extfn_cancel method

To notify the database server that the external library supports cancel processing, your external library must export the following function:

extern "C" void SQL_CALLBACK extfn_cancel( void *cancel_handle );

This function is called asynchronously by the database server whenever the currently executing SQL statement is canceled.

The function uses the cancel_handle to set a flag indicating to the external library functions that the SQL statement has been canceled.

If the function is not exported by the library, the database server assumes that cancel processing is not supported.

A typical implementation of this function follows:

extern "C" void SQL_CALLBACK extfn_cancel( void *cancel_handle )
{
    *(short *)cancel_handle = 1;
}