servers & kits: Rehabilitate app_server restart functionality.

* It's not really possible to distinguish between a first startup
   and a restart inside app_server itself. Due to the new BServer
   setup, the same port will still be used, too. So, change the
   messages sent to just "AppServerStarted".

 * Since the message is sent out much later than the port is created,
   by the time applications see it, the app_server may have already
   been started a while and applications may have connected to it.
   So, check if we really need to reconnect in BApplication before
   actually trying to do that.

 * BWindow now starts with updates disabled, so they must be
   enabled after reconnecting.

After this commit, basic app_server restart functionality works again;
it's restarted automatically by launch_daemon after dying or being killed
and applications automatically reconnect. However, some problems still
linger (e.g. Terminal doesn't always recreate its windows, colors
on the Desktop look wrong, missing desktop background image, etc.)

headers/private/app/RosterPrivate.h

@@ -13,8 +13,7 @@
 #include <Roster.h>
 
 
-const int32 kMsgAppServerRestarted = 'ASRe';
+const int32 kMsgAppServerStarted = '_ASt';
-const int32 kMsgRestartAppServer = 'ReAS';
 
 
 class BRoster::Private {

src/kits/app/Application.cpp

@@ -691,7 +691,7 @@ BApplication::MessageReceived(BMessage* message)
 			be_roster->ActivateApp(Team());
 			break;
 
-		case kMsgAppServerRestarted:
+		case kMsgAppServerStarted:
 			_ReconnectToServer();
 			break;
 
@@ -1454,6 +1454,12 @@ BApplication::_ConnectToServer()
 void
 BApplication::_ReconnectToServer()
 {
+	team_info dummy;
+	if (get_team_info(fServerLink->TargetTeam(), &dummy) == B_OK) {
+		// We're already connected to the correct server.
+		return;
+	}
+
 	// the sender port belongs to the app_server
 	delete_port(fServerLink->ReceiverPort());
 
@@ -1470,7 +1476,7 @@ BApplication::_ReconnectToServer()
 		if (window == NULL)
 			continue;
 		BMessenger windowMessenger(window);
-		windowMessenger.SendMessage(kMsgAppServerRestarted);
+		windowMessenger.SendMessage(kMsgAppServerStarted);
 	}
 
 	reconnect_bitmaps_to_app_server();

src/kits/interface/Window.cpp

@@ -739,7 +739,7 @@ BWindow::MessageReceived(BMessage* message)
 		if (message->what == B_KEY_DOWN)
 			_KeyboardNavigation();
 
-		if (message->what == (int32)kMsgAppServerRestarted) {
+		if (message->what == kMsgAppServerStarted) {
 			fLink->SetSenderPort(
 				BApplication::Private::ServerLink()->SenderPort());
 
@@ -786,6 +786,7 @@ BWindow::MessageReceived(BMessage* message)
 			// connect all views to the server again
 			fTopView->_CreateSelf();
 
+			EnableUpdates();
 			_SendShowOrHideMessage();
 		}
 

src/servers/app/AppServer.cpp

@@ -17,6 +17,7 @@
 #include <AutoDeleter.h>
 #include <LaunchRoster.h>
 #include <PortLink.h>
+#include <RosterPrivate.h>
 
 #include "BitmapManager.h"
 #include "Desktop.h"
@@ -70,15 +71,19 @@ AppServer::AppServer(status_t* status)
 	// Create the bitmap allocator. Object declared in BitmapManager.cpp
 	gBitmapManager = new BitmapManager();
 
+#ifndef HAIKU_TARGET_PLATFORM_LIBBE_TEST
 #if 0
 	// This is not presently needed, as app_server is launched from the login session.
-#ifndef HAIKU_TARGET_PLATFORM_LIBBE_TEST
 	// TODO: check the attached displays, and launch login session for them
 	BMessage data;
 	data.AddString("name", "app_server");
 	data.AddInt32("session", 0);
 	BLaunchRoster().Target("login", data);
 #endif
+
+	// Inform the registrar we've (re)started.
+	BMessage request(kMsgAppServerStarted);
+	BRoster::Private().SendTo(&request, NULL, false);
 #endif
 }
 

src/servers/input/InputServer.cpp

@@ -582,9 +582,10 @@ InputServer::MessageReceived(BMessage* message)
 			return;
 		}
 
-		case kMsgAppServerRestarted:
+		case kMsgAppServerStarted:
 		{
 			BApplication::MessageReceived(message);
+
 			BPrivate::AppServerLink link;
 			link.StartMessage(AS_REGISTER_INPUT_SERVER);
 			link.Flush();

src/servers/registrar/Registrar.cpp

@@ -51,7 +51,7 @@ static const char *kEventQueueName = "timer_thread";
 
 
 /*!	\brief Creates the registrar application class.
-	\param error Passed to the BApplication constructor for returning an
+	\param error Passed to the BServer constructor for returning an
 		   error code.
 */
 Registrar::Registrar(status_t* _error)
@@ -375,9 +375,11 @@ Registrar::_MessageReceived(BMessage *message)
 			}
 			break;
 
-		case kMsgRestartAppServer:
+		case kMsgAppServerStarted:
 		{
-			fRoster->HandleRestartAppServer(message);
+			fRoster->HandleAppServerStarted(message);
+
+			// Don't pass this message on to our BApplication, as that may deadlock.
 			break;
 		}
 
@@ -477,7 +479,7 @@ main()
 			"registrar main() caught exception: %s", exception.what());
 		debugger(buffer);
 	} catch (...) {
-		debugger("registrar main() caught unknown exception");
+		debugger("registrar main() caught unknown exception");
 	}
 
 	PRINT("delete app...\n");

src/servers/registrar/TRoster.cpp

@@ -1141,39 +1141,14 @@ TRoster::HandleSaveRecentLists(BMessage* request)
 
 
 void
-TRoster::HandleRestartAppServer(BMessage* request)
+TRoster::HandleAppServerStarted(BMessage* request)
 {
 	BAutolock _(fLock);
 
-	// TODO: if an app_server is still running, stop it first
-
-	const char* pathString;
-	if (request->FindString("path", &pathString) != B_OK)
-		pathString = "/boot/system/servers";
-	BPath path(pathString);
-	path.Append("app_server");
-	// NOTE: its required at some point that the binary name is "app_server"
-
-	const char **argv = new const char * [2];
-	argv[0] = strdup(path.Path());
-	argv[1] = NULL;
-
-	thread_id threadId = load_image(1, argv, (const char**)environ);
-	int i;
-	for (i = 0; i < 1; i++)
-		delete argv[i];
-	delete [] argv;
-
-	resume_thread(threadId);
-	// give the server some time to create the server port
-	snooze(100000);
-
-	// notify all apps
-	// TODO: whats about ourself?
 	AppInfoListMessagingTargetSet targetSet(fRegisteredApps);
 	if (targetSet.HasNext()) {
 		// send the messages
-		BMessage message(kMsgAppServerRestarted);
+		BMessage message(kMsgAppServerStarted);
 		MessageDeliverer::Default()->DeliverMessage(&message, targetSet);
 	}
 }

src/servers/registrar/TRoster.h

@@ -56,7 +56,7 @@ public:
 			void			HandleLoadRecentLists(BMessage* request);
 			void			HandleSaveRecentLists(BMessage* request);
 
-			void			HandleRestartAppServer(BMessage* request);
+			void			HandleAppServerStarted(BMessage* request);
 
 			void			ClearRecentDocuments();
 			void			ClearRecentFolders();