#include <db_cxx.h> int Dbc::dup(Dbc **cursorp, u_int32_t flags);
The Dbc::dup() method creates a new cursor that uses the same
transaction and locker ID as the original cursor. This is useful when
an application is using locking and requires two or more cursors in
the same thread of control.
The Dbc::dup()
method either returns a non-zero error value or throws an
exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
The flags parameter must be set to 0 or the following flag:
The newly created cursor is initialized to refer to the same position in the database as the original cursor (if any) and hold the same locks (if any). If the DB_POSITION flag is not specified, or the original cursor does not hold a database position and locks, the created cursor is uninitialized and will behave like a cursor newly created using the Db::cursor() method.
The Dbc::dup()
method may fail and throw a DbException
exception, encapsulating one of the following non-zero errors, or return one
of the following non-zero errors:
When a client synchronizes with the master, it is possible for committed
transactions to be rolled back. This invalidates all the database and cursor
handles opened in the replication environment. Once this occurs, an attempt to use
such a handle will
throw a DbRepHandleDeadException (if
your application is configured to throw exceptions), or
return DB_REP_HANDLE_DEAD.
The application will need to discard the handle and open a new one in order to
continue processing.
The operation was blocked by client/master synchronization.
DbDeadlockException is thrown if
your Berkeley DB API is configured to throw exceptions.
Otherwise, DB_REP_LOCKOUT is returned.