fix(jsonrpc): normalize error responses and fatal handling

framework/src/main/java/org/tron/core/services/jsonrpc/JsonRpcErrorResolver.java

@@ -1,50 +1,140 @@
 package org.tron.core.services.jsonrpc;
 
 import com.fasterxml.jackson.databind.JsonNode;
-import com.googlecode.jsonrpc4j.ErrorData;
 import com.googlecode.jsonrpc4j.ErrorResolver;
 import com.googlecode.jsonrpc4j.JsonRpcError;
 import com.googlecode.jsonrpc4j.JsonRpcErrors;
+import com.googlecode.jsonrpc4j.ProxyUtil;
 import com.googlecode.jsonrpc4j.ReflectionUtil;
 import java.lang.reflect.Method;
 import java.util.List;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
+import org.tron.core.exception.TronError;
 import org.tron.core.exception.jsonrpc.JsonRpcException;
 
 /**
  * {@link ErrorResolver} that uses annotations.
  */
+@Slf4j(topic = "API")
 public enum JsonRpcErrorResolver implements ErrorResolver {
   INSTANCE;
 
+  private static final Set<String> SEEN_FAILURES = ConcurrentHashMap.newKeySet();
+
   /**
    * {@inheritDoc}
    */
   @Override
   public JsonError resolveError(
       Throwable thrownException, Method method, List<JsonNode> arguments) {
-    JsonRpcError resolver = getResolverForException(thrownException, method);
-    if (notFoundResolver(resolver)) {
-      return null;
+    Error fatal = findFatalCause(thrownException);
+    if (fatal != null) {
+      throw fatal;
+    }
+
+    JsonRpcError resolver = method == null
+        ? null : getResolverForException(thrownException, method);
+    if (resolver == null) {
+      logUnhandledException(method, thrownException);
+      return new JsonError(JsonError.INTERNAL_ERROR.code, "Internal error", null);
     }
 
     String message = hasErrorMessage(resolver) ? resolver.message() : thrownException.getMessage();
+    if (StringUtils.isBlank(message)) {
+      message = defaultMessageFor(resolver.code());
+    }
 
-    // data priority: exception > annotation > default ErrorData
+    // data priority: exception > annotation
     Object data = null;
     if (thrownException instanceof JsonRpcException) {
       JsonRpcException jsonRpcException = (JsonRpcException) thrownException;
       data = jsonRpcException.getData();
     }
 
-    if (data == null) {
-      data = hasErrorData(resolver)
-          ? resolver.data()
-          : new ErrorData(resolver.exception().getName(), message);
+    if (data == null && hasErrorData(resolver)) {
+      data = resolver.data();
     }
-    
+
     return new JsonError(resolver.code(), message, data);
   }
 
+  static Error findFatalCause(Throwable throwable) {
+    // Avoid allocations when handling memory exhaustion, without truncating deep cause chains.
+    // Check both fast-pointer steps so cycle detection cannot skip a fatal cause inside a cycle.
+    Throwable slow = throwable;
+    Throwable fast = throwable;
+    while (fast != null) {
+      if (isFatal(fast)) {
+        return (Error) fast;
+      }
+      fast = fast.getCause();
+      if (fast == null) {
+        return null;
+      }
+      if (isFatal(fast)) {
+        return (Error) fast;
+      }
+      fast = fast.getCause();
+      slow = slow.getCause();
+      if (fast == slow) {
+        return null;
+      }
+    }
+    return null;
+  }
+
+  private static boolean isFatal(Throwable cause) {
+    return cause instanceof VirtualMachineError
+        || cause instanceof ThreadDeath
+        || cause instanceof LinkageError
+        || cause instanceof TronError;
+  }
+
+  private static void logUnhandledException(Method method, Throwable thrownException) {
+    String methodName = rpcMethodName(method);
+    String exceptionName = thrownException.getClass().getName();
+    String key = methodName + '\0' + exceptionName;
+    if (SEEN_FAILURES.add(key)) {
+      // The first occurrence retains the Throwable for diagnosis. Repeated failures omit both
+      // the stack and exception message so a request loop cannot flood the WARN log.
+      logger.warn("Unhandled exception in JSON-RPC method {}", methodName, thrownException);
+    } else {
+      logger.debug("Repeated unhandled exception in JSON-RPC method {} ({})",
+          methodName, exceptionName);
+    }
+  }
+
+  static void clearSeenFailuresForTest() {
+    SEEN_FAILURES.clear();
+  }
+
+  private static String rpcMethodName(Method method) {
+    if (method == null) {
+      return "unknown";
+    }
+    try {
+      return ProxyUtil.getMethodName(method);
+    } catch (RuntimeException e) {
+      return method.getName();
+    }
+  }
+
+  private static String defaultMessageFor(int code) {
+    switch (code) {
+      case -32600:
+        return "Invalid Request";
+      case -32601:
+        return "Method not found";
+      case -32602:
+        return "Invalid params";
+      default:
+        return "Internal error";
+    }
+  }
+
   private JsonRpcError getResolverForException(Throwable thrownException, Method method) {
     JsonRpcErrors errors = ReflectionUtil.getAnnotation(method, JsonRpcErrors.class);
     if (hasAnnotations(errors)) {
@@ -57,10 +147,6 @@ private JsonRpcError getResolverForException(Throwable thrownException, Method m
     return null;
   }
 
-  private boolean notFoundResolver(JsonRpcError resolver) {
-    return resolver == null;
-  }
-
   private boolean hasErrorMessage(JsonRpcError em) {
     // noinspection ConstantConditions
     return em.message() != null && !em.message().trim().isEmpty();
@@ -78,4 +164,4 @@ private boolean hasAnnotations(JsonRpcErrors errors) {
   private boolean isExceptionInstanceOfError(Throwable target, JsonRpcError em) {
     return em.exception().isInstance(target);
   }
-}
+}