/* Copyright (C) 2004-2006 MySQL AB 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; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "mysql_priv.h" #include "events.h" #include "event_data_objects.h" #include "event_scheduler.h" #include "event_db_repository.h" #include "sp_head.h" #include "event_queue.h" #ifdef __GNUC__ #if __GNUC__ >= 2 #define SCHED_FUNC __FUNCTION__ #endif #else #define SCHED_FUNC "<unknown>" #endif #define LOCK_SCHEDULER_DATA() lock_data(SCHED_FUNC, __LINE__) #define UNLOCK_SCHEDULER_DATA() unlock_data(SCHED_FUNC, __LINE__) Event_scheduler* Event_scheduler::singleton= NULL; #ifndef DBUG_OFF static LEX_STRING states_names[] = { {(char*) STRING_WITH_LEN("UNINITIALIZED")}, {(char*) STRING_WITH_LEN("INITIALIZED")}, {(char*) STRING_WITH_LEN("COMMENCING")}, {(char*) STRING_WITH_LEN("CANTSTART")}, {(char*) STRING_WITH_LEN("RUNNING")}, {(char*) STRING_WITH_LEN("SUSPENDED")}, {(char*) STRING_WITH_LEN("IN_SHUTDOWN")} }; #endif const char * const Event_scheduler::cond_vars_names[Event_scheduler::COND_LAST] = { "new work", "started or stopped", "suspend or resume" }; /* Event_scheduler* Event_scheduler::singleton= NULL; */ class Worker_thread_param { public: Event_timed *et; pthread_mutex_t LOCK_started; pthread_cond_t COND_started; bool started; Worker_thread_param(Event_timed *etn):et(etn), started(FALSE) { pthread_mutex_init(&LOCK_started, MY_MUTEX_INIT_FAST); pthread_cond_init(&COND_started, NULL); } ~Worker_thread_param() { pthread_mutex_destroy(&LOCK_started); pthread_cond_destroy(&COND_started); } }; /* Prints the stack of infos, warnings, errors from thd to the console so it can be fetched by the logs-into-tables and checked later. SYNOPSIS evex_print_warnings thd - thread used during the execution of the event et - the event itself */ static void evex_print_warnings(THD *thd, Event_timed *et) { MYSQL_ERROR *err; DBUG_ENTER("evex_print_warnings"); if (!thd->warn_list.elements) DBUG_VOID_RETURN; char msg_buf[10 * STRING_BUFFER_USUAL_SIZE]; char prefix_buf[5 * STRING_BUFFER_USUAL_SIZE]; String prefix(prefix_buf, sizeof(prefix_buf), system_charset_info); prefix.length(0); prefix.append("SCHEDULER: ["); append_identifier(thd, &prefix, et->definer_user.str, et->definer_user.length); prefix.append('@'); append_identifier(thd, &prefix, et->definer_host.str, et->definer_host.length); prefix.append("][", 2); append_identifier(thd,&prefix, et->dbname.str, et->dbname.length); prefix.append('.'); append_identifier(thd,&prefix, et->name.str, et->name.length); prefix.append("] ", 2); List_iterator_fast<MYSQL_ERROR> it(thd->warn_list); while ((err= it++)) { String err_msg(msg_buf, sizeof(msg_buf), system_charset_info); /* set it to 0 or we start adding at the end. That's the trick ;) */ err_msg.length(0); err_msg.append(prefix); err_msg.append(err->msg, strlen(err->msg), system_charset_info); err_msg.append("]"); DBUG_ASSERT(err->level < 3); (sql_print_message_handlers[err->level])("%*s", err_msg.length(), err_msg.c_ptr()); } DBUG_VOID_RETURN; } /* Inits an scheduler thread handler, both the main and a worker SYNOPSIS init_event_thread() thd - the THD of the thread. Has to be allocated by the caller. NOTES 1. The host of the thead is my_localhost 2. thd->net is initted with NULL - no communication. RETURN VALUE 0 OK -1 Error */ static int init_event_thread(THD** t, enum enum_thread_type thread_type) { THD *thd= *t; thd->thread_stack= (char*)t; // remember where our stack is DBUG_ENTER("init_event_thread"); thd->client_capabilities= 0; thd->security_ctx->master_access= 0; thd->security_ctx->db_access= 