refactor(vm): extract executeConstantContract for readability

callConstantContract becomes a thin throttle wrapper (acquire / try-finally
/ release); the TVM execution body moves to a private executeConstantContract.
Each method now reads with one concern in mind.

Author: yanghang8612

framework/src/main/java/org/tron/core/Wallet.java

@@ -3238,53 +3238,7 @@ public Transaction callConstantContract(TransactionCapsule trxCap,
       }
     }
     try {
-      Block headBlock;
-      List<BlockCapsule> blockCapsuleList = chainBaseManager.getBlockStore()
-          .getBlockByLatestNum(1);
-      if (CollectionUtils.isEmpty(blockCapsuleList)) {
-        throw new HeaderNotFound("latest block not found");
-      } else {
-        headBlock = blockCapsuleList.get(0).getInstance();
-      }
-
-      BlockCapsule headBlockCapsule = new BlockCapsule(headBlock);
-      TransactionContext context = new TransactionContext(headBlockCapsule, trxCap,
-          StoreFactory.getInstance(), true, false);
-      VMActuator vmActuator = new VMActuator(true);
-
-      vmActuator.validate(context);
-      vmActuator.execute(context);
-
-      ProgramResult result = context.getProgramResult();
-      if (!isEstimating && result.getException() != null
-          || result.getException() instanceof Program.OutOfTimeException) {
-        RuntimeException e = result.getException();
-        logger.warn("Constant call failed for reason: {}", e.getMessage());
-        throw e;
-      }
-
-      TransactionResultCapsule ret = new TransactionResultCapsule();
-      builder.setEnergyUsed(result.getEnergyUsed());
-      builder.setEnergyPenalty(result.getEnergyPenaltyTotal());
-      builder.addConstantResult(ByteString.copyFrom(result.getHReturn()));
-      result.getLogInfoList().forEach(logInfo ->
-          builder.addLogs(LogInfo.buildLog(logInfo)));
-      result.getInternalTransactions().forEach(it ->
-          builder.addInternalTransactions(buildInternalTransaction(it)));
-      ret.setStatus(0, code.SUCESS);
-      if (StringUtils.isNoneEmpty(result.getRuntimeError())) {
-        ret.setStatus(0, code.FAILED);
-        retBuilder
-            .setMessage(ByteString.copyFromUtf8(result.getRuntimeError()))
-            .build();
-      }
-      if (result.isRevert()) {
-        ret.setStatus(0, code.FAILED);
-        retBuilder.setMessage(ByteString.copyFromUtf8("REVERT opcode executed"))
-            .build();
-      }
-      trxCap.setResult(ret);
-      return trxCap.getInstance();
+      return executeConstantContract(trxCap, builder, retBuilder, isEstimating);
     } finally {
       if (acquiredHere) {
         // remove() before release(): clears the slot from this worker's
@@ -3296,6 +3250,66 @@ public Transaction callConstantContract(TransactionCapsule trxCap,
     }
   }
 
+  /**
+   * Runs the actual TVM execution for a constant call. Split out from
+   * {@link #callConstantContract} so the public method stays focused on the
+   * concurrency-cap wrapper (acquire / try-finally / release) and the VM
+   * execution body has no concurrency concerns to read past. Callers must
+   * already hold the permit (or have determined that the cap is not engaged);
+   * this method does no throttling of its own.
+   */
+  private Transaction executeConstantContract(TransactionCapsule trxCap,
+      Builder builder, Return.Builder retBuilder, boolean isEstimating)
+      throws ContractValidateException, ContractExeException, HeaderNotFound, VMIllegalException {
+    Block headBlock;
+    List<BlockCapsule> blockCapsuleList = chainBaseManager.getBlockStore()
+        .getBlockByLatestNum(1);
+    if (CollectionUtils.isEmpty(blockCapsuleList)) {
+      throw new HeaderNotFound("latest block not found");
+    } else {
+      headBlock = blockCapsuleList.get(0).getInstance();
+    }
+
+    BlockCapsule headBlockCapsule = new BlockCapsule(headBlock);
+    TransactionContext context = new TransactionContext(headBlockCapsule, trxCap,
+        StoreFactory.getInstance(), true, false);
+    VMActuator vmActuator = new VMActuator(true);
+
+    vmActuator.validate(context);
+    vmActuator.execute(context);
+
+    ProgramResult result = context.getProgramResult();
+    if (!isEstimating && result.getException() != null
+        || result.getException() instanceof Program.OutOfTimeException) {
+      RuntimeException e = result.getException();
+      logger.warn("Constant call failed for reason: {}", e.getMessage());
+      throw e;
+    }
+
+    TransactionResultCapsule ret = new TransactionResultCapsule();
+    builder.setEnergyUsed(result.getEnergyUsed());
+    builder.setEnergyPenalty(result.getEnergyPenaltyTotal());
+    builder.addConstantResult(ByteString.copyFrom(result.getHReturn()));
+    result.getLogInfoList().forEach(logInfo ->
+        builder.addLogs(LogInfo.buildLog(logInfo)));
+    result.getInternalTransactions().forEach(it ->
+        builder.addInternalTransactions(buildInternalTransaction(it)));
+    ret.setStatus(0, code.SUCESS);
+    if (StringUtils.isNoneEmpty(result.getRuntimeError())) {
+      ret.setStatus(0, code.FAILED);
+      retBuilder
+          .setMessage(ByteString.copyFromUtf8(result.getRuntimeError()))
+          .build();
+    }
+    if (result.isRevert()) {
+      ret.setStatus(0, code.FAILED);
+      retBuilder.setMessage(ByteString.copyFromUtf8("REVERT opcode executed"))
+          .build();
+    }
+    trxCap.setResult(ret);
+    return trxCap.getInstance();
+  }
+
   public SmartContract getContract(GrpcAPI.BytesMessage bytesMessage) {
     byte[] address = bytesMessage.getValue().toByteArray();
     AccountCapsule accountCapsule = chainBaseManager.getAccountStore().get(address);