Add function to enable request handling (ensure that all handlers are

registered before reading requests) and cleanup

bramble-core/src/main/java/org/briarproject/bramble/mailbox/protocol/MailboxProtocol.java

@@ -56,10 +56,6 @@ public class MailboxProtocol implements Runnable {
 
 	}
 
-	public void registerRequestHandler(MailboxRequestHandler handler) {
-		requestHandlers.put(handler.getType(), handler);
-	}
-
 	public void sendKeepAlive() throws IOException {
 		// flush the writer without pending data to send a keepalive
 		if (stopped.get())
@@ -109,12 +105,33 @@ public class MailboxProtocol implements Runnable {
 	 */
 	@Override
 	public void run() {
-		ioExecutor.execute(() -> writeOutgoingMessages());
-		readIncomingMessages();
+		writeOutgoingMessages();
+	}
+
+	/**
+	 * Register a Handler for a specific request type.
+	 * <p>
+	 * NOTE: {@link this#enableRequestHandling()} MUST be called after all handlers
+	 * have been registered!
+	 *
+	 * @param handler
+	 */
+	public void registerRequestHandler(MailboxRequestHandler handler) {
+		if (requestHandlers.containsKey(handler.getType()))
+			throw new RuntimeException(
+					"Handler for " + handler.getType().toString() +
+							" has been registered twice!");
+		requestHandlers.put(handler.getType(), handler);
+	}
+
+	/**
+	 * Request handling once all request handlers are registered
+	 */
+	public void enableRequestHandling() {
+		ioExecutor.execute(() -> readIncomingMessages());
 	}
 
 	private void readIncomingMessages() {
-		readingThread = Thread.currentThread();
 		BdfList bdfMsg;
 
 		while (!stopped.get()) {
@@ -124,7 +141,6 @@ public class MailboxProtocol implements Runnable {
 					throw new EOFException();
 				bdfMsg = mailboxBdfReader.readList();
 			} catch (IOException e) {
-				readingThread.interrupt();
 				handleIOException(true, e);
 				return;
 			}
@@ -153,6 +169,10 @@ public class MailboxProtocol implements Runnable {
 			try {
 				handler.handleRequest(req);
 			} catch (ProtocolException e) {
+				if (!req.hasResponse())
+					throw new RuntimeException(
+							"Protocol exception was thrown for request without response");
+
 				error = e.toString();
 			}
 		} else {