Can serializableConnection() be passed through compute? - Illegal argument in isolate message: object is unsendable

[tomekit]

I am using Drift to store log entries.
Our app uses lots of compute calls.
I would like to instantiate Drift DB inside the compute.

Based on documentation: https://drift.simonbinder.eu/isolates/#simple-sharing

I am trying to pass: db.serializableConnection() to compute as a message/param.

Like this:

final Map<String, Object> params = {}
params["loggerConnection"] = db.serializableConnection()
final result = await compute(function, params);

but I get the:

Error: Invalid argument(s): Illegal argument in isolate message: object is unsendable - Library:'dart:async' Class: _Future@5048458 (see restrictions listed at `SendPort.send()` documentation for more information)
 <- _List len:32 (from dart:core)
 <- _Map len:9 (from dart:_compact_hash)
 <- field message in compute.<anonymous closure> (from package:flutter/src/foundation/_isolates_io.dart)
 <- resultPort in Instance of '_RemoteRunner<String>' (from dart:isolate)
 Stack: #0      Isolate._spawnFunction (dart:isolate-patch/isolate_patch.dart:398:25)
#1      Isolate.spawn (dart:isolate-patch/isolate_patch.dart:378:7)
#2      Isolate.run (dart:isolate:285:15)
#3      compute (package:flutter/src/foundation/_isolates_io.dart:18:18)
#4      compute (package:flutter/src/foundation/isolates.dart:82:19)

I was hoping to use it inside of the compute function like this:

final connection = args["loggerConnection"] as DriftIsolate;
final executor = await connection.connect();
final driftDatabase = AppDatabaseDrift(executor);

Any hint would be appreciated!

[simolus3]

That's exactly how serializableConnection() is supposed to be used. The only problem is that it returns a Future, so you need to use:

params["loggerConnection"] = await db.serializableConnection()

The future itself can't be shared across isolates, but the returned DriftIsolate can.