/***************************************************************************** Copyright (c) 1996, 2009, Innobase Oy. All Rights Reserved. Copyright (c) 2008, Google Inc. Portions of this file contain modifications contributed and copyrighted by Google, Inc. Those modifications are gratefully acknowledged and are described briefly in the InnoDB documentation. The contributions by Google are incorporated with their permission, and subject to the conditions contained in the file COPYING.Google. 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 *****************************************************************************/ /************************************************************************ The index tree adaptive search Created 2/17/1996 Heikki Tuuri *************************************************************************/ #include "btr0sea.h" #ifdef UNIV_NONINL #include "btr0sea.ic" #endif #include "buf0buf.h" #include "page0page.h" #include "page0cur.h" #include "btr0cur.h" #include "btr0pcur.h" #include "btr0btr.h" #include "ha0ha.h" /* Flag: has the search system been enabled? Protected by btr_search_latch and btr_search_enabled_mutex. */ UNIV_INTERN char btr_search_enabled = TRUE; static mutex_t btr_search_enabled_mutex; /* A dummy variable to fool the compiler */ UNIV_INTERN ulint btr_search_this_is_zero = 0; #ifdef UNIV_SEARCH_PERF_STAT UNIV_INTERN ulint btr_search_n_succ = 0; UNIV_INTERN ulint btr_search_n_hash_fail = 0; #endif /* UNIV_SEARCH_PERF_STAT */ /* padding to prevent other memory update hotspots from residing on the same memory cache line as btr_search_latch */ UNIV_INTERN byte btr_sea_pad1[64]; /* The latch protecting the adaptive search system: this latch protects the (1) positions of records on those pages where a hash index has been built. NOTE: It does not protect values of non-ordering fields within a record from being updated in-place! We can use fact (1) to perform unique searches to indexes. */ /* We will allocate the latch from dynamic memory to get it to the same DRAM page as other hotspot semaphores */ UNIV_INTERN rw_lock_t* btr_search_latch_temp; /* padding to prevent other memory update hotspots from residing on the same memory cache line */ UNIV_INTERN byte btr_sea_pad2[64]; UNIV_INTERN btr_search_sys_t* btr_search_sys; /* If the number of records on the page divided by this parameter would have been successfully accessed using a hash index, the index is then built on the page, assuming the global limit has been reached */ #define BTR_SEARCH_PAGE_BUILD_LIMIT 16 /* The global limit for consecutive potentially successful hash searches, before hash index building is started */ #define BTR_SEARCH_BUILD_LIMIT 100 /************************************************************************ Builds a hash index on a page with the given parameters. If the page already has a hash index with different parameters, the old hash index is removed. If index is non-NULL, this function checks if n_fields and n_bytes are sensible values, and does not build a hash index if not. */ static void btr_search_build_page_hash_index( /*=============================*/ dict_index_t* index, /* in: index for which to build, or NULL if not known */ buf_block_t* block, /* in: index page, s- or x-latched */ ulint n_fields,/* in: hash this many full fields */ ulint n_bytes,/* in: hash this many bytes from the next field */ ibool left_side);/* in: hash for searches from left side? */ /********************************************************************* This function should be called before reserving any btr search mutex, if the intended operation might add nodes to the search system hash table. Because of the latching order, once we have reserved the btr search system latch, we cannot allocate a free frame from the buffer pool. Checks that there is a free buffer frame allocated for hash table heap in the btr search system. If not, allocates a free frames for the heap. This check makes it probable that, when have reserved the btr search system latch and we need to allocate a new node to the hash table, it will succeed. However, the check will not guarantee success. */ static void btr_search_check_free_space_in_heap(void) /*=====================================*/ { hash_table_t* table; mem_heap_t* heap; #ifdef UNIV_SYNC_DEBUG ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_SHARED)); ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ table = btr_search_sys->hash_index; heap = table->heap; /* Note that we peek the value of heap->free_block without reserving the latch: this is ok, because we will not guarantee that there will be enough free space in the hash table. */ if (heap->free_block == NULL) { buf_block_t* block = buf_block_alloc(0); rw_lock_x_lock(&btr_search_latch); if (heap->free_block == NULL) { heap->free_block = block; } else { buf_block_free(block); } rw_lock_x_unlock(&btr_search_latch); } } /********************************************************************* Creates and initializes the adaptive search system at a database start. */ UNIV_INTERN void btr_search_sys_create( /*==================*/ ulint hash_size) /* in: hash index hash table size */ { /* We allocate the search latch from dynamic memory: see above at the global variable definition */ btr_search_latch_temp = mem_alloc(sizeof(rw_lock_t)); rw_lock_create(&btr_search_latch, SYNC_SEARCH_SYS); mutex_create(&btr_search_enabled_mutex, SYNC_SEARCH_SYS_CONF); btr_search_sys = mem_alloc(sizeof(btr_search_sys_t)); btr_search_sys->hash_index = ha_create(hash_size, 0, 0); } /************************************************************************ Disable the