More reliable start-up by removing some race conditions in Controller and Network

src/main/java/org/qora/controller/Controller.java

@@ -16,7 +16,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Random;
-import java.util.concurrent.atomic.AtomicReference;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
@@ -116,14 +115,14 @@ public class Controller extends Thread {
 	private static volatile boolean isStopping = false;
 	private static BlockMinter blockMinter = null;
 	private static volatile boolean requestSync = false;
-	private static volatile boolean requestSysTrayUpdate = false;
+	private static volatile boolean requestSysTrayUpdate = true;
 	private static Controller instance;
 
 	private final String buildVersion;
 	private final long buildTimestamp; // seconds
 	private final String[] savedArgs;
 
-	private AtomicReference<BlockData> chainTip = new AtomicReference<>();
+	private volatile BlockData chainTip = null;
 
 	private long repositoryBackupTimestamp = startTime + REPOSITORY_BACKUP_PERIOD; // ms
 	private long ntpCheckTimestamp = startTime; // ms
@@ -188,7 +187,7 @@ public class Controller extends Thread {
 		this.savedArgs = args;
 	}
 
-	private static Controller newInstance(String[] args) {
+	private static synchronized Controller newInstance(String[] args) {
 		instance = new Controller(args);
 		return instance;
 	}
@@ -216,7 +215,7 @@ public class Controller extends Thread {
 
 	/** Returns current blockchain height, or 0 if it's not available. */
 	public int getChainHeight() {
-		BlockData blockData = this.chainTip.get();
+		BlockData blockData = this.chainTip;
 		if (blockData == null)
 			return 0;
 
@@ -225,12 +224,12 @@ public class Controller extends Thread {
 
 	/** Returns highest block, or null if it's not available. */
 	public BlockData getChainTip() {
-		return this.chainTip.get();
+		return this.chainTip;
 	}
 
 	/** Cache new blockchain tip, and also wipe cache of online accounts. */
 	public void setChainTip(BlockData blockData) {
-		this.chainTip.set(blockData);
+		this.chainTip = blockData;
 	}
 
 	public ReentrantLock getBlockchainLock() {
@@ -263,6 +262,8 @@ public class Controller extends Thread {
 			return; // Not System.exit() so that GUI can display error
 		}
 
+		Controller.newInstance(args);
+
 		LOGGER.info("Starting NTP");
 		NTP.start();
 
@@ -301,13 +302,13 @@ public class Controller extends Thread {
 		}
 
 		LOGGER.info("Starting controller");
-		Controller.newInstance(args).start();
+		Controller.getInstance().start();
 
 		LOGGER.info(String.format("Starting networking on port %d", Settings.getInstance().getListenPort()));
 		try {
 			Network network = Network.getInstance();
 			network.start();
-		} catch (Exception e) {
+		} catch (IOException e) {
 			LOGGER.error("Unable to start networking", e);
 			Gui.getInstance().fatalError("Networking failure", e);
 			return; // Not System.exit() so that GUI can display error
@@ -372,15 +373,37 @@ public class Controller extends Thread {
 
 		try {
 			while (!isStopping) {
+				// Maybe update SysTray
+				if (requestSysTrayUpdate) {
+					requestSysTrayUpdate = false;
+					updateSysTray();
+				}
+
 				Thread.sleep(1000);
 
+				final long now = System.currentTimeMillis();
+
+				// Check NTP status
+				if (now >= ntpCheckTimestamp) {
+					Long ntpTime = NTP.getTime();
+
+					if (ntpTime != null) {
+						LOGGER.info(String.format("Adjusting system time by NTP offset: %dms", ntpTime - now));
+						ntpCheckTimestamp = now + NTP_POST_SYNC_CHECK_PERIOD;
+						requestSysTrayUpdate = true;
+					} else {
+						LOGGER.info(String.format("No NTP offset yet"));
+						ntpCheckTimestamp = now + NTP_PRE_SYNC_CHECK_PERIOD;
+						// We can't do much without a valid NTP time
+						continue;
+					}
+				}
+
 				if (requestSync) {
 					requestSync = false;
 					potentiallySynchronize();
 				}
 
