#include <db.h>

int
DB_TXN->set_commit_token(DB_TXN *txn, DB_TXN_TOKEN *buffer);  

The DB_TXN->set_commit_token() method configures the transaction for commit token generation, and accepts the address of an application-supplied buffer to receive the token. The actual generation of the token contents does not occur until commit time.

Commit tokens are used to enable some consistency guarantees for replicated applications. Please see the Read your writes consistency section in the Berkeley DB Programmer's Reference Guide for more information.

The DB_TXN->set_commit_token() method may be called at any time after the DB_ENV->txn_begin() method has been called, and before DB_TXN->commit() has been called.

The DB_TXN->set_commit_token() method returns a non-zero error value on failure and 0 on success.