> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# IParallelProcessingCallback Interface

<Note>
  This interface is implemented in FRE for Linux and Windows.
</Note>

This is a callback interface that is used for managing the parallel processing work and reporting errors which occurred during processing. This interface is implemented on the client-side.

## Methods

| Name                                                                                                                                                    | Description                                                     |
| ------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- |
| [OnWaitIntervalExceeded](/fine-reader/engine/api-reference/supplementary-objects-and-methods/iparallelprocessingcallback/onwaitintervalexceeded-method) | Delivers to the client information about wait interval timeout. |

## Input parameter

The [SetParallelProcessingCallback](/fine-reader/engine/api-reference/engine-object-iengine-interface/supplementary-methods/setparallelprocessingcallback-method) method of the [Engine](/fine-reader/engine/api-reference/engine-object-iengine-interface) object receives a pointer to this interface as an input parameter.

## Remarks

In Linux, this interface does not work if the Engine object is loaded as an out-of-process server.

## See also

[Parallel Processing with ABBYY FineReader Engine](/fine-reader/engine/guided-tour/advanced-techniques/parallel-processing)

[Engine](/fine-reader/engine/api-reference/engine-object-iengine-interface)

[BatchProcessor](/fine-reader/engine/api-reference/batch-processor/batchprocessor)