fix(net): refine TransactionsMsgHandler shutdown and test

Author: 0xbigapple

framework/src/main/java/org/tron/core/net/messagehandler/TransactionsMsgHandler.java

@@ -66,9 +66,10 @@ public void init() {
    */
   public void close() {
     isClosed = true;
-    // Shutdown the producer (scheduler) first to stop generating new tasks
+    // Shutdown the producer (scheduler) first.
+    // Pending tasks in smartContractQueue will be discarded.
     ExecutorServiceManager.shutdownAndAwaitTermination(smartContractExecutor, smartEsName);
-    // Then shutdown the consumer (worker pool) to finish existing tasks
+    // Then shutdown the consumer (worker pool) to finish tasks already submitted to trxHandlePool.
     ExecutorServiceManager.shutdownAndAwaitTermination(trxHandlePool, trxEsName);
   }
 
@@ -141,9 +142,7 @@ private void check(PeerConnection peer, TransactionsMessage msg) throws P2pExcep
   private void handleSmartContract() {
     ExecutorServiceManager.scheduleWithFixedDelay(smartContractExecutor, () -> {
       try {
-        // Stop fetching from queue if the handler is closed
-        while (!isClosed
-            && queue.size() < MAX_SMART_CONTRACT_SUBMIT_SIZE
+        while (queue.size() < MAX_SMART_CONTRACT_SUBMIT_SIZE
             && smartContractQueue.size() > 0) {
           TrxEvent event = smartContractQueue.take();
           ExecutorServiceManager.submit(

framework/src/test/java/org/tron/core/net/messagehandler/TransactionsMsgHandlerTest.java

@@ -133,19 +133,18 @@ public void testProcessMessage() {
   }
 
   @Test
-  public void testProcessMessageAfterClose() {
+  public void testProcessMessageAfterClose() throws Exception {
     TransactionsMsgHandler handler = new TransactionsMsgHandler();
     handler.init();
     handler.close();
 
     PeerConnection peer = Mockito.mock(PeerConnection.class);
     TransactionsMessage msg = Mockito.mock(TransactionsMessage.class);
 
-    try {
-      handler.processMessage(peer, msg);
-    } catch (Exception e) {
-      Assert.fail("Should not throw any exception when closed");
-    }
+    handler.processMessage(peer, msg);
+    
+    // Verify that the handler immediately returned and did not process the message
+    Mockito.verify(msg, Mockito.never()).getTransactions();
   }
 
   class TrxEvent {