#include <db_cxx.h>

int
DbEnv::set_lk_max_lockers(u_int32_t max);

int
DbEnv::get_lk_max_lockers(u_int32_t *, lk_maxp);

Set the maximum number of locking entities supported by the Berkeley DB environment. This value is used by DbEnv::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 database environment's maximum number of lockers may also be configured 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.

The DbEnv::set_lk_max_lockers method configures a database environment, not only operations performed using the specified DbEnv handle.

The DbEnv::set_lk_max_lockers method may not be called after the DbEnv::open method is called. If the database environment already exists when DbEnv::open is called, the information specified to DbEnv::set_lk_max_lockers will be ignored.

The DbEnv::set_lk_max_lockers 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 max parameter is the maximum number simultaneous locking entities supported by the Berkeley DB environment.

The DbEnv::set_lk_max_lockers method may fail and throw DbException, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:

• If the method was called after DbEnv::open was called; or if an invalid flag value or parameter was specified.

The DbEnv::get_lk_max_lockers method returns the maximum number of lockers.

The DbEnv::get_lk_max_lockers method may be called at any time during the life of the application.

The DbEnv::get_lk_max_lockers 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 DbEnv::get_lk_max_lockers method returns the maximum number of lockers in lk_maxp.