mariadb/include/heap.h
Konstantin Osipov 33c57e2f9e WL#5419 "LOCK_open scalability: make tdc_refresh_version
an atomic counter"

Split the large LOCK_open section in open_table(). 
Do not call open_table_from_share() under LOCK_open.
Remove thd->version.

This fixes
Bug#50589 "Server hang on a query evaluated using a temporary 
table"
Bug#51557 "LOCK_open and kernel_mutex are not happy together"
Bug#49463 "LOCK_table and innodb are not nice when handler 
instances are created".

This patch has effect on storage engines that rely on
ha_open() PSEA method being called under LOCK_open.
In particular:

1) NDB is broken and left unfixed. NDB relies on LOCK_open
being kept as part of ha_open(), since it uses auto-discovery.
While previously the NDB open code was race-prone, now
it simply fails on asserts.

2) HEAP engine had a race in ha_heap::open() when
a share for the same table could be added twice
to the list of shares, or a dangling reference to a share
stored in HEAP handler. This patch aims to address this
problem by 'pinning' the newly created share in the 
internal HEAP engine share list until at least one
handler instance is created using that share.


include/heap.h:
  Add members to HP_CREATE_INFO.
  Declare heap_release_share().
sql/lock.cc:
  Remove thd->version, use thd->open_tables->s->version instead.
sql/repl_failsafe.cc:
  Remove thd->version.
sql/sql_base.cc:
  - close_thread_table(): move handler cleanup code outside the critical section protected by LOCK_open.
  - remove thd->version
  - split the large critical section in open_table() that
  opens a new table from share and is protected by LOCK_open
  into 2 critical sections, thus reducing the critical path.
  - make check_if_table_exists() acquire LOCK_open internally.
  - use thd->open_tables->s->version instead of thd->refresh_version to make sure that all tables in
  thd->open_tables are in the same refresh series.
sql/sql_base.h:
  Add declaration for check_if_table_exists().
sql/sql_class.cc:
  Remove init_open_tables_state(), it's now equal to
  reset_open_tables_state().
sql/sql_class.h:
  Remove thd->version, THD::init_open_tables_state().
sql/sql_plugin.cc:
  Use table->m_needs_reopen to mark the table as stale
  rather than manipulate with thd->version, which is no more.
sql/sql_udf.cc:
  Use table->m_needs_reopen to mark the table as stale
  rather than manipulate with thd->version, which is no more.
sql/table.h:
  Remove an unused variable.
sql/tztime.cc:
  Use table->m_needs_reopen to mark the table as stale
  rather than manipulate with thd->version, which is no more.
storage/heap/CMakeLists.txt:
  Add heap tests to cmake build files.
storage/heap/ha_heap.cc:
  Fix a race when ha_heap::ha_open() could insert two 
  HP_SHARE objects into the internal share list or store
  a dangling reference to a share in ha_heap instance,
  or wrongly set implicit_emptied.
storage/heap/hp_create.c:
  Optionally pin a newly created share in the list of shares
  by increasing its open_count. This is necessary to 
  make sure that a newly created share doesn't disappear while
  a HP_INFO object is being created to reference it.
storage/heap/hp_open.c:
  When adding a new HP_INFO object to the list of objects
  in the heap share, make sure the open_count is not increased
  twice.
storage/heap/hp_test1.c:
  Adjust the test to new function signatures.
storage/heap/hp_test2.c:
  Adjust the test to new function signatures.
2010-06-11 19:28:18 +04:00