0; thd->security_ctx->host_or_ip= (char*)my_localhost; my_net_init(&thd->net, 0); thd->net.read_timeout= slave_net_timeout; thd->slave_thread= 0; thd->options|= OPTION_AUTO_IS_NULL; thd->client_capabilities|= CLIENT_MULTI_RESULTS; thd->real_id=pthread_self(); VOID(pthread_mutex_lock(&LOCK_thread_count)); thd->thread_id= thread_id++; threads.append(thd); thread_count++; thread_running++; VOID(pthread_mutex_unlock(&LOCK_thread_count)); if (init_thr_lock() || thd->store_globals()) { thd->cleanup(); DBUG_RETURN(-1); } #if !defined(__WIN__) && !defined(OS2) && !defined(__NETWARE__) sigset_t set; VOID(sigemptyset(&set)); // Get mask in use VOID(pthread_sigmask(SIG_UNBLOCK,&set,&thd->block_signals)); #endif /* Guarantees that we will see the thread in SHOW PROCESSLIST though its vio is NULL. */ thd->system_thread= thread_type; thd->proc_info= "Initialized"; thd->version= refresh_version; thd->set_time(); DBUG_RETURN(0); } /* Inits the main scheduler thread and then calls Event_scheduler::run() of arg. SYNOPSIS event_scheduler_thread() arg void* ptr to Event_scheduler NOTES 1. The host of the thead is my_localhost 2. thd->net is initted with NULL - no communication. 3. The reason to have a proxy function is that it's not possible to use a method as function to be executed in a spawned thread: - our pthread_hander_t macro uses extern "C" - separating thread setup from the real execution loop is also to be considered good. RETURN VALUE 0 OK */ pthread_handler_t event_scheduler_thread(void *arg) { /* needs to be first for thread_stack */ THD *thd= NULL; Event_scheduler *scheduler= (Event_scheduler *) arg; DBUG_ENTER("event_scheduler_thread"); my_thread_init(); pthread_detach_this_thread(); /* note that constructor of THD uses DBUG_ ! */ if (!(thd= new THD) || init_event_thread(&thd, SYSTEM_THREAD_EVENT_SCHEDULER)) { sql_print_error("SCHEDULER: Cannot init manager event thread."); scheduler->report_error_during_start(); } else { thd->security_ctx->set_user((char*)"event_scheduler"); sql_print_information("SCHEDULER: Manager thread booting"); if (Event_scheduler::get_instance()->event_queue->check_system_tables(thd)) scheduler->report_error_during_start(); else scheduler->run(thd); /* NOTE: Don't touch `scheduler` after this point because we have notified the thread which shuts us down that we have finished cleaning. In this very moment a new scheduler thread could be started and a crash is not welcome. */ } /* If we cannot create THD then don't decrease because we haven't touched thread_count and thread_running in init_event_thread() which was never called. In init_event_thread() thread_count and thread_running are always increased even in the case the method returns an error. */ if (thd) { thd->proc_info= "Clearing"; DBUG_ASSERT(thd->net.buff != 0); net_end(&thd->net); pthread_mutex_lock(&LOCK_thread_count); thread_count--; thread_running--; delete thd; pthread_mutex_unlock(&LOCK_thread_count); } my_thread_end(); DBUG_RETURN(0); // Can't return anything here } /* Function that executes an event in a child thread. Setups the environment for the event execution and cleans after that. SYNOPSIS event_worker_thread() arg The Event_timed object to be processed RETURN VALUE 0 OK */ pthread_handler_t event_worker_thread(void *arg) { THD *thd; /* needs to be first for thread_stack */ Worker_thread_param *param= (Worker_thread_param *) arg; Event_timed *event= param->et; int ret; bool startup_error= FALSE; Security_context *save_ctx; /* this one is local and not needed after exec */ Security_context security_ctx; DBUG_ENTER("event_worker_thread"); DBUG_PRINT("enter", ("event=[%s.