/***************************************************************************** Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved. Copyright (c) 2008, 2009 Google Inc. Copyright (c) 2009, Percona Inc. Copyright (c) 2013, 2023, MariaDB Corporation. 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. Portions of this file contain modifications contributed and copyrighted by Percona Inc.. Those modifications are gratefully acknowledged and are described briefly in the InnoDB documentation. The contributions by Percona Inc. are incorporated with their permission, and subject to the conditions contained in the file COPYING.Percona. 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, Fifth Floor, Boston, MA 02110-1335 USA *****************************************************************************/ /**************************************************//** @file srv/srv0srv.cc The database server main program Created 10/8/1995 Heikki Tuuri *******************************************************/ #include "my_global.h" #include "mysql/psi/mysql_stage.h" #include "mysql/psi/psi.h" #include "btr0sea.h" #include "buf0flu.h" #include "buf0lru.h" #include "dict0boot.h" #include "dict0load.h" #include "lock0lock.h" #include "log0recv.h" #include "mem0mem.h" #include "pars0pars.h" #include "que0que.h" #include "row0mysql.h" #include "row0log.h" #include "srv0mon.h" #include "srv0srv.h" #include "srv0start.h" #include "trx0i_s.h" #include "trx0purge.h" #include "ut0mem.h" #include "fil0fil.h" #include "fil0crypt.h" #include "fil0pagecompress.h" #include "trx0types.h" #include #include "log.h" #include "transactional_lock_guard.h" #include /* The following is the maximum allowed duration of a lock wait. */ ulong srv_fatal_semaphore_wait_threshold = DEFAULT_SRV_FATAL_SEMAPHORE_TIMEOUT; /* How much data manipulation language (DML) statements need to be delayed, in microseconds, in order to reduce the lagging of the purge thread. */ ulint srv_dml_needed_delay; const char* srv_main_thread_op_info = ""; /** Prefix used by MySQL to indicate pre-5.1 table name encoding */ const char srv_mysql50_table_name_prefix[10] = "#mysql50#"; /* Server parameters which are read from the initfile */ /* The following three are dir paths which are catenated before file names, where the file name itself may also contain a path */ char* srv_data_home; /** Rollback files directory, can be absolute. */ char* srv_undo_dir; /** The number of tablespaces to use for rollback segments. */ uint srv_undo_tablespaces; /** The number of UNDO tablespaces that are open and ready to use. */ uint32_t srv_undo_tablespaces_open; /** The number of UNDO tablespaces that are active (hosting some rollback segment). It is quite possible that some of the tablespaces doesn't host any of the rollback-segment based on configuration used. */ uint32_t srv_undo_tablespaces_active; /** Rate at which UNDO records should be purged. */ ulong srv_purge_rseg_truncate_frequency; /** Enable or Disable Truncate of UNDO tablespace. Note: If enabled then UNDO tablespace will be selected for truncate. While Server waits for undo-tablespace to truncate if user disables it, truncate action is completed but no new tablespace is marked for truncate (action is never aborted). */ my_bool srv_undo_log_truncate; /** Maximum size of undo tablespace. */ unsigned long long srv_max_undo_log_size; /** Set if InnoDB must operate in read-only mode. We don't do any recovery and open all tables in RO mode instead of RW mode. We don't sync the max trx id to disk either. */ my_bool srv_read_only_mode; /** store to its own file each table created by an user; data dictionary tables are in the system tablespace 0 */ my_bool srv_file_per_table; /** Set if innodb_read_only is set or innodb_force_recovery is SRV_FORCE_NO_UNDO_LOG_SCAN or greater. */ bool high_level_read_only; /** Sort buffer size in index creation */ ulong srv_sort_buf_size; /** Maximum modification log file size for online index creation */ unsigned long long srv_online_max_size; /* If this flag is TRUE, then we will use the native aio of the OS (provided we compiled Innobase with it in), otherwise we will use simulated aio we build below with threads. Currently we support native aio on windows and linux */ my_bool srv_use_native_aio; my_bool srv_numa_interleave; /** copy of innodb_use_atomic_writes; @see innodb_init_params() */ my_bool srv_use_atomic_writes; /** innodb_compression_algorithm; used with page compression */ ulong innodb_compression_algorithm; /*------------------------- LOG FILES ------------------------ */ char* srv_log_group_home_dir; /** The InnoDB redo log file size, or 0 when changing the redo log format at startup (while disallowing writes to the redo log). */ ulonglong srv_log_file_size; /** innodb_flush_log_at_trx_commit */ ulong srv_flush_log_at_trx_commit; /** innodb_flush_log_at_timeout */ uint srv_flush_log_at_timeout; /** innodb_page_size */ ulong srv_page_size; /** log2 of innodb_page_size; @see innodb_init_params() */ uint32_t srv_page_size_shift; /** innodb_adaptive_flushing; try to flush dirty pages so as to avoid IO bursts at the checkpoints. */ my_bool srv_adaptive_flushing; /** innodb_flush_sync; whether to ignore io_capacity at log checkpoints */ my_bool srv_flush_sync; /** common thread pool*/ tpool::thread_pool* srv_thread_pool; /** Maximum number of times allowed to conditionally acquire mutex before switching to blocking wait on the mutex */ #define MAX_MUTEX_NOWAIT 2 /** Check whether the number of failed nonblocking mutex acquisition attempts exceeds maximum allowed value. If so, srv_printf_innodb_monitor() will request mutex acquisition with mysql_mutex_lock(), which will wait until it gets the mutex. */ #define MUTEX_NOWAIT(mutex_skipped) ((mutex_skipped) < MAX_MUTEX_NOWAIT) /** copy of innodb_buffer_pool_size */ ulint srv_buf_pool_size; /** Requested buffer pool chunk size */ size_t srv_buf_pool_chunk_unit; /** innodb_lru_scan_depth; number