TaskWrapper (Eclipse RDF4J 4.2.4)

```
public interface TaskWrapper
```
A TaskWrapper is a facility to wrap Runnable background tasks before they are passed to the Executor. Use-cases include injection of thread-local context variables, or more fine-granular error handling.
All sub-queries sent by the federation engine that make use of the concurrency infrastructure (e.g. ControlledWorkerScheduler) are passing this wrapper.

The concrete implementation can be configured using FedXConfig.withTaskWrapper(TaskWrapper).

Author:

Andreas Schwarte

See Also:

ControlledWorkerScheduler, FedXConfig.withTaskWrapper(TaskWrapper)

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Runnable`	`wrap(Runnable runnable)`	Wrap the given `Runnable` and add custom logic.
`<T> Callable<T>`	`wrap(Callable<T> callable)`	Wrap the given `Callable` and add custom logic.

- Method Detail
  - wrap
```
Runnable wrap(Runnable runnable)
```
    Wrap the given Runnable and add custom logic.
    Use cases include injection of state into the thread-local context, or more fine granular error handling.
    
    Note that when modifying state in ThreadLocal it must be reset properly in a try/finally block.
    
    Parameters:
    
    runnable - the task as generated by the FedX engine
    
    Returns:
    
    the wrapped Runnable
  - wrap
```
<T> Callable<T> wrap(Callable<T> callable)
```
    Wrap the given Callable and add custom logic.
    Use cases include injection of state into the thread-local context, or more fine granular error handling.
    
    Note that when modifying state in ThreadLocal it must be reset properly in a try/finally block.
    
    Parameters:
    
    callable - the task as generated by the FedX engine
    
    Returns:
    
    the wrapped Callable