/***************************************************************************** Copyright (c) 1995, 2015, Oracle and/or its affiliates. All Rights Reserved. Copyright (c) 2008, 2009 Google Inc. Copyright (c) 2009, Percona 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. 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, Suite 500, Boston, MA 02110-1335 USA *****************************************************************************/ /**************************************************//** @file srv/srv0srv.cc The database server main program Created 10/8/1995 Heikki Tuuri *******************************************************/ /* Dummy comment */ #include "srv0srv.h" #include "ut0mem.h" #include "ut0ut.h" #include "os0proc.h" #include "mem0mem.h" #include "mem0pool.h" #include "sync0sync.h" #include "que0que.h" #include "log0online.h" #include "log0recv.h" #include "pars0pars.h" #include "usr0sess.h" #include "lock0lock.h" #include "trx0purge.h" #include "ibuf0ibuf.h" #include "buf0flu.h" #include "buf0lru.h" #include "btr0sea.h" #include "dict0load.h" #include "dict0boot.h" #include "dict0stats_bg.h" /* dict_stats_event */ #include "srv0start.h" #include "row0mysql.h" #include "ha_prototypes.h" #include "trx0i_s.h" #include "os0sync.h" /* for HAVE_ATOMIC_BUILTINS */ #include "srv0mon.h" #include "ut0crc32.h" #include "os0file.h" #include "mysql/plugin.h" #include "mysql/service_thd_wait.h" /* prototypes of new functions added to ha_innodb.cc for kill_idle_transaction */ ibool innobase_thd_is_idle(const void* thd); ib_int64_t innobase_thd_get_start_time(const void* thd); void innobase_thd_kill(ulong thd_id); ulong innobase_thd_get_thread_id(const void* thd); /* prototypes for new functions added to ha_innodb.cc */ ibool innobase_get_slow_log(); /* The following is the maximum allowed duration of a lock wait. */ UNIV_INTERN ulint srv_fatal_semaphore_wait_threshold = 600; /**/ UNIV_INTERN lint srv_kill_idle_transaction = 0; /* How much data manipulation language (DML) statements need to be delayed, in microseconds, in order to reduce the lagging of the purge thread. */ UNIV_INTERN ulint srv_dml_needed_delay = 0; UNIV_INTERN ibool srv_monitor_active = FALSE; UNIV_INTERN ibool srv_error_monitor_active = FALSE; UNIV_INTERN ibool srv_buf_dump_thread_active = FALSE; UNIV_INTERN ibool srv_dict_stats_thread_active = FALSE; UNIV_INTERN 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 */ UNIV_INTERN char* srv_data_home = NULL; /** Rollback files directory, can be absolute. */ UNIV_INTERN char* srv_undo_dir = NULL; /** The number of tablespaces to use for rollback segments. */ UNIV_INTERN ulong srv_undo_tablespaces = 8; /** The number of UNDO tablespaces that are open and ready to use. */ UNIV_INTERN ulint srv_undo_tablespaces_open = 8; /* The number of rollback segments to use */ UNIV_INTERN ulong srv_undo_logs = 1; #ifdef UNIV_LOG_ARCHIVE UNIV_INTERN char* srv_arch_dir = NULL; UNIV_INTERN ulong srv_log_arch_expire_sec = 0; #endif /* UNIV_LOG_ARCHIVE */ /** 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. */ UNIV_INTERN 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 */ UNIV_INTERN my_bool srv_file_per_table; /** The file format to use on new *.ibd files. */ UNIV_INTERN ulint srv_file_format = 0; /** Whether to check file format during startup. A value of UNIV_FORMAT_MAX + 1 means no checking ie. FALSE. The default is to set it to the highest format we support. */ UNIV_INTERN ulint srv_max_file_format_at_startup = UNIV_FORMAT_MAX; /** Set if InnoDB operates in read-only mode or innodb-force-recovery is greater than SRV_FORCE_NO_TRX_UNDO. */ UNIV_INTERN my_bool high_level_read_only; #if UNIV_FORMAT_A # error "UNIV_FORMAT_A must be 0!" #endif /** Place locks to records only i.e. do not use next-key locking except on duplicate key checking and foreign key checking */ UNIV_INTERN ibool srv_locks_unsafe_for_binlog = FALSE; /** Sort buffer size in index creation */ UNIV_INTERN ulong srv_sort_buf_size = 1048576; /** Maximum modification log file size for online index creation */ UNIV_INTERN 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 */ UNIV_INTERN my_bool srv_use_native_aio = TRUE; UNIV_INTERN my_bool srv_numa_interleave = FALSE; #ifdef __WIN__ /* Windows native condition variables. We use runtime loading / function pointers, because they are not available on Windows Server 2003 and Windows XP/2000. We use condition for events on Windows if possible, even if os_event resembles Windows kernel event object well API-wise. The reason is performance, kernel objects are heavyweights and WaitForSingleObject() is a performance killer causing calling thread to context switch. Besides, Innodb is preallocating large number (often millions) of os_events. With kernel event objects it takes a big chunk out of non-paged pool, which is better suited for tasks like IO than for storing idle event objects. */ UNIV_INTERN ibool srv_use_native_conditions = FALSE; #endif /* __WIN__ */ UNIV_INTERN ulint srv_n_data_files = 0; UNIV_INTERN char** srv_data_file_names = NULL; /* size in database pages */ UNIV_INTERN ulint* srv_data_file_sizes = NULL; UNIV_INTERN my_bool srv_track_changed_pages = FALSE; UNIV_INTERN ulonglong srv_max_bitmap_file_size = 100 * 1024 * 1024; UNIV_INTERN ulonglong srv_max_changed_pages = 0; /** When TRUE, fake change transcations take S rather than X row locks. When FALSE, row locks are not taken at all. */ UNIV_INTERN my_bool srv_fake_changes_locks = TRUE; /* if TRUE, then we auto-extend the last data file */ UNIV_INTERN ibool srv_auto_extend_last_data_file = FALSE; /* if != 0, this tells the max size auto-extending may increase the last data file size */ UNIV_INTERN ulint srv_last_file_size_max = 0; /* If the last data file is auto-extended, we add this many pages to it at a time */ UNIV_INTERN ulong srv_auto_extend_increment = 8; UNIV_INTERN ulint* srv_data_file_is_raw_partition = NULL; /* If the following is TRUE we do not allow inserts etc. This protects the user from forgetting the 'newraw' keyword to my.cnf */ UNIV_INTERN ibool srv_created_new_raw = FALSE; UNIV_INTERN char* srv_log_group_home_dir = NULL; UNIV_INTERN ulong srv_n_log_files = SRV_N_LOG_FILES_MAX; /* size in database pages */ UNIV_INTERN ib_uint64_t srv_log_file_size = IB_UINT64_MAX; UNIV_INTERN ib_uint64_t srv_log_file_size_requested; /* size in database pages */ UNIV_INTERN ulint srv_log_buffer_size = ULINT_MAX; UNIV_INTERN uint srv_flush_log_at_timeout = 1; UNIV_INTERN ulong srv_page_size = UNIV_PAGE_SIZE_DEF; UNIV_INTERN ulong srv_page_size_shift = UNIV_PAGE_SIZE_SHIFT_DEF; UNIV_INTERN char srv_use_global_flush_log_at_trx_commit = TRUE; /* Try to flush dirty pages so as to avoid IO bursts at the checkpoints. */ UNIV_INTERN char srv_adaptive_flushing = TRUE; UNIV_INTERN ulint srv_show_locks_held = 10; UNIV_INTERN ulint srv_show_verbose_locks = 0; /** Maximum number of times allowed to conditionally acquire mutex before switching to blocking wait on the mutex */ #define MAX_MUTEX_NOWAIT 20 /** 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 mutex_enter(), which will wait until it gets the mutex. */ #define MUTEX_NOWAIT(mutex_skipped) ((mutex_skipped) < MAX_MUTEX_NOWAIT) /** The sort order table of the MySQL latin1_swedish_ci character set collation */ UNIV_INTERN const byte* srv_latin1_ordering; /* use os/external memory allocator */ UNIV_INTERN my_bool srv_use_sys_malloc = TRUE; /* requested size in kilobytes */ UNIV_INTERN ulint srv_buf_pool_size = ULINT_MAX; /* requested number of buffer pool instances */ UNIV_INTERN ulint srv_buf_pool_instances = 1; /* number of locks to protect buf_pool->page_hash */ UNIV_INTERN ulong srv_n_page_hash_locks = 16; /** Scan depth for LRU flush batch i.e.: number of blocks scanned*/ UNIV_INTERN ulong srv_LRU_scan_depth = 1024; /** whether or not to flush neighbors of a block */ UNIV_INTERN ulong srv_flush_neighbors = 1; /* previously requested size */ UNIV_INTERN ulint srv_buf_pool_old_size; /* current size in kilobytes */ UNIV_INTERN ulint srv_buf_pool_curr_size = 0; /* size in bytes */ UNIV_INTERN ulint srv_mem_pool_size = ULINT_MAX; UNIV_INTERN ulint srv_lock_table_size = ULINT_MAX; /** Query thread preflush algorithm */ UNIV_INTERN ulint srv_foreground_preflush = SRV_FOREGROUND_PREFLUSH_EXP_BACKOFF; /** The maximum time limit for a single LRU tail flush iteration by the page cleaner thread */ UNIV_INTERN ulint srv_cleaner_max_lru_time = 1000; /** The maximum time limit for a single flush list flush iteration by the page cleaner thread */ UNIV_INTERN ulint srv_cleaner_max_flush_time = 1000; /** Page cleaner flush list flush batches are further divided into this chunk size */ UNIV_INTERN ulint srv_cleaner_flush_chunk_size = 100; /** Page cleaner LRU list flush batches are further divided into this chunk size */ UNIV_INTERN ulint srv_cleaner_lru_chunk_size = 100; /** If free list length is lower than this percentage of srv_LRU_scan_depth, page cleaner LRU flushes will issue flush batches to the same instance in a row */ UNIV_INTERN ulint srv_cleaner_free_list_lwm = 10; /** If TRUE, page cleaner heuristics use evicted instead of flushed page counts for its heuristics */ UNIV_INTERN my_bool srv_cleaner_eviction_factor = FALSE; /** Page cleaner LSN age factor formula option */ UNIV_INTERN ulong srv_cleaner_lsn_age_factor = SRV_CLEANER_LSN_AGE_FACTOR_HIGH_CHECKPOINT; /** Empty free list for a query thread handling algorithm option */ UNIV_INTERN ulong srv_empty_free_list_algorithm = SRV_EMPTY_FREE_LIST_BACKOFF; /* This parameter is deprecated. Use srv_n_io_[read|write]_threads instead. */ UNIV_INTERN ulint srv_n_file_io_threads = ULINT_MAX; UNIV_INTERN ulint srv_n_read_io_threads = ULINT_MAX; UNIV_INTERN ulint srv_n_write_io_threads = ULINT_MAX; /* Switch to enable random read ahead. */ UNIV_INTERN my_bool srv_random_read_ahead = FALSE; /* The log block size */ UNIV_INTERN ulint srv_log_block_size = 0; /* User settable value of the number of pages that must be present in the buffer cache and accessed sequentially for InnoDB to trigger a readahead request. */ UNIV_INTERN ulong srv_read_ahead_threshold = 56; #ifdef UNIV_LOG_ARCHIVE UNIV_INTERN ibool srv_log_archive_on = FALSE; UNIV_INTERN ibool srv_archive_recovery = 0; UNIV_INTERN ib_uint64_t srv_archive_recovery_limit_lsn; #endif /* UNIV_LOG_ARCHIVE */ /* This parameter is used to throttle the number of insert buffers that are merged in a batch. By increasing this parameter on a faster disk you can possibly reduce the number of I/O operations performed to complete the merge operation. The value of this parameter is used as is by the background loop when the system is idle (low load), on a busy system the parameter is scaled down by a factor of 4, this is to avoid putting a heavier load on the I/O sub system. */ UNIV_INTERN ulong srv_insert_buffer_batch_size = 20; UNIV_INTERN char* srv_file_flush_method_str = NULL; UNIV_INTERN ulint srv_unix_file_flush_method = SRV_UNIX_FSYNC; UNIV_INTERN ulint srv_win_file_flush_method = SRV_WIN_IO_UNBUFFERED; UNIV_INTERN ulint srv_max_n_open_files = 300; /* Number of IO operations per second the server can do */ UNIV_INTERN ulong srv_io_capacity = 200; UNIV_INTERN ulong srv_max_io_capacity = 400; /* 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. */ UNIV_INTERN ulong srv_max_buf_pool_modified_pct = 75; UNIV_INTERN ulong srv_max_dirty_pages_pct_lwm = 