%s]", event->dbname.str, event->name.str)); my_thread_init(); pthread_detach_this_thread(); if (!(thd= new THD) || init_event_thread(&thd, SYSTEM_THREAD_EVENT_WORKER)) { sql_print_error("SCHEDULER: Startup failure."); startup_error= TRUE; event->spawn_thread_finish(thd); } else event->set_thread_id(thd->thread_id); DBUG_PRINT("info", ("master_access=%d db_access=%d", thd->security_ctx->master_access, thd->security_ctx->db_access)); /* If we don't change it before we send the signal back, then an intermittent DROP EVENT will take LOCK_scheduler_data and try to kill this thread, because event->thread_id is already real. However, because thd->security_ctx->user is not initialized then a crash occurs in kill_one_thread(). Thus, we have to change the context before sending the signal. We are under LOCK_scheduler_data being held by Event_scheduler::run() -> ::execute_top(). */ thd->change_security_context(event->definer_user, event->definer_host, event->dbname, &security_ctx, &save_ctx); DBUG_PRINT("info", ("master_access=%d db_access=%d", thd->security_ctx->master_access, thd->security_ctx->db_access)); /* Signal the scheduler thread that we have started successfully */ pthread_mutex_lock(¶m->LOCK_started); param->started= TRUE; pthread_cond_signal(¶m->COND_started); pthread_mutex_unlock(¶m->LOCK_started); if (!startup_error) { thd->init_for_queries(); thd->enable_slow_log= TRUE; event->set_thread_id(thd->thread_id); sql_print_information("SCHEDULER: [%s.%s of %s] executing in thread %lu", event->dbname.str, event->name.str, event->definer.str, thd->thread_id); ret= event->execute(thd, thd->mem_root); evex_print_warnings(thd, event); sql_print_information("SCHEDULER: [%s.%s of %s] executed. RetCode=%d", event->dbname.str, event->name.str, event->definer.str, ret); if (ret == EVEX_COMPILE_ERROR) sql_print_information("SCHEDULER: COMPILE ERROR for event %s.%s of %s", event->dbname.str, event->name.str, event->definer.str); else if (ret == EVEX_MICROSECOND_UNSUP) sql_print_information("SCHEDULER: MICROSECOND is not supported"); DBUG_PRINT("info", ("master_access=%d db_access=%d", thd->security_ctx->master_access, thd->security_ctx->db_access)); /* If true is returned, we are expected to free it */ if (event->spawn_thread_finish(thd)) { DBUG_PRINT("info", ("Freeing object pointer")); delete event; } } if (thd) { thd->proc_info= "Clearing"; DBUG_ASSERT(thd->net.buff != 0); /* Free it here because net.vio is NULL for us => THD::~THD will check it and won't call net_end(&net); See also replication code. */ net_end(&thd->net); DBUG_PRINT("info", ("Worker thread %lu exiting", thd->thread_id)); VOID(pthread_mutex_lock(&LOCK_thread_count)); thread_count--; thread_running--; delete thd; VOID(pthread_mutex_unlock(&LOCK_thread_count)); } my_thread_end(); DBUG_RETURN(0); // Can't return anything here } /* Constructor of class Event_scheduler. SYNOPSIS Event_scheduler::Event_scheduler() */ Event_scheduler::Event_scheduler() { thread_id= 0; mutex_last_unlocked_at_line= mutex_last_locked_at_line= 0; mutex_last_unlocked_in_func= mutex_last_locked_in_func= ""; cond_waiting_on= COND_NONE; mutex_scheduler_data_locked= FALSE; state= UNINITIALIZED; start_scheduler_suspended= FALSE; LOCK_scheduler_data= &LOCK_data; } /* Returns the singleton instance of the class. SYNOPSIS Event_scheduler::create_instance() RETURN VALUE address */ void Event_scheduler::create_instance(Event_queue *queue) { singleton= new Event_scheduler(); singleton->event_queue= queue; } /* Returns the singleton instance of the class. SYNOPSIS Event_scheduler::get_instance() RETURN