#include <db.h>

int
DB_ENV->set_lk_max_lockers(DB_ENV *dbenv, u_int32_t max);

Description

Set the maximum number of simultaneous locking entities supported by the Berkeley DB lock subsystem. This value is used by DB_ENV->open to estimate how much space to allocate for various lock-table data structures. The default value is 1000 lockers. For specific information on configuring the size of the lock subsystem, see Configuring locking: sizing the system.

The DB_ENV->set_lk_max_lockers method configures a database environment, not only operations performed using the specified DB_ENV handle.

The DB_ENV->set_lk_max_lockers interface may not be called after the DB_ENV->open interface is called. If the database environment already exists when DB_ENV->open is called, the information specified to DB_ENV->set_lk_max_lockers will be ignored.

The DB_ENV->set_lk_max_lockers method returns a non-zero error value on failure and 0 on success.

The database environment's maximum number of lockers may also be set using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "set_lk_max_lockers", one or more whitespace characters, and the number of lockers. Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.

Errors

The DB_ENV->set_lk_max_lockers method may fail and return a non-zero error for the following conditions:

EINVAL

An invalid flag value or parameter was specified.

Called after DB_ENV->open was called.

The DB_ENV->set_lk_max_lockers method may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions. If a catastrophic error has occurred, the DB_ENV->set_lk_max_lockers method may fail and return DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail in the same way.

Class

See Also