50; /* This is the percentage of log capacity at which adaptive flushing, if enabled, will kick in. */ UNIV_INTERN ulong srv_adaptive_flushing_lwm = 10; /* Number of iterations over which adaptive flushing is averaged. */ UNIV_INTERN ulong srv_flushing_avg_loops = 30; /* The tid of the cleaner thread */ UNIV_INTERN os_tid_t srv_cleaner_tid; /* The tid of the LRU manager thread */ UNIV_INTERN os_tid_t srv_lru_manager_tid; /* The tids of the purge threads */ UNIV_INTERN os_tid_t srv_purge_tids[SRV_MAX_N_PURGE_THREADS]; /* The tids of the I/O threads */ UNIV_INTERN os_tid_t srv_io_tids[SRV_MAX_N_IO_THREADS]; /* The tid of the master thread */ UNIV_INTERN os_tid_t srv_master_tid; /* The relative scheduling priority of the cleaner and LRU manager threads */ UNIV_INTERN ulint srv_sched_priority_cleaner = 19; /* The relative scheduling priority of the purge threads */ UNIV_INTERN ulint srv_sched_priority_purge = 19; /* The relative scheduling priority of the I/O threads */ UNIV_INTERN ulint srv_sched_priority_io = 19; /* The relative scheduling priority of the master thread */ UNIV_INTERN ulint srv_sched_priority_master = 19; /* The relative priority of the current thread. If 0, low priority; if 1, high priority. */ UNIV_INTERN UNIV_THREAD_LOCAL ulint srv_current_thread_priority = 0; /* The relative priority of the purge coordinator and worker threads. */ UNIV_INTERN my_bool srv_purge_thread_priority = FALSE; /* The relative priority of the I/O threads. */ UNIV_INTERN my_bool srv_io_thread_priority = FALSE; /* The relative priority of the cleaner thread. */ UNIV_INTERN my_bool srv_cleaner_thread_priority = FALSE; /* The relative priority of the master thread. */ UNIV_INTERN my_bool srv_master_thread_priority = FALSE; /* The number of purge threads to use.*/ UNIV_INTERN ulong srv_n_purge_threads = 1; /* the number of pages to purge in one batch */ UNIV_INTERN ulong srv_purge_batch_size = 20; /* Internal setting for "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 */ UNIV_INTERN ulong srv_innodb_stats_method = SRV_STATS_NULLS_EQUAL; UNIV_INTERN srv_stats_t srv_stats; /* structure to pass status variables to MySQL */ UNIV_INTERN 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. */ UNIV_INTERN ulong srv_force_recovery; #ifndef DBUG_OFF /** Inject a crash at different steps of the recovery process. This is for testing and debugging only. */ UNIV_INTERN ulong srv_force_recovery_crash; #endif /* !DBUG_OFF */ /** Print all user-level transactions deadlocks to mysqld stderr */ UNIV_INTERN my_bool srv_print_all_deadlocks = FALSE; /** Enable INFORMATION_SCHEMA.innodb_cmp_per_index */ UNIV_INTERN my_bool srv_cmp_per_index_enabled = FALSE; /* If the following is set to 1 then we do not run purge and insert buffer merge to completion before shutdown. If it is set to 2, do not even flush the buffer pool to data files at the shutdown: we effectively 'crash' InnoDB (but lose no committed transactions). */ UNIV_INTERN ulint srv_fast_shutdown = 0; /* Generate a innodb_status. file */ UNIV_INTERN ibool srv_innodb_status = FALSE; /* 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 */ UNIV_INTERN unsigned long long srv_stats_transient_sample_pages = 8; UNIV_INTERN my_bool srv_stats_persistent = TRUE; UNIV_INTERN unsigned long long srv_stats_persistent_sample_pages = 20; UNIV_INTERN my_bool srv_stats_auto_recalc = TRUE; UNIV_INTERN ibool srv_use_doublewrite_buf = TRUE; UNIV_INTERN ibool srv_use_atomic_writes = FALSE; #ifdef HAVE_POSIX_FALLOCATE UNIV_INTERN ibool srv_use_posix_fallocate = FALSE; #endif /** doublewrite buffer is 1MB is size i.e.: it can hold 128 16K pages. The following parameter is the size of the buffer that is used for batch flushing i.e.: LRU flushing and flush_list flushing. The rest of the pages are used for single page flushing. */ UNIV_INTERN ulong srv_doublewrite_batch_size = 120; UNIV_INTERN ulong srv_replication_delay = 0; UNIV_INTERN ulint srv_pass_corrupt_table = 0; /* 0:disable 1:enable */ UNIV_INTERN ulint srv_log_checksum_algorithm = SRV_CHECKSUM_ALGORITHM_INNODB; /*-------------------------------------------*/ UNIV_INTERN ulong srv_n_spin_wait_rounds = 30; UNIV_INTERN ulong srv_spin_wait_delay = 6; UNIV_INTERN ibool srv_priority_boost = TRUE; #ifdef UNIV_DEBUG UNIV_INTERN ibool srv_print_thread_releases = FALSE; UNIV_INTERN ibool srv_print_lock_waits = FALSE; UNIV_INTERN ibool srv_print_buf_io = FALSE; UNIV_INTERN ibool srv_print_log_io = FALSE; UNIV_INTERN ibool srv_print_latch_waits = FALSE; #endif /* UNIV_DEBUG */ static ulint srv_n_rows_inserted_old = 0; static ulint srv_n_rows_updated_old = 0; static ulint srv_n_rows_deleted_old = 0; static ulint srv_n_rows_read_old = 0; UNIV_INTERN ulint srv_truncated_status_writes = 0; UNIV_INTERN ulint srv_available_undo_logs = 0; /* Ensure status variables are on separate cache lines */ #define CACHE_LINE_SIZE 64 #define CACHE_ALIGNED __attribute__ ((aligned (CACHE_LINE_SIZE))) UNIV_INTERN byte counters_pad_start[CACHE_LINE_SIZE] __attribute__((unused)) = {0}; UNIV_INTERN ulint srv_read_views_memory CACHE_ALIGNED = 0; UNIV_INTERN ulint srv_descriptors_memory CACHE_ALIGNED = 0; UNIV_INTERN byte counters_pad_end[CACHE_LINE_SIZE] __attribute__((unused)) = {0}; /* Set the following to 0 if you want InnoDB to write messages on stderr on startup/shutdown. */ UNIV_INTERN ibool srv_print_verbose_log = TRUE; UNIV_INTERN my_bool srv_print_innodb_monitor = FALSE; UNIV_INTERN my_bool srv_print_innodb_lock_monitor = FALSE; UNIV_INTERN ibool srv_print_innodb_tablespace_monitor = FALSE; UNIV_INTERN ibool srv_print_innodb_table_monitor = FALSE; /* Array of English strings describing the current state of an i/o handler thread */ UNIV_INTERN const char* srv_io_thread_op_info[SRV_MAX_N_IO_THREADS]; UNIV_INTERN const char* srv_io_thread_function[SRV_MAX_N_IO_THREADS]; UNIV_INTERN time_t srv_last_monitor_time; UNIV_INTERN ib_mutex_t srv_innodb_monitor_mutex; /* Mutex for locking srv_monitor_file. Not created if srv_read_only_mode */ UNIV_INTERN ib_mutex_t srv_monitor_file_mutex; #ifdef UNIV_PFS_MUTEX # ifndef HAVE_ATOMIC_BUILTINS /* Key to register server_mutex with performance schema */ UNIV_INTERN mysql_pfs_key_t server_mutex_key; # endif /* !HAVE_ATOMIC_BUILTINS */ /** Key to register srv_innodb_monitor_mutex with performance schema */ UNIV_INTERN mysql_pfs_key_t srv_innodb_monitor_mutex_key; /** Key to register srv_monitor_file_mutex with performance schema */ UNIV_INTERN mysql_pfs_key_t srv_monitor_file_mutex_key; /** Key to register srv_dict_tmpfile_mutex with performance schema */ UNIV_INTERN mysql_pfs_key_t srv_dict_tmpfile_mutex_key; /** Key to register the mutex with performance schema */ UNIV_INTERN mysql_pfs_key_t srv_misc_tmpfile_mutex_key; /** Key to register srv_sys_t::mutex with performance schema */ UNIV_INTERN mysql_pfs_key_t srv_sys_mutex_key; /** Key to register srv_sys_t::tasks_mutex with performance schema */ UNIV_INTERN mysql_pfs_key_t srv_sys_tasks_mutex_key; #endif /* UNIV_PFS_MUTEX */ /** Temporary file for innodb monitor output */ UNIV_INTERN FILE* srv_monitor_file; /** Mutex for locking srv_dict_tmpfile. Not created if srv_read_only_mode. This mutex has a very high rank; threads reserving it should not be holding any InnoDB latches. */ UNIV_INTERN ib_mutex_t srv_dict_tmpfile_mutex; /** Temporary file for output from the data dictionary */ UNIV_INTERN FILE* srv_dict_tmpfile; /** Mutex for locking srv_misc_tmpfile. Not created if srv_read_only_mode. This mutex has a very low rank; threads reserving it should not acquire any further latches or sleep before releasing this one. */ UNIV_INTERN ib_mutex_t srv_misc_tmpfile_mutex; /** Temporary file for miscellanous diagnostic output */ UNIV_INTERN FILE* srv_misc_tmpfile; UNIV_INTERN ulint srv_main_thread_process_no = 0; UNIV_INTERN ulint srv_main_thread_id = 0; /* The following counts are used by the srv_master_thread. */ /** Iterations of the loop bounded by 'srv_active' label. */ static ulint srv_main_active_loops = 0; /** Iterations of the loop bounded by the 'srv_idle' label. */ static ulint srv_main_idle_loops = 0; /** Iterations of the loop bounded by the 'srv_shutdown' label. */ static ulint srv_main_shutdown_loops = 0; /** Log writes involving flush. */ static ulint srv_log_writes_and_flush = 0; /* 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; /* Interval in seconds at which various tasks are performed by the master thread when server is active. In order to balance the workload, we should try to keep intervals such that they are not multiple of each other. For example, if we have intervals for various tasks defined as 5, 10, 15, 60 then all tasks will be performed when current_time % 60 == 0 and no tasks will be performed when current_time % 5 != 0. */ # define SRV_MASTER_CHECKPOINT_INTERVAL (7) # define SRV_MASTER_PURGE_INTERVAL (10) #ifdef MEM_PERIODIC_CHECK # define SRV_MASTER_MEM_VALIDATE_INTERVAL (13) #endif /* MEM_PERIODIC_CHECK */ # define SRV_MASTER_DICT_LRU_INTERVAL (47) /** Acquire the system_mutex. */ #define srv_sys_mutex_enter() do { \ mutex_enter(&srv_sys->mutex); \ } while (0) /** Test if the system mutex is owned. */ #define srv_sys_mutex_own() (mutex_own(&srv_sys->mutex) \ && !srv_read_only_mode) /** Release the system mutex. */ #define srv_sys_mutex_exit() do { \ mutex_exit(&srv_sys->mutex); \ } while (0) #define fetch_lock_wait_timeout(trx) \ ((trx)->lock.allowed_to_wait \ ? thd_lock_wait_timeout((trx)->mysql_thd) \ : 0) /* 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 mutex reserved -- process executing in user mode; (b) with lock mutex reserved -- process executing in kernel mode; The server has several backgroind threads all running at the same priority as user threads. It periodically checks if here is anything happening in the server which requires intervention of the master thread. Such situations may be, for example, when flushing of dirty blocks is needed in the buffer pool or old version of database rows have to be cleaned away (purged). The user can configure a separate dedicated purge thread(s) too, in which case the master thread does not do any purging. 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 os_thread_get_curr_id. 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{ ib_mutex_t tasks_mutex; /*!< variable protecting the tasks queue */ UT_LIST_BASE_NODE_T(que_thr_t) tasks; /*!< task queue */ ib_mutex_t mutex; /*!< variable protecting the fields below. */ ulint n_sys_threads; /*!< size of the sys_threads array */ srv_slot_t* sys_threads; /*!< server thread table */ ulint n_threads_active[SRV_MASTER + 1]; /*!< number of threads active in a thread class */ srv_stats_t::ulint_ctr_1_t activity_count; /*!