adaptive hash search system and empty the index. */ UNIV_INTERN void btr_search_disable(void) /*====================*/ { mutex_enter(&btr_search_enabled_mutex); rw_lock_x_lock(&btr_search_latch); btr_search_enabled = FALSE; /* Clear all block->is_hashed flags and remove all entries from btr_search_sys->hash_index. */ buf_pool_drop_hash_index(); /* btr_search_enabled_mutex should guarantee this. */ ut_ad(!btr_search_enabled); rw_lock_x_unlock(&btr_search_latch); mutex_exit(&btr_search_enabled_mutex); } /************************************************************************ Enable the adaptive hash search system. */ UNIV_INTERN void btr_search_enable(void) /*====================*/ { mutex_enter(&btr_search_enabled_mutex); rw_lock_x_lock(&btr_search_latch); btr_search_enabled = TRUE; rw_lock_x_unlock(&btr_search_latch); mutex_exit(&btr_search_enabled_mutex); } /********************************************************************* Creates and initializes a search info struct. */ UNIV_INTERN btr_search_t* btr_search_info_create( /*===================*/ /* out, own: search info struct */ mem_heap_t* heap) /* in: heap where created */ { btr_search_t* info; info = mem_heap_alloc(heap, sizeof(btr_search_t)); #ifdef UNIV_DEBUG info->magic_n = BTR_SEARCH_MAGIC_N; #endif /* UNIV_DEBUG */ info->ref_count = 0; info->root_guess = NULL; info->hash_analysis = 0; info->n_hash_potential = 0; info->last_hash_succ = FALSE; #ifdef UNIV_SEARCH_PERF_STAT info->n_hash_succ = 0; info->n_hash_fail = 0; info->n_patt_succ = 0; info->n_searches = 0; #endif /* UNIV_SEARCH_PERF_STAT */ /* Set some sensible values */ info->n_fields = 1; info->n_bytes = 0; info->left_side = TRUE; return(info); } /********************************************************************* Returns the value of ref_count. The value is protected by btr_search_latch. */ UNIV_INTERN ulint btr_search_info_get_ref_count( /*==========================*/ /* out: ref_count value. */ btr_search_t* info) /* in: search info. */ { ulint ret; ut_ad(info); #ifdef UNIV_SYNC_DEBUG ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_SHARED)); ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ rw_lock_s_lock(&btr_search_latch); ret = info->ref_count; rw_lock_s_unlock(&btr_search_latch); return(ret); } /************************************************************************* Updates the search info of an index about hash successes. NOTE that info is NOT protected by any semaphore, to save CPU time! Do not assume its fields are consistent. */ static void btr_search_info_update_hash( /*========================*/ btr_search_t* info, /* in/out: search info */ btr_cur_t* cursor) /* in: cursor which was just positioned */ { dict_index_t* index; ulint n_unique; int cmp; #ifdef UNIV_SYNC_DEBUG ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_SHARED)); ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ index = cursor->index; if (dict_index_is_ibuf(index)) { /* So many deletes are performed on an insert buffer tree that we do not consider a hash index useful on it: */ return; } n_unique = dict_index_get_n_unique_in_tree(index); if (info->n_hash_potential == 0) { goto set_new_recomm; } /* Test if the search would have succeeded using the recommended hash prefix */ if (info->n_fields >= n_unique && cursor->up_match >= n_unique) { increment_potential: info->n_hash_potential++; return; } cmp = ut_pair_cmp(info->n_fields, info->n_bytes, cursor->low_match, cursor->low_bytes); if (info->left_side ? cmp <= 0 : cmp > 0) { goto set_new_recomm; } cmp = ut_pair_cmp(info->n_fields, info->n_bytes, cursor->up_match, cursor->up_bytes); if (info->left_side ? cmp <= 0 : cmp > 0) { goto increment_potential; } set_new_recomm: /* We have to set a new recommendation; skip the hash analysis for a while to avoid unnecessary CPU time usage when there is no chance for success */ info->hash_analysis = 0; cmp = ut_pair_cmp(cursor->up_match, cursor->up_bytes, cursor->low_match, cursor->low_bytes); if (cmp == 0) { info->n_hash_potential = 0; /* For extra safety, we set some sensible values here */ info->n_fields = 1; info->n_bytes = 0; info->left_side = TRUE; } else if (cmp > 0) { info->n_hash_potential = 1; if (cursor->up_match >= n_unique) { info->n_fields = n_unique; info->n_bytes = 0; } else if (cursor->low_match < cursor->up_match) { info->n_fields = cursor->low_match + 1; info->n_bytes = 0; } else { info->n_fields = cursor->low_match; info->n_bytes = cursor->low_bytes + 1; } info->left_side = TRUE; } else { info->n_hash_potential = 1; if (cursor->low_match >= n_unique) { info->n_fields = n_unique; info->n_bytes = 0; } else if (cursor->low_match > cursor->up_match) { info->n_fields = cursor->up_match + 1; info->n_bytes = 0; } else { info->n_fields = cursor->up_match; info->n_bytes = cursor->up_bytes + 1; } info->left_side = FALSE; } } /************************************************************************* Updates the block search info on hash successes. NOTE that info and block->n_hash_helps, n_fields, n_bytes, side are NOT protected by any semaphore, to save CPU time! Do not assume the fields are consistent. */ static ibool btr_search_update_block_hash_info( /*==============================*/ /* out: TRUE if building a (new) hash index on the block is recommended */ btr_search_t* info, /* in: search info */ buf_block_t* block, /* in: buffer block */ btr_cur_t* cursor __attribute__((unused))) /* in: cursor */ { #ifdef UNIV_SYNC_DEBUG ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_SHARED)); ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX)); ut_ad(rw_lock_own(&block->lock, RW_LOCK_SHARED) || rw_lock_own(&block->lock, RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ ut_ad(cursor); info->last_hash_succ = FALSE; ut_a(buf_block_state_valid(block)); ut_ad(info->magic_n == BTR_SEARCH_MAGIC_N); if ((block->n_hash_helps > 0) && (info->n_hash_potential > 0) && (block->n_fields == info->n_fields) && (block->n_bytes == info->n_bytes) && (block->left_side == info->left_side)) { if ((block->is_hashed) && (block->curr_n_fields == info->n_fields) && (block->curr_n_bytes == info->n_bytes) && (block->curr_left_side == info->left_side)) { /* The search would presumably have succeeded using the hash index */ info->last_hash_succ = TRUE; } block->n_hash_helps++; } else { block->n_hash_helps = 1; block->n_fields = info->n_fields; block->n_bytes = info->n_bytes; block->left_side = info->left_side; } #ifdef UNIV_DEBUG if (cursor->index->table->does_not_fit_in_memory) { block->n_hash_helps = 0; } #endif /* UNIV_DEBUG */ if ((block->n_hash_helps > page_get_n_recs(block->frame) / BTR_SEARCH_PAGE_BUILD_LIMIT) && (info->n_hash_potential >= BTR_SEARCH_BUILD_LIMIT)) { if ((!block->is_hashed) || (block->n_hash_helps > 2 * page_get_n_recs(block->frame)) || (block->n_fields != block->curr_n_fields) || (block->n_bytes != block->curr_n_bytes) || (block->left_side != block->curr_left_side)) { /* Build a new hash index on the page */ return(TRUE); } } return(FALSE); } /************************************************************************* Updates a hash node reference when it has been unsuccessfully used in a search which could have succeeded with the used hash parameters. This can happen because when building a hash index for a page, we do not check what happens at page boundaries, and therefore there can be misleading hash nodes. Also, collisions in the fold value can lead to misleading references. This function lazily fixes these imperfections in the hash index. */ static void btr_search_update_hash_ref( /*=======================*/ btr_search_t* info, /* in: search info */ buf_block_t* block, /* in: buffer block where cursor positioned */ btr_cur_t* cursor) /* in: cursor */ { ulint fold; rec_t* rec; dulint index_id; ut_ad(cursor->flag == BTR_CUR_HASH_FAIL); #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&btr_search_latch, RW_LOCK_EX)); ut_ad(rw_lock_own(&(block->lock), RW_LOCK_SHARED) || rw_lock_own(&(block->lock), RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ ut_ad(page_align(btr_cur_get_rec(cursor)) == buf_block_get_frame(block)); if (!block->is_hashed) { return; } ut_a(block->index == cursor->index); ut_a(!dict_index_is_ibuf(cursor->index)); if ((info->n_hash_potential > 0) && (block->curr_n_fields == info->n_fields) && (block->curr_n_bytes == info->n_bytes) && (block->curr_left_side == info->left_side)) { mem_heap_t* heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; rec_offs_init(offsets_); rec = btr_cur_get_rec(cursor); if (!page_rec_is_user_rec(rec)) { return; } index_id = cursor->index->id; fold = rec_fold(rec, rec_get_offsets(rec, cursor->index, offsets_, ULINT_UNDEFINED, &heap), block->curr_n_fields, block->curr_n_bytes, index_id); if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&btr_search_latch, RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ ha_insert_for_fold(btr_search_sys->hash_index, fold, block, rec); } } /************************************************************************* Updates the search info. */ UNIV_INTERN void btr_search_info_update_slow( /*========================*/ btr_search_t* info, /* in/out: search info */ btr_cur_t* cursor) /* in: cursor which was just positioned */ { buf_block_t* block; ibool build_index; ulint* params; ulint* params2; #ifdef UNIV_SYNC_DEBUG ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_SHARED)); ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ block = btr_cur_get_block(cursor); /* NOTE that the following two function calls do NOT protect info or block->n_fields etc. with any semaphore, to save CPU time! We cannot assume the fields are consistent when we return from those functions! */ btr_search_info_update_hash(info, cursor); build_index = btr_search_update_block_hash_info(info, block, cursor); if (build_index || (cursor->flag == BTR_CUR_HASH_FAIL)) { btr_search_check_free_space_in_heap(); } if (cursor->flag == BTR_CUR_HASH_FAIL) { /* Update the hash node reference, if appropriate */ #ifdef UNIV_SEARCH_PERF_STAT btr_search_n_hash_fail++; #endif /* UNIV_SEARCH_PERF_STAT */ rw_lock_x_lock(&btr_search_latch); btr_search_update_hash_ref(info, block, cursor); rw_lock_x_unlock(&btr_search_latch); } if (build_index) { /* Note that since we did not protect block->n_fields etc. with any semaphore, the values can be inconsistent. We have to check inside the function call that they make sense. We also malloc an array and store the values there to make sure the compiler does not let the function call parameters change inside the called function. It might be that the compiler would optimize the call just to pass pointers to block. */ params = mem_alloc(3 * sizeof(ulint)); params[0] = block->n_fields; params[1] = block->n_bytes; params[2] = block->left_side; /* Make sure the compiler cannot deduce the values and do optimizations */ params2 = params + btr_search_this_is_zero; btr_search_build_page_hash_index(cursor->index, block, params2[0], params2[1], params2[2]); mem_free(params); } } /********************************************************************** Checks if a guessed position for a tree cursor is right. Note that if mode is PAGE_CUR_LE, which is used in inserts, and the function returns TRUE, then cursor->up_match and cursor->low_match both have sensible values. */ static ibool btr_search_check_guess( /*===================*/ /* out: TRUE if success */ btr_cur_t* cursor, /* in: guessed cursor position */ ibool can_only_compare_to_cursor_rec, /* in: if we do not have a latch on the page of cursor, but only a latch on btr_search_latch, then ONLY the columns of the record UNDER the cursor are protected, not the next or previous record in the chain: we cannot look at the next or previous record to check our guess! */ const dtuple_t* tuple, /* in: data tuple */ ulint mode, /* in: PAGE_CUR_L, PAGE_CUR_LE, PAGE_CUR_G, or PAGE_CUR_GE */ mtr_t* mtr) /* in: mtr */ { rec_t* rec; ulint n_unique; ulint match; ulint bytes; int cmp; mem_heap_t* heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; ulint* offsets = offsets_; ibool success = FALSE; rec_offs_init(offsets_); n_unique = dict_index_get_n_unique_in_tree(cursor->index); rec = btr_cur_get_rec(cursor); ut_ad(page_rec_is_user_rec(rec)); match = 0; bytes = 0; offsets = rec_get_offsets(rec, cursor->index, offsets, n_unique, &heap); cmp = page_cmp_dtuple_rec_with_match(tuple, rec, offsets, &match, &bytes); if (mode == PAGE_CUR_GE) { if (cmp == 1) { goto exit_func; } cursor->up_match = match; if (match >= n_unique) { success = TRUE; goto exit_func; } } else if (mode == PAGE_CUR_LE) { if (cmp == -1) { goto exit_func; } cursor->low_match = match; } else if (mode == PAGE_CUR_G) { if (cmp != -1) { goto exit_func; } } else if (mode == PAGE_CUR_L) { if (cmp != 1) { goto exit_func; } } if (can_only_compare_to_cursor_rec) { /* Since we could not determine if our guess is right just by looking at the record under the cursor, return FALSE */ goto exit_func; } match = 0; bytes = 0; if ((mode == PAGE_CUR_G) || (mode == PAGE_CUR_GE)) { rec_t* prev_rec; ut_ad(!page_rec_is_infimum(rec)); prev_rec = page_rec_get_prev(rec); if (page_rec_is_infimum(prev_rec)) { success = btr_page_get_prev(page_align(prev_rec), mtr) == FIL_NULL; goto exit_func; } offsets = rec_get_offsets(prev_rec, cursor->index, offsets, n_unique, &heap); cmp = page_cmp_dtuple_rec_with_match(tuple, prev_rec, offsets, &match, &bytes); if (mode == PAGE_CUR_GE) { success = cmp == 1; } else { success = cmp != -1; } goto exit_func; } else { rec_t* next_rec; ut_ad(!page_rec_is_supremum(rec)); next_rec = page_rec_get_next(rec); if (page_rec_is_supremum(next_rec)) { if (btr_page_get_next(page_align(next_rec), mtr) == FIL_NULL) { cursor->up_match = 0; success = TRUE; } goto exit_func; } offsets = rec_get_offsets(next_rec, cursor->index, offsets, n_unique, &heap); cmp = page_cmp_dtuple_rec_with_match(tuple, next_rec, offsets, &match, &bytes); if (mode == PAGE_CUR_LE) { success = cmp == -1; cursor->up_match = match; } else { success = cmp != 1; } } exit_func: if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } return(success); } /********************************************************************** Tries to guess the right search position based on the hash search info of the index. Note that if mode is PAGE_CUR_LE, which is used in inserts, and the function returns TRUE, then cursor->up_match and cursor->low_match both have sensible values. */ UNIV_INTERN ibool btr_search_guess_on_hash( /*=====================*/ /* out: TRUE if succeeded */ dict_index_t* index, /* in: index */ btr_search_t* info, /* in: index search info */ const dtuple_t* tuple, /* in: logical record */ ulint mode, /* in: PAGE_CUR_L, ... */ ulint latch_mode, /* in: BTR_SEARCH_LEAF, ...; NOTE that only if has_search_latch is 0, we will have a latch set on the cursor page, otherwise we assume the caller uses his search latch to protect the record! */ btr_cur_t* cursor, /* out: tree cursor */ ulint has_search_latch,/* in: latch mode the caller currently has on btr_search_latch: RW_S_LATCH, RW_X_LATCH, or 0 */ mtr_t* mtr) /* in: mtr */ { buf_block_t* block; rec_t* rec; ulint fold; dulint index_id; #ifdef notdefined btr_cur_t cursor2; btr_pcur_t pcur; #endif ut_ad(index && info && tuple && cursor && mtr); ut_ad((latch_mode == BTR_SEARCH_LEAF) || (latch_mode == BTR_MODIFY_LEAF)); /* Note that, for efficiency, the struct info may not be protected by any latch here! */ if (UNIV_UNLIKELY(info->n_hash_potential == 0)) { return(FALSE); } cursor->n_fields = info->n_fields; cursor->n_bytes = info->n_bytes; if (UNIV_UNLIKELY(dtuple_get_n_fields(tuple) < cursor->n_fields + (cursor->n_bytes > 0))) { return(FALSE); } index_id = index->id; #ifdef UNIV_SEARCH_PERF_STAT info->n_hash_succ++; #endif fold = dtuple_fold(tuple, cursor->n_fields, cursor->n_bytes, index_id); cursor->fold = fold; cursor->flag = BTR_CUR_HASH; if (UNIV_LIKELY(!has_search_latch)) { rw_lock_s_lock(&btr_search_latch); if (UNIV_UNLIKELY(!btr_search_enabled)) { goto failure_unlock; } } ut_ad(rw_lock_get_writer(&btr_search_latch) != RW_LOCK_EX); ut_ad(rw_lock_get_reader_count(&btr_search_latch) > 0); rec = ha_search_and_get_data(btr_search_sys->hash_index, fold); if (UNIV_UNLIKELY(!rec)) { goto failure_unlock; } block = buf_block_align(rec); if (UNIV_LIKELY(!has_search_latch)) { if (UNIV_UNLIKELY( !buf_page_get_known_nowait(latch_mode, block, BUF_MAKE_YOUNG, __FILE__, __LINE__, mtr))) { goto failure_unlock; } rw_lock_s_unlock(&btr_search_latch); buf_block_dbg_add_level(block, SYNC_TREE_NODE_FROM_HASH); } if (UNIV_UNLIKELY(buf_block_get_state(block) != BUF_BLOCK_FILE_PAGE)) { ut_ad(buf_block_get_state(block) == BUF_BLOCK_REMOVE_HASH); if (UNIV_LIKELY(!has_search_latch)) { btr_leaf_page_release(block, latch_mode, mtr); } goto failure; } ut_ad(page_rec_is_user_rec(rec)); btr_cur_position(index, rec, block, cursor); /* Check the validity of the guess within the page */ /* If we only have the