lock_manager.h

Go to the documentation of this file.

/*
 * Copyright 2008 Search Solution Corporation
 * Copyright 2016 CUBRID Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */


/*
 *  Overview: LOCK MANAGMENT MODULE (AT THE SERVER) -- Interface --
 *
 */

#ifndef _LOCK_MANAGER_H_
#define _LOCK_MANAGER_H_

#ident "$Id$"

#include "config.h"
#if defined(SERVER_MODE)
#include "connection_error.h"
#endif /* SERVER_MODE */
#include "error_manager.h"
#include "locator.h"
#include "log_comm.h"
#include "oid.h"
#include "storage_common.h"
#include "thread_compat.hpp"

#include <time.h>
#include <stdio.h>

enum
{
  LK_GRANTED = 1,
  LK_NOTGRANTED = 2,
  LK_NOTGRANTED_DUE_ABORTED = 3,
  LK_NOTGRANTED_DUE_TIMEOUT = 4,
  LK_NOTGRANTED_DUE_ERROR = 5,
  LK_GRANTED_PUSHINSET_LOCKONE = 6,
  LK_GRANTED_PUSHINSET_RELOCKALL = 7
};

enum
{
/* Value to timeout immediately.. not wait */
  LK_ZERO_WAIT = 0,
/* Value to wait forever */
  LK_INFINITE_WAIT = -1,
/* Value to force a timeout without setting errors */
  LK_FORCE_ZERO_WAIT = -2
};

enum
{ LK_UNCOND_LOCK, LK_COND_LOCK };

typedef enum
{
  NO_KEY_LOCK_ESCALATION = 0,
  NEED_KEY_LOCK_ESCALATION = 1,
  KEY_LOCK_ESCALATED = 2
} KEY_LOCK_ESCALATION;

/*****************************/
/* Lock Heap Entry Structure */
/*****************************/
typedef struct lk_entry LK_ENTRY;
struct lk_entry
{
#if defined(SERVER_MODE)
  struct lk_res *res_head;  /* back to resource entry */
  THREAD_ENTRY *thrd_entry; /* thread entry pointer */
  int tran_index;       /* transaction table index */
  LOCK granted_mode;        /* granted lock mode */
  LOCK blocked_mode;        /* blocked lock mode */
  int count;            /* number of lock requests */
  UINT64 del_id;        /* delete transaction ID (for latch free) */
  LK_ENTRY *stack;      /* pointer to retired stack */
  LK_ENTRY *next;       /* next entry */
  LK_ENTRY *tran_next;      /* list of locks that trans. holds */
  LK_ENTRY *tran_prev;      /* list of locks that trans. holds */
  LK_ENTRY *class_entry;    /* ptr. to class lk_entry */
  int ngranules;        /* number of finer granules */
  int instant_lock_count;   /* number of instant lock requests */
  int bind_index_in_tran;
  XASL_ID xasl_id;
#else               /* not SERVER_MODE */
  int dummy;
#endif              /* not SERVER_MODE */
};

typedef struct lk_acqobj_lock LK_ACQOBJ_LOCK;
struct lk_acqobj_lock
{
  OID oid;          /* lock resource object identifier */
  OID class_oid;        /* only needed in case of instance lock */
  LOCK lock;            /* lock mode */
};

typedef struct lk_acquired_locks LK_ACQUIRED_LOCKS;
struct lk_acquired_locks
{
  LK_ACQOBJ_LOCK *obj;      /* The list of acquired object locks */
  unsigned int nobj_locks;  /* Number of actual object locks */
};

/* During delete and update operation,
 * if the number of objects to be deleted or updated is larger than
 * lock escalation threshold, we should acquire a lock on the class
 * instead of acquiring a lock on each instance.
 */

/* composite locking for delete and update operation */
typedef struct lk_lockcomp_class LK_LOCKCOMP_CLASS;
struct lk_lockcomp_class
{
  OID class_oid;
  LK_ENTRY *class_lock_ptr;
  int num_inst_oids;
  int max_inst_oids;
  OID *inst_oid_space;
  LK_LOCKCOMP_CLASS *next;
};

typedef struct lk_lockcomp LK_LOCKCOMP;
struct lk_lockcomp
{
  int tran_index;
  int wait_msecs;
  LK_ENTRY *root_class_ptr;
  LK_LOCKCOMP_CLASS *class_list;
};

typedef struct lk_composite_lock LK_COMPOSITE_LOCK;
struct lk_composite_lock
{
  LK_LOCKCOMP lockcomp;
};

/* type of locking resource */
typedef enum
{
  LOCK_RESOURCE_INSTANCE,   /* An instance resource */
  LOCK_RESOURCE_CLASS,      /* A class resource */
  LOCK_RESOURCE_ROOT_CLASS, /* A root class resource */
  LOCK_RESOURCE_OBJECT      /* An object resource */
} LOCK_RESOURCE_TYPE;

/*
 * Lock Resource key structure
 */
typedef struct lk_res_key LK_RES_KEY;
struct lk_res_key
{
  LOCK_RESOURCE_TYPE type;  /* type of resource: class,instance */
  OID oid;
  OID class_oid;
};

/*
 * Lock Resource Entry Structure
 */
typedef struct lk_res LK_RES;
struct lk_res
{
  LK_RES_KEY key;       /* lock resource's hash key */
  LOCK total_holders_mode;  /* total mode of the holders */
  LOCK total_waiters_mode;  /* total mode of the waiters */
  LK_ENTRY *holder;     /* lock holder list */
  LK_ENTRY *waiter;     /* lock waiter list */
  LK_ENTRY *non2pl;     /* non2pl list */
  pthread_mutex_t res_mutex;    /* resource mutex */
  LK_RES *hash_next;        /* for hash chain */
  LK_RES *stack;        /* for freelist */
  UINT64 del_id;        /* delete transaction ID (for latch free) */

