Berkeley DB

Db::fd

						#include <db_cxx.h>
						int
						Db::fd(int *fdp);
					

Description

The Db::fd method copies a file descriptor representative of the underlying database into the memory referenced by fdp. A file descriptor referencing the same file will be returned to all processes that call Db::open with the same file argument. This file descriptor may be safely used as an argument to the fcntl(2) and flock(2) locking functions. The file descriptor is not necessarily associated with any of the underlying files actually used by the access method.

The Db::fd method only supports a coarse-grained form of locking. Applications should use the lock manager where possible.

The Db::fd method either returns a non-zero error value or throws an exception that encapsulates ...