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C

/* Copyright (C) 2000-2004 MySQL AB, 2009 Sun Microsystems, Inc
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* This file should be included when using heap_database_functions */
/* Author: Michael Widenius */
#ifndef _heap_h
#define _heap_h
#ifdef __cplusplus
extern "C" {
#endif
#ifndef _my_base_h
#include <my_base.h>
#endif
#ifdef THREAD
#include <my_pthread.h>
#include <thr_lock.h>
#endif
#include "my_handler.h"
#include "my_tree.h"
/* defines used by heap-funktions */
#define HP_MAX_LEVELS 4 /* 128^5 records is enough */
#define HP_PTRS_IN_NOD 128
/* struct used with heap_funktions */
typedef struct st_heapinfo /* Struct from heap_info */
{
ulong records; /* Records in database */
ulong deleted; /* Deleted records in database */
ulong max_records;
ulonglong data_length;
ulonglong index_length;
uint reclength; /* Length of one record */
int errkey;
ulonglong auto_increment;
} HEAPINFO;
/* Structs used by heap-database-handler */
typedef struct st_heap_ptrs
{
uchar *blocks[HP_PTRS_IN_NOD]; /* pointers to HP_PTRS or records */
} HP_PTRS;
struct st_level_info
{
/* Number of unused slots in *last_blocks HP_PTRS block (0 for 0th level) */
uint free_ptrs_in_block;
/*
Maximum number of records that can be 'contained' inside of each element
of last_blocks array. For level 0 - 1, for level 1 - HP_PTRS_IN_NOD, for
level 2 - HP_PTRS_IN_NOD^2 and so forth.
*/
ulong records_under_level;
/*
Ptr to last allocated HP_PTRS (or records buffer for level 0) on this
level.
*/
HP_PTRS *last_blocks;
};
/*
Heap table records and hash index entries are stored in HP_BLOCKs.
HP_BLOCK is used as a 'growable array' of fixed-size records. Size of record
is recbuffer bytes.
The internal representation is as follows:
HP_BLOCK is a hierarchical structure of 'blocks'.
A block at level 0 is an array records_in_block records.
A block at higher level is an HP_PTRS structure with pointers to blocks at
lower levels.
At the highest level there is one top block. It is stored in HP_BLOCK::root.
See hp_find_block for a description of how record pointer is obtained from
its index.
See hp_get_new_block
*/
typedef struct st_heap_block
{
HP_PTRS *root; /* Top-level block */
struct st_level_info level_info[HP_MAX_LEVELS+1];
uint levels; /* number of used levels */
uint records_in_block; /* Records in one heap-block */
uint recbuffer; /* Length of one saved record */
ulong last_allocated; /* number of records there is allocated space for */
} HP_BLOCK;
struct st_heap_info; /* For referense */
typedef struct st_hp_keydef /* Key definition with open */
{
uint flag; /* HA_NOSAME | HA_NULL_PART_KEY */
uint keysegs; /* Number of key-segment */
uint length; /* Length of key (automatic) */
uint8 algorithm; /* HASH / BTREE */
HA_KEYSEG *seg;
HP_BLOCK block; /* Where keys are saved */
/*
Number of buckets used in hash table. Used only to provide
#records estimates for heap key scans.
*/
ha_rows hash_buckets;
TREE rb_tree;
int (*write_key)(struct st_heap_info *info, struct st_hp_keydef *keyinfo,
const uchar *record, uchar *recpos);
int (*delete_key)(struct st_heap_info *info, struct st_hp_keydef *keyinfo,
const uchar *record, uchar *recpos, int flag);
uint (*get_key_length)(struct st_hp_keydef *keydef, const uchar *key);
} HP_KEYDEF;
typedef struct st_heap_share
{
HP_BLOCK block;
HP_KEYDEF *keydef;
ulong min_records,max_records; /* Params to open */
ulonglong data_length,index_length,max_table_size;
uint key_stat_version; /* version to indicate insert/delete */
uint records; /* records */
uint blength; /* records rounded up to 2^n */
uint deleted; /* Deleted records in database */
uint reclength; /* Length of one record */
uint changed;
uint keys,max_key_length;
uint currently_disabled_keys; /* saved value from "keys" when disabled */
uint open_count;
uchar *del_link; /* Link to next block with del. rec */
char * name; /* Name of "memory-file" */
#ifdef THREAD
THR_LOCK lock;
