# 8. Handle heavy task with isolate
Date: 2022-06-29
## Status
Accepted
## Context
- Use isolate to handle heavy task
## Decision
- Initialize the IsolateManager to help manage the list of tasks and isolate
```
final isolateManager = IsolateManager();
await isolateManager.initialize(isolatesCount: 1);
```
+ `isolatesCount`: The number of isolates created and run concurrently. Depends on your device's processor.
- Perform task processing by calling `execute` function
```
isolateManager.execute(
arguments,
handleTaskAction,
onUpdateProgress
);
```
+ `arguments`: Parameters passed to the function handling heavy tasks.
+ `handleTaskAction`: Function to handle heavy tasks
+ `onUpdateProgress`: Callback function every time a value is sent from `new isolate` to `main isolate` via `sendPort`
- The return value is a `Completer`
- Communicate between two isolates
To see a visual representation of this process, take a look at the image below:
## Consequences
- No UI block when handling long-term tasks.
- Increase application performance, smoother application.
## Reference
-