Berkeley DB: lock_get
Полезная информация

lock_get


#include <db.h>

int lock_get(DB_LOCKTAB *lt, u_int32_t locker, u_int32_t flags, const DBT *obj, const db_lockmode_t lock_mode, DB_LOCK *lock);

Description

The lock_get function is a simple interface to the lock_vec functionality.

It is equivalent to calling the lock_vec function with the lt, locker and flags arguments, and a single element list array, for which the op field is DB_LOCK_GET, and the obj, lock_mode and lock fields are represented by the arguments of the same name.

Note that the type of the obj argument to lock_get is different from the obj element found in the DB_LOCKREQ structure.

The lock_get function returns success and failure as described for the lock_vec function.

The lock_get function returns the value of errno on failure, and 0 on success.

Errors

If a fatal error occurs in Berkeley DB, the lock_get function may fail and return DB_RUNRECOVERY, at which point all subsequent database calls will also return DB_RUNRECOVERY.

The lock_get function may fail and return errno for any of the errors specified for the following Berkeley DB and C library functions: abort(3), fcntl(3), fflush(3), fprintf(3), fsync(3), getpid(3), lock_detect, lseek(3), memcpy(3), memset(3), mmap(3), munmap(3), pstat_getdynamic(3), shmat(3), shmdt(3), strerror(3), sysconf(3), vfprintf(3), vsnprintf(3), and write(3).

In addition, the lock_get function may fail and return errno for the following conditions:

EINVAL
An invalid flag value or parameter was specified.

See Also

lock_close, lock_detect, lock_get, lock_id, lock_open, lock_put, lock_stat, lock_unlink and lock_vec.