VALUE address */ Event_scheduler* Event_scheduler::get_instance() { DBUG_ENTER("Event_scheduler::get_instance"); DBUG_RETURN(singleton); } /* The implementation of full-fledged initialization. SYNOPSIS Event_scheduler::init() RETURN VALUE FALSE OK TRUE Error */ bool Event_scheduler::init(Event_db_repository *db_repo) { int i= 0; bool ret= FALSE; DBUG_ENTER("Event_scheduler::init"); DBUG_PRINT("enter", ("this=%p", this)); LOCK_SCHEDULER_DATA(); init_alloc_root(&scheduler_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC); for (;i < COND_LAST; i++) if (pthread_cond_init(&cond_vars[i], NULL)) { sql_print_error("SCHEDULER: Unable to initalize conditions"); ret= TRUE; goto end; } state= INITIALIZED; end: UNLOCK_SCHEDULER_DATA(); DBUG_RETURN(ret); } /* Frees all memory allocated by the scheduler object. SYNOPSIS Event_scheduler::destroy() RETURN VALUE FALSE OK TRUE Error */ void Event_scheduler::destroy() { DBUG_ENTER("Event_scheduler"); LOCK_SCHEDULER_DATA(); switch (state) { case UNINITIALIZED: break; case INITIALIZED: int i; for (i= 0; i < COND_LAST; i++) pthread_cond_destroy(&cond_vars[i]); state= UNINITIALIZED; break; default: sql_print_error("SCHEDULER: Destroying while state is %d", state); /* I trust my code but ::safe() > ::sorry() */ DBUG_ASSERT(0); break; } UNLOCK_SCHEDULER_DATA(); DBUG_VOID_RETURN; } extern pthread_attr_t connection_attrib; /* Starts the event scheduler SYNOPSIS Event_scheduler::start() RETURN VALUE FALSE OK TRUE Error */ bool Event_scheduler::start() { bool ret= FALSE; pthread_t th; DBUG_ENTER("Event_scheduler::start"); LOCK_SCHEDULER_DATA(); /* If already working or starting don't make another attempt */ DBUG_ASSERT(state == INITIALIZED); if (state > INITIALIZED) { DBUG_PRINT("info", ("scheduler is already running or starting")); ret= TRUE; goto end; } /* Now if another thread calls start it will bail-out because the branch above will be executed. Thus no two or more child threads will be forked. If the child thread cannot start for some reason then `state` is set to CANTSTART and COND_started is also signaled. In this case we set `state` back to INITIALIZED so another attempt to start the scheduler can be made. */ state= COMMENCING; /* Fork */ if (pthread_create(&th, &connection_attrib, event_scheduler_thread, (void*)this)) { DBUG_PRINT("error", ("cannot create a new thread")); state= INITIALIZED; ret= TRUE; goto end; } /* Wait till the child thread has booted (w/ or wo success) */ while (!(state == SUSPENDED || state == RUNNING) && state != CANTSTART) cond_wait(COND_started_or_stopped, LOCK_scheduler_data); /* If we cannot start for some reason then don't prohibit further attempts. Set back to INITIALIZED. */ if (state == CANTSTART) { state= INITIALIZED; ret= TRUE; goto end; } end: UNLOCK_SCHEDULER_DATA(); DBUG_RETURN(ret); } /* Starts the event scheduler in suspended mode. SYNOPSIS Event_scheduler::start_suspended() RETURN VALUE TRUE OK FALSE Error */ bool Event_scheduler::start_suspended() { DBUG_ENTER("Event_scheduler::start_suspended"); start_scheduler_suspended= TRUE; DBUG_RETURN(start()); } /* Report back that we cannot start. Used for ocasions where we can't go into ::run() and have to report externally. SYNOPSIS Event_scheduler::report_error_during_start() */ inline void Event_scheduler::report_error_during_start() { DBUG_ENTER("Event_scheduler::report_error_during_start"); LOCK_SCHEDULER_DATA(); state= CANTSTART; DBUG_PRINT("info", ("Sending back COND_started_or_stopped")); pthread_cond_signal(&cond_vars[COND_started_or_stopped]); UNLOCK_SCHEDULER_DATA(); DBUG_VOID_RETURN; } /* The