improve trade state reliability

update trade state atomically on UserThread
nullify error handling on deposits confirmed message
set trade state before deposit request and relay
add checks before deleting wallet
UserThread.await() detects if on UserThread

common/src/main/java/haveno/common/UserThread.java

@@ -45,6 +45,7 @@ public class UserThread {
     @Getter
     @Setter
     private static Executor executor;
+    private static final String USER_THREAD_NAME = "UserThread";
 
     public static void setTimerClass(Class<? extends Timer> timerClass) {
         UserThread.timerClass = timerClass;
@@ -57,21 +58,30 @@ public class UserThread {
     }
 
     public static void execute(Runnable command) {
-        UserThread.executor.execute(command);
+        UserThread.executor.execute(() -> {
+            Thread.currentThread().setName(USER_THREAD_NAME);
+            command.run();
+        });
     }
 
     public static void await(Runnable command) {
-        CountDownLatch latch = new CountDownLatch(1);
-        executor.execute(() -> {
+        if (isUserThread(Thread.currentThread())) {
             command.run();
-            latch.countDown();
-        });
+        } else {
+            CountDownLatch latch = new CountDownLatch(1);
+            execute(command); // run task
+            execute(() -> latch.countDown()); // await next tick
             try {
                 latch.await();
             } catch (InterruptedException e) {
                 throw new RuntimeException(e);
             }
         }
+    }
+
+    public static boolean isUserThread(Thread thread) {
+        return USER_THREAD_NAME.equals(thread.getName());
+    }
 
     // Prefer FxTimer if a delay is needed in a JavaFx class (gui module)
     public static Timer runAfterRandomDelay(Runnable runnable, long minDelayInSec, long maxDelayInSec) {

core/src/main/java/haveno/core/api/XmrConnectionService.java

@@ -647,7 +647,7 @@ public final class XmrConnectionService {
                     if (DevEnv.isDevMode()) e.printStackTrace();
                 }
 
-                // check connection which notifies of changes
+                new Thread(() -> {
                     if (connectionManager.getAutoSwitch()) connectionManager.setConnection(connectionManager.getBestAvailableConnection());
                     else connectionManager.checkConnection();
 
@@ -655,6 +655,7 @@ public final class XmrConnectionService {
                     if (!Boolean.TRUE.equals(connectionManager.isConnected()) && HavenoUtils.havenoSetup != null) {
                         HavenoUtils.havenoSetup.getWalletServiceErrorMsg().set(e.getMessage());
                     }
+                }).start();
             } finally {
                 pollInProgress = false;
             }

core/src/main/java/haveno/core/trade/Trade.java

@@ -802,6 +802,17 @@ public abstract class Trade implements Tradable, Model {
         return this instanceof ArbitratorTrade && isDepositsConfirmed() && walletExists() && syncNormalStartTimeMs == null; // arbitrator idles trade after deposits confirm unless overriden
     }
 
+    public boolean isSyncedWithinTolerance() {
+        synchronized (walletLock) {
+            if (wallet == null) return false;
+            if (!xmrConnectionService.isSyncedWithinTolerance()) return false;
+            Long targetHeight = xmrConnectionService.getTargetHeight();
+            if (targetHeight == null) return false;
+            if (targetHeight - wallet.getHeight() <= 3) return true; // synced if within 3 blocks of target height
+            return false;
+        }
+    }
+
     public void syncAndPollWallet() {
         syncWallet(true);
     }
@@ -880,13 +891,25 @@ public abstract class Trade implements Tradable, Model {
             if (walletExists()) {
                 try {
                     
+                    // check if synced
+                    if (!isSyncedWithinTolerance()) {
+                        log.warn("Refusing to delete wallet for {} {} because it is not synced within tolerance", getClass().getSimpleName(), getId());
+                        return;
+                    }
+
+                    // check if balance > 0
+                    if (wallet.getBalance().compareTo(BigInteger.ZERO) > 0) {
+                        log.warn("Refusing to delete wallet for {} {} because it contains a balance", getClass().getSimpleName(), getId());
+                        return;
+                    }
+
                     // check if funds deposited but payout not unlocked
                     if (isDepositsPublished() && !isPayoutUnlocked()) {
                         throw new RuntimeException("Refusing to delete wallet for " + getClass().getSimpleName() + " " + getId() + " because the deposit txs have been published but payout tx has not unlocked");
                     }
 
                     // force stop the wallet
-                    if (wallet != null) stopWallet();
+                    stopWallet();
 
