Connection cannot be closed

[zs856]

Hi. I am currently building a Flutter app and making use of the Redis package. I found the connection cannot be closed when I invoke cmd.get_connection().close() until I close the app (Platform: Windows desktop, Edge, and Android app) My flutter verison is: 3.13 Dart Version: Dart SDK version: 3.1.4 (stable) (Tue Oct 17 14:55:53 2023 +0000) on "windows_x64" Redis package version: 4.0.0 Here below is a snippet of codes: In file A, I have a function to create a Command:

//import 'package:flutter/foundation.dart';
import 'package:redis/redis.dart';

Future<Command> createCmd() async {
  Command cmd = await RedisConnection().connect(
      'my-redis-cloud-host', port);
  await cmd.send_object([
    "AUTH",
    "account",
    "secret"
  ]).then((var response) {
    print(response);
  });
  return cmd;
}

In file B, I have other functions to use this Command I created in file A: The function below will be called by 11 elements in a ListView at the same time.

Future<String> readGameRunningState(String gameId) async {
  Command cmd = await createCmd();
  String jobName = await cmd.send_object([
    "GET",
    "key",
  ]);
  await cmd.get_connection().close();
  var logger = Logger();
  logger.d("Connection is closed!: jobName");
  return jobName;

Any suggestion will be helpful. Thank you.

[ra1u]

Hi.

Can you provide more info about where your code gets stuck? In case this code executes, but is not stucked (runs trough close()) I suspect, there must be some other operation that opens, but does not close connection.

Regarding open/close I have just pushed test designed in similar fassion to what you have just described https://github.com/ra1u/redis-dart/commit/23af8c6c7be642043995879bf3e3ebbec2aae0f5. This test runs as expected (it pass), but feel free to modify, so we can learn, if we have indeed bug in this libraray.

Kind regards, Luka

[zs856]

I figured out the reason now.

Reason

1. I didn't figure out what send_object might return (a value or a null)
2. I didn't use the try-catch clause in the async code block so I didn't see any error report.
3. In my case, send_object executes the GET command and cannot get any matched key so it returns null. Obviously, a null cannot be assigned to a String variable.

   Solution

   change

   String jobName = await cmd.send_object([
   "GET",
   "key",
   ]);

   To

   dynamic jobName = await cmd.send_object([
   "GET",
   "key",
   ]);

   and check whether jobName is null.