-				final long now = System.currentTimeMillis();
-
 				// Clean up arbitrary data request cache
 				final long requestMinimumTimestamp = now - ARBITRARY_REQUEST_TIMEOUT;
 				arbitraryDataRequests.entrySet().removeIf(entry -> entry.getValue().getC() < requestMinimumTimestamp);
@@ -391,21 +414,6 @@ public class Controller extends Thread {
 					RepositoryManager.backup(true);
 				}
 
-				// Check NTP status
-				if (now >= ntpCheckTimestamp) {
-					Long ntpTime = NTP.getTime();
-
-					if (ntpTime != null) {
-						LOGGER.info(String.format("Adjusting system time by NTP offset: %dms", ntpTime - now));
-						ntpCheckTimestamp = now + NTP_POST_SYNC_CHECK_PERIOD;
-					} else {
-						LOGGER.info(String.format("No NTP offset yet"));
-						ntpCheckTimestamp = now + NTP_PRE_SYNC_CHECK_PERIOD;
-					}
-
-					requestSysTrayUpdate = true;
-				}
-
 				// Prune stuck/slow/old peers
 				try {
 					Network.getInstance().prunePeers();
@@ -419,12 +427,6 @@ public class Controller extends Thread {
 					deleteExpiredTransactions();
 				}
 
-				// Maybe update SysTray
-				if (requestSysTrayUpdate) {
-					requestSysTrayUpdate = false;
-					updateSysTray();
-				}
-
 				// Perform tasks to do with managing online accounts list
 				if (now >= onlineAccountsTasksTimestamp) {
 					onlineAccountsTasksTimestamp = now + ONLINE_ACCOUNTS_TASKS_INTERVAL;

src/main/java/org/qora/network/Network.java

@@ -118,30 +118,6 @@ public class Network {
 	// Constructors
 
 	private Network() {
-		// Grab P2P port from settings
-		int listenPort = Settings.getInstance().getListenPort();
-
-		// Grab P2P bind address from settings
-		try {
-			InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
-			InetSocketAddress endpoint = new InetSocketAddress(bindAddr, listenPort);
-
-			channelSelector = Selector.open();
-
-			// Set up listen socket
-			serverChannel = ServerSocketChannel.open();
-			serverChannel.configureBlocking(false);
-			serverChannel.setOption(StandardSocketOptions.SO_REUSEADDR, true);
-			serverChannel.bind(endpoint, LISTEN_BACKLOG);
-			serverChannel.register(channelSelector, SelectionKey.OP_ACCEPT);
-		} catch (UnknownHostException e) {
-			LOGGER.error(String.format("Can't bind listen socket to address %s", Settings.getInstance().getBindAddress()));
-			throw new RuntimeException("Can't bind listen socket to address", e);
-		} catch (IOException e) {
-			LOGGER.error(String.format("Can't create listen socket: %s", e.getMessage()));
-			throw new RuntimeException("Can't create listen socket", e);
-		}
-
 		connectedPeers = new ArrayList<>();
 		selfPeers = new ArrayList<>();
 
@@ -169,14 +145,38 @@ public class Network {
 		networkEPC = new NetworkProcessor(networkExecutor);
 	}
 
-	public void start() {
+	public void start() throws IOException {
+		// Grab P2P port from settings
+		int listenPort = Settings.getInstance().getListenPort();
+
+		// Grab P2P bind address from settings
+		try {
+			InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
+			InetSocketAddress endpoint = new InetSocketAddress(bindAddr, listenPort);
+
+			channelSelector = Selector.open();
+
+			// Set up listen socket
+			serverChannel = ServerSocketChannel.open();
+			serverChannel.configureBlocking(false);
+			serverChannel.setOption(StandardSocketOptions.SO_REUSEADDR, true);
+			serverChannel.bind(endpoint, LISTEN_BACKLOG);
+			serverChannel.register(channelSelector, SelectionKey.OP_ACCEPT);
+		} catch (UnknownHostException e) {
+			LOGGER.error(String.format("Can't bind listen socket to address %s", Settings.getInstance().getBindAddress()));
+			throw new IOException("Can't bind listen socket to address", e);
+		} catch (IOException e) {
+			LOGGER.error(String.format("Can't create listen socket: %s", e.getMessage()));
+			throw new IOException("Can't create listen socket", e);
+		}
+
 		// Start up first networking thread
 		networkEPC.start();
 	}
 
 	// Getters / setters
 
-	public static Network getInstance() {
+	public static synchronized Network getInstance() {
 		if (instance == null)
 			instance = new Network();