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    "DriverKit: 19.0 -"
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  "framework" : "USBDriverKit",
  "identifier" : "/documentation/USBDriverKit/IOUSBHostPipe/CompleteAsyncIO",
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  "title" : "CompleteAsyncIO"
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# CompleteAsyncIO

Handles the completion of an asynchronous I/O request.

```
virtual void CompleteAsyncIO(OSAction *action, IOReturn status, uint32_t actualByteCount, uint64_t completionTimestamp);
```

## Parameters

`action`

A pointer to the <doc://com.apple.documentation/documentation/DriverKit/OSAction> object of the request.

`status`

The result of the operation.

`actualByteCount`

The number of bytes that the operation actually transferred.

`completionTimestamp`

The absolute time that the transfer completed.

## Discussion

Implement a custom version of this method and use the <doc://com.apple.documentation/documentation/DriverKit/TYPE> macro to let the system know that your method conforms to this prototype.

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