,10 @@ bool App::Init()
 
 	cookie_parser.set_dependency(&winix_model);
 
-	plugin.Call((Session*)0, WINIX_PLUGIN_INIT);
+	if( !AddSystemThreads() )
+		return false;
 
-return true;
+	return InitializePlugins();
 }
 
 
@@ -2788,6 +2816,15 @@ int sig;
 }
 
 
+bool App::AddSystemThreads()
+{
+	bool ok = true;
+
+	ok = ok && system.thread_manager.Add(&session_manager, L"session_manager");
+
+	return ok;
+}
+
 
 void App::StartThreads()
 {
@@ -2797,7 +2834,7 @@ void App::StartThreads()
 	// special thread only for signals
 	pthread_create(&signal_thread, 0, SpecialThreadForSignals, this);
 
-	system.thread_manager.Add(&session_manager, L"session_manager");
+	// start all threads from thread manager
 	system.thread_manager.StartAll();
 }