golden hour

/usr/include/mysql/server/private

File/Folder	Size	Actions
aria_backup.h	1.51 KB
assume_aligned.h	2.29 KB
atomic	-
authors.h	9.9 KB
backup.h	1.21 KB
bounded_queue.h	6.67 KB
client_settings.h	1.89 KB
compat56.h	2.23 KB
config.h	14.18 KB
contributors.h	4.76 KB
create_options.h	4.42 KB
custom_conf.h	1.06 KB
datadict.h	1.53 KB
debug_sync.h	2 KB
derived_handler.h	2.32 KB
derror.h	980 B
des_key_file.h	1.21 KB
discover.h	1.53 KB
dur_prop.h	1.06 KB
embedded_priv.h	1.62 KB
event_data_objects.h	4.09 KB
event_db_repository.h	3.56 KB
event_parse_data.h	2.83 KB
event_queue.h	3.36 KB
event_scheduler.h	3.21 KB
events.h	4.59 KB
field.h	211.96 KB
field_comp.h	1.15 KB
filesort.h	6.67 KB
filesort_utils.h	8 KB
ft_global.h	3.04 KB
gcalc_slicescan.h	16.87 KB
gcalc_tools.h	11.62 KB
grant.h	2.69 KB
group_by_handler.h	3.45 KB
gstream.h	2.38 KB
ha_partition.h	62.22 KB
ha_sequence.h	5.94 KB
handle_connections_win.h	884 B
handler.h	188.39 KB
hash.h	4.34 KB
hash_filo.h	5.55 KB
heap.h	9.2 KB
hostname.h	5.29 KB
ilist.h	6.85 KB
init.h	852 B
innodb_priv.h	1.29 KB
item.h	263.12 KB
item_cmpfunc.h	128.01 KB
item_create.h	11.22 KB
item_func.h	124.59 KB
item_geofunc.h	34.69 KB
item_jsonfunc.h	19.8 KB
item_row.h	5.43 KB
item_strfunc.h	64.55 KB
item_subselect.h	56.19 KB
item_sum.h	69.2 KB
item_timefunc.h	57.85 KB
item_vers.h	3.79 KB
item_windowfunc.h	32.61 KB
item_xmlfunc.h	4.36 KB
key.h	2 KB
keycaches.h	1.95 KB
lex.h	28.9 KB
lex_ident.h	2.07 KB
lex_string.h	3.97 KB
lex_symbol.h	1.29 KB
lf.h	6.31 KB
lock.h	2.15 KB
log.h	44.46 KB
log_event.h	178.94 KB
log_event_data_type.h	1.85 KB
log_event_old.h	19.32 KB
log_slow.h	1.98 KB
maria.h	5.73 KB
mariadb.h	1.25 KB
mdl.h	36.78 KB
mem_root_array.h	6.94 KB
message.h	1.17 KB
multi_range_read.h	22.58 KB
my_alarm.h	2.37 KB
my_apc.h	4.62 KB
my_atomic.h	7.11 KB
my_atomic_wrapper.h	2.92 KB
my_base.h	26.5 KB
my_bit.h	6.05 KB
my_bitmap.h	5.22 KB
my_check_opt.h	2.56 KB
my_compare.h	10.93 KB
my_context.h	6.59 KB
my_counter.h	1.68 KB
my_cpu.h	4.85 KB
my_crypt.h	904 B
my_decimal.h	13.43 KB
my_default.h	1.84 KB
my_handler_errors.h	4.74 KB
my_json_writer.h	17.9 KB
my_libwrap.h	1.16 KB
my_md5.h	1.45 KB
my_minidump.h	848 B
my_nosys.h	1.4 KB
my_rdtsc.h	8.15 KB
my_rnd.h	1.04 KB
my_service_manager.h	1.47 KB
my_stack_alloc.h	6.2 KB
my_stacktrace.h	3.14 KB
my_time.h	10.22 KB
my_tree.h	3.9 KB
my_uctype.h	67.9 KB
