PoolCallback (Apache Tomcat 9.0.115 API Documentation)

```
@Deprecated
public interface PoolCallback
```
Deprecated.
The scope of the APR/Native Library will be reduced in Tomcat 9.1.x / Tomcat Native 2.x and has been reduced in Tomcat 10.1.x / Tomcat Native 2.x onwards to only include those components required to provide OpenSSL integration with the NIO and NIO2 connectors.

PoolCallback Interface.

- Method Summary
  
  All Methods Instance Methods Abstract Methods Deprecated Methods
  Modifier and Type Method Description
  
  int callback()
  Deprecated.
  
  Called when the pool is destroyed or cleared

- Method Detail
  - callback
```
int callback()
```
    Deprecated.
    
    Called when the pool is destroyed or cleared
    
    Returns:
    
    Function must return APR_SUCCESS