---
title: SetUsedLen
framework: DriverKit
role: symbol
role_heading: Instance Method
path: driverkit/ioextensiblepaniclog/setusedlen
---

# SetUsedLen

## Declaration

```occ
virtual kern_return_t SetUsedLen(uint32_t used_len);
```

## Parameters

- `used_len`: The length of the buffer used by the client.

## Return Value

Return Value 0 in case of success. Negative in case of an error.

## Discussion

Discussion This function is called to set the used len of the buffer