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/* Copyright (C) 2006 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
#ifndef _lockman_h
#define _lockman_h
/*
Lock levels:
^^^^^^^^^^^
N - "no lock", not a lock, used sometimes internally to simplify the code
S - Shared
X - eXclusive
IS - Intention Shared
IX - Intention eXclusive
SIX - Shared + Intention eXclusive
LS - Loose Shared
LX - Loose eXclusive
SLX - Shared + Loose eXclusive
LSIX - Loose Shared + Intention eXclusive
*/
enum lockman_lock_type { N, S, X, IS, IX, SIX, LS, LX, SLX, LSIX, LOCK_TYPE_LAST };
struct lockman_lock;
typedef struct st_lock_owner LOCK_OWNER;
struct st_lock_owner {
LF_PINS *pins; /* must be allocated from lockman's pinbox */
struct lockman_lock *all_locks; /* a LIFO */
LOCK_OWNER *waiting_for;
pthread_cond_t *cond; /* transactions waiting for this, wait on 'cond' */
pthread_mutex_t *mutex; /* mutex is required to use 'cond' */
uint16 loid;
};
typedef LOCK_OWNER *loid_to_lo_func(uint16);
typedef struct {
LF_DYNARRAY array; /* hash itself */
LF_ALLOCATOR alloc; /* allocator for elements */
int32 volatile size; /* size of array */
int32 volatile count; /* number of elements in the hash */
uint lock_timeout;
loid_to_lo_func *loid_to_lo;
} LOCKMAN;
#define DIDNT_GET_THE_LOCK 0
enum lockman_getlock_result {
NO_MEMORY_FOR_LOCK=1, DEADLOCK, LOCK_TIMEOUT,
GOT_THE_LOCK,
GOT_THE_LOCK_NEED_TO_LOCK_A_SUBRESOURCE,
GOT_THE_LOCK_NEED_TO_INSTANT_LOCK_A_SUBRESOURCE
};
void lockman_init(LOCKMAN *, loid_to_lo_func *, uint);
void lockman_destroy(LOCKMAN *);
enum lockman_getlock_result lockman_getlock(LOCKMAN *lm, LOCK_OWNER *lo,
uint64 resource,
enum lockman_lock_type lock);
int lockman_release_locks(LOCKMAN *, LOCK_OWNER *);
#ifdef EXTRA_DEBUG
void print_lockhash(LOCKMAN *lm);
#endif
#endif
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