internal loop of the event scheduler SYNOPSIS Event_scheduler::run() thd Thread RETURN VALUE FALSE OK TRUE Failure */ bool Event_scheduler::run(THD *thd) { int ret; struct timespec abstime; DBUG_ENTER("Event_scheduler::run"); DBUG_PRINT("enter", ("thd=%p", thd)); LOCK_SCHEDULER_DATA(); ret= event_queue->load_events_from_db(thd); if (!ret) { thread_id= thd->thread_id; state= start_scheduler_suspended? SUSPENDED:RUNNING; start_scheduler_suspended= FALSE; } else state= CANTSTART; DBUG_PRINT("info", ("Sending back COND_started_or_stopped")); pthread_cond_signal(&cond_vars[COND_started_or_stopped]); if (ret) { UNLOCK_SCHEDULER_DATA(); DBUG_RETURN(TRUE); } if (!check_n_suspend_if_needed(thd)) UNLOCK_SCHEDULER_DATA(); sql_print_information("SCHEDULER: Manager thread started with id %lu", thd->thread_id); abstime.tv_nsec= 0; while ((state == SUSPENDED || state == RUNNING)) { Event_timed *et; LOCK_SCHEDULER_DATA(); if (check_n_wait_for_non_empty_queue(thd)) continue; /* On TRUE data is unlocked, go back to the beginning */ if (check_n_suspend_if_needed(thd)) continue; /* Guaranteed locked here */ if (state == IN_SHUTDOWN || shutdown_in_progress) { UNLOCK_SCHEDULER_DATA(); break; } DBUG_ASSERT(state == RUNNING); // et= (Event_timed *)queue_top(&event_queue->queue); et= event_queue->get_top(); /* Skip disabled events */ if (et->status != Event_timed::ENABLED) { /* It could be a one-timer scheduled for a time, already in the past when the scheduler was suspended. */ sql_print_information("SCHEDULER: Found a disabled event %*s.%*s in the queue", et->dbname.length, et->dbname.str, et->name.length, et->name.str); queue_remove(&event_queue->queue, 0); /* ToDo: check this again */ if (et->dropped) et->drop(thd); delete et; UNLOCK_SCHEDULER_DATA(); continue; } thd->proc_info= (char *)"Computing"; DBUG_PRINT("evex manager",("computing time to sleep till next exec")); /* Timestamp is in UTC */ abstime.tv_sec= sec_since_epoch_TIME(&et->execute_at); thd->end_time(); if (abstime.tv_sec > thd->query_start()) { /* Event trigger time is in the future */ thd->proc_info= (char *)"Sleep"; DBUG_PRINT("info", ("Going to sleep. Should wakeup after approx %d secs", abstime.tv_sec - thd->query_start())); DBUG_PRINT("info", ("Entering condition because waiting for activation")); /* Use THD::enter_cond()/exit_cond() or we won't be able to kill a sleeping thread. Though ::stop() can do it by sending COND_new_work an user can't by just issuing 'KILL x'; . In the latter case pthread_cond_timedwait() will wait till `abstime`. "Sleeping until next time" */ thd->enter_cond(&cond_vars[COND_new_work],LOCK_scheduler_data,"Sleeping"); pthread_cond_timedwait(&cond_vars[COND_new_work], LOCK_scheduler_data, &abstime); DBUG_PRINT("info", ("Manager woke up. state is %d", state)); /* If we get signal we should recalculate the whether it's the right time because there could be : 1. Spurious wake-up 2. The top of the queue was changed (new one becase of add/drop/replace) */ /* This will do implicit UNLOCK_SCHEDULER_DATA() */ thd->exit_cond(""); } else { thd->proc_info= (char *)"Executing"; /* Execute the event. An error may occur if a thread cannot be forked. In this case stop the manager. We should enter ::execute_top() with locked LOCK_scheduler_data. */ int ret= execute_top(thd, et); UNLOCK_SCHEDULER_DATA(); if (ret) break; } } thd->proc_info= (char *)"Cleaning"; LOCK_SCHEDULER_DATA(); /* It's possible that a user has used (SQL)COM_KILL. Hence set the appropriate state because it is only set by ::stop(). */ if (state != IN_SHUTDOWN) { DBUG_PRINT("info", ("We