mysql_mutex_t intern_lock; /* Locking for use with _locking */
#endif
my_bool delete_on_close;
LIST open_list;
uint auto_key;
uint auto_key_type; /* real type of the auto key segment */
ulonglong auto_increment;
} HP_SHARE;
struct st_hp_hash_info;
typedef struct st_heap_info
{
HP_SHARE *s;
uchar *current_ptr;
struct st_hp_hash_info *current_hash_ptr;
ulong current_record,next_block;
int lastinx,errkey;
int mode; /* Mode of file (READONLY..) */
uint opt_flag,update;
uchar *lastkey; /* Last used key with rkey */
uchar *recbuf; /* Record buffer for rb-tree keys */
enum ha_rkey_function last_find_flag;
TREE_ELEMENT *parents[MAX_TREE_HEIGHT+1];
TREE_ELEMENT **last_pos;
uint lastkey_len;
my_bool implicit_emptied;
#ifdef THREAD
THR_LOCK_DATA lock;
#endif
LIST open_list;
} HP_INFO;
typedef struct st_heap_create_info
{
HP_KEYDEF *keydef;
ulong max_records;
ulong min_records;
uint auto_key; /* keynr [1 - maxkey] for auto key */
uint auto_key_type;
uint keys;
uint reclength;
ulonglong max_table_size;
ulonglong auto_increment;
my_bool with_auto_increment;
my_bool internal_table;
/*
TRUE if heap_create should 'pin' the created share by setting
open_count to 1. Is only looked at if not internal_table.
*/
my_bool pin_share;
} HP_CREATE_INFO;
/* Prototypes for heap-functions */
extern HP_INFO *heap_open(const char *name, int mode);
extern HP_INFO *heap_open_from_share(HP_SHARE *share, int mode);
extern HP_INFO *heap_open_from_share_and_register(HP_SHARE *share, int mode);
extern void heap_release_share(HP_SHARE *share, my_bool internal_table);
extern int heap_close(HP_INFO *info);
extern int heap_write(HP_INFO *info,const uchar *buff);
extern int heap_update(HP_INFO *info,const uchar *old,const uchar *newdata);
extern int heap_rrnd(HP_INFO *info,uchar *buf,uchar *pos);
extern int heap_scan_init(HP_INFO *info);
extern int heap_scan(register HP_INFO *info, uchar *record);
extern int heap_delete(HP_INFO *info,const uchar *buff);
extern int heap_info(HP_INFO *info,HEAPINFO *x,int flag);
extern int heap_create(const char *name,
HP_CREATE_INFO *create_info, HP_SHARE **share,
my_bool *created_new_share);
extern int heap_delete_table(const char *name);
extern void heap_drop_table(HP_INFO *info);
extern int heap_extra(HP_INFO *info,enum ha_extra_function function);
extern int heap_reset(HP_INFO *info);
extern int heap_rename(const char *old_name,const char *new_name);
extern int heap_panic(enum ha_panic_function flag);
extern int heap_rsame(HP_INFO *info,uchar *record,int inx);
extern int heap_rnext(HP_INFO *info,uchar *record);
extern int heap_rprev(HP_INFO *info,uchar *record);
extern int heap_rfirst(HP_INFO *info,uchar *record,int inx);
extern int heap_rlast(HP_INFO *info,uchar *record,int inx);
extern void heap_clear(HP_INFO *info);
extern void heap_clear_keys(HP_INFO *info);
extern int heap_disable_indexes(HP_INFO *info);
extern int heap_enable_indexes(HP_INFO *info);
extern int heap_indexes_are_disabled(HP_INFO *info);
extern void heap_update_auto_increment(HP_INFO *info, const uchar *record);
ha_rows hp_rb_records_in_range(HP_INFO *info, int inx, key_range *min_key,
key_range *max_key);
int hp_panic(enum ha_panic_function flag);
int heap_rkey(HP_INFO *info, uchar *record, int inx, const uchar *key,
key_part_map keypart_map, enum ha_rkey_function find_flag);
extern uchar * heap_find(HP_INFO *info,int inx,const uchar *key);
extern int heap_check_heap(HP_INFO *info, my_bool print_status);
extern uchar *heap_position(HP_INFO *info);
/* The following is for programs that uses the old HEAP interface where
pointer to rows where a long instead of a (uchar*).
*/
#if defined(WANT_OLD_HEAP_VERSION) || defined(OLD_HEAP_VERSION)
extern int heap_rrnd_old(HP_INFO *info,uchar *buf,ulong pos);
extern ulong heap_position_old(HP_INFO *info);
#endif
#ifdef OLD_HEAP_VERSION
typedef ulong HEAP_PTR;
#define heap_position(A) heap_position_old(A)
#define heap_rrnd(A,B,C) heap_rrnd_old(A,B,C)
#else
typedef uchar *HEAP_PTR;
#endif
#ifdef __cplusplus
}
#endif
#endif