< For tracking server activity */ }; #ifndef HAVE_ATOMIC_BUILTINS /** Mutex protecting some server global variables. */ UNIV_INTERN ib_mutex_t server_mutex; #endif /* !HAVE_ATOMIC_BUILTINS */ static srv_sys_t* srv_sys = NULL; /** Event to signal the monitor thread. */ UNIV_INTERN os_event_t srv_monitor_event; /** Event to signal the error thread */ UNIV_INTERN os_event_t srv_error_event; /** Event to signal the buffer pool dump/load thread */ UNIV_INTERN os_event_t srv_buf_dump_event; /** The buffer pool dump/load file name */ UNIV_INTERN char* srv_buf_dump_filename; /** Boolean config knobs that tell InnoDB to dump the buffer pool at shutdown and/or load it during startup. */ UNIV_INTERN char srv_buffer_pool_dump_at_shutdown = FALSE; UNIV_INTERN char srv_buffer_pool_load_at_startup = FALSE; /** Slot index in the srv_sys->sys_threads array for the purge thread. */ static const ulint SRV_PURGE_SLOT = 1; /** Slot index in the srv_sys->sys_threads array for the master thread. */ static const ulint SRV_MASTER_SLOT = 0; UNIV_INTERN os_event_t srv_checkpoint_completed_event; UNIV_INTERN os_event_t srv_redo_log_tracked_event; UNIV_INTERN bool srv_redo_log_thread_started = false; /*********************************************************************//** 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: %lu srv_active, " "%lu srv_shutdown, %lu srv_idle\n", srv_main_active_loops, srv_main_shutdown_loops, srv_main_idle_loops); fprintf(file, "srv_master_thread log flush and writes: %lu\n", srv_log_writes_and_flush); } /*********************************************************************//** Sets the info describing an i/o thread current state. */ UNIV_INTERN void srv_set_io_thread_op_info( /*======================*/ ulint i, /*!< in: the 'segment' of the i/o thread */ const char* str) /*!< in: constant char string describing the state */ { ut_a(i < SRV_MAX_N_IO_THREADS); srv_io_thread_op_info[i] = str; } /*********************************************************************//** Resets the info describing an i/o thread current state. */ UNIV_INTERN void srv_reset_io_thread_op_info() /*=========================*/ { for (ulint i = 0; i < UT_ARR_SIZE(srv_io_thread_op_info); ++i) { srv_io_thread_op_info[i] = "not started yet"; } } #ifdef UNIV_DEBUG /*********************************************************************//** Validates the type of a thread table slot. @return TRUE if ok */ static ibool srv_thread_type_validate( /*=====================*/ srv_thread_type type) /*!< in: thread type */ { switch (type) { case SRV_NONE: break; case SRV_WORKER: case SRV_PURGE: case SRV_MASTER: return(TRUE); } ut_error; return(FALSE); } #endif /* UNIV_DEBUG */ /*********************************************************************//** Gets the type of a thread table slot. @return thread type */ static srv_thread_type srv_slot_get_type( /*==============*/ const srv_slot_t* slot) /*!< in: thread slot */ { srv_thread_type type = slot->type; ut_ad(srv_thread_type_validate(type)); return(type); } /*********************************************************************//** Reserves a slot in the thread table for the current thread. @return reserved slot */ static srv_slot_t* srv_reserve_slot( /*=============*/ srv_thread_type type) /*!< in: type of the thread */ { srv_slot_t* slot = 0; srv_sys_mutex_enter(); ut_ad(srv_thread_type_validate(type)); switch (type) { case SRV_MASTER: slot = &srv_sys->sys_threads[SRV_MASTER_SLOT]; break; case SRV_PURGE: slot = &srv_sys->sys_threads[SRV_PURGE_SLOT]; break; case SRV_WORKER: /* Find an empty slot, skip the master and purge slots. */ for (slot = &srv_sys->sys_threads[2]; slot->in_use; ++slot) { ut_a(slot < &srv_sys->sys_threads[ srv_sys->n_sys_threads]); } break; case SRV_NONE: ut_error; } ut_a(!slot->in_use); slot->in_use = TRUE; slot->suspended = FALSE; slot->type = type; ut_ad(srv_slot_get_type(slot) == type); ++srv_sys->n_threads_active[type]; srv_sys_mutex_exit(); return(slot); } /*********************************************************************//** Suspends the calling thread to wait for the event in its thread slot. @return the current signal count of the event. */ static ib_int64_t srv_suspend_thread_low( /*===================*/ srv_slot_t* slot) /*!< in/out: thread slot */ { ut_ad(!srv_read_only_mode); ut_ad(srv_sys_mutex_own()); ut_ad(slot->in_use); srv_thread_type type = srv_slot_get_type(slot); switch (type) { case SRV_NONE: ut_error; case SRV_MASTER: /* We have only one master thread and it should be the first entry always. */ ut_a(srv_sys->n_threads_active[type] == 1); break; case SRV_PURGE: /* We have only one purge coordinator thread and it should be the second entry always. */ ut_a(srv_sys->n_threads_active[type] == 1); break; case SRV_WORKER: ut_a(srv_n_purge_threads > 1); ut_a(srv_sys->n_threads_active[type] > 0); break; } ut_a(!slot->suspended); slot->suspended = TRUE; ut_a(srv_sys->n_threads_active[type] > 0); srv_sys->n_threads_active[type]--; return(os_event_reset(slot->event)); } /*********************************************************************//** Suspends the calling thread to wait for the event in its thread slot. @return the current signal count of the event. */ static ib_int64_t srv_suspend_thread( /*===============*/ srv_slot_t* slot) /*!< in/out: thread slot */ { srv_sys_mutex_enter(); ib_int64_t sig_count = srv_suspend_thread_low(slot); srv_sys_mutex_exit(); return(sig_count); } /*********************************************************************//** Releases threads of the type given from suspension in the thread table. NOTE! The server mutex has to be reserved by the caller! @return number of threads released: this may be less than n if not enough threads were suspended at the moment. */ UNIV_INTERN ulint srv_release_threads( /*================*/ srv_thread_type type, /*!< in: thread type */ ulint n) /*!< in: number of threads to release */ { ulint i; ulint count = 0; ut_ad(srv_thread_type_validate(type)); ut_ad(n > 0); srv_sys_mutex_enter(); for (i = 0; i < srv_sys->n_sys_threads; i++) { srv_slot_t* slot; slot = &srv_sys->sys_threads[i]; if (slot->in_use && srv_slot_get_type(slot) == type && slot->suspended) { switch (type) { case SRV_NONE: ut_error; case SRV_MASTER: /* We have only one master thread and it should be the first entry always. */ ut_a(n == 1); ut_a(i == SRV_MASTER_SLOT); ut_a(srv_sys->n_threads_active[type] == 0); break; case SRV_PURGE: /* We have only one purge coordinator thread and it should be the second entry always. */ ut_a(n == 1); ut_a(i == SRV_PURGE_SLOT); ut_a(srv_n_purge_threads > 0); ut_a(srv_sys->n_threads_active[type] == 0); break; case SRV_WORKER: ut_a(srv_n_purge_threads > 1); ut_a(srv_sys->n_threads_active[type] < srv_n_purge_threads - 1); break; } slot->suspended = FALSE; ++srv_sys->n_threads_active[type]; os_event_set(slot->event); if (++count == n) { break; } } } srv_sys_mutex_exit(); return(count); } /*********************************************************************//** Release a thread's slot. */ static void srv_free_slot( /*==========*/ srv_slot_t* slot) /*!< in/out: thread slot */ { srv_sys_mutex_enter(); if (!slot->suspended) { /* Mark the thread as inactive. */ srv_suspend_thread_low(slot); } /* Free the slot for reuse. */ ut_ad(slot->in_use); slot->in_use = FALSE; srv_sys_mutex_exit(); } /*********************************************************************//** Initializes the server. */ UNIV_INTERN void srv_init(void) /*==========*/ { ulint n_sys_threads = 0; ulint srv_sys_sz = sizeof(*srv_sys); #ifndef HAVE_ATOMIC_BUILTINS mutex_create(server_mutex_key, &server_mutex, SYNC_ANY_LATCH); #endif /* !HAVE_ATOMIC_BUILTINS */ mutex_create(srv_innodb_monitor_mutex_key, &srv_innodb_monitor_mutex, SYNC_NO_ORDER_CHECK); if (!srv_read_only_mode) { /* Number of purge threads + master thread */ n_sys_threads = srv_n_purge_threads + 1; srv_sys_sz += n_sys_threads * sizeof(*srv_sys->sys_threads); } srv_sys = static_cast(mem_zalloc(srv_sys_sz)); srv_sys->n_sys_threads = n_sys_threads; if (!srv_read_only_mode) { mutex_create(srv_sys_mutex_key, &srv_sys->mutex, SYNC_THREADS); mutex_create(srv_sys_tasks_mutex_key, &srv_sys->tasks_mutex, SYNC_ANY_LATCH); srv_sys->sys_threads = (srv_slot_t*) &srv_sys[1]; for (ulint i = 0; i < srv_sys->n_sys_threads; ++i) { srv_slot_t* slot = &srv_sys->sys_threads[i]; slot->event = os_event_create(); ut_a(slot->event); } srv_error_event = os_event_create(); srv_monitor_event = os_event_create(); srv_buf_dump_event = os_event_create(); srv_checkpoint_completed_event = os_event_create(); if (srv_track_changed_pages) { srv_redo_log_tracked_event = os_event_create(); os_event_set(srv_redo_log_tracked_event); } UT_LIST_INIT(srv_sys->tasks); } /* page_zip_stat_per_index_mutex is acquired from: 1. page_zip_compress() (after SYNC_FSP) 2. page_zip_decompress() 3. i_s_cmp_per_index_fill_low() (where SYNC_DICT is acquired) 4. innodb_cmp_per_index_update(), no other latches since we do not acquire any other latches while holding this mutex, it can have very low level. We pick SYNC_ANY_LATCH for it. */ mutex_create( page_zip_stat_per_index_mutex_key, &page_zip_stat_per_index_mutex, SYNC_ANY_LATCH); /* Create dummy indexes for infimum and supremum records */ dict_ind_init(); srv_conc_init(); /* Initialize some INFORMATION SCHEMA internal structures */ trx_i_s_cache_init(trx_i_s_cache); ut_crc32_init(); dict_mem_init(); } /*********************************************************************//** Frees the data structures created in srv_init(). */ UNIV_INTERN void srv_free(void) /*==========*/ { srv_conc_free(); /* The mutexes srv_sys->mutex and srv_sys->tasks_mutex should have been freed by sync_close() already. */ mem_free(srv_sys); srv_sys = NULL; trx_i_s_cache_free(trx_i_s_cache); if (!srv_read_only_mode) { os_event_free(srv_buf_dump_event); srv_buf_dump_event = NULL; } } /*********************************************************************//** Initializes the synchronization primitives, memory system, and the thread local storage. */ UNIV_INTERN void srv_general_init(void) /*==================*/ { ut_mem_init(); /* Reset the system variables in the recovery module. */ recv_sys_var_init(); os_sync_init(); sync_init(); mem_init(srv_mem_pool_size); que_init(); row_mysql_init(); } /*********************************************************************//** Normalizes init parameter values to use units we use inside InnoDB. */ static void srv_normalize_init_values(void) /*===========================*/ { ulint n; ulint i; n = srv_n_data_files; for (i = 0; i < n; i++) { srv_data_file_sizes[i] = srv_data_file_sizes[i] * ((1024 * 1024) / UNIV_PAGE_SIZE); } srv_last_file_size_max = srv_last_file_size_max * ((1024 * 1024) / UNIV_PAGE_SIZE); srv_log_file_size = srv_log_file_size / UNIV_PAGE_SIZE; srv_log_buffer_size = srv_log_buffer_size / UNIV_PAGE_SIZE; srv_lock_table_size = 5 * (srv_buf_pool_size / UNIV_PAGE_SIZE); } /*********************************************************************//** Boots the InnoDB server. */ UNIV_INTERN void srv_boot(void) /*==========*/ { /* Transform the init parameter values given by MySQL to use units we use inside InnoDB: */ srv_normalize_init_values(); /* Initialize synchronization primitives, memory management, and thread local storage */ srv_general_init(); /* Initialize this module */ srv_init(); srv_mon_create(); } /******************************************************************//** Refreshes the values used to calculate per-second averages. */ static void srv_refresh_innodb_monitor_stats(void) /*==================================*/ { mutex_enter(&srv_innodb_monitor_mutex); srv_last_monitor_time = time(NULL); os_aio_refresh_stats(); btr_cur_n_sea_old = btr_cur_n_sea; btr_cur_n_non_sea_old = btr_cur_n_non_sea; log_refresh_stats(); buf_refresh_io_stats_all(); srv_n_rows_inserted_old = srv_stats.n_rows_inserted; srv_n_rows_updated_old = srv_stats.n_rows_updated; srv_n_rows_deleted_old = srv_stats.n_rows_deleted; srv_n_rows_read_old = srv_stats.n_rows_read; mutex_exit(&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 */ UNIV_INTERN ibool srv_printf_innodb_monitor( /*======================*/ FILE* file, /*!