latch on btr_search_latch, not on the page, it only protects the columns of the record the cursor is positioned on. We cannot look at the next of the previous record to determine if our guess for the cursor position is right. */ if (UNIV_EXPECT (ut_dulint_cmp(index_id, btr_page_get_index_id(block->frame)), 0) || !btr_search_check_guess(cursor, has_search_latch, tuple, mode, mtr)) { if (UNIV_LIKELY(!has_search_latch)) { btr_leaf_page_release(block, latch_mode, mtr); } goto failure; } if (UNIV_LIKELY(info->n_hash_potential < BTR_SEARCH_BUILD_LIMIT + 5)) { info->n_hash_potential++; } #ifdef notdefined /* These lines of code can be used in a debug version to check the correctness of the searched cursor position: */ info->last_hash_succ = FALSE; /* Currently, does not work if the following fails: */ ut_ad(!has_search_latch); btr_leaf_page_release(block, latch_mode, mtr); btr_cur_search_to_nth_level(index, 0, tuple, mode, latch_mode, &cursor2, 0, mtr); if (mode == PAGE_CUR_GE && page_rec_is_supremum(btr_cur_get_rec(&cursor2))) { /* If mode is PAGE_CUR_GE, then the binary search in the index tree may actually take us to the supremum of the previous page */ info->last_hash_succ = FALSE; btr_pcur_open_on_user_rec(index, tuple, mode, latch_mode, &pcur, mtr); ut_ad(btr_pcur_get_rec(&pcur) == btr_cur_get_rec(cursor)); } else { ut_ad(btr_cur_get_rec(&cursor2) == btr_cur_get_rec(cursor)); } /* NOTE that it is theoretically possible that the above assertions fail if the page of the cursor gets removed from the buffer pool meanwhile! Thus it might not be a bug. */ #endif info->last_hash_succ = TRUE; #ifdef UNIV_SEARCH_PERF_STAT btr_search_n_succ++; #endif if (UNIV_LIKELY(!has_search_latch) && buf_page_peek_if_too_old(&block->page)) { buf_page_make_young(&block->page); } /* Increment the page get statistics though we did not really fix the page: for user info only */ buf_pool->n_page_gets++; return(TRUE); /*-------------------------------------------*/ failure_unlock: if (UNIV_LIKELY(!has_search_latch)) { rw_lock_s_unlock(&btr_search_latch); } failure: cursor->flag = BTR_CUR_HASH_FAIL; #ifdef UNIV_SEARCH_PERF_STAT info->n_hash_fail++; if (info->n_hash_succ > 0) { info->n_hash_succ--; } #endif info->last_hash_succ = FALSE; return(FALSE); } /************************************************************************ Drops a page hash index. */ UNIV_INTERN void btr_search_drop_page_hash_index( /*============================*/ buf_block_t* block) /* in: block containing index page, s- or x-latched, or an index page for which we know that block->buf_fix_count == 0 */ { hash_table_t* table; ulint n_fields; ulint n_bytes; const page_t* page; const rec_t* rec; ulint fold; ulint prev_fold; dulint index_id; ulint n_cached; ulint n_recs; ulint* folds; ulint i; mem_heap_t* heap; const dict_index_t* index; ulint* offsets; #ifdef UNIV_SYNC_DEBUG ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_SHARED)); ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ retry: rw_lock_s_lock(&btr_search_latch); page = block->frame; if (UNIV_LIKELY(!block->is_hashed)) { rw_lock_s_unlock(&btr_search_latch); return; } table = btr_search_sys->hash_index; #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&(block->lock), RW_LOCK_SHARED) || rw_lock_own(&(block->lock), RW_LOCK_EX) || (block->page.buf_fix_count == 0)); #endif /* UNIV_SYNC_DEBUG */ n_fields = block->curr_n_fields; n_bytes = block->curr_n_bytes; index = block->index; ut_a(!dict_index_is_ibuf(index)); /* NOTE: The fields of block must not be accessed after releasing btr_search_latch, as the index page might only be s-latched! */ rw_lock_s_unlock(&btr_search_latch); ut_a(n_fields + n_bytes > 0); n_recs = page_get_n_recs(page); /* Calculate and cache fold values into an array for fast deletion from the hash index */ folds = mem_alloc(n_recs * sizeof(ulint)); n_cached = 0; rec = page_get_infimum_rec(page); rec = page_rec_get_next_low(rec, page_is_comp(page)); index_id = btr_page_get_index_id(page); ut_a(0 == ut_dulint_cmp(index_id, index->id)); prev_fold = 0; heap = NULL; offsets = NULL; while (!page_rec_is_supremum(rec)) { offsets = rec_get_offsets(rec, index, offsets, n_fields + (n_bytes > 0), &heap); ut_a(rec_offs_n_fields(offsets) == n_fields + (n_bytes > 0)); fold = rec_fold(rec, offsets, n_fields, n_bytes, index_id); if (fold == prev_fold && prev_fold != 0) { goto next_rec; } /* Remove all hash nodes pointing to this page from the hash chain */ folds[n_cached] = fold; n_cached++; next_rec: rec = page_rec_get_next_low(rec, page_rec_is_comp(rec)); prev_fold = fold; } if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } rw_lock_x_lock(&btr_search_latch); if (UNIV_UNLIKELY(!block->is_hashed)) { /* Someone else has meanwhile dropped the hash index */ goto cleanup; } ut_a(block->index == index); if (UNIV_UNLIKELY(block->curr_n_fields != n_fields) || UNIV_UNLIKELY(block->curr_n_bytes != n_bytes)) { /* Someone else has meanwhile built a new hash index on the page, with different parameters */ rw_lock_x_unlock(&btr_search_latch); mem_free(folds); goto retry; } for (i = 0; i < n_cached; i++) { ha_remove_all_nodes_to_page(table, folds[i], page); } ut_a(index->search_info->ref_count > 0); index->search_info->ref_count--; block->is_hashed = FALSE; block->index = NULL; cleanup: #if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG if (UNIV_UNLIKELY(block->n_pointers)) { /* Corruption */ ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: Corruption of adaptive hash index." " After dropping\n" "InnoDB: the hash index to a page of %s," " still %lu hash nodes remain.