                     // delete wallet
                     log.info("Deleting wallet for {} {}", getClass().getSimpleName(), getId());
@@ -1279,7 +1302,7 @@ public abstract class Trade implements Tradable, Model {
         }
 
         this.state = state;
-        UserThread.execute(() -> {
+        UserThread.await(() -> {
             stateProperty.set(state);
             phaseProperty.set(state.getPhase());
         });
@@ -1310,9 +1333,7 @@ public abstract class Trade implements Tradable, Model {
         }
 
         this.payoutState = payoutState;
-        UserThread.execute(() -> {
-            payoutStateProperty.set(payoutState);
-        });
+        UserThread.await(() -> payoutStateProperty.set(payoutState));
     }
 
     public void setDisputeState(DisputeState disputeState) {

core/src/main/java/haveno/core/trade/TradeManager.java

@@ -1225,7 +1225,7 @@ public class TradeManager implements PersistedDataHost, DecryptedDirectMessageLi
     }
 
     private void removeTradeOnError(Trade trade) {
-        log.warn("TradeManager.removeTradeOnError() " + trade.getId());
+        log.warn("TradeManager.removeTradeOnError() tradeId={}, state={}", trade.getId(), trade.getState());
         synchronized (tradableList) {
 
             // unreserve taker key images

core/src/main/java/haveno/core/trade/protocol/TradeProtocol.java

@@ -429,7 +429,7 @@ public abstract class TradeProtocol implements DecryptedDirectMessageListener, D
                     .using(new TradeTaskRunner(trade,
                         () -> {
                             stopTimeout();
-                            this.errorMessageHandler = null;
+                            this.errorMessageHandler = null; // TODO: set this when trade state is >= DEPOSIT_PUBLISHED
                             handleTaskRunnerSuccess(sender, response);
                             if (tradeResultHandler != null) tradeResultHandler.handleResult(trade); // trade is initialized
                         },
@@ -446,6 +446,7 @@ public abstract class TradeProtocol implements DecryptedDirectMessageListener, D
         System.out.println(getClass().getSimpleName() + ".handle(DepositsConfirmedMessage)");
         synchronized (trade) {
             latchTrade();
+            this.errorMessageHandler = null;
             expect(new Condition(trade)
                     .with(response)
                     .from(sender))

core/src/main/java/haveno/core/trade/protocol/tasks/ArbitratorProcessDepositRequest.java

@@ -112,6 +112,10 @@ public class ArbitratorProcessDepositRequest extends TradeTask {
             // TODO (woodser): add small delay so tx has head start against double spend attempts?
             if (processModel.getMaker().getDepositTxHex() != null && processModel.getTaker().getDepositTxHex() != null) {
 
+                // update trade state
+                trade.setState(Trade.State.SAW_ARRIVED_PUBLISH_DEPOSIT_TX_REQUEST);
+                processModel.getTradeManager().requestPersistence();
+
                 // relay txs
                 MoneroSubmitTxResult makerResult = daemon.submitTxHex(processModel.getMaker().getDepositTxHex(), true);
                 MoneroSubmitTxResult takerResult = daemon.submitTxHex(processModel.getTaker().getDepositTxHex(), true);

core/src/main/java/haveno/core/trade/protocol/tasks/ProcessSignContractResponse.java

@@ -84,6 +84,11 @@ public class ProcessSignContractResponse extends TradeTask {
                         trade.getSelf().getDepositTx().getKey(),
                         trade.getSelf().getPaymentAccountKey());
 
+                // update trade state
+                trade.setState(Trade.State.SENT_PUBLISH_DEPOSIT_TX_REQUEST);
+                processModel.getTradeManager().requestPersistence();
+                trade.addInitProgressStep();
+
                 // send request to arbitrator
                 log.info("Sending {} to arbitrator {}; offerId={}; uid={}", request.getClass().getSimpleName(), trade.getArbitrator().getNodeAddress(), trade.getId(), request.getUid());
                 processModel.getP2PService().sendEncryptedDirectMessage(trade.getArbitrator().getNodeAddress(), trade.getArbitrator().getPubKeyRing(), request, new SendDirectMessageListener() {
@@ -101,11 +106,6 @@ public class ProcessSignContractResponse extends TradeTask {
                         failed();
                     }
                 });
-
-                // deposit is requested
-                trade.setState(Trade.State.SENT_PUBLISH_DEPOSIT_TX_REQUEST);
-                trade.addInitProgressStep();
-                processModel.getTradeManager().requestPersistence();
             } else {
                 log.info("Waiting for another contract signature to send deposit request");
                 complete(); // does not yet have needed signatures