of blocks scanned in LRU flush batch */ ulong srv_LRU_scan_depth; /** innodb_flush_neighbors; whether or not to flush neighbors of a block */ ulong srv_flush_neighbors; /** Previously requested size */ ulint srv_buf_pool_old_size; /** Current size as scaling factor for the other components */ ulint srv_buf_pool_base_size; /** Current size in bytes */ ulint srv_buf_pool_curr_size; /** Dump this % of each buffer pool during BP dump */ ulong srv_buf_pool_dump_pct; /** Abort load after this amount of pages */ #ifdef UNIV_DEBUG ulong srv_buf_pool_load_pages_abort = LONG_MAX; #endif /** Lock table size in bytes */ ulint srv_lock_table_size = ULINT_MAX; /** the value of innodb_checksum_algorithm */ ulong srv_checksum_algorithm; /** innodb_read_io_threads */ uint srv_n_read_io_threads; /** innodb_write_io_threads */ uint srv_n_write_io_threads; /** innodb_random_read_ahead */ my_bool srv_random_read_ahead; /** innodb_read_ahead_threshold; the number of pages that must be present in the buffer cache and accessed sequentially for InnoDB to trigger a readahead request. */ ulong srv_read_ahead_threshold; /** copy of innodb_open_files; @see innodb_init_params() */ ulint srv_max_n_open_files; /** innodb_io_capacity */ ulong srv_io_capacity; /** innodb_io_capacity_max */ ulong srv_max_io_capacity; /* The InnoDB main thread tries to keep the ratio of modified pages in the buffer pool to all database pages in the buffer pool smaller than the following number. But it is not guaranteed that the value stays below that during a time of heavy update/insert activity. */ /** innodb_max_dirty_pages_pct */ double srv_max_buf_pool_modified_pct; /** innodb_max_dirty_pages_pct_lwm */ double srv_max_dirty_pages_pct_lwm; /** innodb_adaptive_flushing_lwm; the percentage of log capacity at which adaptive flushing, if enabled, will kick in. */ double srv_adaptive_flushing_lwm; /** innodb_flushing_avg_loops; number of iterations over which adaptive flushing is averaged */ ulong srv_flushing_avg_loops; /** innodb_purge_threads; the number of purge tasks to use */ uint srv_n_purge_threads; /** innodb_purge_batch_size, in pages */ ulong srv_purge_batch_size; /** innodb_stats_method decides how InnoDB treats NULL value when collecting statistics. By default, it is set to SRV_STATS_NULLS_EQUAL(0), ie. all NULL value are treated equal */ ulong srv_innodb_stats_method; srv_stats_t srv_stats; /* structure to pass status variables to MySQL */ export_var_t export_vars; /** Normally 0. When nonzero, skip some phases of crash recovery, starting from SRV_FORCE_IGNORE_CORRUPT, so that data can be recovered by SELECT or mysqldump. When this is nonzero, we do not allow any user modifications to the data. */ ulong srv_force_recovery; /** innodb_print_all_deadlocks; whether to print all user-level transactions deadlocks to the error log */ my_bool srv_print_all_deadlocks; /** innodb_cmp_per_index_enabled; enable INFORMATION_SCHEMA.innodb_cmp_per_index */ my_bool srv_cmp_per_index_enabled; /** innodb_fast_shutdown=1 skips the purge of transaction history. innodb_fast_shutdown=2 effectively crashes the server (no log checkpoint). innodb_fast_shutdown=3 is a clean shutdown that skips the rollback of active transaction (to be done on restart). */ uint srv_fast_shutdown; /** copy of innodb_status_file; generate a innodb_status. file */ ibool srv_innodb_status; /** innodb_stats_transient_sample_pages; When estimating number of different key values in an index, sample this many index pages, there are 2 ways to calculate statistics: * persistent stats that are calculated by ANALYZE TABLE and saved in the innodb database. * quick transient stats, that are used if persistent stats for the given table/index are not found in the innodb database */ unsigned long long srv_stats_transient_sample_pages; /** innodb_stats_persistent */ my_bool srv_stats_persistent; /** innodb_stats_include_delete_marked */ my_bool srv_stats_include_delete_marked; /** innodb_stats_persistent_sample_pages */ unsigned long long srv_stats_persistent_sample_pages; /** innodb_stats_auto_recalc */ my_bool srv_stats_auto_recalc; /** innodb_stats_modified_counter; The number of rows modified before we calculate new statistics (default 0 = current limits) */ unsigned long long srv_stats_modified_counter; /** innodb_stats_traditional; enable traditional statistic calculation based on number of configured pages */ my_bool srv_stats_sample_traditional; my_bool srv_use_doublewrite_buf; /** innodb_sync_spin_loops */ ulong srv_n_spin_wait_rounds; /** innodb_spin_wait_delay */ uint srv_spin_wait_delay; /** Number of initialized rollback segments for persistent undo log */ ulong srv_available_undo_logs; /** Current mode of operation */ enum srv_operation_mode srv_operation; /** whether this is the server's first start after mariabackup --prepare */ bool srv_start_after_restore; /* Set the following to 0 if you want InnoDB to write messages on stderr on startup/shutdown. Not enabled on the embedded server. */ ibool srv_print_verbose_log; my_bool srv_print_innodb_monitor; my_bool srv_print_innodb_lock_monitor; /** innodb_force_primary_key; whether to disallow CREATE TABLE without PRIMARY KEY */ my_bool srv_force_primary_key; /** Key version to encrypt the temporary tablespace */ my_bool innodb_encrypt_temporary_tables; my_bool srv_immediate_scrub_data_uncompressed; static time_t srv_last_monitor_time; static mysql_mutex_t srv_innodb_monitor_mutex; /** Mutex protecting page_zip_stat_per_index */ mysql_mutex_t page_zip_stat_per_index_mutex; /** Mutex for locking srv_monitor_file */ mysql_mutex_t srv_monitor_file_mutex; /** Temporary file for innodb monitor output */ FILE* srv_monitor_file; /** Mutex for locking srv_misc_tmpfile */ mysql_mutex_t srv_misc_tmpfile_mutex; /** Temporary file for miscellanous diagnostic output */ FILE* srv_misc_tmpfile; /* The following counts are used by the srv_master_callback. */ /** Iterations of the