### Berkeley DB Reference Guide: Upgrading Berkeley DB Applications |

### Release 3.3: DB->set_malloc, DB->set_realloc

There are two new methods in the Berkeley DB 3.3 release: DB_ENV->set_alloc and DB->set_alloc. These functions allow applications to specify a set of allocation functions for the Berkeley DB library to use when allocating memory to be owned by the application and when freeing memory that was originally allocated by the application.

The new methods affect or replace the following historic methods:

DB->set_malloc
  The DB->set_malloc method has been replaced in its entirety. Applications using this method should replace the call with a call to DB->set_alloc.
DB->set_realloc
  The DB->set_realloc method has been replaced in its entirety. Applications using this method should replace the call with a call to DB->set_alloc.
DB->stat
  The historic db_malloc argument to the DB->stat method has been replaced. Applications using this method should do as follows: if the argument is NULL, it should simply be removed. If non-NULL, it should be replaced with a call to DB->set_alloc.
lock_stat
  The historic db_malloc argument to the lock_stat function has been replaced. Applications using this function should do as follows: if the argument is NULL, it should simply be removed. If non-NULL, it should be replaced with a call to DB_ENV->set_alloc.
log_archive
  The historic db_malloc argument to the log_archive function has been replaced. Applications using this function should do as follows: if the argument is NULL, it should simply be removed. If non-NULL, it should be replaced with a call to DB_ENV->set_alloc.
log_stat
  The historic db_malloc argument to the log_stat function has been replaced. Applications using this function should do as follows: if the argument is NULL, it should simply be removed. If non-NULL, it should be replaced with a call to DB_ENV->set_alloc.
memp_stat
  The historic db_malloc argument to the memp_stat function has been replaced. Applications using this function should do as follows: if the argument is NULL, it should simply be removed. If non-NULL, it should be replaced with a call to DB_ENV->set_alloc.
txn_stat
  The historic db_malloc argument to the txn_stat function has been replaced. Applications using this function should do as follows: if the argument is NULL, it should simply be removed. If non-NULL, it should be replaced with a call to DB_ENV->set_alloc.

One potential incompatibility for historic applications is that the allocation functions for a database environment must now be set before the environment is opened. Historically, Berkeley DB applications could open the environment first, and subsequently call the DB->set_malloc and DB->set_realloc methods; that use is no longer supported.

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