my_user.h	1.1 KB
myisam.h	17.11 KB
myisamchk.h	4.61 KB
myisammrg.h	4.78 KB
myisampack.h	14.58 KB
mysql_async.h	1.77 KB
mysqld.h	38.7 KB
mysqld_default_groups.h	204 B
mysqld_suffix.h	1.17 KB
mysys_err.h	2.95 KB
nt_servc.h	2.94 KB
opt_range.h	57.58 KB
opt_subselect.h	14.21 KB
opt_trace.h	8.11 KB
opt_trace_context.h	3.21 KB
parse_file.h	4.11 KB
partition_element.h	5.09 KB
partition_info.h	18.85 KB
password.h	1.14 KB
pfs_file_provider.h	3.08 KB
pfs_idle_provider.h	1.35 KB
pfs_memory_provider.h	1.59 KB
pfs_metadata_provider.h	1.85 KB
pfs_socket_provider.h	2.21 KB
pfs_stage_provider.h	1.52 KB
pfs_statement_provider.h	4.25 KB
pfs_table_provider.h	2.56 KB
pfs_thread_provider.h	5.43 KB
pfs_transaction_provider.h	2.78 KB
privilege.h	27.9 KB
probes_mysql.h	973 B
probes_mysql_dtrace.h	32.23 KB
probes_mysql_nodtrace.h	4.89 KB
procedure.h	6.57 KB
protocol.h	12.32 KB
proxy_protocol.h	548 B
queues.h	3.46 KB
records.h	3.03 KB
repl_failsafe.h	1.55 KB
replication.h	15.73 KB
rijndael.h	1.67 KB
rowid_filter.h	15.13 KB
rpl_constants.h	3.28 KB
rpl_filter.h	4.43 KB
rpl_gtid.h	13.31 KB
rpl_injector.h	9.43 KB
rpl_mi.h	13.65 KB
rpl_parallel.h	13.57 KB
rpl_record.h	1.55 KB
rpl_record_old.h	1.37 KB
rpl_reporting.h	2.96 KB
rpl_rli.h	31.8 KB
rpl_tblmap.h	3.1 KB
rpl_utility.h	9.4 KB
scheduler.h	2.99 KB
scope.h	1.76 KB
select_handler.h	2.18 KB
semisync.h	2.23 KB
semisync_master.h	22.7 KB
semisync_master_ack_receiver.h	5.73 KB
semisync_slave.h	3.47 KB
service_versions.h	2 KB
session_tracker.h	13.96 KB
set_var.h	16.1 KB
slave.h	11.99 KB
source_revision.h	67 B
sp.h	22.02 KB
sp_cache.h	2 KB
sp_head.h	63.05 KB
sp_pcontext.h	24.31 KB
sp_rcontext.h	14 KB
span.h	3.84 KB
spatial.h	21.82 KB
sql_acl.h	13.8 KB
sql_admin.h	2.78 KB
sql_alloc.h	1.83 KB
sql_alter.h	11.86 KB
sql_analyse.h	11.23 KB
sql_analyze_stmt.h	11.48 KB
sql_array.h	6.79 KB
sql_audit.h	13.62 KB
sql_base.h	24.83 KB
sql_basic_types.h	9.28 KB
sql_binlog.h	895 B
sql_bitmap.h	7.66 KB
sql_bootstrap.h	1.63 KB
sql_cache.h	21.15 KB
sql_callback.h	1.51 KB
sql_class.h	250.08 KB
sql_cmd.h	9.13 KB
sql_connect.h	3.99 KB
sql_const.h	10.94 KB
sql_crypt.h	1.4 KB
sql_cte.h	16.15 KB
sql_cursor.h	2.26 KB
sql_db.h	2.16 KB
sql_debug.h	4.65 KB
sql_delete.h	1.31 KB
sql_derived.h	1.26 KB
sql_digest.h	3.73 KB
sql_digest_stream.h	1.53 KB
sql_do.h	954 B
sql_error.h	38.12 KB
sql_explain.h	27.1 KB
