1 /*****************************************************************************
2 
3 Copyright (c) 1997, 2011, Oracle and/or its affiliates. All Rights Reserved.
4 
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License, version 2.0,
7 as published by the Free Software Foundation.
8 
9 This program is also distributed with certain software (including
10 but not limited to OpenSSL) that is licensed under separate terms,
11 as designated in a particular file or component or in included license
12 documentation.  The authors of MySQL hereby grant you an additional
13 permission to link the program and your derivative works with the
14 separately licensed software that they have included with MySQL.
15 
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 GNU General Public License, version 2.0, for more details.
20 
21 You should have received a copy of the GNU General Public License along with
22 this program; if not, write to the Free Software Foundation, Inc.,
23 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
24 
25 *****************************************************************************/
26 
27 /**************************************************//**
28 @file ha/hash0hash.cc
29 The simple hash table utility
30 
31 Created 5/20/1997 Heikki Tuuri
32 *******************************************************/
33 
34 #include "hash0hash.h"
35 #ifdef UNIV_NONINL
36 #include "hash0hash.ic"
37 #endif
38 
39 #include "mem0mem.h"
40 
41 #ifndef UNIV_HOTBACKUP
42 
43 # ifdef UNIV_PFS_MUTEX
44 UNIV_INTERN mysql_pfs_key_t	hash_table_mutex_key;
45 # endif /* UNIV_PFS_MUTEX */
46 
47 # ifdef UNIV_PFS_RWLOCK
48 UNIV_INTERN mysql_pfs_key_t	hash_table_rw_lock_key;
49 # endif /* UNIV_PFS_RWLOCK */
50 /************************************************************//**
51 Reserves the mutex for a fold value in a hash table. */
52 UNIV_INTERN
53 void
hash_mutex_enter(hash_table_t * table,ulint fold)54 hash_mutex_enter(
55 /*=============*/
56 	hash_table_t*	table,	/*!< in: hash table */
57 	ulint		fold)	/*!< in: fold */
58 {
59 	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
60 	mutex_enter(hash_get_mutex(table, fold));
61 }
62 
63 /************************************************************//**
64 Releases the mutex for a fold value in a hash table. */
65 UNIV_INTERN
66 void
hash_mutex_exit(hash_table_t * table,ulint fold)67 hash_mutex_exit(
68 /*============*/
69 	hash_table_t*	table,	/*!< in: hash table */
70 	ulint		fold)	/*!< in: fold */
71 {
72 	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
73 	mutex_exit(hash_get_mutex(table, fold));
74 }
75 
76 /************************************************************//**
77 Reserves all the mutexes of a hash table, in an ascending order. */
78 UNIV_INTERN
79 void
hash_mutex_enter_all(hash_table_t * table)80 hash_mutex_enter_all(
81 /*=================*/
82 	hash_table_t*	table)	/*!< in: hash table */
83 {
84 	ulint	i;
85 
86 	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
87 	for (i = 0; i < table->n_sync_obj; i++) {
88 
89 		mutex_enter(table->sync_obj.mutexes + i);
90 	}
91 }
92 
93 /************************************************************//**
94 Releases all the mutexes of a hash table. */
95 UNIV_INTERN
96 void
hash_mutex_exit_all(hash_table_t * table)97 hash_mutex_exit_all(
98 /*================*/
99 	hash_table_t*	table)	/*!< in: hash table */
100 {
101 	ulint	i;
102 
103 	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
104 	for (i = 0; i < table->n_sync_obj; i++) {
105 
106 		mutex_exit(table->sync_obj.mutexes + i);
107 	}
108 }
109 
110 /************************************************************//**
111 Releases all but the passed in mutex of a hash table. */
112 UNIV_INTERN
113 void
hash_mutex_exit_all_but(hash_table_t * table,ib_prio_mutex_t * keep_mutex)114 hash_mutex_exit_all_but(
115 /*====================*/
116 	hash_table_t*		table,		/*!< in: hash table */
117 	ib_prio_mutex_t*	keep_mutex)	/*!< in: mutex to keep */
118 {
119 	ulint	i;
120 
121 	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
122 	for (i = 0; i < table->n_sync_obj; i++) {
123 
124 		ib_prio_mutex_t* mutex = table->sync_obj.mutexes + i;
125 		if (UNIV_LIKELY(keep_mutex != mutex)) {
126 			mutex_exit(mutex);
127 		}
128 	}
129 
130 	ut_ad(mutex_own(keep_mutex));
131 }
132 
133 /************************************************************//**
134 s-lock a lock for a fold value in a hash table. */
135 UNIV_INTERN
136 void
hash_lock_s(hash_table_t * table,ulint fold)137 hash_lock_s(
138 /*========*/
139 	hash_table_t*	table,	/*!< in: hash table */
140 	ulint		fold)	/*!< in: fold */
141 {
