better usage of synchronized in some places

src/main/java/eu/siacs/conversations/entities/Conversation.java

@@ -57,7 +57,7 @@ public class Conversation extends AbstractEntity {
 
 	private Jid nextCounterpart;
 
-	protected ArrayList<Message> messages = new ArrayList<>();
+	protected final ArrayList<Message> messages = new ArrayList<>();
 	protected Account account = null;
 
 	private transient SessionImpl otrSession;
@@ -148,10 +148,6 @@ public class Conversation extends AbstractEntity {
 		}
 	}
 
-	public void setMessages(ArrayList<Message> msgs) {
-		this.messages = msgs;
-	}
-
 	public String getName() {
 		if (getMode() == MODE_MULTI && getMucOptions().getSubject() != null) {
 			return getMucOptions().getSubject();

src/main/java/eu/siacs/conversations/services/XmppConnectionService.java

@@ -139,7 +139,7 @@ public class XmppConnectionService extends Service {
 	private MessageGenerator mMessageGenerator = new MessageGenerator(this);
 	private PresenceGenerator mPresenceGenerator = new PresenceGenerator(this);
 	private List<Account> accounts;
-	private CopyOnWriteArrayList<Conversation> conversations = null;
+	private final CopyOnWriteArrayList<Conversation> conversations = new CopyOnWriteArrayList<Conversation>();
 	private JingleConnectionManager mJingleConnectionManager = new JingleConnectionManager(
 			this);
 	private HttpConnectionManager mHttpConnectionManager = new HttpConnectionManager(
@@ -486,27 +486,23 @@ public class XmppConnectionService extends Service {
 			}
 		};
 
-		this.databaseBackend = DatabaseBackend
+		this.databaseBackend = DatabaseBackend.getInstance(getApplicationContext());
-			.getInstance(getApplicationContext());
 		this.accounts = databaseBackend.getAccounts();
 
 		for (Account account : this.accounts) {
 			account.initOtrEngine(this);
 			this.databaseBackend.readRoster(account.getRoster());
 		}
+		initConversations();
 		this.mergePhoneContactsWithRoster();
-		this.getConversations();
 
-		getContentResolver().registerContentObserver(
+		getContentResolver().registerContentObserver(ContactsContract.Contacts.CONTENT_URI, true, contactObserver);
-				ContactsContract.Contacts.CONTENT_URI, true, contactObserver);
 		this.fileObserver.startWatching();
-		this.pgpServiceConnection = new OpenPgpServiceConnection(
+		this.pgpServiceConnection = new OpenPgpServiceConnection(getApplicationContext(), "org.sufficientlysecure.keychain");
-				getApplicationContext(), "org.sufficientlysecure.keychain");
 		this.pgpServiceConnection.bindToService();
 
 		this.pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
-		this.wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
+		this.wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,"XmppConnectionService");
-				"XmppConnectionService");
 		toggleForegroundService();
 	}
 
@@ -878,21 +874,23 @@ public class XmppConnectionService extends Service {
 				});
 	}
 
-	public List<Conversation> getConversations() {
+	private void initConversations() {
-		if (this.conversations == null) {
+		synchronized (this.conversations) {
 			Hashtable<String, Account> accountLookupTable = new Hashtable<>();
 			for (Account account : this.accounts) {
 				accountLookupTable.put(account.getUuid(), account);
 			}
-			this.conversations = databaseBackend
+			this.conversations.addAll(databaseBackend.getConversations(Conversation.STATUS_AVAILABLE));
-				.getConversations(Conversation.STATUS_AVAILABLE);
 			for (Conversation conv : this.conversations) {
 				Account account = accountLookupTable.get(conv.getAccountUuid());
 				conv.setAccount(account);
-				conv.setMessages(databaseBackend.getMessages(conv, 50));
+				conv.addAll(0, databaseBackend.getMessages(conv, 50));
 				checkDeletedFiles(conv);
 			}
 		}
+	}
+
+	public List<Conversation> getConversations() {
 		return this.conversations;
 	}
 
@@ -923,12 +921,11 @@ public class XmppConnectionService extends Service {
 		}
 	}
 
-	public void populateWithOrderedConversations(List<Conversation> list) {
+	public void populateWithOrderedConversations(final List<Conversation> list) {
 		populateWithOrderedConversations(list, true);
 	}
 
-	public void populateWithOrderedConversations(List<Conversation> list,
+	public void populateWithOrderedConversations(final List<Conversation> list, boolean includeConferences) {
-			boolean includeConferences) {
 		list.clear();
 		if (includeConferences) {
 			list.addAll(getConversations());
@@ -992,6 +989,7 @@ public class XmppConnectionService extends Service {
 
 	public Conversation findOrCreateConversation(final Account account, final Jid jid,
 			final boolean muc) {
+		synchronized (this.conversations) {
 			Conversation conversation = find(account, jid);
 			if (conversation != null) {
 				return conversation;
@@ -1005,8 +1003,7 @@ public class XmppConnectionService extends Service {
 				} else {
 					conversation.setMode(Conversation.MODE_SINGLE);
 				}
-			conversation.setMessages(databaseBackend.getMessages(conversation,
+				conversation.addAll(0, databaseBackend.getMessages(conversation, 50));
-						50));
 				this.databaseBackend.updateConversation(conversation);
 			} else {
 				String conversationName;
@@ -1029,8 +1026,10 @@ public class XmppConnectionService extends Service {
 			updateConversationUi();
 			return conversation;
 		}
+	}
 
 	public void archiveConversation(Conversation conversation) {
+		synchronized (this.conversations) {
 			if (conversation.getMode() == Conversation.MODE_MULTI) {
 				if (conversation.getAccount().getStatus() == Account.State.ONLINE) {
 					Bookmark bookmark = conversation.getBookmark();
@@ -1047,6 +1046,7 @@ public class XmppConnectionService extends Service {
 			this.conversations.remove(conversation);
 			updateConversationUi();
 		}
+	}
 
 	public void clearConversationHistory(Conversation conversation) {
 		this.databaseBackend.deleteMessagesInConversation(conversation);
@@ -1075,6 +1075,7 @@ public class XmppConnectionService extends Service {
 	}
 
 	public void deleteAccount(Account account) {
+		synchronized (this.conversations) {
 			for (Conversation conversation : conversations) {
 				if (conversation.getAccount() == account) {
 					if (conversation.getMode() == Conversation.MODE_MULTI) {
@@ -1093,6 +1094,7 @@ public class XmppConnectionService extends Service {
 			updateAccountUi();
 			UIHelper.showErrorNotification(getApplicationContext(), getAccounts());
 		}
+	}
 
 	private void removeStaleListeners() {
 		boolean removedListener = false;

src/main/java/eu/siacs/conversations/ui/ConversationFragment.java

@@ -94,7 +94,7 @@ public class ConversationFragment extends Fragment {
 		}
 	};
 	protected ListView messagesView;
-	protected List<Message> messageList = new ArrayList<>();
+	final protected List<Message> messageList = new ArrayList<>();
 	protected MessageAdapter messageListAdapter;
 	protected Contact contact;
 	private EditMessage mEditMessage;