sql_expression_cache.h	4.26 KB
sql_get_diagnostics.h	7.68 KB
sql_handler.h	2.84 KB
sql_help.h	920 B
sql_hset.h	3.56 KB
sql_i_s.h	7.97 KB
sql_insert.h	2.39 KB
sql_join_cache.h	47.44 KB
sql_lex.h	166.31 KB
sql_lifo_buffer.h	9.45 KB
sql_limit.h	2.38 KB
sql_list.h	21.56 KB
sql_load.h	1.25 KB
sql_locale.h	2.64 KB
sql_manager.h	960 B
sql_mode.h	6.58 KB
sql_parse.h	8.26 KB
sql_partition.h	11.75 KB
sql_partition_admin.h	5.8 KB
sql_plist.h	7.55 KB
sql_plugin.h	7.39 KB
sql_plugin_compat.h	2.18 KB
sql_prepare.h	11.14 KB
sql_priv.h	17.67 KB
sql_profile.h	7.63 KB
sql_reload.h	1.01 KB
sql_rename.h	982 B
sql_repl.h	2.96 KB
sql_schema.h	3.23 KB
sql_select.h	86.56 KB
sql_sequence.h	5.06 KB
sql_servers.h	1.74 KB
sql_show.h	9.39 KB
sql_signal.h	3.28 KB
sql_sort.h	21.39 KB
sql_statistics.h	11.96 KB
sql_string.h	36.43 KB
sql_table.h	11.07 KB
sql_tablespace.h	956 B
sql_test.h	1.55 KB
sql_time.h	8.18 KB
sql_trigger.h	10.76 KB
sql_truncate.h	2.03 KB
sql_tvc.h	2.36 KB
sql_type.h	286 KB
sql_type_geom.h	18.53 KB
sql_type_int.h	9.73 KB
sql_type_json.h	6 KB
sql_type_real.h	1.23 KB
sql_type_string.h	1.59 KB
sql_udf.h	4.74 KB
sql_union.h	1.04 KB
sql_update.h	1.88 KB
sql_view.h	2.33 KB
sql_window.h	6.65 KB
ssl_compat.h	3.07 KB
strfunc.h	2.22 KB
structs.h	25.13 KB
sys_vars_shared.h	2.67 KB
t_ctype.h	5.51 KB
table.h	112.29 KB
table_cache.h	4.13 KB
thr_alarm.h	2.87 KB
thr_lock.h	6.7 KB
thr_malloc.h	1.17 KB
thr_timer.h	1.53 KB
thread_cache.h	5.77 KB
thread_pool_priv.h	4 KB
threadpool.h	4.51 KB
threadpool_generic.h	3.83 KB
transaction.h	1.43 KB
tzfile.h	4.9 KB
tztime.h	3.32 KB
uniques.h	4.1 KB
unireg.h	7.43 KB
vers_string.h	2.47 KB
violite.h	9.71 KB
waiting_threads.h	4.43 KB
welcome_copyright_notice.h	1.19 KB
win_tzname_data.h	6.35 KB
winservice.h	1.17 KB
wqueue.h	1.53 KB
wsrep.h	3.23 KB
wsrep_applier.h	2.64 KB
wsrep_binlog.h	3.36 KB
wsrep_client_service.h	2.5 KB
wsrep_client_state.h	1.53 KB
wsrep_condition_variable.h	1.45 KB
wsrep_high_priority_service.h	4.8 KB
wsrep_mutex.h	1.19 KB
wsrep_mysqld.h	19.88 KB
wsrep_mysqld_c.h	1.2 KB
wsrep_on.h	1.68 KB
wsrep_priv.h	1.6 KB
wsrep_schema.h	4.54 KB
wsrep_server_service.h	3.55 KB
wsrep_server_state.h	2.23 KB
wsrep_sst.h	3.86 KB
wsrep_storage_service.h	1.77 KB
wsrep_thd.h	10.58 KB
wsrep_trans_observer.h	17.81 KB
wsrep_types.h	997 B
wsrep_utils.h	9.07 KB
wsrep_var.h	4.17 KB
wsrep_xid.h	1.42 KB
xa.h	1.69 KB