  // *INDENT-OFF*
  lk_res ();
  ~lk_res ();
  // *INDENT-ON*
};

#if defined(SERVER_MODE)
extern void lock_remove_all_inst_locks (THREAD_ENTRY * thread_p, int tran_index, const OID * class_oid, LOCK lock);
#endif /* SERVER_MODE */
extern int lock_initialize (void);
extern void lock_finalize (void);
extern int lock_hold_object_instant (THREAD_ENTRY * thread_p, const OID * oid, const OID * class_oid, LOCK lock);
extern int lock_object_wait_msecs (THREAD_ENTRY * thread_p, const OID * oid, const OID * class_oid, LOCK lock,
                   int cond_flag, int wait_msecs);
extern int lock_object (THREAD_ENTRY * thread_p, const OID * oid, const OID * class_oid, LOCK lock, int cond_flag);
extern int lock_subclass (THREAD_ENTRY * thread_p, const OID * subclass_oid, const OID * superclass_oid, LOCK lock,
              int cond_flag);
extern int lock_object_with_btid (THREAD_ENTRY * thread_p, const OID * oid, const OID * class_oid, const BTID * btid,
                  LOCK lock, int cond_flag);
extern int lock_scan (THREAD_ENTRY * thread_p, const OID * class_oid, int cond_flag, LOCK class_lock);
extern int lock_classes_lock_hint (THREAD_ENTRY * thread_p, LC_LOCKHINT * lockhint);
extern void lock_remove_object_lock (THREAD_ENTRY * thread_p, const OID * oid, const OID * class_oid, LOCK lock);
extern void lock_unlock_object_donot_move_to_non2pl (THREAD_ENTRY * thread_p, const OID * oid, const OID * class_oid,
                             LOCK lock);
extern void lock_unlock_object (THREAD_ENTRY * thread_p, const OID * oid, const OID * class_oid, LOCK lock, bool force);
extern void lock_unlock_objects_lock_set (THREAD_ENTRY * thread_p, LC_LOCKSET * lockset);
extern void lock_unlock_classes_lock_hint (THREAD_ENTRY * thread_p, LC_LOCKHINT * lockhint);
extern void lock_unlock_all (THREAD_ENTRY * thread_p);
extern LOCK lock_get_object_lock (const OID * oid, const OID * class_oid);
extern bool lock_has_xlock (THREAD_ENTRY * thread_p);
#if defined (ENABLE_UNUSED_FUNCTION)
extern bool lock_has_lock_transaction (int tran_index);
#endif
extern bool lock_is_waiting_transaction (int tran_index);
extern LK_ENTRY *lock_get_class_lock (THREAD_ENTRY * thread_p, const OID * class_oid);
extern void lock_notify_isolation_incons (THREAD_ENTRY * thread_p,
                      bool (*fun) (const OID * class_oid, const OID * oid, void *args), void *args);
extern int lock_reacquire_crash_locks (THREAD_ENTRY * thread_p, LK_ACQUIRED_LOCKS * acqlocks, int tran_index);
extern void lock_unlock_all_shared_get_all_exclusive (THREAD_ENTRY * thread_p, LK_ACQUIRED_LOCKS * acqlocks);
extern void lock_dump_acquired (FILE * fp, LK_ACQUIRED_LOCKS * acqlocks);
extern void lock_start_instant_lock_mode (int tran_index);
extern void lock_stop_instant_lock_mode (THREAD_ENTRY * thread_p, int tran_index, bool need_unlock);
extern bool lock_is_instant_lock_mode (int tran_index);
extern void lock_clear_deadlock_victim (int tran_index);
extern unsigned int lock_get_number_object_locks (void);
extern int lock_initialize_composite_lock (THREAD_ENTRY * thread_p, LK_COMPOSITE_LOCK * comp_lock);
extern int lock_add_composite_lock (THREAD_ENTRY * thread_p, LK_COMPOSITE_LOCK * comp_lock, const OID * oid,
                    const OID * class_oid);
extern int lock_finalize_composite_lock (THREAD_ENTRY * thread_p, LK_COMPOSITE_LOCK * comp_lock);
extern void lock_abort_composite_lock (LK_COMPOSITE_LOCK * comp_lock);
extern int lock_get_lock_holder_tran_index (THREAD_ENTRY * thread_p, char **out_buf, int waiter_index, LK_RES * res);
extern int lock_has_lock_on_object (const OID * oid, const OID * class_oid, LOCK lock);
extern int lock_rep_read_tran (THREAD_ENTRY * thread_p, LOCK lock, int cond_flag);
extern int lock_demote_class_lock (THREAD_ENTRY * thread_p, const OID * oid, LOCK lock, LOCK * ex_lock);
extern void lock_demote_read_class_lock_for_checksumdb (THREAD_ENTRY * thread_p, int tran_index, const OID * class_oid);
extern const char *lock_wait_state_to_string (int state);
extern void lock_force_thread_timeout_lock (THREAD_ENTRY * thread_p);

#if defined (SERVER_MODE)
extern void lock_deadlock_detect_daemon_get_stats (UINT64 * statsp);
#endif // SERVER_MODE
#endif /* _LOCK_MANAGER_H_ */