loop bounded by 'srv_active' label. */ ulint srv_main_active_loops; /** Iterations of the loop bounded by the 'srv_idle' label. */ ulint srv_main_idle_loops; /** Log writes involving flush. */ ulint srv_log_writes_and_flush; /* This is only ever touched by the master thread. It records the time when the last flush of log file has happened. The master thread ensures that we flush the log files at least once per second. */ static time_t srv_last_log_flush_time; /** Buffer pool dump status frequence in percentages */ ulong srv_buf_dump_status_frequency; /* IMPLEMENTATION OF THE SERVER MAIN PROGRAM ========================================= There is the following analogue between this database server and an operating system kernel: DB concept equivalent OS concept ---------- --------------------- transaction -- process; query thread -- thread; lock -- semaphore; kernel -- kernel; query thread execution: (a) without lock_sys.latch reserved -- process executing in user mode; (b) with lock_sys.latch reserved -- process executing in kernel mode; The server has several background threads all running at the same priority as user threads. The threads which we call user threads serve the queries of the MySQL server. They run at normal priority. When there is no activity in the system, also the master thread suspends itself to wait for an event making the server totally silent. There is still one complication in our server design. If a background utility thread obtains a resource (e.g., mutex) needed by a user thread, and there is also some other user activity in the system, the user thread may have to wait indefinitely long for the resource, as the OS does not schedule a background thread if there is some other runnable user thread. This problem is called priority inversion in real-time programming. One solution to the priority inversion problem would be to keep record of which thread owns which resource and in the above case boost the priority of the background thread so that it will be scheduled and it can release the resource. This solution is called priority inheritance in real-time programming. A drawback of this solution is that the overhead of acquiring a mutex increases slightly, maybe 0.2 microseconds on a 100 MHz Pentium, because the thread has to call pthread_self. This may be compared to 0.5 microsecond overhead for a mutex lock-unlock pair. Note that the thread cannot store the information in the resource , say mutex, itself, because competing threads could wipe out the information if it is stored before acquiring the mutex, and if it stored afterwards, the information is outdated for the time of one machine instruction, at least. (To be precise, the information could be stored to lock_word in mutex if the machine supports atomic swap.) The above solution with priority inheritance may become actual in the future, currently we do not implement any priority twiddling solution. Our general aim is to reduce the contention of all mutexes by making them more fine grained. The thread table contains information of the current status of each thread existing in the system, and also the event semaphores used in suspending the master thread and utility threads when they have nothing to do. The thread table can be seen as an analogue to the process table in a traditional Unix implementation. */ /** The server system struct */ struct srv_sys_t{ mysql_mutex_t tasks_mutex; /*!< variable protecting the tasks queue */ UT_LIST_BASE_NODE_T(que_thr_t) tasks; /*!< task queue */ srv_stats_t::ulint_ctr_1_t activity_count; /*!< For tracking server activity */ }; static srv_sys_t srv_sys; /* Structure shared by timer and coordinator_callback. No protection necessary since timer and task never run in parallel (being in the same task group of size 1). */ struct purge_coordinator_state { /** Snapshot of the last history length before the purge call.*/ size_t m_history_length; Atomic_counter m_running; private: ulint count; ulint n_use_threads; ulint n_threads; ulint lsn_lwm; ulint lsn_hwm; ulonglong start_time; ulint lsn_age_factor; static constexpr ulint adaptive_purge_threshold= 20; static constexpr ulint safety_net= 20; ulint series[innodb_purge_threads_MAX + 1]; inline void compute_series(); inline void lazy_init(); void refresh(bool full); public: inline void do_purge(); }; static purge_coordinator_state purge_state; /** threadpool timer for srv_monitor_task() */ std::unique_ptr srv_monitor_timer; /** The buffer pool dump/load file name */ char* srv_buf_dump_filename; /** Boolean config knobs that tell InnoDB to dump the buffer pool at shutdown and/or load it during startup. */ char srv_buffer_pool_dump_at_shutdown = TRUE; char srv_buffer_pool_load_at_startup = TRUE; #ifdef HAVE_PSI_STAGE_INTERFACE /** Performance schema stage event for monitoring ALTER TABLE progress in ha_innobase::commit_inplace_alter_table(). */ PSI_stage_info srv_stage_alter_table_end = {0, "alter table (end)", PSI_FLAG_STAGE_PROGRESS}; /** Performance schema stage event for monitoring ALTER TABLE progress row_merge_insert_index_tuples(). */ PSI_stage_info srv_stage_alter_table_insert = {0, "alter table (insert)", PSI_FLAG_STAGE_PROGRESS}; /** Performance schema stage event for monitoring ALTER TABLE progress row_log_apply(). */ PSI_stage_info srv_stage_alter_table_log_index = {0, "alter table (log apply index)", PSI_FLAG_STAGE_PROGRESS}; /** Performance schema stage event for monitoring ALTER TABLE progress row_log_table_apply(). */ PSI_stage_info srv_stage_alter_table_log_table = {0, "alter table (log apply table)", PSI_FLAG_STAGE_PROGRESS}; /** Performance schema stage event for monitoring ALTER TABLE progress row_merge_sort(). */ PSI_stage_info srv_stage_alter_table_merge_sort = {0, "alter table (merge sort)", PSI_FLAG_STAGE_PROGRESS}; /** Performance schema stage event for monitoring ALTER TABLE progress row_merge_read_clustered_index(). */ PSI_stage_info srv_stage_alter_table_read_pk_internal_sort = {0, "alter table (read PK and internal sort)", PSI_FLAG_STAGE_PROGRESS}; /** Performance schema stage event for monitoring buffer pool load progress. */ PSI_stage_info srv_stage_buffer_pool_load = {0, "buffer pool load", PSI_FLAG_STAGE_PROGRESS}; #endif /* HAVE_PSI_STAGE_INTERFACE */ /*********************************************************************//** Prints counters for work done by srv_master_thread. */ static void srv_print_master_thread_info( /*=========================*/ FILE *file) /* in: output stream */ { fprintf(file, "srv_master_thread loops: " ULINTPF " srv_active, " ULINTPF " srv_idle\n" "srv_master_thread log flush and writes: " ULINTPF "\n", srv_main_active_loops, srv_main_idle_loops, srv_log_writes_and_flush); } static void thread_pool_thread_init() { my_thread_init(); pfs_register_thread(thread_pool_thread_key); } static void thread_pool_thread_end() { pfs_delete_thread(); my_thread_end(); } void srv_thread_pool_init() { DBUG_ASSERT(!srv_thread_pool); #if defined (_WIN32) srv_thread_pool= tpool::create_thread_pool_win(); #else srv_thread_pool= tpool::create_thread_pool_generic(); #endif srv_thread_pool->set_thread_callbacks(thread_pool_thread_init, thread_pool_thread_end); } void srv_thread_pool_end() { ut_ad(!srv_master_timer); delete srv_thread_pool; srv_thread_pool= nullptr; } static bool need_srv_free; /** Initialize the server. */ static void srv_init() { mysql_mutex_init(srv_innodb_monitor_mutex_key, &srv_innodb_monitor_mutex, nullptr); mysql_mutex_init(srv_threads_mutex_key, &srv_sys.tasks_mutex, nullptr); UT_LIST_INIT(srv_sys.tasks, &que_thr_t::queue); need_srv_free = true; mysql_mutex_init(page_zip_stat_per_index_mutex_key, &page_zip_stat_per_index_mutex, nullptr); /* Initialize some INFORMATION SCHEMA internal structures */ trx_i_s_cache_init(trx_i_s_cache); } /*********************************************************************//** Frees the data structures created in srv_init(). */ void srv_free(void) /*==========*/ { if (!need_srv_free) { return; } mysql_mutex_destroy(&srv_innodb_monitor_mutex); mysql_mutex_destroy(&page_zip_stat_per_index_mutex); mysql_mutex_destroy(&srv_sys.tasks_mutex); trx_i_s_cache_free(trx_i_s_cache); srv_thread_pool_end(); } /*********************************************************************//** Boots the InnoDB server. */ void srv_boot() { #ifndef NO_ELISION if (transactional_lock_enabled()) sql_print_information("InnoDB: Using transactional memory"); #endif buf_dblwr.init(); srv_thread_pool_init(); trx_pool_init(); srv_init(); } /******************************************************************//** Refreshes the values used to calculate per-second averages. */ static void srv_refresh_innodb_monitor_stats(time_t current_time) { mysql_mutex_lock(&srv_innodb_monitor_mutex); if (difftime(current_time, srv_last_monitor_time) < 60) { /* We refresh InnoDB Monitor values so that averages are printed from at most 60 last seconds */ mysql_mutex_unlock(&srv_innodb_monitor_mutex); return; } srv_last_monitor_time = current_time; os_aio_refresh_stats(); #ifdef BTR_CUR_HASH_ADAPT btr_cur_n_sea_old = btr_cur_n_sea; btr_cur_n_non_sea_old = btr_cur_n_non_sea; #endif /* BTR_CUR_HASH_ADAPT */ buf_refresh_io_stats(); mysql_mutex_unlock(&srv_innodb_monitor_mutex); } /******************************************************************//** Outputs to a file the output of the InnoDB Monitor. @return FALSE if not all information printed due to failure to obtain necessary mutex */ ibool srv_printf_innodb_monitor( /*======================*/ FILE* file, /*!< in: output stream */ ibool nowait, /*!< in: whether to wait for lock_sys.latch */ ulint* trx_start_pos, /*!< out: file position of the start of the list of active transactions */ ulint* trx_end) /*!< out: file position of the end of the list of active transactions */ { double time_elapsed; time_t current_time; ibool ret; mysql_mutex_lock(&srv_innodb_monitor_mutex); current_time = time(NULL); /* We add 0.001 seconds to time_elapsed to prevent division by zero if two users happen to call SHOW ENGINE INNODB STATUS at the same time */ time_elapsed = difftime(current_time, srv_last_monitor_time) + 0.001; srv_last_monitor_time = time(NULL); fputs("\n=====================================\n", file); ut_print_timestamp(file); fprintf(file, " INNODB MONITOR OUTPUT\n" "=====================================\n" "Per second averages calculated from the last %lu seconds\n", (ulong) time_elapsed); fputs("-----------------\n" "BACKGROUND THREAD\n" "-----------------\n", file); srv_print_master_thread_info(file); /* This section is intentionally left blank, for tools like "innotop" */ fputs("----------\n" "SEMAPHORES\n" "----------\n", file); /* End of intentionally blank section */ /* Conceptually, srv_innodb_monitor_mutex has a very high latching order level, while dict_foreign_err_mutex has a very low level. Therefore we can reserve the latter mutex here without a danger of a deadlock of threads. */ mysql_mutex_lock(&dict_foreign_err_mutex); if (!srv_read_only_mode && ftell(dict_foreign_err_file) != 0L) { fputs("------------------------\n" "LATEST FOREIGN KEY ERROR\n" "------------------------\n", file); ut_copy_file(file, dict_foreign_err_file); } mysql_mutex_unlock(&dict_foreign_err_mutex); /* Only if lock_print_info_summary proceeds correctly, before we call the lock_print_info_all_transactions to print all the lock information. IMPORTANT NOTE: This function acquires exclusive lock_sys.latch on success. */ ret = lock_print_info_summary(file, nowait); if (ret) { if (trx_start_pos) { long t = ftell(file); if (t < 0) { *trx_start_pos = ULINT_UNDEFINED; } else { *trx_start_pos = (ulint) t; } } /* NOTE: The following function will release the lock_sys.latch that lock_print_info_summary() acquired. */ lock_print_info_all_transactions(file); if (trx_end) { long t = ftell(file); if (t < 0) { *trx_end = ULINT_UNDEFINED; } else { *trx_end = (ulint) t; } } } fputs("--------\n" "FILE I/O\n" "--------\n", file); os_aio_print(file); #ifdef BTR_CUR_HASH_ADAPT if (btr_search_enabled) { fputs("-------------------\n" "ADAPTIVE HASH INDEX\n" "-------------------\n", file); for (ulint i = 0; i < btr_ahi_parts; ++i) { const auto part= &btr_search_sys.parts[i]; part->latch.rd_lock(SRW_LOCK_CALL); ut_ad(part->heap->type == MEM_HEAP_FOR_BTR_SEARCH); fprintf(file, "Hash table size " ULINTPF ", node heap has " ULINTPF " buffer(s)\n", part->table.n_cells, part->heap->base.count - !part->heap->free_block); part->latch.rd_unlock(); } const ulint with_ahi = btr_cur_n_sea; const ulint without_ahi = btr_cur_n_non_sea; fprintf(file, "%.2f hash searches/s, %.2f non-hash searches/s\n", static_cast(with_ahi - btr_cur_n_sea_old) / time_elapsed, static_cast(without_ahi - btr_cur_n_non_sea_old) / time_elapsed); btr_cur_n_sea_old = with_ahi; btr_cur_n_non_sea_old = without_ahi; } #endif /* BTR_CUR_HASH_ADAPT */ fputs("---\n" "LOG\n" "---\n", file); log_print(file); fputs("----------------------\n" "BUFFER POOL AND MEMORY\n" "----------------------\n", file); fprintf(file, "Total large memory allocated " ULINTPF "\n" "Dictionary memory allocated " ULINTPF "\n", ulint{os_total_large_mem_allocated}, dict_sys.rough_size()); buf_print_io(file); fputs("--------------\n" "ROW OPERATIONS\n" "--------------\n", file); fprintf(file, ULINTPF " read views open inside InnoDB\n", trx_sys.view_count()); if (ulint n_reserved = fil_system.sys_space->n_reserved_extents) { fprintf(file, ULINTPF " tablespace extents now reserved for" " B-tree split operations\n", n_reserved); } fprintf(file, "state: %s\n", srv_main_thread_op_info); fputs("----------------------------\n" "END OF INNODB MONITOR OUTPUT\n" "============================\n", file); mysql_mutex_unlock(&srv_innodb_monitor_mutex); fflush(file); return(ret); } /******************************************************************//** Function to pass InnoDB status variables to MySQL */ void srv_export_innodb_status(void) /*==========================*/ { fil_crypt_stat_t crypt_stat; if (!srv_read_only_mode) { fil_crypt_total_stat(&crypt_stat); } #ifdef BTR_CUR_HASH_ADAPT export_vars.innodb_ahi_hit = btr_cur_n_sea; export_vars.innodb_ahi_miss = btr_cur_n_non_sea; ulint mem_adaptive_hash = 0; for (ulong i = 0; i < btr_ahi_parts; i++) { const auto part= &btr_search_sys.parts[i]; part->latch.rd_lock(SRW_LOCK_CALL); if (part->heap) { ut_ad(part->heap->type == MEM_HEAP_FOR_BTR_SEARCH); mem_adaptive_hash += mem_heap_get_size(part->heap) + part->table.n_cells * sizeof(hash_cell_t); } part->latch.rd_unlock(); } export_vars.innodb_mem_adaptive_hash = mem_adaptive_hash; #endif export_vars.innodb_mem_dictionary = dict_sys.rough_size(); mysql_mutex_lock(&srv_innodb_monitor_mutex); export_vars.innodb_data_pending_reads = ulint(MONITOR_VALUE(MONITOR_OS_PENDING_READS)); export_vars.innodb_data_pending_writes = ulint(MONITOR_VALUE(MONITOR_OS_PENDING_WRITES)); export_vars.innodb_data_read = srv_stats.data_read; export_vars.innodb_data_reads = os_n_file_reads; export_vars.innodb_data_writes = os_n_file_writes; buf_dblwr.lock(); ulint dblwr = buf_dblwr.submitted(); export_vars.innodb_dblwr_pages_written = buf_dblwr.written(); export_vars.innodb_dblwr_writes = buf_dblwr.batches(); buf_dblwr.unlock(); export_vars.innodb_data_written = srv_stats.data_written + dblwr; export_vars.innodb_buffer_pool_bytes_data = buf_pool.stat.LRU_bytes + (UT_LIST_GET_LEN(buf_pool.unzip_LRU) << srv_page_size_shift); #ifdef UNIV_DEBUG export_vars.innodb_buffer_pool_pages_latched = buf_get_latched_pages_number(); #endif /* UNIV_DEBUG */ export_vars.innodb_buffer_pool_pages_total = buf_pool.get_n_pages(); export_vars.innodb_buffer_pool_pages_misc = buf_pool.get_n_pages() - UT_LIST_GET_LEN(buf_pool.LRU) - UT_LIST_GET_LEN(buf_pool.free); export_vars.innodb_max_trx_id = trx_sys.get_max_trx_id(); export_vars.innodb_history_list_length = trx_sys.history_size_approx(); mysql_mutex_lock(&lock_sys.wait_mutex); export_vars.innodb_row_lock_waits = lock_sys.get_wait_cumulative(); export_vars.innodb_row_lock_current_waits= lock_sys.get_wait_pending(); export_vars.innodb_row_lock_time = lock_sys.get_wait_time_cumulative() / 1000; export_vars.innodb_row_lock_time_max = lock_sys.get_wait_time_max() / 1000; mysql_mutex_unlock(&lock_sys.wait_mutex); export_vars.innodb_row_lock_time_avg= export_vars.innodb_row_lock_waits ? static_cast(export_vars.innodb_row_lock_time / export_vars.innodb_row_lock_waits) : 0; export_vars.innodb_page_compression_saved = srv_stats.page_compression_saved; export_vars.innodb_pages_page_compressed = srv_stats.pages_page_compressed; export_vars.innodb_page_compressed_trim_op = srv_stats.page_compressed_trim_op; export_vars.innodb_pages_page_decompressed = srv_stats.pages_page_decompressed; export_vars.innodb_pages_page_compression_error = srv_stats.pages_page_compression_error; export_vars.innodb_pages_decrypted = srv_stats.pages_decrypted; export_vars.innodb_pages_encrypted = srv_stats.pages_encrypted; export_vars.innodb_n_merge_blocks_encrypted = srv_stats.n_merge_blocks_encrypted; export_vars.innodb_n_merge_blocks_decrypted = srv_stats.n_merge_blocks_decrypted; export_vars.innodb_n_rowlog_blocks_encrypted = srv_stats.n_rowlog_blocks_encrypted; export_vars.innodb_n_rowlog_blocks_decrypted = srv_stats.n_rowlog_blocks_decrypted; export_vars.innodb_n_temp_blocks_encrypted = srv_stats.n_temp_blocks_encrypted; export_vars.innodb_n_temp_blocks_decrypted = srv_stats.n_temp_blocks_decrypted; export_vars.innodb_onlineddl_rowlog_rows = onlineddl_rowlog_rows; export_vars.innodb_onlineddl_rowlog_pct_used = onlineddl_rowlog_pct_used; export_vars.innodb_onlineddl_pct_progress = onlineddl_pct_progress; if (!srv_read_only_mode) { export_vars.innodb_encryption_rotation_pages_read_from_cache = crypt_stat.pages_read_from_cache; export_vars.innodb_encryption_rotation_pages_read_from_disk = crypt_stat.pages_read_from_disk; export_vars.innodb_encryption_rotation_pages_modified = crypt_stat.pages_modified; export_vars.innodb_encryption_rotation_pages_flushed = crypt_stat.pages_flushed; export_vars.innodb_encryption_rotation_estimated_iops = crypt_stat.estimated_iops; export_vars.innodb_encryption_key_requests = srv_stats.n_key_requests; } mysql_mutex_unlock(&srv_innodb_monitor_mutex); log_sys.latch.rd_lock(SRW_LOCK_CALL); export_vars.innodb_lsn_current = log_sys.get_lsn(); export_vars.innodb_lsn_flushed = log_sys.get_flushed_lsn(); export_vars.innodb_lsn_last_checkpoint = log_sys.last_checkpoint_lsn; export_vars.innodb_checkpoint_max_age = static_cast( log_sys.max_checkpoint_age); log_sys.latch.rd_unlock(); export_vars.innodb_os_log_written = export_vars.innodb_lsn_current - recv_sys.lsn; export_vars.innodb_checkpoint_age = static_cast( export_vars.innodb_lsn_current - export_vars.innodb_lsn_last_checkpoint); } struct srv_monitor_state_t { time_t last_monitor_time; ulint mutex_skipped; bool last_srv_print_monitor; srv_monitor_state_t() : mutex_skipped(0), last_srv_print_monitor(false) { srv_last_monitor_time = time(NULL); last_monitor_time= srv_last_monitor_time; } }; static srv_monitor_state_t monitor_state; /** A task which prints the info output by various InnoDB monitors.*/ static void srv_monitor() { time_t current_time = time(NULL); if (difftime(current_time, monitor_state.last_monitor_time) >= 15) { monitor_state.last_monitor_time = current_time; if (srv_print_innodb_monitor) { /* Reset mutex_skipped counter everytime srv_print_innodb_monitor changes. This is to ensure we will not be blocked by lock_sys.latch for short duration information printing */ if (!monitor_state.last_srv_print_monitor) { monitor_state.mutex_skipped = 0; monitor_state.last_srv_print_monitor = true; } if (!srv_printf_innodb_monitor(stderr, MUTEX_NOWAIT(monitor_state.mutex_skipped), NULL, NULL)) { monitor_state.mutex_skipped++; } else { /* Reset the counter */ monitor_state.mutex_skipped = 0; } } else { monitor_state.last_monitor_time = 0; } /* We don't create the temp files or associated mutexes in read-only-mode */ if (!srv_read_only_mode && srv_innodb_status) { mysql_mutex_lock(&srv_monitor_file_mutex); rewind(srv_monitor_file); if (!srv_printf_innodb_monitor(srv_monitor_file, MUTEX_NOWAIT(monitor_state.mutex_skipped), NULL, NULL)) { monitor_state.mutex_skipped++; } else { monitor_state.mutex_skipped = 0; } os_file_set_eof(srv_monitor_file); mysql_mutex_unlock(&srv_monitor_file_mutex); } } srv_refresh_innodb_monitor_stats(current_time); } /** Periodic task which prints the info output by various InnoDB monitors.*/ void srv_monitor_task(void*) { /* number of successive fatal timeouts observed */ static lsn_t old_lsn = recv_sys.lsn; ut_ad(!srv_read_only_mode); /* Try to track a strange bug reported by Harald Fuchs and others, where the lsn seems to decrease at times */ lsn_t new_lsn = log_sys.get_lsn(); ut_a(new_lsn >= old_lsn); old_lsn = new_lsn; /* Update the statistics collected for deciding LRU eviction policy. */ buf_LRU_stat_update(); ulonglong now = my_hrtime_coarse().val; const ulong threshold = srv_fatal_semaphore_wait_threshold; if (ulonglong start = dict_sys.oldest_wait()) { if (now >= start) { now -= start; ulong waited = static_cast(now / 1000000); if (waited >= threshold) { ib::fatal() << dict_sys.fatal_msg; } if (waited == threshold / 4 || waited == threshold / 2 || waited == threshold / 4 * 3) { ib::warn() << "Long wait (" << waited << " seconds) for dict_sys.latch"; } } } srv_monitor(); } /******************************************************************//** Increment the server activity count. */ void srv_inc_activity_count(void) /*========================*/ { srv_sys.activity_count.inc(); } #ifdef UNIV_DEBUG /** @return whether purge or master task is active */ bool srv_any_background_activity() { if (purge_sys.enabled() || srv_master_timer.get()) { ut_ad(!srv_read_only_mode); return true; } return false; } #endif /* UNIV_DEBUG */ static void purge_worker_callback(void*); static void purge_coordinator_callback(void*); static tpool::task_group purge_task_group; tpool::waitable_task purge_worker_task(purge_worker_callback, nullptr, &purge_task_group); static tpool::task_group purge_coordinator_task_group(1); static tpool::waitable_task purge_coordinator_task (purge_coordinator_callback, nullptr, &purge_coordinator_task_group); static tpool::timer *purge_coordinator_timer; /** Wake up the purge threads if there is work to do. */ void srv_wake_purge_thread_if_not_active() { ut_ad(!srv_read_only_mode); if (purge_sys.enabled() && !purge_sys.paused() && trx_sys.history_exists()) { if(++purge_state.m_running == 1) { srv_thread_pool->submit_task(&purge_coordinator_task); } } } /** @return whether the purge tasks are active */ bool purge_sys_t::running() const { return purge_coordinator_task.is_running(); } /** Suspend purge in data dictionary tables */ void purge_sys_t::stop_SYS() { latch.rd_lock(SRW_LOCK_CALL); ++m_SYS_paused; latch.rd_unlock(); } /** Stop purge during FLUSH TABLES FOR EXPORT */ void purge_sys_t::stop() { for (;;) { latch.wr_lock(SRW_LOCK_CALL); if (!enabled()) { /* Shutdown must have been initiated during FLUSH TABLES FOR EXPORT. */ ut_ad(!srv_undo_sources); latch.wr_unlock(); return; } ut_ad(srv_n_purge_threads > 0); if (!must_wait_SYS()) break; latch.wr_unlock(); std::this_thread::sleep_for(std::chrono::seconds(1)); } const auto paused= m_paused++; latch.wr_unlock(); if (!paused) { ib::info() << "Stopping purge"; MONITOR_ATOMIC_INC(MONITOR_PURGE_STOP_COUNT); purge_coordinator_task.disable(); } } /** Resume purge in data dictionary tables */ void purge_sys_t::resume_SYS(void *) { ut_d(const auto s=) purge_sys.m_SYS_paused--; ut_ad(s); } /** Resume purge at UNLOCK TABLES after FLUSH TABLES FOR EXPORT */ void purge_sys_t::resume() { if (!enabled()) { /* Shutdown must have been initiated during FLUSH TABLES FOR EXPORT. */ ut_ad(!srv_undo_sources); return; } ut_ad(!srv_read_only_mode); ut_ad(srv_force_recovery < SRV_FORCE_NO_BACKGROUND); purge_coordinator_task.enable(); latch.wr_lock(SRW_LOCK_CALL); int32_t paused= m_paused--; ut_a(paused); if (paused == 1) { ib::info() << "Resuming purge"; purge_state.m_running = 0; srv_wake_purge_thread_if_not_active(); MONITOR_ATOMIC_INC(MONITOR_PURGE_RESUME_COUNT); } latch.wr_unlock(); } /*******************************************************************//** Get current server activity count. @return activity count. */ ulint srv_get_activity_count(void) /*========================*/ { return(srv_sys.activity_count); } /** Check if srv_inc_activity_count() has been called. @param activity_count copy of srv_sys.activity_count @return whether the activity_count had changed */ static bool srv_check_activity(ulint *activity_count) { ulint new_activity_count= srv_sys.activity_count; if (new_activity_count != *activity_count) { *activity_count= new_activity_count; return true; } return false; } /********************************************************************//** The master thread is tasked to ensure that flush of log file happens once every second in the background. This is to ensure that not more than one second of trxs are lost in case of crash when innodb_flush_logs_at_trx_commit != 1 */ static void srv_sync_log_buffer_in_background() { time_t current_time = time(NULL); srv_main_thread_op_info = "flushing log"; if (difftime(current_time, srv_last_log_flush_time) >= srv_flush_log_at_timeout) { log_buffer_flush_to_disk(); srv_last_log_flush_time = current_time; srv_log_writes_and_flush++; } } /** Perform periodic tasks whenever the server is active. @param counter_time microsecond_interval_timer() */ static void srv_master_do_active_tasks(ulonglong counter_time) { ++srv_main_active_loops; MONITOR_INC(MONITOR_MASTER_ACTIVE_LOOPS); if (!(counter_time % (47 * 1000000ULL))) { srv_main_thread_op_info = "enforcing dict cache limit"; if (ulint n_evicted = dict_sys.evict_table_LRU(true)) { MONITOR_INC_VALUE( MONITOR_SRV_DICT_LRU_EVICT_COUNT_ACTIVE, n_evicted); } MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_DICT_LRU_MICROSECOND, counter_time); } } /** Perform periodic tasks whenever the server is idle. @param counter_time microsecond_interval_timer() */ static void srv_master_do_idle_tasks(ulonglong counter_time) { ++srv_main_idle_loops; MONITOR_INC(MONITOR_MASTER_IDLE_LOOPS); srv_main_thread_op_info = "enforcing dict cache limit"; if (ulint n_evicted = dict_sys.evict_table_LRU(false)) { MONITOR_INC_VALUE( MONITOR_SRV_DICT_LRU_EVICT_COUNT_IDLE, n_evicted); } MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_DICT_LRU_MICROSECOND, counter_time); } /** The periodic master task controlling the server. */ void srv_master_callback(void*) { static ulint old_activity_count; ut_a(srv_shutdown_state <= SRV_SHUTDOWN_INITIATED); MONITOR_INC(MONITOR_MASTER_THREAD_SLEEP); if (!purge_state.m_running) srv_wake_purge_thread_if_not_active(); ulonglong counter_time= microsecond_interval_timer(); srv_sync_log_buffer_in_background(); MONITOR_INC_TIME_IN_MICRO_SECS(MONITOR_SRV_LOG_FLUSH_MICROSECOND, counter_time); if (srv_check_activity(&old_activity_count)) srv_master_do_active_tasks(counter_time); else srv_master_do_idle_tasks(counter_time); srv_main_thread_op_info= "sleeping"; } /** @return whether purge should exit due to shutdown */ static bool srv_purge_should_exit() { ut_ad(srv_shutdown_state <= SRV_SHUTDOWN_CLEANUP); if (srv_undo_sources) return false; if (srv_fast_shutdown) return true; /* Slow shutdown was requested. */ const size_t history_size= trx_sys.history_size(); if (history_size) { static time_t progress_time; time_t now= time(NULL); if (now - progress_time >= 15) { progress_time= now; #if defined HAVE_SYSTEMD && !defined EMBEDDED_LIBRARY service_manager_extend_timeout(INNODB_EXTEND_TIMEOUT_INTERVAL, "InnoDB: to purge %zu transactions", history_size); sql_print_information("InnoDB: to purge %zu transactions", history_size); #endif } return false; } return !trx_sys.any_active_transactions(); } /*********************************************************************//** Fetch and execute a task from the work queue. @param [in,out] slot purge worker thread slot @return true if a task was executed */ static bool srv_task_execute() { ut_ad(!srv_read_only_mode); ut_ad(srv_force_recovery < SRV_FORCE_NO_BACKGROUND); mysql_mutex_lock(&srv_sys.tasks_mutex); if (que_thr_t* thr = UT_LIST_GET_FIRST(srv_sys.tasks)) { ut_a(que_node_get_type(thr->child) == QUE_NODE_PURGE); UT_LIST_REMOVE(srv_sys.tasks, thr); mysql_mutex_unlock(&srv_sys.tasks_mutex); que_run_threads(thr); return true; } ut_ad(UT_LIST_GET_LEN(srv_sys.tasks) == 0); mysql_mutex_unlock(&srv_sys.tasks_mutex); return false; } static void purge_create_background_thds(int ); std::mutex purge_thread_count_mtx; void srv_update_purge_thread_count(uint n) { std::lock_guard lk(purge_thread_count_mtx); ut_ad(n > 0); ut_ad(n <= innodb_purge_threads_MAX); srv_n_purge_threads = n; srv_purge_thread_count_changed = 1; } Atomic_counter srv_purge_thread_count_changed; inline void purge_coordinator_state::do_purge() { ut_ad(!srv_read_only_mode); lazy_init(); ut_ad(n_threads); bool wakeup= false; purge_coordinator_timer->disarm(); while (purge_sys.enabled() && !purge_sys.paused()) { loop: wakeup= false; const auto now= my_interval_timer(); const auto sigcount= m_running; if (now - start_time >= 1000000) { refresh(false); start_time= now; } const auto old_activity_count= srv_sys.activity_count; const auto history_size= trx_sys.history_size(); if (UNIV_UNLIKELY(srv_purge_thread_count_changed)) { /* Read the fresh value of srv_n_purge_threads, reset the changed flag. Both are protected by purge_thread_count_mtx. This code does not run concurrently, it is executed by a single purge_coordinator thread, and no races involving srv_purge_thread_count_changed are possible. */ { std::lock_guard lk(purge_thread_count_mtx); n_threads= n_use_threads= srv_n_purge_threads; srv_purge_thread_count_changed= 