DB_TXN->discard()
#include <db.h>
int
DB_TXN->discard(DB_TXN *tid, u_int32_t flags); The DB_TXN->discard() method frees up all the per-process resources associated with the specified DB_TXN handle, neither committing nor aborting the transaction. This call may be used only after calls to DB_ENV->txn_recover() when there are multiple global transaction managers recovering transactions in a single Berkeley DB environment. Any transactions returned by DB_ENV->txn_recover() that are not handled by the current global transaction manager should be discarded using DB_TXN->discard().
All open cursors in the transaction are closed and the first cursor close error, if any, is returned.
The DB_TXN->discard() method returns a non-zero error value on failure and 0 on success. The errors values that this method returns include the error values of DBcursor->close() and the following:
DB_LOCK_DEADLOCK
A transactional database environment operation was selected to resolve a deadlock.
DB_LOCK_NOTGRANTED
A Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time.
You attempted to open a database handle that is configured for no waiting exclusive locking, but the exclusive lock could not be immediately obtained. See DB->set_lk_exclusive() for more information.
EINVAL
If the cursor is already closed; or if an invalid flag value or parameter was specified.
After DB_TXN->discard() has been called, regardless of its return, the DB_TXN handle may not be accessed again.
Parameters
flags
The flags parameter is currently unused, and must be set to 0.
Errors
The DB_TXN->discard() method may fail and return one of the following non-zero errors:
EINVAL
If the transaction handle does not refer to a transaction that was recovered into a prepared but not yet completed state; or if an invalid flag value or parameter was specified.