DbEnv::set_lk_conflicts

API Ref

#include <db_cxx.h>

int DbEnv::set_lk_conflicts(u_int8_t *conflicts, int nmodes);

int DbEnv::get_lk_conflicts(const u_int8_t **lk_conflictsp, int *lk_modesp);


Description: DbEnv::set_lk_conflicts

Set the locking conflicts matrix.

If DbEnv::set_lk_conflicts is never called, a standard conflicts array is used; see Standard Lock Modes for more information.

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

The DbEnv::set_lk_conflicts 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_conflicts will be ignored.

The DbEnv::set_lk_conflicts 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.

Parameters

conflicts
The conflicts parameter is the new locking conflicts matrix. The conflicts parameter is an nmodes by nmodes array. A non-0 value for the array element indicates that requested_mode and held_mode conflict:
conflicts[requested_mode][held_mode]

The not-granted mode must be represented by 0.

nmodes
The nmodes parameter is the size of the lock conflicts matrix.

Errors

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

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

If the conflicts array could not be copied, the DbEnv::set_lk_conflicts method will fail and either return ENOMEM or throw a DbMemoryException.


Description: dbenv_get_lk_conflicts

The DbEnv::get_lk_conflicts method returns the current conflicts array.

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

The DbEnv::get_lk_conflicts 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.

Parameters

lk_conflictsp
The lk_conflictsp parameter references memory into which a pointer to the current conflicts array is copied.
lk_modesp
The lk_modesp parameter references memory into which the size of the current conflicts array is copied.

Class

DbEnv, DbLock

See Also

Locking Subsystem and Related Methods

APIRef

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