142 
143 	prio_rw_lock_t* lock = hash_get_lock(table, fold);
144 
145 	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
146 	ut_ad(lock);
147 
148 #ifdef UNIV_SYNC_DEBUG
149 	ut_ad(!rw_lock_own(lock, RW_LOCK_SHARED));
150 	ut_ad(!rw_lock_own(lock, RW_LOCK_EX));
151 #endif /* UNIV_SYNC_DEBUG */
152 
153 	rw_lock_s_lock(lock);
154 }
155 
156 /************************************************************//**
157 x-lock a lock for a fold value in a hash table. */
158 UNIV_INTERN
159 void
hash_lock_x(hash_table_t * table,ulint fold)160 hash_lock_x(
161 /*========*/
162 	hash_table_t*	table,	/*!< in: hash table */
163 	ulint		fold)	/*!< in: fold */
164 {
165 
166 	prio_rw_lock_t* lock = hash_get_lock(table, fold);
167 
168 	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
169 	ut_ad(lock);
170 
171 #ifdef UNIV_SYNC_DEBUG
172 	ut_ad(!rw_lock_own(lock, RW_LOCK_SHARED));
173 	ut_ad(!rw_lock_own(lock, RW_LOCK_EX));
174 #endif /* UNIV_SYNC_DEBUG */
175 
176 	rw_lock_x_lock(lock);
177 }
178 
179 /************************************************************//**
180 unlock an s-lock for a fold value in a hash table. */
181 UNIV_INTERN
182 void
hash_unlock_s(hash_table_t * table,ulint fold)183 hash_unlock_s(
184 /*==========*/
185 
186 	hash_table_t*	table,	/*!< in: hash table */
187 	ulint		fold)	/*!< in: fold */
188 {
189 
190 	prio_rw_lock_t* lock = hash_get_lock(table, fold);
191 
192 	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
193 	ut_ad(lock);
194 
195 #ifdef UNIV_SYNC_DEBUG
196 	ut_ad(rw_lock_own(lock, RW_LOCK_SHARED));
197 #endif /* UNIV_SYNC_DEBUG */
198 
199 	rw_lock_s_unlock(lock);
200 }
201 
202 /************************************************************//**
203 unlock x-lock for a fold value in a hash table. */
204 UNIV_INTERN
205 void
hash_unlock_x(hash_table_t * table,ulint fold)206 hash_unlock_x(
207 /*==========*/
208 	hash_table_t*	table,	/*!< in: hash table */
209 	ulint		fold)	/*!< in: fold */
210 {
211 	prio_rw_lock_t* lock = hash_get_lock(table, fold);
212 
213 	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
214 	ut_ad(lock);
215 
216 #ifdef UNIV_SYNC_DEBUG
217 	ut_ad(rw_lock_own(lock, RW_LOCK_EX));
218 #endif /* UNIV_SYNC_DEBUG */
219 
220 	rw_lock_x_unlock(lock);
221 }
222 
223 /************************************************************//**
224 Reserves all the locks of a hash table, in an ascending order. */
225 UNIV_INTERN
226 void
hash_lock_x_all(hash_table_t * table)227 hash_lock_x_all(
228 /*============*/
229 	hash_table_t*	table)	/*!< in: hash table */
230 {
231 	ulint	i;
232 
233 	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
234 	for (i = 0; i < table->n_sync_obj; i++) {
235 
236 		prio_rw_lock_t* lock = table->sync_obj.rw_locks + i;
237 #ifdef UNIV_SYNC_DEBUG
238 		ut_ad(!rw_lock_own(lock, RW_LOCK_SHARED));
239 		ut_ad(!rw_lock_own(lock, RW_LOCK_EX));
240 #endif /* UNIV_SYNC_DEBUG */
241 
242 		rw_lock_x_lock(lock);
243 	}
244 }
245 
246 /************************************************************//**
247 Releases all the locks of a hash table, in an ascending order. */
248 UNIV_INTERN
249 void
hash_unlock_x_all(hash_table_t * table)250 hash_unlock_x_all(
251 /*==============*/
252 	hash_table_t*	table)	/*!< in: hash table */
253 {
254 	ulint	i;
255 
256 	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
257 	for (i = 0; i < table->n_sync_obj; i++) {
258 
259 		prio_rw_lock_t* lock = table->sync_obj.rw_locks + i;
260 #ifdef UNIV_SYNC_DEBUG
261 		ut_ad(rw_lock_own(lock, RW_LOCK_EX));
262 #endif /* UNIV_SYNC_DEBUG */
263 
264 		rw_lock_x_unlock(lock);
265 	}
266 }
267 
268 /************************************************************//**
269 Releases all but passed in lock of a hash table, */
270 UNIV_INTERN
271 void
hash_unlock_x_all_but(hash_table_t * table,prio_rw_lock_t * keep_lock)272 hash_unlock_x_all_but(
273 /*==================*/
274 	hash_table_t*	table,		/*!< in: hash table */
275 	prio_rw_lock_t*	keep_lock)	/*!< in: lock to keep */
276 {
277 	ulint	i;
278 
279 	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
280 	for (i = 0; i < table->n_sync_obj; i++) {
281 
282 		prio_rw_lock_t* lock = table->sync_obj.rw_locks + i;
283 #ifdef UNIV_SYNC_DEBUG
284 		ut_ad(rw_lock_own(lock, RW_LOCK_EX));
285 #endif /* UNIV_SYNC_DEBUG */
286 
287 		if (UNIV_LIKELY(keep_lock != lock)) {
288 			rw_lock_x_unlock(lock);
289 		}
290 	}
291 }
292 
293 #endif /* !UNIV_HOTBACKUP */
294 
295 /*************************************************************//**
296 Creates a hash table with >= n array cells. The actual number of cells is
297 chosen to be a prime number slightly bigger than n.
