I’m currently working with isolates to send queries in parallel to a database server. I have a connector-object to build the connection to the database and I would like to share that across all isolates, so I don’t have to create a separate connection for every isolate.
So far it seems that I can only share special serializable objects between isolates. I’m using the send- and receive-ports for messaging. For other objects (such as my connector-object) the dart-vm yields the error:
Illegal argument(s): Illegal argument in isolate message : (object extends NativeWrapper)
Do you know of any way to share a generic object-instance between multiple isolates? Or do I have to create a separate instance for each isolate?
from the SendPort.send method code doc
* In the special circumstances when two isolates share the same code and are * running in the same process (e.g. isolates created via [Isolate.spawn]), it * is also possible to send object instances (which would be copied in the * process). This is currently only supported by the dartvm. For now, the * dart2js compiler only supports the restricted messages described above.
I assume that objects that are wrappers of native objects aren’t supported either.
It seems currently the only way is to create a new connection in each isolate.
Always working are these kinds of values
* The content of [message] can be: primitive values (null, num, bool, double, * String), instances of [SendPort], and lists and maps whose elements are any * of these. List and maps are also allowed to be cyclic.
Answered By – Günter Zöchbauer
Answer Checked By – Mary Flores (FlutterFixes Volunteer)