# DbEnv::set_lk_max_lockers

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    #include <db_cxx.h>

    int
    DbEnv::set_lk_max_lockers(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 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 DbEnv::set_lk_max_lockers interface may be used only to configure Berkeley DB before the DbEnv::open interface is called.

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 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 DbEnv::set_lk_max_lockers method may fail and throw an exception or return a non-zero error for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

  Called after DbEnv::open was called.

The DbEnv::set_lk_max_lockers method may fail and throw an exception or return a non-zero error for errors specified for other Berkeley DB and C library or system methods. If a catastrophic error has occurred, the DbEnv::set_lk_max_lockers method may fail and either return DB_RUNRECOVERY or throw an exception encapsulating DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail in the same way.

# Class

DbEnv, DbLock

# See Also

DbEnv::set_lk_conflicts, DbEnv::set_lk_detect, DbEnv::set_lk_max_lockers, DbEnv::set_lk_max_locks, DbEnv::set_lk_max_objects, DbEnv::lock_detect, DbEnv::lock_get, DbEnv::lock_id, DbEnv::lock_id_free, DbEnv::lock_put, DbEnv::lock_stat, and DbEnv::lock_vec.`

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