298 @return	own: created table */
299 UNIV_INTERN
300 hash_table_t*
hash_create(ulint n)301 hash_create(
302 /*========*/
303 	ulint	n)	/*!< in: number of array cells */
304 {
305 	hash_cell_t*	array;
306 	ulint		prime;
307 	hash_table_t*	table;
308 
309 	prime = ut_find_prime(n);
310 
311 	table = static_cast<hash_table_t*>(mem_alloc(sizeof(hash_table_t)));
312 
313 	array = static_cast<hash_cell_t*>(
314 		ut_malloc(sizeof(hash_cell_t) * prime));
315 
316 	/* The default type of hash_table is HASH_TABLE_SYNC_NONE i.e.:
317 	the caller is responsible for access control to the table. */
318 	table->type = HASH_TABLE_SYNC_NONE;
319 	table->array = array;
320 	table->n_cells = prime;
321 #ifndef UNIV_HOTBACKUP
322 # if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
323 	table->adaptive = FALSE;
324 # endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
325 	table->n_sync_obj = 0;
326 	table->sync_obj.mutexes = NULL;
327 	table->heaps = NULL;
328 #endif /* !UNIV_HOTBACKUP */
329 	table->heap = NULL;
330 	ut_d(table->magic_n = HASH_TABLE_MAGIC_N);
331 
332 	/* Initialize the cell array */
333 	hash_table_clear(table);
334 
335 	return(table);
336 }
337 
338 /*************************************************************//**
339 Frees a hash table. */
340 UNIV_INTERN
341 void
hash_table_free(hash_table_t * table)342 hash_table_free(
343 /*============*/
344 	hash_table_t*	table)	/*!< in, own: hash table */
345 {
346 	ut_ad(table);
347 	ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
348 
349 	ut_free(table->array);
350 	mem_free(table);
351 }
352 
353 #ifndef UNIV_HOTBACKUP
354 /*************************************************************//**
355 Creates a sync object array to protect a hash table.
356 ::sync_obj can be mutexes or rw_locks depening on the type of
357 hash table. */
358 UNIV_INTERN
359 void
hash_create_sync_obj_func(hash_table_t * table,enum hash_table_sync_t type,ulint sync_level,ulint n_sync_obj)360 hash_create_sync_obj_func(
361 /*======================*/
362 	hash_table_t*		table,	/*!< in: hash table */
363 	enum hash_table_sync_t	type,	/*!< in: HASH_TABLE_SYNC_MUTEX
364 					or HASH_TABLE_SYNC_RW_LOCK */
365 #ifdef UNIV_SYNC_DEBUG
366 	ulint			sync_level,/*!< in: latching order level
367 					of the mutexes: used in the
368 					debug version */
369 #endif /* UNIV_SYNC_DEBUG */
370 	ulint			n_sync_obj)/*!< in: number of sync objects,
371 					must be a power of 2 */
372 {
373 	ulint	i;
374 
375 	ut_ad(table);
376 	ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
377 	ut_a(n_sync_obj > 0);
378 	ut_a(ut_is_2pow(n_sync_obj));
379 
380 	table->type = type;
381 
382 	switch (type) {
383 	case HASH_TABLE_SYNC_MUTEX:
384 		table->sync_obj.mutexes = static_cast<ib_prio_mutex_t*>(
385 			mem_alloc(n_sync_obj * sizeof(ib_prio_mutex_t)));
386 
387 		for (i = 0; i < n_sync_obj; i++) {
388 			mutex_create(hash_table_mutex_key,
389 			     table->sync_obj.mutexes + i, sync_level);
390 		}
391 
392 		break;
393 
394 	case HASH_TABLE_SYNC_RW_LOCK:
395 		table->sync_obj.rw_locks = static_cast<prio_rw_lock_t*>(
396 			mem_alloc(n_sync_obj * sizeof(prio_rw_lock_t)));
397 
398 		for (i = 0; i < n_sync_obj; i++) {
399 			rw_lock_create(hash_table_rw_lock_key,
400 			     table->sync_obj.rw_locks + i, sync_level);
401 		}
402 
403 		break;
404 
405 	case HASH_TABLE_SYNC_NONE:
406 		ut_error;
407 	}
408 
409 	table->n_sync_obj = n_sync_obj;
410 }
411 #endif /* !UNIV_HOTBACKUP */
412