,I'Berkeley DB: lock_detect[P

lock_detect





#include <db.h>

intlock_detect(DB_LOCKTAB *lt,& u_int32_t flags, u_int32_t atype);





Description



EThe lock_detect function runs one iteration of the deadlock detector.EThe deadlock detector traverses the lock table, and for each deadlock@it finds, marks one of the participating transactions for abort.

ZThe flags value is specified by logically OR'ing together one or more of thefollowing values:

_

DB_LOCK_CONFLICT
Only run the deadlock detector if a lock conflict has occurred since1the last time that the deadlock detector was run.


FThe atype parameter specifies which transaction to abort in thecase of deadlock.HIt must be set to one of values described for the lk_detect fieldof theDB_ENV structure.

The lock_detect function is the underlying function used by the db_deadlock utility.xSee the db_deadlock utility source code for an example of using lock_detectin a POSIX 1003.1 environment.

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



Errors

TIf a fatal error occurs in Berkeley DB, the lock_detect function may fail and returnFDB_RUNRECOVERY, at which point all subsequent database calls will alsoreturn DB_RUNRECOVERY.

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



See Also

:lock_close, lock_detect,6lock_get,4lock_id,8lock_open,3lock_put,8lock_stat,;lock_unlinkand6lock_vec.