It takes too long to create "isolate"

[govanyjj]

When I execute the following code, I find that waiting for success takes about 1 second or more. Also, when I need to create "isolation" multiple times in my application, I usually wait a long time. When waiting for a long time, I use "CALL STACK" in vscode and use pause> Continue to operate a single "isolate", Then "isolate" will execute correctly and give a return value, otherwise it will wait forever.

int begin = DateTime.now().millisecondsSinceEpoch;
    Isolate isolate = await Isolate.spawn(command.params['method'], argparams,
        debugName: command.params['token'],
        errorsAreFatal: true,
        onError: _onError);
    print(
        "Isolate.spawn ${command.params['token']} complete:cost time:${DateTime.now().millisecondsSinceEpoch - begin}");

I/flutter (29746): Isolate.spawn parsecore complete:cost time:5882
I/flutter (29746): Isolate.spawn hubCore complete:cost time:5911
I/flutter (29746): Isolate.spawn preparse complete:cost time:2071
I/flutter (29746): Isolate.spawn preparse complete:cost time:2549

What can I do to get the return value of "isolate.spwan" quickly?

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[mraleph]

Can you provide a way to reproduce the issue, e.g. the code and step by step guide? It should not take seconds to spawn an isolate.

• Do you see this sort of delays when you run your application outside of the IDE (e.g. when you just use flutter run from command line)
• Do you see this sort of delays in release builds of your application? (flutter run --release).

/cc @mkustermann @aam

[govanyjj]

Can you provide a way to reproduce the issue, e.g. the code and step by step guide? It should not take seconds to spawn an isolate.

* Do you see this sort of delays when you run your application outside of the IDE (e.g. when you just use `flutter run` from command line)

* Do you see this sort of delays in release builds of your application? (`flutter run --release`).

/cc @mkustermann @aam

Hi@mraleph : Thank you for your reply. When I tried to use the two suggestions you gave, currently testing it can give a response within 30 milliseconds quickly, and there is no long-term unresponsive situation under the IDE.

Reproduced in the IDE, as shown in the following code: Github

This is the result of running in vscode

I/flutter (30706): create isolate finish cost time 7801
I/flutter (30706): create isolate finish cost time 7834
I/flutter (30706): create isolate finish cost time 7754
I/flutter (30706): create isolate finish cost time 9757
I/flutter (30706): create isolate finish cost time 9685
I/flutter (30706): create isolate finish cost time 9907

Version: 1.43.2
Commit: 0ba0ca52957102ca3527cf479571617f0de6ed50
Date: 2020-03-24T07:34:57.037Z
Electron: 7.1.11
Chrome: 78.0.3904.130
Node.js: 12.8.1
V8: 7.8.279.23-electron.0
OS: Darwin x64 19.2.0

This is the result of running in Android Studio

I/flutter (30843): create isolate finish cost time 3024
I/flutter (30843): create isolate finish cost time 3013
I/flutter (30843): create isolate finish cost time 2962
I/flutter (30843): create isolate finish cost time 3000
I/flutter (30843): create isolate finish cost time 3029
I/flutter (30843): create isolate finish cost time 3020
I/flutter (30843): create isolate finish cost time 3023
I/flutter (30843): create isolate finish cost time 3031

Android Studio 3.6
Build #AI-192.7142.36.36.6200805, built on February 12, 2020
Runtime version: 1.8.0_212-release-1586-b4-5784211 x86_64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
macOS 10.15.2
GC: ParNew, ConcurrentMarkSweep
Memory: 1979M
Cores: 12 

[mraleph]

Sounds like this is caused by IDE debugger being attached.

@rmacnak-google @bkonyi do you maybe recognize the issue?