0; } refresh(true); start_time= now; } else if (history_size > m_history_length) { /* dynamically adjust the purge thread based on redo log fill factor */ if (n_use_threads < n_threads && lsn_age_factor < lsn_lwm) { more_threads: ++n_use_threads; lsn_hwm= lsn_lwm; lsn_lwm-= series[n_use_threads]; } else if (n_use_threads > 1 && lsn_age_factor >= lsn_hwm) { fewer_threads: --n_use_threads; lsn_lwm= lsn_hwm; lsn_hwm+= series[n_use_threads]; } else if (n_use_threads == 1 && lsn_age_factor >= 100 - safety_net) { wakeup= true; break; } } else if (n_threads > n_use_threads && srv_max_purge_lag && m_history_length > srv_max_purge_lag) goto more_threads; else if (n_use_threads > 1 && old_activity_count == srv_sys.activity_count) goto fewer_threads; ut_ad(n_use_threads); ut_ad(n_use_threads <= n_threads); m_history_length= history_size; if (history_size && trx_purge(n_use_threads, !(++count % srv_purge_rseg_truncate_frequency) || purge_sys.truncate.current || (srv_shutdown_state != SRV_SHUTDOWN_NONE && srv_fast_shutdown == 0))) continue; if (m_running == sigcount) { /* Purge was not woken up by srv_wake_purge_thread_if_not_active() */ /* The magic number 5000 is an approximation for the case where we have cached undo log records which prevent truncate of rollback segments. */ wakeup= history_size && (history_size >= 5000 || history_size != trx_sys.history_size_approx()); break; } else if (!trx_sys.history_exists()) break; if (!srv_purge_should_exit()) goto loop; } if (wakeup) purge_coordinator_timer->set_time(10, 0); m_running= 0; } inline void purge_coordinator_state::compute_series() { ulint points= n_threads; memset(series, 0, sizeof series); constexpr ulint spread= 100 - adaptive_purge_threshold - safety_net; /* We distribute spread across n_threads, e.g.: spread of 60 is distributed across n_threads=4 as: 6+12+18+24 */ const ulint additional_points= (points * (points + 1)) / 2; if (spread % additional_points == 0) { /* Arithmetic progression is possible. */ const ulint delta= spread / additional_points; ulint growth= delta; do { series[points--]= growth; growth += delta; } while (points); return; } /* Use average distribution to spread across the points */ const ulint delta= spread / points; ulint total= 0; do { series[points--]= delta; total+= delta; } while (points); for (points= 1; points <= n_threads && total++ < spread; ) series[points++]++; } inline void purge_coordinator_state::lazy_init() { if (n_threads) return; n_threads= n_use_threads= srv_n_purge_threads; refresh(true); start_time= my_interval_timer(); } void purge_coordinator_state::refresh(bool full) { if (full) { compute_series(); lsn_lwm= adaptive_purge_threshold; lsn_hwm= adaptive_purge_threshold + series[n_threads]; } log_sys.latch.rd_lock(SRW_LOCK_CALL); const lsn_t last= log_sys.last_checkpoint_lsn, max_age= log_sys.max_checkpoint_age; log_sys.latch.rd_unlock(); lsn_age_factor= ulint(((log_sys.get_lsn() - last) * 100) / max_age); } static std::list purge_thds; static std::mutex purge_thd_mutex; extern void* thd_attach_thd(THD*); extern void thd_detach_thd(void *); static int n_purge_thds; /* Ensure that we have at least n background THDs for purge */ static void purge_create_background_thds(int n) { THD *thd= current_thd; std::unique_lock lk(purge_thd_mutex); while (n_purge_thds < n) { purge_thds.push_back(innobase_create_background_thd("InnoDB purge worker")); n_purge_thds++; } set_current_thd(thd); } static THD *acquire_thd(void **ctx) { std::unique_lock lk(purge_thd_mutex); ut_a(!purge_thds.empty()); THD* thd = purge_thds.front(); purge_thds.pop_front(); lk.unlock(); /* Set current thd, and thd->mysys_var as well, it might be used by something in the server.*/ *ctx = thd_attach_thd(thd); return thd; } static void release_thd(THD *thd, void *ctx) { thd_detach_thd(ctx); std::unique_lock lk(purge_thd_mutex); purge_thds.push_back(thd); lk.unlock(); set_current_thd(0); } static void purge_worker_callback(void*) { ut_ad(!current_thd); ut_ad(!srv_read_only_mode); ut_ad(srv_force_recovery < SRV_FORCE_NO_BACKGROUND); void *ctx; THD *thd= acquire_thd(&ctx); while (srv_task_execute()) ut_ad(purge_sys.running()); release_thd(thd,ctx); } static void purge_coordinator_callback(void*) { void *ctx; THD *thd= acquire_thd(&ctx); purge_state.do_purge(); release_thd(thd, ctx); } void srv_init_purge_tasks() { purge_create_background_thds(innodb_purge_threads_MAX); purge_coordinator_timer= srv_thread_pool->create_timer (purge_coordinator_callback, nullptr); } static void srv_shutdown_purge_tasks() { purge_coordinator_task.disable(); delete purge_coordinator_timer; purge_coordinator_timer= nullptr; purge_worker_task.wait(); std::unique_lock lk(purge_thd_mutex); while (!purge_thds.empty()) { destroy_background_thd(purge_thds.front()); purge_thds.pop_front(); } n_purge_thds= 0; } /**********************************************************************//** Enqueues a task to server task queue and releases a worker thread, if there is a suspended one. */ void srv_que_task_enqueue_low( /*=====================*/ que_thr_t* thr) /*!< in: query thread */ { ut_ad(!srv_read_only_mode); mysql_mutex_lock(&srv_sys.tasks_mutex); UT_LIST_ADD_LAST(srv_sys.tasks, thr); mysql_mutex_unlock(&srv_sys.tasks_mutex); } #ifdef UNIV_DEBUG /** @return number of tasks in queue */ ulint srv_get_task_queue_length() { ulint n_tasks; ut_ad(!srv_read_only_mode); mysql_mutex_lock(&srv_sys.tasks_mutex); n_tasks = UT_LIST_GET_LEN(srv_sys.tasks); mysql_mutex_unlock(&srv_sys.tasks_mutex); return(n_tasks); } #endif /** Shut down the purge threads. */ void srv_purge_shutdown() { if (purge_sys.enabled()) { if (!srv_fast_shutdown && !opt_bootstrap) srv_update_purge_thread_count(innodb_purge_threads_MAX); while(!srv_purge_should_exit()) { ut_a(!purge_sys.paused()); srv_wake_purge_thread_if_not_active(); purge_coordinator_task.wait(); } purge_sys.coordinator_shutdown(); srv_shutdown_purge_tasks(); } }