< in: output stream */ ibool nowait, /*!< in: whether to wait for the lock_sys_t:: mutex */ 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; ulint n_reserved; ibool ret; ulong btr_search_sys_constant; ulong btr_search_sys_variable; ulint lock_sys_subtotal; ulint recv_sys_subtotal; ulint i; trx_t* trx; mutex_enter(&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); fputs("----------\n" "SEMAPHORES\n" "----------\n", file); sync_print(file); /* Conceptually, srv_innodb_monitor_mutex has a very high latching order level in sync0sync.h, while dict_foreign_err_mutex has a very low level 135. Therefore we can reserve the latter mutex here without a danger of a deadlock of threads. */ mutex_enter(&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); } mutex_exit(&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 the lock mutex 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: If we get here then we have the lock mutex. This function will release the lock mutex that we acquired when we called the lock_print_info_summary() function earlier. */ 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); fputs("-------------------------------------\n" "INSERT BUFFER AND ADAPTIVE HASH INDEX\n" "-------------------------------------\n", file); ibuf_print(file); fprintf(file, "%.2f hash searches/s, %.2f non-hash searches/s\n", (btr_cur_n_sea - btr_cur_n_sea_old) / time_elapsed, (btr_cur_n_non_sea - btr_cur_n_non_sea_old) / time_elapsed); btr_cur_n_sea_old = btr_cur_n_sea; btr_cur_n_non_sea_old = btr_cur_n_non_sea; fputs("---\n" "LOG\n" "---\n", file); log_print(file); fputs("----------------------\n" "BUFFER POOL AND MEMORY\n" "----------------------\n", file); fprintf(file, "Total memory allocated " ULINTPF "; in additional pool allocated " ULINTPF "\n", ut_total_allocated_memory, mem_pool_get_reserved(mem_comm_pool)); fprintf(file, "Total memory allocated by read views " ULINTPF "\n", os_atomic_increment_lint(&srv_read_views_memory, 0)); /* Calculate AHI constant and variable memory allocations */ btr_search_sys_constant = 0; btr_search_sys_variable = 0; ut_ad(btr_search_sys->hash_tables); for (i = 0; i < btr_search_index_num; i++) { hash_table_t* ht = btr_search_sys->hash_tables[i]; ut_ad(ht); ut_ad(ht->heap); /* Multiple mutexes/heaps are currently never used for adaptive hash index tables. */ ut_ad(!ht->n_sync_obj); ut_ad(!ht->heaps); btr_search_sys_variable += mem_heap_get_size(ht->heap); btr_search_sys_constant += ht->n_cells * sizeof(hash_cell_t); } lock_sys_subtotal = 0; if (trx_sys) { mutex_enter(&trx_sys->mutex); trx = UT_LIST_GET_FIRST(trx_sys->mysql_trx_list); while (trx) { lock_sys_subtotal += ((trx->lock.lock_heap) ? mem_heap_get_size(trx->lock.lock_heap) : 0); trx = UT_LIST_GET_NEXT(mysql_trx_list, trx); } mutex_exit(&trx_sys->mutex); } recv_sys_subtotal = ((recv_sys && recv_sys->addr_hash) ? mem_heap_get_size(recv_sys->heap) : 0); fprintf(file, "Internal hash tables (constant factor + variable factor)\n" " Adaptive hash index %lu \t(%lu + " ULINTPF ")\n" " Page hash %lu (buffer pool 0 only)\n" " Dictionary cache %lu \t(%lu + " ULINTPF ")\n" " File system %lu \t(%lu + " ULINTPF ")\n" " Lock system %lu \t(%lu + " ULINTPF ")\n" " Recovery system %lu \t(%lu + " ULINTPF ")\n", btr_search_sys_constant + btr_search_sys_variable, btr_search_sys_constant, btr_search_sys_variable, (ulong) (buf_pool_from_array(0)->page_hash->n_cells * sizeof(hash_cell_t)), (ulong) (dict_sys ? ((dict_sys->table_hash->n_cells + dict_sys->table_id_hash->n_cells ) * sizeof(hash_cell_t) + dict_sys->size) : 0), (ulong) (dict_sys ? ((dict_sys->table_hash->n_cells + dict_sys->table_id_hash->n_cells ) * sizeof(hash_cell_t)) : 0), dict_sys ? (dict_sys->size) : 0, (ulong) (fil_system_hash_cells() * sizeof(hash_cell_t) + fil_system_hash_nodes()), (ulong) (fil_system_hash_cells() * sizeof(hash_cell_t)), fil_system_hash_nodes(), (ulong) ((lock_sys ? (lock_sys->rec_hash->n_cells * sizeof(hash_cell_t)) : 0) + lock_sys_subtotal), (ulong) (lock_sys ? (lock_sys->rec_hash->n_cells * sizeof(hash_cell_t)) : 0), lock_sys_subtotal, (ulong) (((recv_sys && recv_sys->addr_hash) ? (recv_sys->addr_hash->n_cells * sizeof(hash_cell_t)) : 0) + recv_sys_subtotal), (ulong) ((recv_sys && recv_sys->addr_hash) ? (recv_sys->addr_hash->n_cells * sizeof(hash_cell_t)) : 0), recv_sys_subtotal); fprintf(file, "Dictionary memory allocated " ULINTPF "\n", dict_sys->size); buf_print_io(file); fputs("--------------\n" "ROW OPERATIONS\n" "--------------\n", file); fprintf(file, "%ld queries inside InnoDB, %lu queries in queue\n", (long) srv_conc_get_active_threads(), srv_conc_get_waiting_threads()); mutex_enter(&trx_sys->mutex); fprintf(file, "%lu read views open inside InnoDB\n", UT_LIST_GET_LEN(trx_sys->view_list)); fprintf(file, "%lu RW transactions active inside InnoDB\n", UT_LIST_GET_LEN(trx_sys->rw_trx_list)); fprintf(file, "%lu RO transactions active inside InnoDB\n", UT_LIST_GET_LEN(trx_sys->ro_trx_list)); fprintf(file, "%lu out of %lu descriptors used\n", trx_sys->descr_n_used, trx_sys->descr_n_max); if (UT_LIST_GET_LEN(trx_sys->view_list)) { read_view_t* view = UT_LIST_GET_LAST(trx_sys->view_list); if (view) { fprintf(file, "---OLDEST VIEW---\n"); read_view_print(file, view); fprintf(file, "-----------------\n"); } } mutex_exit(&trx_sys->mutex); n_reserved = fil_space_get_n_reserved_extents(0); if (n_reserved > 0) { fprintf(file, "%lu tablespace extents now reserved for" " B-tree split operations\n", (ulong) n_reserved); } #ifdef UNIV_LINUX fprintf(file, "Main thread process no. %lu, id %lu, state: %s\n", (ulong) srv_main_thread_process_no, (ulong) srv_main_thread_id, srv_main_thread_op_info); #else fprintf(file, "Main thread id %lu, state: %s\n", (ulong) srv_main_thread_id, srv_main_thread_op_info); #endif fprintf(file, "Number of rows inserted " ULINTPF ", updated " ULINTPF ", deleted " ULINTPF ", read " ULINTPF "\n", (ulint) srv_stats.n_rows_inserted, (ulint) srv_stats.n_rows_updated, (ulint) srv_stats.n_rows_deleted, (ulint) srv_stats.n_rows_read); fprintf(file, "%.2f inserts/s, %.2f updates/s," " %.2f deletes/s, %.2f reads/s\n", ((ulint) srv_stats.n_rows_inserted - srv_n_rows_inserted_old) / time_elapsed, ((ulint) srv_stats.n_rows_updated - srv_n_rows_updated_old) / time_elapsed, ((ulint) srv_stats.n_rows_deleted - srv_n_rows_deleted_old) / time_elapsed, ((ulint) srv_stats.n_rows_read - srv_n_rows_read_old) / time_elapsed); srv_n_rows_inserted_old = srv_stats.n_rows_inserted; srv_n_rows_updated_old = srv_stats.n_rows_updated; srv_n_rows_deleted_old = srv_stats.n_rows_deleted; srv_n_rows_read_old = srv_stats.n_rows_read; fputs("----------------------------\n" "END OF INNODB MONITOR OUTPUT\n" "============================\n", file); mutex_exit(&srv_innodb_monitor_mutex); fflush(file); return(ret); } /******************************************************************//** Function to pass InnoDB status variables to MySQL */ UNIV_INTERN void srv_export_innodb_status(void) /*==========================*/ { buf_pool_stat_t stat; buf_pools_list_size_t buf_pools_list_size; ulint LRU_len; ulint free_len; ulint flush_list_len; ulint mem_adaptive_hash, mem_dictionary; read_view_t* oldest_view; ulint i; buf_get_total_stat(&stat); buf_get_total_list_len(&LRU_len, &free_len, &flush_list_len); buf_get_total_list_size_in_bytes(&buf_pools_list_size); mem_adaptive_hash = 0; ut_ad(btr_search_sys->hash_tables); for (i = 0; i < btr_search_index_num; i++) { hash_table_t* ht = btr_search_sys->hash_tables[i]; ut_ad(ht); ut_ad(ht->heap); /* Multiple mutexes/heaps are currently never used for adaptive hash index tables. */ ut_ad(!ht->n_sync_obj); ut_ad(!ht->heaps); mem_adaptive_hash += mem_heap_get_size(ht->heap); mem_adaptive_hash += ht->n_cells * sizeof(hash_cell_t); } mem_dictionary = (dict_sys ? ((dict_sys->table_hash->n_cells + dict_sys->table_id_hash->n_cells ) * sizeof(hash_cell_t) + dict_sys->size) : 0); mutex_enter(&srv_innodb_monitor_mutex); export_vars.innodb_data_pending_reads = os_n_pending_reads; export_vars.innodb_data_pending_writes = os_n_pending_writes; export_vars.innodb_data_pending_fsyncs = fil_n_pending_log_flushes + fil_n_pending_tablespace_flushes; export_vars.innodb_adaptive_hash_hash_searches = btr_cur_n_sea; export_vars.innodb_adaptive_hash_non_hash_searches = btr_cur_n_non_sea; export_vars.innodb_background_log_sync = srv_log_writes_and_flush; export_vars.innodb_data_fsyncs = os_n_fsyncs; 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; export_vars.innodb_data_written = srv_stats.data_written; export_vars.innodb_buffer_pool_read_requests = stat.n_page_gets; export_vars.innodb_buffer_pool_write_requests = srv_stats.buf_pool_write_requests; export_vars.innodb_buffer_pool_wait_free = srv_stats.buf_pool_wait_free; export_vars.innodb_buffer_pool_pages_flushed = srv_stats.buf_pool_flushed; export_vars.innodb_buffer_pool_reads = srv_stats.buf_pool_reads; export_vars.innodb_buffer_pool_read_ahead_rnd = stat.n_ra_pages_read_rnd; export_vars.innodb_buffer_pool_read_ahead = stat.n_ra_pages_read; export_vars.innodb_buffer_pool_read_ahead_evicted = stat.n_ra_pages_evicted; export_vars.innodb_buffer_pool_pages_LRU_flushed = stat.buf_lru_flush_page_count; export_vars.innodb_buffer_pool_pages_data = LRU_len; export_vars.innodb_buffer_pool_bytes_data = buf_pools_list_size.LRU_bytes + buf_pools_list_size.unzip_LRU_bytes; export_vars.innodb_buffer_pool_pages_dirty = flush_list_len; export_vars.innodb_buffer_pool_bytes_dirty = buf_pools_list_size.flush_list_bytes; export_vars.innodb_buffer_pool_pages_free = free_len; export_vars.innodb_deadlocks = srv_stats.lock_deadlock_count; #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() - LRU_len - free_len; export_vars.innodb_buffer_pool_pages_made_young = stat.n_pages_made_young; export_vars.innodb_buffer_pool_pages_made_not_young = stat.n_pages_not_made_young; export_vars.innodb_buffer_pool_pages_old = 0; for (i = 0; i < srv_buf_pool_instances; i++) { buf_pool_t* buf_pool = buf_pool_from_array(i); export_vars.innodb_buffer_pool_pages_old += buf_pool->LRU_old_len; } export_vars.innodb_checkpoint_age = (log_sys->lsn - log_sys->last_checkpoint_lsn); export_vars.innodb_checkpoint_max_age = log_sys->max_checkpoint_age; export_vars.innodb_history_list_length = trx_sys->rseg_history_len; ibuf_export_ibuf_status( &export_vars.innodb_ibuf_size, &export_vars.innodb_ibuf_free_list, &export_vars.innodb_ibuf_segment_size, &export_vars.innodb_ibuf_merges, &export_vars.innodb_ibuf_merged_inserts, &export_vars.innodb_ibuf_merged_delete_marks, &export_vars.innodb_ibuf_merged_deletes, &export_vars.innodb_ibuf_discarded_inserts, &export_vars.innodb_ibuf_discarded_delete_marks, &export_vars.innodb_ibuf_discarded_deletes); export_vars.innodb_lsn_current = log_sys->lsn; export_vars.innodb_lsn_flushed = log_sys->flushed_to_disk_lsn; export_vars.innodb_lsn_last_checkpoint = log_sys->last_checkpoint_lsn; export_vars.innodb_master_thread_active_loops = srv_main_active_loops; export_vars.innodb_master_thread_idle_loops = srv_main_idle_loops; export_vars.innodb_max_trx_id = trx_sys->max_trx_id; export_vars.innodb_mem_adaptive_hash = mem_adaptive_hash; export_vars.innodb_mem_dictionary = mem_dictionary; export_vars.innodb_mem_total = ut_total_allocated_memory; export_vars.innodb_mutex_os_waits = mutex_os_wait_count; export_vars.innodb_mutex_spin_rounds = mutex_spin_round_count; export_vars.innodb_mutex_spin_waits = mutex_spin_wait_count; export_vars.innodb_s_lock_os_waits = rw_lock_stats.rw_s_os_wait_count; export_vars.innodb_s_lock_spin_rounds = rw_lock_stats.rw_s_spin_round_count; export_vars.innodb_s_lock_spin_waits = rw_lock_stats.rw_s_spin_wait_count; export_vars.innodb_x_lock_os_waits = rw_lock_stats.rw_x_os_wait_count; export_vars.innodb_x_lock_spin_rounds = rw_lock_stats.rw_x_spin_round_count; export_vars.innodb_x_lock_spin_waits = rw_lock_stats.rw_x_spin_wait_count; oldest_view = UT_LIST_GET_LAST(trx_sys->view_list); export_vars.innodb_oldest_view_low_limit_trx_id = oldest_view ? oldest_view->low_limit_id : 0; export_vars.innodb_purge_trx_id = purge_sys->limit.trx_no; export_vars.innodb_purge_undo_no = purge_sys->limit.undo_no; export_vars.innodb_current_row_locks = lock_sys->rec_num; #ifdef HAVE_ATOMIC_BUILTINS export_vars.innodb_have_atomic_builtins = 1; #else export_vars.innodb_have_atomic_builtins = 0; #endif export_vars.innodb_page_size = UNIV_PAGE_SIZE; export_vars.innodb_log_waits = srv_stats.log_waits; export_vars.innodb_os_log_written = srv_stats.os_log_written; export_vars.innodb_os_log_fsyncs = fil_n_log_flushes; export_vars.innodb_os_log_pending_fsyncs = fil_n_pending_log_flushes; export_vars.innodb_os_log_pending_writes = srv_stats.os_log_pending_writes; export_vars.innodb_log_write_requests = srv_stats.log_write_requests; export_vars.innodb_log_writes = srv_stats.log_writes; export_vars.innodb_dblwr_pages_written = srv_stats.dblwr_pages_written; export_vars.innodb_dblwr_writes = srv_stats.dblwr_writes; export_vars.innodb_pages_created = stat.n_pages_created; export_vars.innodb_pages_read = stat.n_pages_read; export_vars.innodb_pages_written = stat.n_pages_written; export_vars.innodb_row_lock_waits = srv_stats.n_lock_wait_count; export_vars.innodb_row_lock_current_waits = srv_stats.n_lock_wait_current_count; export_vars.innodb_row_lock_time = srv_stats.n_lock_wait_time / 1000; if (srv_stats.n_lock_wait_count > 0) { export_vars.innodb_row_lock_time_avg = (ulint) (srv_stats.n_lock_wait_time / 1000 / srv_stats.n_lock_wait_count); } else { export_vars.innodb_row_lock_time_avg = 0; } export_vars.innodb_row_lock_time_max = lock_sys->n_lock_max_wait_time / 1000; export_vars.innodb_rows_read = srv_stats.n_rows_read; export_vars.innodb_rows_inserted = srv_stats.n_rows_inserted; export_vars.innodb_rows_updated = srv_stats.n_rows_updated; export_vars.innodb_rows_deleted = srv_stats.n_rows_deleted; export_vars.innodb_num_open_files = fil_n_file_opened; export_vars.innodb_truncated_status_writes = srv_truncated_status_writes; export_vars.innodb_available_undo_logs = srv_available_undo_logs; export_vars.innodb_read_views_memory = os_atomic_increment_lint(&srv_read_views_memory, 0); export_vars.innodb_descriptors_memory = os_atomic_increment_lint(&srv_descriptors_memory, 0); #ifdef UNIV_DEBUG rw_lock_s_lock(&purge_sys->latch); trx_id_t done_trx_no = purge_sys->done.trx_no; trx_id_t up_limit_id = purge_sys->view ? purge_sys->view->up_limit_id : 0; rw_lock_s_unlock(&purge_sys->latch); mutex_enter(&trx_sys->mutex); trx_id_t max_trx_id = trx_sys->rw_max_trx_id; mutex_exit(&trx_sys->mutex); if (!done_trx_no || max_trx_id < done_trx_no - 1) { export_vars.innodb_purge_trx_id_age = 0; } else { export_vars.innodb_purge_trx_id_age = (ulint) (max_trx_id - done_trx_no + 1); } if (!up_limit_id || max_trx_id < up_limit_id) { export_vars.innodb_purge_view_trx_id_age = 0; } else { export_vars.innodb_purge_view_trx_id_age = (ulint) (max_trx_id - up_limit_id); } #endif /* UNIV_DEBUG */ mutex_exit(&srv_innodb_monitor_mutex); } /*********************************************************************//** A thread which prints the info output by various InnoDB monitors. @return a dummy parameter */ extern "C" UNIV_INTERN os_thread_ret_t DECLARE_THREAD(srv_monitor_thread)( /*===============================*/ void* arg __attribute__((unused))) /*!< in: a dummy parameter required by os_thread_create */ { ib_int64_t sig_count; double time_elapsed; time_t current_time; time_t last_table_monitor_time; time_t last_tablespace_monitor_time; time_t last_monitor_time; ulint mutex_skipped; ibool last_srv_print_monitor; ut_ad(!srv_read_only_mode); #ifdef UNIV_DEBUG_THREAD_CREATION fprintf(stderr, "Lock timeout thread starts, id %lu\n", os_thread_pf(os_thread_get_curr_id())); #endif /* UNIV_DEBUG_THREAD_CREATION */ #ifdef UNIV_PFS_THREAD pfs_register_thread(srv_monitor_thread_key); #endif /* UNIV_PFS_THREAD */ srv_monitor_active = TRUE; UT_NOT_USED(arg); srv_last_monitor_time = ut_time(); last_table_monitor_time = ut_time(); last_tablespace_monitor_time = ut_time(); last_monitor_time = ut_time(); mutex_skipped = 0; last_srv_print_monitor = srv_print_innodb_monitor; loop: /* Wake up every 5 seconds to see if we need to print monitor information or if signalled at shutdown. */ sig_count = os_event_reset(srv_monitor_event); os_event_wait_time_low(srv_monitor_event, 5000000, sig_count); current_time = ut_time(); time_elapsed = difftime(current_time, last_monitor_time); if (time_elapsed > 15) { last_monitor_time = ut_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->mutex for short duration information printing, such as requested by sync_array_print_long_waits() */ if (!last_srv_print_monitor) { mutex_skipped = 0; last_srv_print_monitor = TRUE; } if (!srv_printf_innodb_monitor(stderr, MUTEX_NOWAIT(mutex_skipped), NULL, NULL)) { mutex_skipped++; } else { /* Reset the counter */ mutex_skipped = 0; } } else { last_srv_print_monitor = FALSE; } /* We don't create the temp files or associated mutexes in read-only-mode */ if (!srv_read_only_mode && srv_innodb_status) { mutex_enter(&srv_monitor_file_mutex); rewind(srv_monitor_file); if (!srv_printf_innodb_monitor(srv_monitor_file, MUTEX_NOWAIT(mutex_skipped), NULL, NULL)) { mutex_skipped++; } else { mutex_skipped = 0; } os_file_set_eof(srv_monitor_file); mutex_exit(&srv_monitor_file_mutex); } if (srv_print_innodb_tablespace_monitor && difftime(current_time, last_tablespace_monitor_time) > 60) { last_tablespace_monitor_time = ut_time(); fputs("========================" "========================\n", stderr); ut_print_timestamp(stderr); fputs(" INNODB TABLESPACE MONITOR OUTPUT\n" "========================" "========================\n", stderr); fsp_print(0); fputs("Validating tablespace\n", stderr); fsp_validate(0); fputs("Validation ok\n" "---------------------------------------\n" "END OF INNODB TABLESPACE MONITOR OUTPUT\n" "=======================================\n", stderr); } if (srv_print_innodb_table_monitor && difftime(current_time, last_table_monitor_time) > 60) { last_table_monitor_time = ut_time(); fprintf(stderr, "Warning: %s\n", DEPRECATED_MSG_INNODB_TABLE_MONITOR); fputs("===========================================\n", stderr); ut_print_timestamp(stderr); fputs(" INNODB TABLE MONITOR OUTPUT\n" "===========================================\n", stderr); dict_print(); fputs("-----------------------------------\n" "END OF INNODB TABLE MONITOR OUTPUT\n" "==================================\n", stderr); fprintf(stderr, "Warning: %s\n", DEPRECATED_MSG_INNODB_TABLE_MONITOR); } } if (srv_shutdown_state >= SRV_SHUTDOWN_CLEANUP) { goto exit_func; } if (srv_print_innodb_monitor || srv_print_innodb_lock_monitor || srv_print_innodb_tablespace_monitor || srv_print_innodb_table_monitor) { goto loop; } goto loop; exit_func: srv_monitor_active = FALSE; /* We count the number of threads in os_thread_exit(). A created thread should always use that to exit and not use return() to exit. */ os_thread_exit(NULL); OS_THREAD_DUMMY_RETURN; } /*********************************************************************//** A thread which prints warnings about semaphore waits which have lasted too long. These can be used to track bugs which cause hangs. @return a dummy parameter */ extern "C" UNIV_INTERN os_thread_ret_t DECLARE_THREAD(srv_error_monitor_thread)( /*=====================================*/ void* arg __attribute__((unused))) /*!< in: a dummy parameter required by os_thread_create */ { /* number of successive fatal timeouts observed */ ulint fatal_cnt = 0; lsn_t old_lsn; lsn_t new_lsn; ib_int64_t sig_count; /* longest waiting thread for a semaphore */ os_thread_id_t waiter = os_thread_get_curr_id(); os_thread_id_t old_waiter = waiter; /* the semaphore that is being waited for */ const void* sema = NULL; const void* old_sema = NULL; ut_ad(!srv_read_only_mode); old_lsn = srv_start_lsn; #ifdef UNIV_DEBUG_THREAD_CREATION fprintf(stderr, "Error monitor thread starts, id %lu\n", os_thread_pf(os_thread_get_curr_id())); #endif /* UNIV_DEBUG_THREAD_CREATION */ #ifdef UNIV_PFS_THREAD pfs_register_thread(srv_error_monitor_thread_key); #endif /* UNIV_PFS_THREAD */ srv_error_monitor_active = TRUE; loop: /* Try to track a strange bug reported by Harald Fuchs and others, where the lsn seems to decrease at times */ new_lsn = log_get_lsn(); if (new_lsn < old_lsn) { ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: Error: old log sequence number " LSN_PF " was greater\n" "InnoDB: than the new log sequence number " LSN_PF "!\n" "InnoDB: Please submit a bug report" " to http://bugs.mysql.com\n", old_lsn, new_lsn); ut_ad(0); } old_lsn = new_lsn; if (difftime(time(NULL), srv_last_monitor_time) > 60) { /* We referesh InnoDB Monitor values so that averages are printed from at most 60 last seconds */ srv_refresh_innodb_monitor_stats(); } /* Update the statistics collected for deciding LRU eviction policy. */ buf_LRU_stat_update(); /* In case mutex_exit is not a memory barrier, it is theoretically possible some threads are left waiting though the semaphore is already released. Wake up those threads: */ sync_arr_wake_threads_if_sema_free(); if (sync_array_print_long_waits(&waiter, &sema) && sema == old_sema && os_thread_eq(waiter, old_waiter)) { fatal_cnt++; if (fatal_cnt > 10) { fprintf(stderr, "InnoDB: Error: semaphore wait has lasted" " > %lu seconds\n" "InnoDB: We intentionally crash the server," " because it appears to be hung.