Replace synchronization semaphore with async messages

* Remove SyncToServices, I will probably readd it in future
but this time using a local synchronization service more than
relying on the media_server to release the semaphore.
* Due to some discussions today in mailing list I decided
to step back and retry the initial way to notify media rosters
about media services status. It is woking by using two different
notifications for reconnecting to the media_server and notifying
the local subscribers.
* This speed up the media services restart.
* Sorry for the noise and very thanks for reviewing my code to
everyone.

headers/os/media/MediaRoster.h

@@ -44,10 +44,6 @@ public:
 	// Check if the media services are running.
 	static	bool				IsRunning();
 
-	// This functions blocks until the media services are available,
-	// don't abuse of it.
-	static	status_t			SyncToServices(bigtime_t timeout = -1);
-
 	// Getting common instances of system nodes:
 			status_t			GetVideoInput(media_node* _node);
 			status_t			GetAudioInput(media_node* _node);

headers/private/media/ServerInterface.h

@@ -30,6 +30,8 @@ enum {
 
 	// sent by the rescan thread
 	MEDIA_SERVER_RESCAN_COMPLETED,
+	// sent to rosters when rescan is completed
+	MEDIA_SERVER_ALIVE,
 
 	// media add-on server
 	MEDIA_ADD_ON_SERVER_PLAY_MEDIA = '_TRU'
@@ -373,7 +375,6 @@ struct server_register_app_request : request_data {
 };
 
 struct server_register_app_reply : reply_data {
-	sem_id					global_synchro;
 };
 
 struct server_unregister_app_request : request_data {

src/kits/media/MediaRoster.cpp

@@ -107,7 +107,6 @@ static bool sServerIsUp = false;
 static List<RosterNotification> sNotificationList;
 static BLocker sInitLocker("BMediaRoster::Roster locker");
 static List<LocalNode> sRegisteredNodes;
-static sem_id sGlobalSynchro = -1;
 
 
 class MediaRosterUndertaker {
@@ -3345,27 +3344,6 @@ BMediaRoster::IsRunning()
 }
 
 
-status_t
-BMediaRoster::SyncToServices(bigtime_t timeout)
-{
-	if (!IsRunning())
-		return B_ERROR;
-
-	TRACE("BMediaRoster::SyncToServer: Syncing to the media server");
-
-	// This sem is valid only when the server started
-	// but it's not ready to supply the services.
-	if (sGlobalSynchro > -1)
-		acquire_sem_etc(sGlobalSynchro, 1, B_RELATIVE_TIMEOUT, timeout);
-
-	// TODO: Ideally this function should take into account
-	// the startup latencies of the system nodes and sleep
-	// for the resulting sum.
-
-	return B_OK;
-}
-
-
 ssize_t
 BMediaRoster::AudioBufferSizeFor(int32 channelCount, uint32 sampleFormat,
 	float frameRate, bus_type busKind)
@@ -3465,34 +3443,12 @@ BMediaRoster::MessageReceived(BMessage* message)
 
 			TRACE("BMediaRoster::MessageReceived media services are going up.");
 
-			// Send the notification to our subscribers
 			if (BMediaRoster::IsRunning()) {
-				SyncToServices();
+				// Wait for media services to wake up and restore our friendship
-				sServerIsUp = true;
-				sGlobalSynchro = -1;
-				// Wait for media services to wake up
-				// TODO: This should be solved so that the server
-				// have a way to notify us when the system is really
-				// ready to run and we avoid sleeping.
-				snooze(2000000);
-				// Restore our friendship with the media servers
 				if (MediaRosterEx(this)->BuildConnections() != B_OK) {
 					TRACE("BMediaRoster::MessageReceived can't reconnect"
 						"to media_server.");
 				}
-
-				for (int32 i = 0; i < sNotificationList.CountItems(); i++) {
-					RosterNotification* current;
-					if (sNotificationList.Get(i, &current) != true)
-						return;
-					if (current->what == B_MEDIA_SERVER_STARTED) {
-						if (current->messenger.SendMessage(
-								B_MEDIA_SERVER_STARTED) != B_OK) {
-							if(!current->messenger.IsValid())
-								sNotificationList.Remove(i);
-						}
-					}
-				}
 			}
 			return;
 		}
@@ -3527,6 +3483,31 @@ BMediaRoster::MessageReceived(BMessage* message)
 			return;
 		}
 
+		case MEDIA_SERVER_ALIVE:
+		{
+			if (!BMediaRoster::IsRunning())
+				return;
+
+			sServerIsUp = true;
+
+			TRACE("BMediaRoster::MessageReceived media services are"
+				" finally up.");
+
+			// Send the notification to our subscribers
+			for (int32 i = 0; i < sNotificationList.CountItems(); i++) {
+				RosterNotification* current;
+				if (sNotificationList.Get(i, &current) != true)
+					return;
+				if (current->what == B_MEDIA_SERVER_STARTED) {
+					if (current->messenger.SendMessage(
+							B_MEDIA_SERVER_STARTED) != B_OK) {
+						if(!current->messenger.IsValid())
+							sNotificationList.Remove(i);
+					}
+				}
+			}
+		}
+
 		case NODE_FINAL_RELEASE:
 		{
 			// This function is called by a BMediaNode to delete

src/servers/media/AppManager.cpp

@@ -50,14 +50,11 @@ AppManager::AppManager()
 	:
 	BLocker("media app manager")
 {
-	fGlobalSynchro = create_sem(0, "media server global synchro");
 }
 