Edit: thread_cache.h

/*
  Copyright (C) 2020 MariaDB Foundation

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 St, Fifth Floor, Boston, MA 02110-1335  USA
*/

/**
  MariaDB thread cache for "one thread per connection" scheduler.

Thread cache allows to re-use threads (as well as THD objects) for
  subsequent connections.
*/
class Thread_cache
{
  mutable mysql_cond_t COND_thread_cache;
  mutable mysql_cond_t COND_flush_thread_cache;
  mutable mysql_mutex_t LOCK_thread_cache;
  /** Queue of new connection requests. */
  I_List<CONNECT> list;
  /** Number of threads parked in the cache. */
  ulong cached_thread_count;
  /** Number of active flush requests. */
  uint32_t kill_cached_threads;
  /**
    PFS stuff, only used during initialization.
    Unfortunately needs to survive till destruction.
  */
  PSI_cond_key key_COND_thread_cache, key_COND_flush_thread_cache;
  PSI_mutex_key key_LOCK_thread_cache;

public:
  void init()
  {
#ifdef HAVE_PSI_INTERFACE
    PSI_cond_info conds[]=
    {
      { &key_COND_thread_cache, "COND_thread_cache", PSI_FLAG_GLOBAL },
      { &key_COND_flush_thread_cache, "COND_flush_thread_cache",
        PSI_FLAG_GLOBAL }
    };
    PSI_mutex_info mutexes[]=
    {
      { &key_LOCK_thread_cache, "LOCK_thread_cache", PSI_FLAG_GLOBAL }
    };
    mysql_mutex_register("sql", mutexes, array_elements(mutexes));
    mysql_cond_register("sql", conds, array_elements(conds));
#endif
    mysql_mutex_init(key_LOCK_thread_cache, &LOCK_thread_cache,
                     MY_MUTEX_INIT_FAST);
    mysql_cond_init(key_COND_thread_cache, &COND_thread_cache, 0);
    mysql_cond_init(key_COND_flush_thread_cache, &COND_flush_thread_cache, 0);
    list.empty();
    kill_cached_threads= 0;
    cached_thread_count= 0;
  }

void destroy()
  {
    DBUG_ASSERT(cached_thread_count == 0);
    DBUG_ASSERT(list.is_empty());
    mysql_cond_destroy(&COND_flush_thread_cache);
    mysql_cond_destroy(&COND_thread_cache);
    mysql_mutex_destroy(&LOCK_thread_cache);
  }

/**
    Flushes thread cache.

Awakes parked threads and requests them to shutdown.
    Waits until last parked thread leaves the cache.
  */
  void flush()
  {
    mysql_mutex_lock(&LOCK_thread_cache);
    kill_cached_threads++;
    while (cached_thread_count)
    {
      mysql_cond_broadcast(&COND_thread_cache);
      mysql_cond_wait(&COND_flush_thread_cache, &LOCK_thread_cache);
    }
    kill_cached_threads--;
    mysql_mutex_unlock(&LOCK_thread_cache);
  }

/**
    Flushes thread cache and forbids threads parking in the cache.

This is a pre-shutdown hook.
  */
  void final_flush()
  {
    kill_cached_threads++;
    flush();
  }

/**
    Requests parked thread to serve new connection.

@return
      @retval true connection is enqueued and parked thread is about to serve it
      @retval false thread cache is empty
  */
  bool enqueue(CONNECT *connect)
  {
    mysql_mutex_lock(&LOCK_thread_cache);
    if (cached_thread_count)
    {
      list.push_back(connect);
      cached_thread_count--;
      mysql_mutex_unlock(&LOCK_thread_cache);
      mysql_cond_signal(&COND_thread_cache);
      return true;
    }
    mysql_mutex_unlock(&LOCK_thread_cache);
    return false;
  }

/**
    Parks thread in the cache.

Thread execution is suspended until either of the following occurs:
    - thread is requested to serve new connection;
    - thread cache is flushed;
    - THREAD_CACHE_TIMEOUT elapsed.

@return
      @retval pointer to CONNECT if requested to serve new connection
      @retval 0 if thread cache is flushed or on timeout
  */
  CONNECT *park()
  {
    struct timespec abstime;
    CONNECT *connect;
    bool flushed= false;
    DBUG_ENTER("Thread_cache::park");
    set_timespec(abstime, THREAD_CACHE_TIMEOUT);

/*
      Delete the instrumentation for the job that just completed,
      before parking this pthread in the cache (blocked on COND_thread_cache).
    */
    PSI_CALL_delete_current_thread();

#ifndef DBUG_OFF
    while (_db_is_pushed_())
      _db_pop_();
#endif

mysql_mutex_lock(&LOCK_thread_cache);
    if ((connect= list.get()))
      cached_thread_count++;
    else if (cached_thread_count < thread_cache_size && !kill_cached_threads)
    {
      /* Don't kill the thread, just put it in cache for reuse */
      DBUG_PRINT("info", ("Adding thread to cache"));
      cached_thread_count++;
      for (;;)
      {
        int error= mysql_cond_timedwait(&COND_thread_cache, &LOCK_thread_cache,
                                         &abstime);
        flushed= kill_cached_threads;
        if ((connect= list.get()))
          break;
        else if (flushed || error == ETIMEDOUT || error == ETIME)
        {
          /*
            If timeout, end thread.
            If a new thread is requested, we will handle the call, even if we
            got a timeout (as we are already awake and free)
          */
          cached_thread_count--;
          break;
        }
      }
    }
    mysql_mutex_unlock(&LOCK_thread_cache);
    if (flushed)
      mysql_cond_signal(&COND_flush_thread_cache);
    DBUG_RETURN(connect);
  }

/** Returns the number of parked threads. */
  ulong size() const
  {
    mysql_mutex_lock(&LOCK_thread_cache);
    ulong r= cached_thread_count;
    mysql_mutex_unlock(&LOCK_thread_cache);
    return r;
  }
};

extern Thread_cache thread_cache;