\n", (ulong) srv_fatal_semaphore_wait_threshold); ut_error; } } else { fatal_cnt = 0; old_waiter = waiter; old_sema = sema; } if (srv_kill_idle_transaction && trx_sys) { trx_t* trx; time_t now; rescan_idle: now = time(NULL); mutex_enter(&trx_sys->mutex); trx = UT_LIST_GET_FIRST(trx_sys->mysql_trx_list); while (trx) { if (trx->state == TRX_STATE_ACTIVE && trx->mysql_thd && innobase_thd_is_idle(trx->mysql_thd)) { ib_int64_t start_time = innobase_thd_get_start_time(trx->mysql_thd); ulong thd_id = innobase_thd_get_thread_id(trx->mysql_thd); if (trx->last_stmt_start != start_time) { trx->idle_start = now; trx->last_stmt_start = start_time; } else if (difftime(now, trx->idle_start) > srv_kill_idle_transaction) { /* kill the session */ mutex_exit(&trx_sys->mutex); innobase_thd_kill(thd_id); goto rescan_idle; } } trx = UT_LIST_GET_NEXT(mysql_trx_list, trx); } mutex_exit(&trx_sys->mutex); } /* Flush stderr so that a database user gets the output to possible MySQL error file */ fflush(stderr); sig_count = os_event_reset(srv_error_event); os_event_wait_time_low(srv_error_event, 1000000, sig_count); if (srv_shutdown_state < SRV_SHUTDOWN_CLEANUP) { goto loop; } srv_error_monitor_active = FALSE; /* We count the number of threads in os_thread_exit(). A created thread should always use that to exit and not use return() to exit. */ os_thread_exit(NULL); OS_THREAD_DUMMY_RETURN; } /******************************************************************//** Increment the server activity count. */ UNIV_INTERN void srv_inc_activity_count(void) /*========================*/ { srv_sys->activity_count.inc(); } /**********************************************************************//** Check whether any background thread is active. If so return the thread type. @return SRV_NONE if all are suspended or have exited, thread type if any are still active. */ UNIV_INTERN srv_thread_type srv_get_active_thread_type(void) /*============================*/ { srv_thread_type ret = SRV_NONE; if (srv_read_only_mode) { return(SRV_NONE); } srv_sys_mutex_enter(); for (ulint i = SRV_WORKER; i <= SRV_MASTER; ++i) { if (srv_sys->n_threads_active[i] != 0) { ret = static_cast(i); break; } } srv_sys_mutex_exit(); /* Check only on shutdown. */ if (ret == SRV_NONE && srv_shutdown_state != SRV_SHUTDOWN_NONE && trx_purge_state() != PURGE_STATE_DISABLED && trx_purge_state() != PURGE_STATE_EXIT) { ret = SRV_PURGE; } return(ret); } /**********************************************************************//** Check whether any background thread are active. If so print which thread is active. Send the threads wakeup signal. @return name of thread that is active or NULL */ UNIV_INTERN const char* srv_any_background_threads_are_active(void) /*=======================================*/ { const char* thread_active = NULL; if (srv_read_only_mode) { return(NULL); } else if (srv_error_monitor_active) { thread_active = "srv_error_monitor_thread"; } else if (lock_sys->timeout_thread_active) { thread_active = "srv_lock_timeout thread"; } else if (srv_monitor_active) { thread_active = "srv_monitor_thread"; } else if (srv_buf_dump_thread_active) { thread_active = "buf_dump_thread"; } else if (srv_dict_stats_thread_active) { thread_active = "dict_stats_thread"; } os_event_set(srv_error_event); os_event_set(srv_monitor_event); os_event_set(srv_buf_dump_event); os_event_set(lock_sys->timeout_event); os_event_set(dict_stats_event); return(thread_active); } /******************************************************************//** A thread which follows the redo log and outputs the changed page bitmap. @return a dummy value */ extern "C" UNIV_INTERN os_thread_ret_t DECLARE_THREAD(srv_redo_log_follow_thread)( /*=======================================*/ void* arg __attribute__((unused))) /*!< in: a dummy parameter required by os_thread_create */ { ut_ad(!srv_read_only_mode); #ifdef UNIV_DEBUG_THREAD_CREATION fprintf(stderr, "Redo log follower thread starts, id %lu\n", os_thread_pf(os_thread_get_curr_id())); #endif #ifdef UNIV_PFS_THREAD pfs_register_thread(srv_log_tracking_thread_key); #endif my_thread_init(); srv_redo_log_thread_started = true; do { os_event_wait(srv_checkpoint_completed_event); os_event_reset(srv_checkpoint_completed_event); #ifdef UNIV_DEBUG if (!srv_track_changed_pages) { continue; } #endif if (srv_shutdown_state < SRV_SHUTDOWN_LAST_PHASE) { if (!log_online_follow_redo_log()) { /* TODO: sync with I_S log tracking status? */ ib_logf(IB_LOG_LEVEL_ERROR, "log tracking bitmap write failed, " "stopping log tracking thread!\n"); break; } os_event_set(srv_redo_log_tracked_event); } } while (srv_shutdown_state < SRV_SHUTDOWN_LAST_PHASE); srv_track_changed_pages = FALSE; log_online_read_shutdown(); os_event_set(srv_redo_log_tracked_event); srv_redo_log_thread_started = false; /* Defensive, not required */ my_thread_end(); os_thread_exit(NULL); OS_THREAD_DUMMY_RETURN; } /*************************************************************//** Removes old archived transaction log files. Both parameters couldn't be provided at the same time */ dberr_t purge_archived_logs( time_t before_date, /*!< in: all files modified before timestamp should be removed */ lsn_t before_no) /*!< in: files with this number in name and earler should be removed */ { log_group_t* group = UT_LIST_GET_FIRST(log_sys->log_groups); os_file_dir_t dir; os_file_stat_t fileinfo; char archived_log_filename[OS_FILE_MAX_PATH]; char namegen[OS_FILE_MAX_PATH]; ulint dirnamelen; if (srv_arch_dir) { dir = os_file_opendir(srv_arch_dir, FALSE); if (!dir) { ib_logf(IB_LOG_LEVEL_WARN, "opening archived log directory %s failed. " "Purge archived logs are not available\n", srv_arch_dir); /* failed to open directory */ return(DB_ERROR); } } else { /* log archive directory is not specified */ return(DB_ERROR); } dirnamelen = strlen(srv_arch_dir); memcpy(archived_log_filename, srv_arch_dir, dirnamelen); if (dirnamelen && archived_log_filename[dirnamelen - 1] != SRV_PATH_SEPARATOR) { archived_log_filename[dirnamelen++] = SRV_PATH_SEPARATOR; } memset(&fileinfo, 0, sizeof(fileinfo)); while(!os_file_readdir_next_file(srv_arch_dir, dir, &fileinfo) ) { if (strncmp(fileinfo.name, IB_ARCHIVED_LOGS_PREFIX, IB_ARCHIVED_LOGS_PREFIX_LEN)) { continue; } if (dirnamelen + strlen(fileinfo.name) + 2 > OS_FILE_MAX_PATH) continue; snprintf(archived_log_filename + dirnamelen, OS_FILE_MAX_PATH, "%s", fileinfo.name); if (before_no) { ib_uint64_t log_file_no = strtoull(fileinfo.name + IB_ARCHIVED_LOGS_PREFIX_LEN, NULL, 10); if (log_file_no == 0 || before_no <= log_file_no) { continue; } } else { fileinfo.mtime = 0; if (os_file_get_status(archived_log_filename, &fileinfo, false) != DB_SUCCESS || fileinfo.mtime == 0) { continue; } if (before_date == 0 || fileinfo.mtime > before_date) { continue; } } /* We are going to delete archived file. Acquire log_sys->mutex to make sure that we are the only who try to delete file. This also prevents log system from using this file. Do not delete file if it is currently in progress of writting or have pending IO. This is enforced by checking: 1. fil_space_contains_node. 2. group->archived_offset % group->file_size != 0, i.e. there is archive in progress and we are going to delete it. This covers 3 cases: a. Usual case when we have one archive in progress, both 1 and 2 are TRUE b. When we have more then 1 archive in fil_space, this can happen when flushed LSN range crosses file boundary c. When we have empty fil_space, but existing file will be opened once archiving operation is requested. This usually happens on startup. */ mutex_enter(&log_sys->mutex); log_archived_file_name_gen(namegen, sizeof(namegen), group->id, group->archived_file_no); if (fil_space_contains_node(group->archive_space_id, archived_log_filename) || (group->archived_offset % group->file_size != 0 && strcmp(namegen, archived_log_filename) == 0)) { mutex_exit(&log_sys->mutex); continue; } if (!os_file_delete_if_exists(innodb_file_data_key, archived_log_filename)) { ib_logf(IB_LOG_LEVEL_WARN, "can't delete archived log file %s.\n", archived_log_filename); mutex_exit(&log_sys->mutex); os_file_closedir(dir); return(DB_ERROR); } mutex_exit(&log_sys->mutex); } os_file_closedir(dir); return(DB_SUCCESS); } /*******************************************************************//** Tells the InnoDB server that there has been activity in the database and wakes up the master thread if it is suspended (not sleeping). Used in the MySQL interface. Note that there is a small chance that the master thread stays suspended (we do not protect our operation with the srv_sys_t->mutex, for performance reasons). */ UNIV_INTERN void srv_active_wake_master_thread(void) /*===============================*/ { if (srv_read_only_mode) { return; } ut_ad(!srv_sys_mutex_own()); srv_inc_activity_count(); if (srv_sys->n_threads_active[SRV_MASTER] == 0) { srv_slot_t* slot; srv_sys_mutex_enter(); slot = &srv_sys->sys_threads[SRV_MASTER_SLOT]; /* Only if the master thread has been started. */ if (slot->in_use) { ut_a(srv_slot_get_type(slot) == SRV_MASTER); if (slot->suspended) { slot->suspended = FALSE; ++srv_sys->n_threads_active[SRV_MASTER]; os_event_set(slot->event); } } srv_sys_mutex_exit(); } } /*******************************************************************//** Tells the purge thread that there has been activity in the database and wakes up the purge thread if it is suspended (not sleeping). Note that there is a small chance that the purge thread stays suspended (we do not protect our check with the srv_sys_t:mutex and the purge_sys->latch, for performance reasons). */ UNIV_INTERN void srv_wake_purge_thread_if_not_active(void) /*=====================================*/ { ut_ad(!srv_sys_mutex_own()); if (purge_sys->state == PURGE_STATE_RUN && srv_sys->n_threads_active[SRV_PURGE] == 0) { srv_release_threads(SRV_PURGE, 1); } } /*******************************************************************//** Wakes up the master thread if it is suspended or being suspended. */ UNIV_INTERN void srv_wake_master_thread(void) /*========================*/ { ut_ad(!srv_sys_mutex_own()); srv_inc_activity_count(); srv_release_threads(SRV_MASTER, 1); } /*******************************************************************//** Get current server activity count. We don't hold srv_sys::mutex while reading this value as it is only used in heuristics. @return activity count. */ UNIV_INTERN ulint srv_get_activity_count(void) /*========================*/ { return(srv_sys->activity_count); } /*******************************************************************//** Check if there has been any activity. @return FALSE if no change in activity counter. */ UNIV_INTERN ibool srv_check_activity( /*===============*/ ulint old_activity_count) /*!< in: old activity count */ { return(srv_sys->activity_count != old_activity_count); } /********************************************************************//** 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(void) /*===================================*/ { 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_sync_in_background(TRUE); srv_last_log_flush_time = current_time; srv_log_writes_and_flush++; } } /********************************************************************//** Make room in the table cache by evicting an unused table. @return number of tables evicted. */ static ulint srv_master_evict_from_table_cache( /*==============================*/ ulint pct_check) /*!< in: max percent to check */ { ulint n_tables_evicted = 0; rw_lock_x_lock(&dict_operation_lock); dict_mutex_enter_for_mysql(); n_tables_evicted = dict_make_room_in_cache( innobase_get_table_cache_size(), pct_check); dict_mutex_exit_for_mysql(); rw_lock_x_unlock(&dict_operation_lock); return(n_tables_evicted); } /*********************************************************************//** This function prints progress message every 60 seconds during server shutdown, for any activities that master thread is pending on. */ static void srv_shutdown_print_master_pending( /*==============================*/ ib_time_t* last_print_time, /*!< last time the function print the message */ ulint n_tables_to_drop, /*!< number of tables to be dropped */ ulint n_bytes_merged) /*!