Berkeley DB: DbEnv::set_lk_conflicts
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++

DbEnv::set_lk_conflicts |

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    #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`

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