 
 AppManager::~AppManager()
 {
-	if (fGlobalSynchro != -1)
-		delete_sem(fGlobalSynchro);
 }
 
 
@@ -70,8 +67,7 @@ AppManager::HasTeam(team_id team)
 
 
 status_t
-AppManager::RegisterTeam(team_id team, const BMessenger& messenger,
+AppManager::RegisterTeam(team_id team, const BMessenger& messenger)
-	sem_id* sync)
 {
 	BAutolock lock(this);
 
@@ -88,8 +84,6 @@ AppManager::RegisterTeam(team_id team, const BMessenger& messenger,
 		return B_NO_MEMORY;
 	}
 
-	*sync = fGlobalSynchro;
-
 	return B_OK;
 }
 
@@ -157,9 +151,13 @@ AppManager::Dump()
 
 
 void
-AppManager::UnlockGlobalSynchro()
+AppManager::NotifyRosters()
 {
-	delete_sem(fGlobalSynchro);
+	BAutolock lock(this);
+
+	AppMap::iterator iterator = fMap.begin();
+	for (; iterator != fMap.end(); iterator++)
+		iterator->second.SendMessage(MEDIA_SERVER_ALIVE);
 }
 
 

src/servers/media/AppManager.h

@@ -18,7 +18,7 @@ public:
 								~AppManager();
 
 			status_t			RegisterTeam(team_id team,
-									const BMessenger& messenger, sem_id* sync);
+									const BMessenger& messenger);
 			status_t			UnregisterTeam(team_id team);
 			bool				HasTeam(team_id team);
 
@@ -28,7 +28,7 @@ public:
 
 			void				Dump();
 
-			void				UnlockGlobalSynchro();
+			void				NotifyRosters();
 
 private:
 			void				_CleanupTeam(team_id team);
@@ -37,7 +37,6 @@ private:
 			typedef std::map<team_id, BMessenger> AppMap;
 
 			AppMap				fMap;
-			sem_id				fGlobalSynchro;
 };
 
 

src/servers/media/DefaultManager.cpp

@@ -413,9 +413,6 @@ DefaultManager::_RescanThread()
 			add_on_server_rescan_finished_notify_command cmd;
 			SendToAddOnServer(ADD_ON_SERVER_RESCAN_FINISHED_NOTIFY, &cmd,
 				sizeof(cmd));
-
-			BMessage msg(MEDIA_SERVER_RESCAN_COMPLETED);
-			be_app->PostMessage(&msg);
 		}
 
 		locker.Lock();
@@ -423,6 +420,9 @@ DefaultManager::_RescanThread()
 
 	fRescanThread = -1;
 
+	BMessage msg(MEDIA_SERVER_RESCAN_COMPLETED);
+	be_app->PostMessage(&msg);
+
 	TRACE("DefaultManager::_RescanThread() leave\n");
 }
 

src/servers/media/Jamfile

@@ -2,7 +2,7 @@ SubDir HAIKU_TOP src servers media ;
 
 SetSubDirSupportedPlatformsBeOSCompatible ;
 
-UsePrivateHeaders media shared storage app ;
+UsePrivateHeaders app media shared storage ;
 UsePrivateSystemHeaders ;
 
 AddResources media_server : media_server.rdef ;

src/servers/media/media_server.cpp

@@ -37,13 +37,13 @@ char __dont_remove_copyright_from_binary[] = "Copyright (c) 2002, 2003 "
 #include <string.h>
 
 #include <Alert.h>
-#include <Server.h>
 #include <Autolock.h>
 #include <Directory.h>
 #include <Roster.h>
 #include <MediaDefs.h>
 #include <MediaFormats.h>
 #include <Messenger.h>
+#include <Server.h>
 
 #include <syscalls.h>
 
@@ -307,7 +307,7 @@ ServerApp::_HandleMessage(int32 code, const void* data, size_t size)
 			server_register_app_reply reply;
 
 			status_t status = gAppManager->RegisterTeam(request.team,
-				request.messenger, &reply.global_synchro);
+				request.messenger);
 			request.SendReply(status, &reply, sizeof(reply));
 			break;
 		}
@@ -942,7 +942,7 @@ ServerApp::MessageReceived(BMessage* msg)
 
 		case MEDIA_SERVER_RESCAN_COMPLETED:
 		{
-			gAppManager->UnlockGlobalSynchro();
+			gAppManager->NotifyRosters();
 			progress_startup(100, NULL, NULL);
 			break;
 		}