\n", index->name, (ulong) block->n_pointers); rw_lock_x_unlock(&btr_search_latch); btr_search_validate(); } else { rw_lock_x_unlock(&btr_search_latch); } #else /* UNIV_AHI_DEBUG || UNIV_DEBUG */ rw_lock_x_unlock(&btr_search_latch); #endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */ mem_free(folds); } /************************************************************************ Drops a page hash index when a page is freed from a fseg to the file system. Drops possible hash index if the page happens to be in the buffer pool. */ UNIV_INTERN void btr_search_drop_page_hash_when_freed( /*=================================*/ ulint space, /* in: space id */ ulint zip_size, /* in: compressed page size in bytes or 0 for uncompressed pages */ ulint page_no) /* in: page number */ { buf_block_t* block; mtr_t mtr; if (!buf_page_peek_if_search_hashed(space, page_no)) { return; } mtr_start(&mtr); /* We assume that if the caller has a latch on the page, then the caller has already dropped the hash index for the page, and we never get here. Therefore we can acquire the s-latch to the page without having to fear a deadlock. */ block = buf_page_get_gen(space, zip_size, page_no, RW_S_LATCH, NULL, BUF_GET_IF_IN_POOL, __FILE__, __LINE__, &mtr); /* Because the buffer pool mutex was released by buf_page_peek_if_search_hashed(), it is possible that the block was removed from the buffer pool by another thread before buf_page_get_gen() got a chance to acquire the buffer pool mutex again. Thus, we must check for a NULL return. */ if (UNIV_LIKELY(block != NULL)) { buf_block_dbg_add_level(block, SYNC_TREE_NODE_FROM_HASH); btr_search_drop_page_hash_index(block); } mtr_commit(&mtr); } /************************************************************************ Builds a hash index on a page with the given parameters. If the page already has a hash index with different parameters, the old hash index is removed. If index is non-NULL, this function checks if n_fields and n_bytes are sensible values, and does not build a hash index if not. */ static void btr_search_build_page_hash_index( /*=============================*/ dict_index_t* index, /* in: index for which to build */ buf_block_t* block, /* in: index page, s- or x-latched */ ulint n_fields,/* in: hash this many full fields */ ulint n_bytes,/* in: hash this many bytes from the next field */ ibool left_side)/* in: hash for searches from left side? */ { hash_table_t* table; page_t* page; rec_t* rec; rec_t* next_rec; ulint fold; ulint next_fold; dulint index_id; ulint n_cached; ulint n_recs; ulint* folds; rec_t** recs; ulint i; mem_heap_t* heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; ulint* offsets = offsets_; rec_offs_init(offsets_); ut_ad(index); ut_a(!dict_index_is_ibuf(index)); table = btr_search_sys->hash_index; page = buf_block_get_frame(block); #ifdef UNIV_SYNC_DEBUG ut_ad(!rw_lock_own(&btr_search_latch, RW_LOCK_EX)); ut_ad(rw_lock_own(&(block->lock), RW_LOCK_SHARED) || rw_lock_own(&(block->lock), RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ rw_lock_s_lock(&btr_search_latch); if (block->is_hashed && ((block->curr_n_fields != n_fields) || (block->curr_n_bytes != n_bytes) || (block->curr_left_side != left_side))) { rw_lock_s_unlock(&btr_search_latch); btr_search_drop_page_hash_index(block); } else { rw_lock_s_unlock(&btr_search_latch); } n_recs = page_get_n_recs(page); if (n_recs == 0) { return; } /* Check that the values for hash index build are sensible */ if (n_fields + n_bytes == 0) { return; } if (dict_index_get_n_unique_in_tree(index) < n_fields || (dict_index_get_n_unique_in_tree(index) == n_fields && n_bytes > 0)) { return; } /* Calculate and cache fold values and corresponding records into an array for fast insertion to the hash index */ folds = mem_alloc(n_recs * sizeof(ulint)); recs = mem_alloc(n_recs * sizeof(rec_t*)); n_cached = 0; index_id = btr_page_get_index_id(page); rec = page_rec_get_next(page_get_infimum_rec(page)); offsets = rec_get_offsets(rec, index, offsets, n_fields + (n_bytes > 0), &heap); if (!page_rec_is_supremum(rec)) { ut_a(n_fields <= rec_offs_n_fields(offsets)); if (n_bytes > 0) { ut_a(n_fields < rec_offs_n_fields(offsets)); } } fold = rec_fold(rec, offsets, n_fields, n_bytes, index_id); if (left_side) { folds[n_cached] = fold; recs[n_cached] = rec; n_cached++; } for (;;) { next_rec = page_rec_get_next(rec); if (page_rec_is_supremum(next_rec)) { if (!left_side) { folds[n_cached] = fold; recs[n_cached] = rec; n_cached++; } break; } offsets = rec_get_offsets(next_rec, index, offsets, n_fields + (n_bytes > 0), &heap); next_fold = rec_fold(next_rec, offsets, n_fields, n_bytes, index_id); if (fold != next_fold) { /* Insert an entry into the hash index */ if (left_side) { folds[n_cached] = next_fold; recs[n_cached] = next_rec; n_cached++; } else { folds[n_cached] = fold; recs[n_cached] = rec; n_cached++; } } rec = next_rec; fold = next_fold; } btr_search_check_free_space_in_heap(); rw_lock_x_lock(&btr_search_latch); if (UNIV_UNLIKELY(!btr_search_enabled)) { goto exit_func; } if (block->is_hashed && ((block->curr_n_fields != n_fields) || (block->curr_n_bytes != n_bytes) || (block->curr_left_side != left_side))) { goto exit_func; } /* This counter is decremented every time we drop page hash index entries and is incremented here. Since we can rebuild hash index for a page that is already hashed, we have to take care not to increment the counter in that case. */ if (!block->is_hashed) { index->search_info->ref_count++; } block->is_hashed = TRUE; block->n_hash_helps = 0; block->curr_n_fields = n_fields; block->curr_n_bytes = n_bytes; block->curr_left_side = left_side; block->index = index; for (i = 0; i < n_cached; i++) { ha_insert_for_fold(table, folds[i], block, recs[i]); } exit_func: rw_lock_x_unlock(&btr_search_latch); mem_free(folds); mem_free(recs); if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } } /************************************************************************ Moves or deletes hash entries for moved records. If new_page is already hashed, then the hash index for page, if any, is dropped. If new_page is not hashed, and page is hashed, then a new hash index is built to new_page with the same parameters as page (this often happens when a page is split). */ UNIV_INTERN void btr_search_move_or_delete_hash_entries( /*===================================*/ buf_block_t* new_block, /* in: records are copied to this page */ buf_block_t* block, /* in: index page from which records were copied, and the copied records will be deleted from this page */ dict_index_t* index) /* in: record descriptor */ { ulint n_fields; ulint n_bytes; ibool left_side; #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&(block->lock), RW_LOCK_EX)); ut_ad(rw_lock_own(&(new_block->lock), RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ ut_a(!new_block->is_hashed || new_block->index == index); ut_a(!block->is_hashed || block->index == index); ut_a(!(new_block->is_hashed || block->is_hashed) || !dict_index_is_ibuf(index)); rw_lock_s_lock(&btr_search_latch); if (new_block->is_hashed) { rw_lock_s_unlock(&btr_search_latch); btr_search_drop_page_hash_index(block); return; } if (block->is_hashed) { n_fields = block->curr_n_fields; n_bytes = block->curr_n_bytes; left_side = block->curr_left_side; new_block->n_fields = block->curr_n_fields; new_block->n_bytes = block->curr_n_bytes; new_block->left_side = left_side; rw_lock_s_unlock(&btr_search_latch); ut_a(n_fields + n_bytes > 0); btr_search_build_page_hash_index(index, new_block, n_fields, n_bytes, left_side); ut_ad(n_fields == block->curr_n_fields); ut_ad(n_bytes == block->curr_n_bytes); ut_ad(left_side == block->curr_left_side); return; } rw_lock_s_unlock(&btr_search_latch); } /************************************************************************ Updates the page hash index when a single record is deleted from a page. */ UNIV_INTERN void btr_search_update_hash_on_delete( /*=============================*/ btr_cur_t* cursor) /* in: cursor which was positioned on the record to delete using btr_cur_search_..., the record is not yet deleted */ { hash_table_t* table; buf_block_t* block; rec_t* rec; ulint fold; dulint index_id; ibool found; ulint offsets_[REC_OFFS_NORMAL_SIZE]; mem_heap_t* heap = NULL; rec_offs_init(offsets_); rec = btr_cur_get_rec(cursor); block = btr_cur_get_block(cursor); #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&(block->lock), RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ if (!block->is_hashed) { return; } ut_a(block->index == cursor->index); ut_a(block->curr_n_fields + block->curr_n_bytes > 0); ut_a(!dict_index_is_ibuf(cursor->index)); table = btr_search_sys->hash_index; index_id = cursor->index->id; fold = rec_fold(rec, rec_get_offsets(rec, cursor->index, offsets_, ULINT_UNDEFINED, &heap), block->curr_n_fields, block->curr_n_bytes, index_id); if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } rw_lock_x_lock(&btr_search_latch); found = ha_search_and_delete_if_found(table, fold, rec); rw_lock_x_unlock(&btr_search_latch); } /************************************************************************ Updates the page hash index when a single record is inserted on a page. */ UNIV_INTERN void btr_search_update_hash_node_on_insert( /*==================================*/ btr_cur_t* cursor) /* in: cursor which was positioned to the place to insert using btr_cur_search_..., and the new record has been inserted next to the cursor */ { hash_table_t* table; buf_block_t* block; rec_t* rec; rec = btr_cur_get_rec(cursor); block = btr_cur_get_block(cursor); #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&(block->lock), RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ if (!block->is_hashed) { return; } ut_a(block->index == cursor->index); ut_a(!dict_index_is_ibuf(cursor->index)); rw_lock_x_lock(&btr_search_latch); if ((cursor->flag == BTR_CUR_HASH) && (cursor->n_fields == block->curr_n_fields) && (cursor->n_bytes == block->curr_n_bytes) && !block->curr_left_side) { table = btr_search_sys->hash_index; ha_search_and_update_if_found(table, cursor->fold, rec, block, page_rec_get_next(rec)); rw_lock_x_unlock(&btr_search_latch); } else { rw_lock_x_unlock(&btr_search_latch); btr_search_update_hash_on_insert(cursor); } } /************************************************************************ Updates the page hash index when a single record is inserted on a page. */ UNIV_INTERN void btr_search_update_hash_on_insert( /*=============================*/ btr_cur_t* cursor) /* in: cursor which was positioned to the place to insert using btr_cur_search_..., and the new record has been inserted next to the cursor */ { hash_table_t* table; buf_block_t* block; rec_t* rec; rec_t* ins_rec; rec_t* next_rec; dulint index_id; ulint fold; ulint ins_fold; ulint next_fold = 0; /* remove warning (??? bug ???) */ ulint n_fields; ulint n_bytes; ibool left_side; ibool locked = FALSE; mem_heap_t* heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; ulint* offsets = offsets_; rec_offs_init(offsets_); table = btr_search_sys->hash_index; btr_search_check_free_space_in_heap(); rec = btr_cur_get_rec(cursor); block = btr_cur_get_block(cursor); #ifdef UNIV_SYNC_DEBUG ut_ad(rw_lock_own(&(block->lock), RW_LOCK_EX)); #endif /* UNIV_SYNC_DEBUG */ if (!block->is_hashed) { return; } ut_a(block->index == cursor->index); ut_a(!dict_index_is_ibuf(cursor->index)); index_id = cursor->index->id; n_fields = block->curr_n_fields; n_bytes = block->curr_n_bytes; left_side = block->curr_left_side; ins_rec = page_rec_get_next(rec); next_rec = page_rec_get_next(ins_rec); offsets = rec_get_offsets(ins_rec, cursor->index, offsets, ULINT_UNDEFINED, &heap); ins_fold = rec_fold(ins_rec, offsets, n_fields, n_bytes, index_id); if (!page_rec_is_supremum(next_rec)) { offsets = rec_get_offsets(next_rec, cursor->index, offsets, n_fields + (n_bytes > 0), &heap); next_fold = rec_fold(next_rec, offsets, n_fields, n_bytes, index_id); } if (!page_rec_is_infimum(rec)) { offsets = rec_get_offsets(rec, cursor->index, offsets, n_fields + (n_bytes > 0), &heap); fold = rec_fold(rec, offsets, n_fields, n_bytes, index_id); } else { if (left_side) { rw_lock_x_lock(&btr_search_latch); locked = TRUE; ha_insert_for_fold(table, ins_fold, block, ins_rec); } goto check_next_rec; } if (fold != ins_fold) { if (!locked) { rw_lock_x_lock(&btr_search_latch); locked = TRUE; } if (!left_side) { ha_insert_for_fold(table, fold, block, rec); } else { ha_insert_for_fold(table, ins_fold, block, ins_rec); } } check_next_rec: if (page_rec_is_supremum(next_rec)) { if (!left_side) { if (!locked) { rw_lock_x_lock(&btr_search_latch); locked = TRUE; } ha_insert_for_fold(table, ins_fold, block, ins_rec); } goto function_exit; } if (ins_fold != next_fold) { if (!locked) { rw_lock_x_lock(&btr_search_latch); locked = TRUE; } if (!left_side) { ha_insert_for_fold(table, ins_fold, block, ins_rec); /* fputs("Hash insert for ", stderr); dict_index_name_print(stderr, cursor->index); fprintf(stderr, " fold %lu\n", ins_fold); */ } else { ha_insert_for_fold(table, next_fold, block, next_rec); } } function_exit: if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } if (locked) { rw_lock_x_unlock(&btr_search_latch); } } /************************************************************************ Validates the search system. */ UNIV_INTERN ibool btr_search_validate(void) /*=====================*/ /* out: TRUE if ok */ { ha_node_t* node; ulint n_page_dumps = 0; ibool ok = TRUE; ulint i; ulint cell_count; mem_heap_t* heap = NULL; ulint offsets_[REC_OFFS_NORMAL_SIZE]; ulint* offsets = offsets_; /* How many cells to check before temporarily releasing btr_search_latch. */ ulint chunk_size = 10000; rec_offs_init(offsets_); rw_lock_x_lock(&btr_search_latch); buf_pool_mutex_enter(); cell_count = hash_get_n_cells(btr_search_sys->hash_index); for (i = 0; i < cell_count; i++) { /* We release btr_search_latch every once in a while to give other queries a chance to run. */ if ((i != 0) && ((i % chunk_size) == 0)) { buf_pool_mutex_exit(); rw_lock_x_unlock(&btr_search_latch); os_thread_yield(); rw_lock_x_lock(&btr_search_latch); buf_pool_mutex_enter(); } node = hash_get_nth_cell(btr_search_sys->hash_index, i)->node; for (; node != NULL; node = node->next) { const buf_block_t* block = buf_block_align(node->data); const buf_block_t* hash_block; if (UNIV_LIKELY(buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE)) { /* The space and offset are only valid for file blocks. It is possible that the block is being freed (BUF_BLOCK_REMOVE_HASH, see the assertion and the comment below) */ hash_block = buf_block_hash_get( buf_block_get_space(block), buf_block_get_page_no(block)); } else { hash_block = NULL; } if (hash_block) { ut_a(hash_block == block); } else { /* When a block is being freed, buf_LRU_search_and_free_block() first removes the block from buf_pool->page_hash by calling buf_LRU_block_remove_hashed_page(). After that, it invokes btr_search_drop_page_hash_index() to remove the block from btr_search_sys->hash_index. */ ut_a(buf_block_get_state(block) == BUF_BLOCK_REMOVE_HASH); } ut_a(!dict_index_is_ibuf(block->index)); offsets = rec_get_offsets((const rec_t*) node->data, block->index, offsets, block->curr_n_fields + (block->curr_n_bytes > 0), &heap); if (!block->is_hashed || node->fold != rec_fold((rec_t*)(node->data), offsets, block->curr_n_fields, block->curr_n_bytes, btr_page_get_index_id(block->frame))) { const page_t* page = block->frame; ok = FALSE; ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: Error in an adaptive hash" " index pointer to page %lu\n" "InnoDB: ptr mem address %p" " index id %lu %lu," " node fold %lu, rec fold %lu\n", (ulong) page_get_page_no(page), node->data, (ulong) ut_dulint_get_high( btr_page_get_index_id(page)), (ulong) ut_dulint_get_low( btr_page_get_index_id(page)), (ulong) node->fold, (ulong) rec_fold((rec_t*)(node->data), offsets, block->curr_n_fields, block->curr_n_bytes, btr_page_get_index_id( page))); fputs("InnoDB: Record ", stderr); rec_print_new(stderr, (rec_t*)node->data, offsets); fprintf(stderr, "\nInnoDB: on that page." " Page mem address %p, is hashed %lu," " n fields %lu, n bytes %lu\n" "InnoDB: side %lu\n", (void*) page, (ulong) block->is_hashed, (ulong) block->curr_n_fields, (ulong) block->curr_n_bytes, (ulong) block->curr_left_side); if (n_page_dumps < 20) { buf_page_print(page, 0); n_page_dumps++; } } } } for (i = 0; i < cell_count; i += chunk_size) { ulint end_index = ut_min(i + chunk_size - 1, cell_count - 1); /* We release btr_search_latch every once in a while to give other queries a chance to run. */ if (i != 0) { buf_pool_mutex_exit(); rw_lock_x_unlock(&btr_search_latch); os_thread_yield(); rw_lock_x_lock(&btr_search_latch); buf_pool_mutex_enter(); } if (!ha_validate(btr_search_sys->hash_index, i, end_index)) { ok = FALSE; } } buf_pool_mutex_exit(); rw_lock_x_unlock(&btr_search_latch); if (UNIV_LIKELY_NULL(heap)) { mem_heap_free(heap); } return(ok); }