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/*****************************************************************************
Copyright (c) 1996, 2015, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2018, MariaDB Corporation.
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, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/lock0types.h
The transaction lock system global types
Created 5/7/1996 Heikki Tuuri
*******************************************************/
#include "dict0types.h"
#include "ut0lst.h"
#ifndef lock0types_h
#define lock0types_h
#define lock_t ib_lock_t
struct lock_t;
struct lock_table_t;
/* Basic lock modes */
enum lock_mode {
LOCK_IS = 0, /* intention shared */
LOCK_IX, /* intention exclusive */
LOCK_S, /* shared */
LOCK_X, /* exclusive */
LOCK_AUTO_INC, /* locks the auto-inc counter of a table
in an exclusive mode */
LOCK_NONE, /* this is used elsewhere to note consistent read */
LOCK_NUM = LOCK_NONE, /* number of lock modes */
LOCK_NONE_UNSET = 255
};
/** Convert the given enum value into string.
@param[in] mode the lock mode
@return human readable string of the given enum value */
inline
const char* lock_mode_string(enum lock_mode mode)
{
switch (mode) {
case LOCK_IS:
return("LOCK_IS");
case LOCK_IX:
return("LOCK_IX");
case LOCK_S:
return("LOCK_S");
case LOCK_X:
return("LOCK_X");
case LOCK_AUTO_INC:
return("LOCK_AUTO_INC");
case LOCK_NONE:
return("LOCK_NONE");
case LOCK_NONE_UNSET:
return("LOCK_NONE_UNSET");
default:
ut_error;
}
}
/** A table lock */
struct lock_table_t {
dict_table_t* table; /*!< database table in dictionary
cache */
UT_LIST_NODE_T(ib_lock_t)
locks; /*!< list of locks on the same
table */
/** Print the table lock into the given output stream
@param[in,out] out the output stream
@return the given output stream. */
std::ostream& print(std::ostream& out) const;
};
/** Record lock for a page */
struct lock_rec_t {
ib_uint32_t space; /*!< space id */
ib_uint32_t page_no; /*!< page number */
ib_uint32_t n_bits; /*!< number of bits in the lock
bitmap; NOTE: the lock bitmap is
placed immediately after the
lock struct */
/** Print the record lock into the given output stream
@param[in,out] out the output stream
@return the given output stream. */
std::ostream& print(std::ostream& out) const;
};
/** Print the record lock into the given output stream
@param[in,out] out the output stream
@return the given output stream. */
inline
std::ostream& lock_rec_t::print(std::ostream& out) const
{
out << "[lock_rec_t: space=" << space << ", page_no=" << page_no
<< ", n_bits=" << n_bits << "]";
return(out);
}
inline
std::ostream&
operator<<(std::ostream& out, const lock_rec_t& lock)
{
return(lock.print(out));
}
#define LOCK_MODE_MASK 0xFUL /*!< mask used to extract mode from the
type_mode field in a lock */
/** Lock types */
/* @{ */
#define LOCK_TABLE 16U /*!< table lock */
#define LOCK_REC 32U /*!< record lock */
#define LOCK_TYPE_MASK 0xF0UL /*!< mask used to extract lock type from the
type_mode field in a lock */
#if LOCK_MODE_MASK & LOCK_TYPE_MASK
# error "LOCK_MODE_MASK & LOCK_TYPE_MASK"
#endif
#define LOCK_WAIT 256U /*!< Waiting lock flag; when set, it
means that the lock has not yet been
granted, it is just waiting for its
turn in the wait queue */
/* Precise modes */
#define LOCK_ORDINARY 0 /*!< this flag denotes an ordinary
next-key lock in contrast to LOCK_GAP
or LOCK_REC_NOT_GAP */
#define LOCK_GAP 512U /*!< when this bit is set, it means that the
lock holds only on the gap before the record;
for instance, an x-lock on the gap does not
give permission to modify the record on which
the bit is set; locks of this type are created
when records are removed from the index chain
of records */
#define LOCK_REC_NOT_GAP 1024U /*!< this bit means that the lock is only on
the index record and does NOT block inserts
to the gap before the index record; this is
used in the case when we retrieve a record
with a unique key, and is also used in
locking plain SELECTs (not part of UPDATE
or DELETE) when the user has set the READ
COMMITTED isolation level */
#define LOCK_INSERT_INTENTION 2048U/*!< this bit is set when we place a waiting
gap type record lock request in order to let
an insert of an index record to wait until
there are no conflicting locks by other
transactions on the gap; note that this flag
remains set when the waiting lock is granted,
or if the lock is inherited to a neighboring
record */
#define LOCK_PREDICATE 8192U /*!< Predicate lock */
#define LOCK_PRDT_PAGE 16384U /*!< Page lock */
#if (LOCK_WAIT|LOCK_GAP|LOCK_REC_NOT_GAP|LOCK_INSERT_INTENTION|LOCK_PREDICATE|LOCK_PRDT_PAGE)&LOCK_MODE_MASK
# error
#endif
#if (LOCK_WAIT|LOCK_GAP|LOCK_REC_NOT_GAP|LOCK_INSERT_INTENTION|LOCK_PREDICATE|LOCK_PRDT_PAGE)&LOCK_TYPE_MASK
# error
#endif
/* @} */
/** Lock struct; protected by lock_sys.mutex */
struct ib_lock_t
{
trx_t* trx; /*!< transaction owning the
lock */
UT_LIST_NODE_T(ib_lock_t)
trx_locks; /*!< list of the locks of the
transaction */
dict_index_t* index; /*!< index for a record lock */
ib_lock_t* hash; /*!< hash chain node for a record
lock. The link node in a singly linked
list, used during hashing. */
/* Statistics for how long lock has been held and time
how long this lock had to be waited before it was granted */
time_t requested_time; /*!< Lock request time */
ulint wait_time; /*!< Time waited this lock or 0 */
union {
lock_table_t tab_lock;/*!< table lock */
lock_rec_t rec_lock;/*!< record lock */
} un_member; /*!< lock details */
ib_uint32_t type_mode; /*!< lock type, mode, LOCK_GAP or
LOCK_REC_NOT_GAP,
LOCK_INSERT_INTENTION,
wait flag, ORed */
/** Determine if the lock object is a record lock.
@return true if record lock, false otherwise. */
bool is_record_lock() const
{
return(type() == LOCK_REC);
}
bool is_waiting() const
{
return(type_mode & LOCK_WAIT);
}
bool is_gap() const
{
return(type_mode & LOCK_GAP);
}
bool is_record_not_gap() const
{
return(type_mode & LOCK_REC_NOT_GAP);
}
bool is_insert_intention() const
{
return(type_mode & LOCK_INSERT_INTENTION);
}
ulint type() const {
return(type_mode & LOCK_TYPE_MASK);
}
enum lock_mode mode() const
{
return(static_cast<enum lock_mode>(type_mode & LOCK_MODE_MASK));
}
/** Print the lock object into the given output stream.
@param[in,out] out the output stream
@return the given output stream. */
std::ostream& print(std::ostream& out) const;
/** Convert the member 'type_mode' into a human readable string.
@return human readable string */
std::string type_mode_string() const;
const char* type_string() const
{
switch (type_mode & LOCK_TYPE_MASK) {
case LOCK_REC:
return("LOCK_REC");
case LOCK_TABLE:
return("LOCK_TABLE");
default:
ut_error;
}
}
};
typedef UT_LIST_BASE_NODE_T(ib_lock_t) trx_lock_list_t;
#endif /* lock0types_h */
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