< number of change buffer just merged */ { ib_time_t current_time; double time_elapsed; current_time = ut_time(); time_elapsed = ut_difftime(current_time, *last_print_time); if (time_elapsed > 60) { *last_print_time = ut_time(); if (n_tables_to_drop) { ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: Waiting for " "%lu table(s) to be dropped\n", (ulong) n_tables_to_drop); } /* Check change buffer merge, we only wait for change buffer merge if it is a slow shutdown */ if (!srv_fast_shutdown && n_bytes_merged) { ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: Waiting for change " "buffer merge to complete\n" " InnoDB: number of bytes of change buffer " "just merged: %lu\n", n_bytes_merged); } } } /*********************************************************************//** Perform the tasks that the master thread is supposed to do when the server is active. There are two types of tasks. The first category is of such tasks which are performed at each inovcation of this function. We assume that this function is called roughly every second when the server is active. The second category is of such tasks which are performed at some interval e.g.: purge, dict_LRU cleanup etc. */ static void srv_master_do_active_tasks(void) /*============================*/ { ib_time_t cur_time = ut_time(); ullint counter_time = ut_time_us(NULL); /* First do the tasks that we are suppose to do at each invocation of this function. */ ++srv_main_active_loops; MONITOR_INC(MONITOR_MASTER_ACTIVE_LOOPS); /* ALTER TABLE in MySQL requires on Unix that the table handler can drop tables lazily after there no longer are SELECT queries to them. */ srv_main_thread_op_info = "doing background drop tables"; row_drop_tables_for_mysql_in_background(); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_BACKGROUND_DROP_TABLE_MICROSECOND, counter_time); if (srv_shutdown_state > 0) { return; } /* make sure that there is enough reusable space in the redo log files */ srv_main_thread_op_info = "checking free log space"; log_free_check(); /* Do an ibuf merge */ srv_main_thread_op_info = "doing insert buffer merge"; counter_time = ut_time_us(NULL); ibuf_contract_in_background(0, FALSE); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_IBUF_MERGE_MICROSECOND, counter_time); /* Flush logs if needed */ srv_main_thread_op_info = "flushing log"; srv_sync_log_buffer_in_background(); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_LOG_FLUSH_MICROSECOND, counter_time); /* Now see if various tasks that are performed at defined intervals need to be performed. */ #ifdef MEM_PERIODIC_CHECK /* Check magic numbers of every allocated mem block once in SRV_MASTER_MEM_VALIDATE_INTERVAL seconds */ if (cur_time % SRV_MASTER_MEM_VALIDATE_INTERVAL == 0) { mem_validate_all_blocks(); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_MEM_VALIDATE_MICROSECOND, counter_time); } #endif if (srv_shutdown_state > 0) { return; } if (srv_shutdown_state > 0) { return; } if (cur_time % SRV_MASTER_DICT_LRU_INTERVAL == 0) { srv_main_thread_op_info = "enforcing dict cache limit"; srv_master_evict_from_table_cache(50); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_DICT_LRU_MICROSECOND, counter_time); } if (srv_shutdown_state > 0) { return; } /* Make a new checkpoint */ if (cur_time % SRV_MASTER_CHECKPOINT_INTERVAL == 0) { srv_main_thread_op_info = "making checkpoint"; log_checkpoint(TRUE, FALSE); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_CHECKPOINT_MICROSECOND, counter_time); } } /*********************************************************************//** Perform the tasks that the master thread is supposed to do whenever the server is idle. We do check for the server state during this function and if the server has entered the shutdown phase we may return from the function without completing the required tasks. Note that the server can move to active state when we are executing this function but we don't check for that as we are suppose to perform more or less same tasks when server is active. */ static void srv_master_do_idle_tasks(void) /*==========================*/ { ullint counter_time; ++srv_main_idle_loops; MONITOR_INC(MONITOR_MASTER_IDLE_LOOPS); /* ALTER TABLE in MySQL requires on Unix that the table handler can drop tables lazily after there no longer are SELECT queries to them. */ counter_time = ut_time_us(NULL); srv_main_thread_op_info = "doing background drop tables"; row_drop_tables_for_mysql_in_background(); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_BACKGROUND_DROP_TABLE_MICROSECOND, counter_time); if (srv_shutdown_state > 0) { return; } /* make sure that there is enough reusable space in the redo log files */ srv_main_thread_op_info = "checking free log space"; log_free_check(); /* Do an ibuf merge */ counter_time = ut_time_us(NULL); srv_main_thread_op_info = "doing insert buffer merge"; ibuf_contract_in_background(0, TRUE); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_IBUF_MERGE_MICROSECOND, counter_time); if (srv_shutdown_state > 0) { return; } srv_main_thread_op_info = "enforcing dict cache limit"; srv_master_evict_from_table_cache(100); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_DICT_LRU_MICROSECOND, counter_time); /* Flush logs if needed */ srv_sync_log_buffer_in_background(); MONITOR_INC_TIME_IN_MICRO_SECS( MONITOR_SRV_LOG_FLUSH_MICROSECOND, counter_time); if (srv_shutdown_state > 0) { return; } /* Make a new checkpoint */ srv_main_thread_op_info = "making checkpoint"; log_checkpoint(TRUE, FALSE); MONITOR_INC_TIME_IN_MICRO_SECS(MONITOR_SRV_CHECKPOINT_MICROSECOND, counter_time); if (srv_shutdown_state > 0) { return; } if (srv_log_arch_expire_sec) { srv_main_thread_op_info = "purging archived logs"; purge_archived_logs(ut_time() - srv_log_arch_expire_sec, 0); } } /*********************************************************************//** Perform the tasks during shutdown. The tasks that we do at shutdown depend on srv_fast_shutdown: 2 => very fast shutdown => do no book keeping 1 => normal shutdown => clear drop table queue and make checkpoint 0 => slow shutdown => in addition to above do complete purge and ibuf merge @return TRUE if some work was done. FALSE otherwise */ static ibool srv_master_do_shutdown_tasks( /*=========================*/ ib_time_t* last_print_time)/*!< last time the function print the message */ { ulint n_bytes_merged = 0; ulint n_tables_to_drop = 0; ut_ad(!srv_read_only_mode); ++srv_main_shutdown_loops; ut_a(srv_shutdown_state > 0); /* In very fast shutdown none of the following is necessary */ if (srv_fast_shutdown == 2) { return(FALSE); } /* ALTER TABLE in MySQL requires on Unix that the table handler can drop tables lazily after there no longer are SELECT queries to them. */ srv_main_thread_op_info = "doing background drop tables"; n_tables_to_drop = row_drop_tables_for_mysql_in_background(); /* make sure that there is enough reusable space in the redo log files */ srv_main_thread_op_info = "checking free log space"; log_free_check(); /* In case of normal shutdown we don't do ibuf merge or purge */ if (srv_fast_shutdown == 1) { goto func_exit; } /* Do an ibuf merge */ srv_main_thread_op_info = "doing insert buffer merge"; n_bytes_merged = ibuf_contract_in_background(0, TRUE); /* Flush logs if needed */ srv_sync_log_buffer_in_background(); func_exit: /* Make a new checkpoint about once in 10 seconds */ srv_main_thread_op_info = "making checkpoint"; log_checkpoint(TRUE, FALSE); /* Print progress message every 60 seconds during shutdown */ if (srv_shutdown_state > 0 && srv_print_verbose_log) { srv_shutdown_print_master_pending( last_print_time, n_tables_to_drop, n_bytes_merged); } return(n_bytes_merged || n_tables_to_drop); } /*********************************************************************//** Puts master thread to sleep. At this point we are using polling to service various activities. Master thread sleeps for one second before checking the state of the server again */ static void srv_master_sleep(void) /*==================*/ { srv_main_thread_op_info = "sleeping"; os_thread_sleep(1000000); srv_main_thread_op_info = ""; } /*********************************************************************//** The master thread controlling the server. @return a dummy parameter */ extern "C" UNIV_INTERN os_thread_ret_t DECLARE_THREAD(srv_master_thread)( /*==============================*/ void* arg __attribute__((unused))) /*!< in: a dummy parameter required by os_thread_create */ { srv_slot_t* slot; ulint old_activity_count = srv_get_activity_count(); ib_time_t last_print_time; ut_ad(!srv_read_only_mode); srv_master_tid = os_thread_get_tid(); os_thread_set_priority(srv_master_tid, srv_sched_priority_master); #ifdef UNIV_DEBUG_THREAD_CREATION fprintf(stderr, "Master thread starts, id %lu\n", os_thread_pf(os_thread_get_curr_id())); #endif /* UNIV_DEBUG_THREAD_CREATION */ #ifdef UNIV_PFS_THREAD pfs_register_thread(srv_master_thread_key); #endif /* UNIV_PFS_THREAD */ srv_main_thread_process_no = os_proc_get_number(); srv_main_thread_id = os_thread_pf(os_thread_get_curr_id()); slot = srv_reserve_slot(SRV_MASTER); ut_a(slot == srv_sys->sys_threads); last_print_time = ut_time(); loop: if (srv_force_recovery >= SRV_FORCE_NO_BACKGROUND) { goto suspend_thread; } while (srv_shutdown_state == SRV_SHUTDOWN_NONE) { srv_master_sleep(); MONITOR_INC(MONITOR_MASTER_THREAD_SLEEP); srv_current_thread_priority = srv_master_thread_priority; if (srv_check_activity(old_activity_count)) { old_activity_count = srv_get_activity_count(); srv_master_do_active_tasks(); } else { srv_master_do_idle_tasks(); } } while (srv_master_do_shutdown_tasks(&last_print_time)) { /* Shouldn't loop here in case of very fast shutdown */ ut_ad(srv_fast_shutdown < 2); } suspend_thread: srv_main_thread_op_info = "suspending"; srv_suspend_thread(slot); /* DO NOT CHANGE THIS STRING. innobase_start_or_create_for_mysql() waits for database activity to die down when converting < 4.1.x databases, and relies on this string being exactly as it is. InnoDB manual also mentions this string in several places. */ srv_main_thread_op_info = "waiting for server activity"; os_event_wait(slot->event); if (srv_shutdown_state == SRV_SHUTDOWN_EXIT_THREADS) { os_thread_exit(NULL); } goto loop; OS_THREAD_DUMMY_RETURN; /* Not reached, avoid compiler warning */ } /*********************************************************************//** Check if purge should stop. @return true if it should shutdown. */ static bool srv_purge_should_exit( /*==============*/ ulint n_purged) /*!< in: pages purged in last batch */ { switch (srv_shutdown_state) { case SRV_SHUTDOWN_NONE: /* Normal operation. */ break; case SRV_SHUTDOWN_CLEANUP: case SRV_SHUTDOWN_EXIT_THREADS: /* Exit unless slow shutdown requested or all done. */ return(srv_fast_shutdown != 0 || n_purged == 0); case SRV_SHUTDOWN_LAST_PHASE: case SRV_SHUTDOWN_FLUSH_PHASE: ut_error; } return(false); } /*********************************************************************//** Fetch and execute a task from the work queue. @return true if a task was executed */ static bool srv_task_execute(void) /*==================*/ { que_thr_t* thr = NULL; ut_ad(!srv_read_only_mode); ut_a(srv_force_recovery < SRV_FORCE_NO_BACKGROUND); mutex_enter(&srv_sys->tasks_mutex); if (UT_LIST_GET_LEN(srv_sys->tasks) > 0) { thr = UT_LIST_GET_FIRST(srv_sys->tasks); ut_a(que_node_get_type(thr->child) == QUE_NODE_PURGE); UT_LIST_REMOVE(queue, srv_sys->tasks, thr); } mutex_exit(&srv_sys->tasks_mutex); if (thr != NULL) { que_run_threads(thr); os_atomic_inc_ulint( &purge_sys->bh_mutex, &purge_sys->n_completed, 1); srv_inc_activity_count(); } return(thr != NULL); } static ulint purge_tid_i = 0; /*********************************************************************//** Worker thread that reads tasks from the work queue and executes them. @return a dummy parameter */ extern "C" UNIV_INTERN os_thread_ret_t DECLARE_THREAD(srv_worker_thread)( /*==============================*/ void* arg __attribute__((unused))) /*!