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# Isolate Example
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A sample application that demonstrate best practices when using [`isolates`](https://api.dartlang.org/stable/2.3.1/dart-isolate/Isolate-class.html).
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## Goals
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* Display the performance benefits of isolates when using them in the right situation.
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* Show how to use the `compute` method for straightforward computations.
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* Demonstrate how to initialize and use an isolate.
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* Show the cost of moving data between isolates and provide alternatives.
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## The important bits
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### `page_one.dart`
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Compares running a large computation on the main isolate with running the same calculation
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on a second isolate. When the main isolate is used, Flutter is unable to render new frames, and
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the `SmoothAnimationWidget`'s animation freezes.
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### `page_two.dart`
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Creates an isolate used to run an infinite loop that sums batches of 100M randomly generated
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numbers at a time. Users can start, terminate, pause, and resume the isolate, as well as modify
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how the calculation is performed.
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### `page_three.dart`
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Demonstrates how expensive it is to move large amounts of data between isolates and a
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better alternative to move data. This page creates an isolate that can add up a list of numbers
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and gives users three options for how to provide it with input:
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* Send values normally using a List
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* Send the values using TransferableTypedData
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* Generate the values on the second isolate, so no copying is necessary
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Users can then compare the performance of each approach using the displayed timestamps.
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## Questions/issues
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If you have a general question about any of the techniques you see in
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the sample, the best places to go are:
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* [The FlutterDev Google Group](https://groups.google.com/forum/#!forum/flutter-dev)
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* [The Flutter Gitter channel](https://gitter.im/flutter/flutter)
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* [StackOverflow](https://stackoverflow.com/questions/tagged/flutter)
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If you run into an issue with the sample itself, please file an issue
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in the [main Flutter repo](https://github.com/flutter/flutter/issues).
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