DbLockTab::stat(DB_LOCK_STAT **statp, void *(*db_malloc)(size_t));
The DbLockTab::stat method
creates a statistical structure and copies pointers to it into
user-specified memory locations.
Statistical structure are created in allocated memory.
db_malloc is non-NULL, it is called to allocate the memory,
otherwise, the library function malloc(3)) is used.
The function db_malloc must match the calling conventions of
the malloc(3)) library routine.
Regardless, the caller is responsible for deallocating the returned
To deallocate the returned memory, free each returned memory pointer;
pointers inside the memory do not need to be individually freed.
The lock region statistics are stored in a structure of type
DB_LOCK_STAT. The following DB_LOCK_STAT fields will be filled in:
The magic number that identifies a file as a lock file.
The version of the lock file type.
The number of references to the region.
The size of the region.
The maximum number of locks possible.
The number of lock modes.
The number of unique objects locked.
The number of unique lockers.
The total number of locks not immediately available due to conflicts.
The total number of locks requested.
The total number of locks released.
The number of deadlocks detected.
The number of times that a thread of control was forced to wait before
obtaining the region lock.
The number of times that a thread of control was able to obtain
the region lock without waiting.
method either returns errno or throws an exception that
encapsulates an errno on failure, and 0 on success.
If a fatal error occurs in Berkeley DB, the DbLockTab::stat method may fail and either
return DB_RUNRECOVERY or throw an exception encapsulating DB_RUNRECOVERY,
at which point all subsequent database calls will also fail in the same
way. Methods marked as returning errno will, by default, throw
an exception that encapsulates the error information. The default error
behavior can be changed, see DbException.
method may fail and throw an exception
for any of the errors specified for the following Berkeley DB and C library