< in: a dummy parameter required by os_thread_create */ { srv_slot_t* slot; ulint tid_i = os_atomic_increment_ulint(&purge_tid_i, 1); ut_ad(tid_i < srv_n_purge_threads); ut_ad(!srv_read_only_mode); ut_a(srv_force_recovery < SRV_FORCE_NO_BACKGROUND); srv_purge_tids[tid_i] = os_thread_get_tid(); os_thread_set_priority(srv_purge_tids[tid_i], srv_sched_priority_purge); #ifdef UNIV_DEBUG_THREAD_CREATION ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: worker thread starting, id %lu\n", os_thread_pf(os_thread_get_curr_id())); #endif /* UNIV_DEBUG_THREAD_CREATION */ slot = srv_reserve_slot(SRV_WORKER); ut_a(srv_n_purge_threads > 1); srv_sys_mutex_enter(); ut_a(srv_sys->n_threads_active[SRV_WORKER] < srv_n_purge_threads); srv_sys_mutex_exit(); /* We need to ensure that the worker threads exit after the purge coordinator thread. Otherwise the purge coordinaor can end up waiting forever in trx_purge_wait_for_workers_to_complete() */ do { srv_suspend_thread(slot); os_event_wait(slot->event); srv_current_thread_priority = srv_purge_thread_priority; if (srv_task_execute()) { /* If there are tasks in the queue, wakeup the purge coordinator thread. */ srv_wake_purge_thread_if_not_active(); } /* Note: we are checking the state without holding the purge_sys->latch here. */ } while (purge_sys->state != PURGE_STATE_EXIT); srv_free_slot(slot); rw_lock_x_lock(&purge_sys->latch); ut_a(!purge_sys->running); ut_a(purge_sys->state == PURGE_STATE_EXIT); ut_a(srv_shutdown_state > SRV_SHUTDOWN_NONE); rw_lock_x_unlock(&purge_sys->latch); #ifdef UNIV_DEBUG_THREAD_CREATION ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: Purge worker thread exiting, id %lu\n", os_thread_pf(os_thread_get_curr_id())); #endif /* UNIV_DEBUG_THREAD_CREATION */ /* We count the number of threads in os_thread_exit(). A created thread should always use that to exit and not use return() to exit. */ os_thread_exit(NULL); OS_THREAD_DUMMY_RETURN; /* Not reached, avoid compiler warning */ } /*********************************************************************//** Do the actual purge operation. @return length of history list before the last purge batch. */ static ulint srv_do_purge( /*=========*/ ulint n_threads, /*!< in: number of threads to use */ ulint* n_total_purged) /*!< in/out: total pages purged */ { ulint n_pages_purged; static ulint count = 0; static ulint n_use_threads = 0; static ulint rseg_history_len = 0; ulint old_activity_count = srv_get_activity_count(); ut_a(n_threads > 0); ut_ad(!srv_read_only_mode); /* Purge until there are no more records to purge and there is no change in configuration or server state. If the user has configured more than one purge thread then we treat that as a pool of threads and only use the extra threads if purge can't keep up with updates. */ if (n_use_threads == 0) { n_use_threads = n_threads; } do { srv_current_thread_priority = srv_purge_thread_priority; if (trx_sys->rseg_history_len > rseg_history_len || (srv_max_purge_lag > 0 && rseg_history_len > srv_max_purge_lag)) { /* History length is now longer than what it was when we took the last snapshot. Use more threads. */ if (n_use_threads < n_threads) { ++n_use_threads; } } else if (srv_check_activity(old_activity_count) && n_use_threads > 1) { /* History length same or smaller since last snapshot, use fewer threads. */ --n_use_threads; old_activity_count = srv_get_activity_count(); } /* Ensure that the purge threads are less than what was configured. */ ut_a(n_use_threads > 0); ut_a(n_use_threads <= n_threads); /* Take a snapshot of the history list before purge. */ if ((rseg_history_len = trx_sys->rseg_history_len) == 0) { break; } n_pages_purged = trx_purge( n_use_threads, srv_purge_batch_size, (++count % TRX_SYS_N_RSEGS) == 0); *n_total_purged += n_pages_purged; } while (!srv_purge_should_exit(n_pages_purged) && n_pages_purged > 0 && purge_sys->state == PURGE_STATE_RUN); return(rseg_history_len); } /*********************************************************************//** Suspend the purge coordinator thread. */ static void srv_purge_coordinator_suspend( /*==========================*/ srv_slot_t* slot, /*!< in/out: Purge coordinator thread slot */ ulint rseg_history_len) /*!< in: history list length before last purge */ { ut_ad(!srv_read_only_mode); ut_a(slot->type == SRV_PURGE); bool stop = false; /** Maximum wait time on the purge event, in micro-seconds. */ static const ulint SRV_PURGE_MAX_TIMEOUT = 10000; ib_int64_t sig_count = srv_suspend_thread(slot); do { ulint ret; rw_lock_x_lock(&purge_sys->latch); purge_sys->running = false; rw_lock_x_unlock(&purge_sys->latch); /* We don't wait right away on the the non-timed wait because we want to signal the thread that wants to suspend purge. */ if (stop) { os_event_wait_low(slot->event, sig_count); ret = 0; } else if (rseg_history_len <= trx_sys->rseg_history_len) { ret = os_event_wait_time_low( slot->event, SRV_PURGE_MAX_TIMEOUT, sig_count); } else { /* We don't want to waste time waiting, if the history list increased by the time we got here, unless purge has been stopped. */ ret = 0; } srv_sys_mutex_enter(); /* The thread can be in state !suspended after the timeout but before this check if another thread sent a wakeup signal. */ if (slot->suspended) { slot->suspended = FALSE; ++srv_sys->n_threads_active[slot->type]; ut_a(srv_sys->n_threads_active[slot->type] == 1); } srv_sys_mutex_exit(); sig_count = srv_suspend_thread(slot); rw_lock_x_lock(&purge_sys->latch); stop = (srv_shutdown_state == SRV_SHUTDOWN_NONE && purge_sys->state == PURGE_STATE_STOP); if (!stop) { ut_a(purge_sys->n_stop == 0); purge_sys->running = true; } else { ut_a(purge_sys->n_stop > 0); /* Signal that we are suspended. */ os_event_set(purge_sys->event); } rw_lock_x_unlock(&purge_sys->latch); if (ret == OS_SYNC_TIME_EXCEEDED) { /* No new records added since wait started then simply wait for new records. The magic number 5000 is an approximation for the case where we have cached UNDO log records which prevent truncate of the UNDO segments. */ if (rseg_history_len == trx_sys->rseg_history_len && trx_sys->rseg_history_len < 5000) { stop = true; } } } while (stop); srv_sys_mutex_enter(); if (slot->suspended) { slot->suspended = FALSE; ++srv_sys->n_threads_active[slot->type]; ut_a(srv_sys->n_threads_active[slot->type] == 1); } srv_sys_mutex_exit(); } /*********************************************************************//** Purge coordinator thread that schedules the purge tasks. @return a dummy parameter */ extern "C" UNIV_INTERN os_thread_ret_t DECLARE_THREAD(srv_purge_coordinator_thread)( /*=========================================*/ void* arg __attribute__((unused))) /*!< in: a dummy parameter required by os_thread_create */ { srv_slot_t* slot; ulint n_total_purged = ULINT_UNDEFINED; ut_ad(!srv_read_only_mode); ut_a(srv_n_purge_threads >= 1); ut_a(trx_purge_state() == PURGE_STATE_INIT); ut_a(srv_force_recovery < SRV_FORCE_NO_BACKGROUND); srv_purge_tids[0] = os_thread_get_tid(); os_thread_set_priority(srv_purge_tids[0], srv_sched_priority_purge); rw_lock_x_lock(&purge_sys->latch); purge_sys->running = true; purge_sys->state = PURGE_STATE_RUN; rw_lock_x_unlock(&purge_sys->latch); #ifdef UNIV_PFS_THREAD pfs_register_thread(srv_purge_thread_key); #endif /* UNIV_PFS_THREAD */ #ifdef UNIV_DEBUG_THREAD_CREATION ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: Purge coordinator thread created, id %lu\n", os_thread_pf(os_thread_get_curr_id())); #endif /* UNIV_DEBUG_THREAD_CREATION */ slot = srv_reserve_slot(SRV_PURGE); ulint rseg_history_len = trx_sys->rseg_history_len; do { /* If there are no records to purge or the last purge didn't purge any records then wait for activity. */ if (srv_shutdown_state == SRV_SHUTDOWN_NONE && (purge_sys->state == PURGE_STATE_STOP || n_total_purged == 0)) { srv_purge_coordinator_suspend(slot, rseg_history_len); } if (srv_purge_should_exit(n_total_purged)) { ut_a(!slot->suspended); break; } n_total_purged = 0; srv_current_thread_priority = srv_purge_thread_priority; rseg_history_len = srv_do_purge( srv_n_purge_threads, &n_total_purged); srv_inc_activity_count(); } while (!srv_purge_should_exit(n_total_purged)); /* Ensure that we don't jump out of the loop unless the exit condition is satisfied. */ ut_a(srv_purge_should_exit(n_total_purged)); ulint n_pages_purged = ULINT_MAX; /* Ensure that all records are purged if it is not a fast shutdown. This covers the case where a record can be added after we exit the loop above. */ while (srv_fast_shutdown == 0 && n_pages_purged > 0) { n_pages_purged = trx_purge(1, srv_purge_batch_size, false); } /* This trx_purge is called to remove any undo records (added by background threads) after completion of the above loop. When srv_fast_shutdown != 0, a large batch size can cause significant delay in shutdown ,so reducing the batch size to magic number 20 (which was default in 5.5), which we hope will be sufficient to remove all the undo records */ const uint temp_batch_size = 20; n_pages_purged = trx_purge(1, srv_purge_batch_size <= temp_batch_size ? srv_purge_batch_size : temp_batch_size, true); ut_a(n_pages_purged == 0 || srv_fast_shutdown != 0); /* The task queue should always be empty, independent of fast shutdown state. */ ut_a(srv_get_task_queue_length() == 0); srv_free_slot(slot); /* Note that we are shutting down. */ rw_lock_x_lock(&purge_sys->latch); purge_sys->state = PURGE_STATE_EXIT; purge_sys->running = false; rw_lock_x_unlock(&purge_sys->latch); #ifdef UNIV_DEBUG_THREAD_CREATION ut_print_timestamp(stderr); fprintf(stderr, " InnoDB: Purge coordinator exiting, id %lu\n", os_thread_pf(os_thread_get_curr_id())); #endif /* UNIV_DEBUG_THREAD_CREATION */ /* Ensure that all the worker threads quit. */ if (srv_n_purge_threads > 1) { srv_release_threads(SRV_WORKER, srv_n_purge_threads - 1); } /* We count the number of threads in os_thread_exit(). A created thread should always use that to exit and not use return() to exit. */ os_thread_exit(NULL); OS_THREAD_DUMMY_RETURN; /* Not reached, avoid compiler warning */ } /**********************************************************************//** Enqueues a task to server task queue and releases a worker thread, if there is a suspended one. */ UNIV_INTERN void srv_que_task_enqueue_low( /*=====================*/ que_thr_t* thr) /*!< in: query thread */ { ut_ad(!srv_read_only_mode); mutex_enter(&srv_sys->tasks_mutex); UT_LIST_ADD_LAST(queue, srv_sys->tasks, thr); mutex_exit(&srv_sys->tasks_mutex); srv_release_threads(SRV_WORKER, 1); } /**********************************************************************//** Get count of tasks in the queue. @return number of tasks in queue */ UNIV_INTERN ulint srv_get_task_queue_length(void) /*===========================*/ { ulint n_tasks; ut_ad(!srv_read_only_mode); mutex_enter(&srv_sys->tasks_mutex); n_tasks = UT_LIST_GET_LEN(srv_sys->tasks); mutex_exit(&srv_sys->tasks_mutex); return(n_tasks); } /**********************************************************************//** Wakeup the purge threads. */ UNIV_INTERN void srv_purge_wakeup(void) /*==================*/ { ut_ad(!srv_read_only_mode); if (srv_force_recovery < SRV_FORCE_NO_BACKGROUND) { srv_release_threads(SRV_PURGE, 1); if (srv_n_purge_threads > 1) { ulint n_workers = srv_n_purge_threads - 1; srv_release_threads(SRV_WORKER, n_workers); } } }