'http request not executed when run in isolate

Why is the request not executed?

import 'package:http/http.dart' as http;

String req(String x) {
  print("$x req");
  doReq() async {
    final url = Uri.parse("http://google.com");
    print("$x $url");
    final re = await http.get(url);
    print("$x re:");
    print(re.body);
  }
  doReq();
  print("$x done");
  return "ok";
}

// somewhere in the UI
ElevatedButton(
  child: const Text("run"),
  onPressed: () {
    print("in main isolate");
    req("1");
    print("in separate isolate");
    compute(req, "2");
  },
);

Output:

I/flutter (20379): in main isolate
I/flutter (20379): 1 req
I/flutter (20379): 1 http://google.com
I/flutter (20379): 1 done
I/flutter (20379): in separate isolate
I/flutter (20379): 1 re:
I/flutter (20379): <!doctype html>...
I/flutter (20379): 2 req
I/flutter (20379): 2 http://google.com
I/flutter (20379): 2 done

The request is not executed when req runs in an isolate - why and how can I fix this?

flutter

Solution 1:^[1]

Flutter's compute immediately closes the spawned isolate after the method returns and any returned Future is completed. Since your req function synchronously returns a string, the HTTP request will not have completed by the time the isolate is destroyed.

If you await the doReq() call (and return a Future<String> from req), you will probably see the response body both times.

Sources

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Source: Stack Overflow

Solution	Source
Solution 1	Nitrodon

'http request not executed when run in isolate

Solution 1:[1]

Sources

Related Questions

Solution 1:^[1]