got KILL but the but not from ::stop()")); state= IN_SHUTDOWN; } UNLOCK_SCHEDULER_DATA(); sql_print_information("SCHEDULER: Shutting down"); thd->proc_info= (char *)"Cleaning queue"; clean_memory(thd); THD_CHECK_SENTRY(thd); /* free mamager_root memory but don't destroy the root */ thd->proc_info= (char *)"Cleaning memory root"; free_root(&scheduler_root, MYF(0)); THD_CHECK_SENTRY(thd); /* We notify the waiting thread which shutdowns us that we have cleaned. There are few more instructions to be executed in this pthread but they don't affect manager structures thus it's safe to signal already at this point. */ LOCK_SCHEDULER_DATA(); thd->proc_info= (char *)"Sending shutdown signal"; DBUG_PRINT("info", ("Sending COND_started_or_stopped")); if (state == IN_SHUTDOWN) pthread_cond_signal(&cond_vars[COND_started_or_stopped]); state= INITIALIZED; /* We set it here because ::run() can stop not only because of ::stop() call but also because of `KILL x` */ thread_id= 0; sql_print_information("SCHEDULER: Stopped"); UNLOCK_SCHEDULER_DATA(); /* We have modified, we set back */ thd->query= NULL; thd->query_length= 0; DBUG_RETURN(FALSE); } /* Executes the top element of the queue. Auxiliary method for ::run(). SYNOPSIS Event_scheduler::execute_top() RETURN VALUE FALSE OK TRUE Failure NOTE NO locking is done. EXPECTED is that the caller should have locked the queue (w/ LOCK_scheduler_data). */ bool Event_scheduler::execute_top(THD *thd, Event_timed *et) { int spawn_ret_code; bool ret= FALSE; DBUG_ENTER("Event_scheduler::execute_top"); DBUG_PRINT("enter", ("thd=%p", thd)); /* Is it good idea to pass a stack address ?*/ Worker_thread_param param(et); pthread_mutex_lock(¶m.LOCK_started); /* We don't lock LOCK_scheduler_data fpr workers_increment() because it's a pre-requisite for calling the current_method. */ switch ((spawn_ret_code= et->spawn_now(event_worker_thread, ¶m))) { case EVENT_EXEC_CANT_FORK: /* We don't lock LOCK_scheduler_data here because it's a pre-requisite for calling the current_method. */ sql_print_error("SCHEDULER: Problem while trying to create a thread"); ret= TRUE; break; case EVENT_EXEC_ALREADY_EXEC: /* We don't lock LOCK_scheduler_data here because it's a pre-requisite for calling the current_method. */ sql_print_information("SCHEDULER: %s.%s in execution. Skip this time.", et->dbname.str, et->name.str); if ((et->flags & EVENT_EXEC_NO_MORE) || et->status == Event_timed::DISABLED) event_queue->remove_top(); else event_queue->top_changed(); break; default: DBUG_ASSERT(!spawn_ret_code); if ((et->flags & EVENT_EXEC_NO_MORE) || et->status == Event_timed::DISABLED) event_queue->remove_top(); else event_queue->top_changed(); /* We don't lock LOCK_scheduler_data here because it's a pre-requisite for calling the current_method. */ if (likely(!spawn_ret_code)) { /* Wait the forked thread to start */ do { pthread_cond_wait(¶m.COND_started, ¶m.LOCK_started); } while (!param.started); } /* param was allocated on the stack so no explicit delete as well as in this moment it's no more used in the spawned thread so it's safe to be deleted. */ break; } pthread_mutex_unlock(¶m.LOCK_started); /* `param` is on the stack and will be destructed by the compiler */ DBUG_RETURN(ret); } /* Cleans the scheduler's queue. Auxiliary method for ::run(). SYNOPSIS Event_scheduler::clean_queue() thd Thread */ void Event_scheduler::clean_memory(THD *thd) { CHARSET_INFO *scs= system_charset_info; uint i; DBUG_ENTER("Event_scheduler::clean_queue"); DBUG_PRINT("enter", ("thd=%p", thd)); LOCK_SCHEDULER_DATA(); stop_all_running_events(thd); UNLOCK_SCHEDULER_DATA(); sql_print_information("SCHEDULER: Emptying the queue"); event_queue->empty_queue(); DBUG_VOID_RETURN; } /* Stops all running events SYNOPSIS Event_scheduler::stop_all_running_events() thd Thread NOTE LOCK_scheduler data must be acquired prior to call to this method */ void Event_scheduler::stop_all_running_events(THD *thd) { CHARSET_INFO *scs= system_charset_info; uint i; DYNAMIC_ARRAY running_threads; THD *tmp; DBUG_ENTER("Event_scheduler::stop_all_running_events"); DBUG_PRINT("enter", ("workers_count=%d", workers_count())); my_init_dynamic_array(&running_threads, sizeof(ulong), 10, 10); bool had_super= FALSE; VOID(pthread_mutex_lock(&LOCK_thread_count)); // For unlink from list I_List_iterator<THD> it(threads); while ((tmp=it++)) { if (tmp->command == COM_DAEMON) continue; if (tmp->system_thread == SYSTEM_THREAD_EVENT_WORKER) push_dynamic(&running_threads, (gptr) &tmp->thread_id); } VOID(pthread_mutex_unlock(&LOCK_thread_count)); /* We need temporarily SUPER_ACL to be able to kill our offsprings */ if (!(thd->security_ctx->master_access & SUPER_ACL)) thd->security_ctx->master_access|= SUPER_ACL; else had_super= TRUE; char tmp_buff[10*STRING_BUFFER_USUAL_SIZE]; char int_buff[STRING_BUFFER_USUAL_SIZE]; String tmp_string(tmp_buff, sizeof(tmp_buff), scs); String int_string(int_buff, sizeof(int_buff), scs); tmp_string.length(0); for (i= 0; i < running_threads.elements; ++i) { int ret; ulong thd_id= *dynamic_element(&running_threads, i, ulong*); int_string.set((longlong) thd_id,scs); tmp_string.append(int_string); if (i < running_threads.elements - 1) tmp_string.append(' '); if ((ret= kill_one_thread(thd, thd_id, FALSE))) { sql_print_error("SCHEDULER: Error killing %lu code=%d", thd_id, ret); break; } } if (running_threads.elements) sql_print_information("SCHEDULER: Killing workers :%s", tmp_string.c_ptr()); if (!had_super) thd->security_ctx->master_access &= ~SUPER_ACL; delete_dynamic(&running_threads); sql_print_information("SCHEDULER: Waiting for worker threads to finish"); while (workers_count()) my_sleep(100000); DBUG_VOID_RETURN; } /* Stops the event scheduler SYNOPSIS Event_scheduler::stop() RETURN VALUE OP_OK OK OP_CANT_KILL Error during stopping of manager thread OP_NOT_RUNNING Manager not working NOTE The caller must have acquited LOCK_scheduler_data. */ int Event_scheduler::stop() { THD *thd= current_thd; DBUG_ENTER("Event_scheduler::stop"); DBUG_PRINT("enter", ("thd=%p", current_thd)); LOCK_SCHEDULER_DATA(); if (!(state == SUSPENDED || state == RUNNING)) { /* One situation to be here is if there was a start that forked a new thread but the new thread did not acquire yet LOCK_scheduler_data. Hence, in this case return an error. */ DBUG_PRINT("info", ("manager not running but %d. doing nothing", state)); UNLOCK_SCHEDULER_DATA(); DBUG_RETURN(OP_NOT_RUNNING); } state= IN_SHUTDOWN; DBUG_PRINT("info", ("Manager thread has id %d", thread_id)); sql_print_information("SCHEDULER: Killing manager thread %lu", thread_id); /* Sending the COND_new_work to ::run() is a way to get this working without race conditions. If we use kill_one_thread() it will call THD::awake() and because in ::run() both THD::enter_cond()/::exit_cond() are used, THD::awake() will try to lock LOCK_scheduler_data. If we UNLOCK it before, then the pthread_cond_signal(COND_started_or_stopped) could be signaled in ::run() and we can miss the signal before we relock. A way is to use another mutex for this shutdown procedure but better not. */ pthread_cond_signal(&cond_vars[COND_new_work]); /* Or we are suspended - then we should wake up */ pthread_cond_signal(&cond_vars[COND_suspend_or_resume]); /* Guarantee we don't catch spurious signals */ sql_print_information("SCHEDULER: Waiting the manager thread to reply"); while (state != INITIALIZED) { DBUG_PRINT("info", ("Waiting for COND_started_or_stopped from the manager " "thread. Current value of state is %d . " "workers count=%d", state, workers_count())); cond_wait(COND_started_or_stopped, LOCK_scheduler_data); } DBUG_PRINT("info", ("Manager thread has cleaned up. Set state to INIT")); UNLOCK_SCHEDULER_DATA(); DBUG_RETURN(OP_OK); } /* Suspends or resumes the scheduler. SUSPEND - it won't execute any event till resumed. RESUME - it will resume if suspended. SYNOPSIS Event_scheduler::suspend_or_resume() RETURN VALUE OP_OK OK */ int Event_scheduler::suspend_or_resume( enum Event_scheduler::enum_suspend_or_resume action) { DBUG_ENTER("Event_scheduler::suspend_or_resume"); DBUG_PRINT("enter", ("action=%d", action)); LOCK_SCHEDULER_DATA(); if ((action == SUSPEND && state == SUSPENDED) || (action == RESUME && state == RUNNING)) { DBUG_PRINT("info", ("Either trying to suspend suspended or resume " "running scheduler. Doing nothing.")); } else { /* Wake the main thread up if he is asleep */ DBUG_PRINT("info", ("Sending signal")); if (action==SUSPEND) { state= SUSPENDED; pthread_cond_signal(&cond_vars[COND_new_work]); } else { state= RUNNING; pthread_cond_signal(&cond_vars[COND_suspend_or_resume]); } DBUG_PRINT("info", ("Waiting on COND_suspend_or_resume")); cond_wait(COND_suspend_or_resume, LOCK_scheduler_data); DBUG_PRINT("info", ("Got response")); } UNLOCK_SCHEDULER_DATA(); DBUG_RETURN(OP_OK); } /* Returns the number of executing events. SYNOPSIS Event_scheduler::workers_count() */ uint Event_scheduler::workers_count() { THD *tmp; uint count= 0; DBUG_ENTER("Event_scheduler::workers_count"); VOID(pthread_mutex_lock(&LOCK_thread_count)); // For unlink from list I_List_iterator<THD> it(threads); while ((tmp=it++)) { if (tmp->command == COM_DAEMON) continue; if (tmp->system_thread == SYSTEM_THREAD_EVENT_WORKER) ++count; } VOID(pthread_mutex_unlock(&LOCK_thread_count)); DBUG_PRINT("exit", ("%d", count)); DBUG_RETURN(count); } /* Checks and suspends if needed SYNOPSIS Event_scheduler::check_n_suspend_if_needed() thd Thread RETURN VALUE FALSE Not suspended, we haven't slept TRUE We were suspended. LOCK_scheduler_data is unlocked. NOTE The caller should have locked LOCK_scheduler_data! The mutex will be unlocked in case this function returns TRUE */ bool Event_scheduler::check_n_suspend_if_needed(THD *thd) { bool was_suspended= FALSE; DBUG_ENTER("Event_scheduler::check_n_suspend_if_needed"); if (thd->killed && !shutdown_in_progress) { state= SUSPENDED; thd->killed= THD::NOT_KILLED; } if (state == SUSPENDED) { thd->enter_cond(&cond_vars[COND_suspend_or_resume], LOCK_scheduler_data, "Suspended"); /* Send back signal to the thread that asked us to suspend operations */ pthread_cond_signal(&cond_vars[COND_suspend_or_resume]); sql_print_information("SCHEDULER: Suspending operations"); was_suspended= TRUE; } while (state == SUSPENDED) { cond_wait(COND_suspend_or_resume, LOCK_scheduler_data); DBUG_PRINT("info", ("Woke up after waiting on COND_suspend_or_resume")); if (state != SUSPENDED) { pthread_cond_signal(&cond_vars[COND_suspend_or_resume]); sql_print_information("SCHEDULER: Resuming operations"); } } if (was_suspended) { event_queue->recalculate_queue(thd); /* This will implicitly unlock LOCK_scheduler_data */ thd->exit_cond(""); } DBUG_RETURN(was_suspended); } /* Checks for empty queue and waits till new element gets in SYNOPSIS Event_scheduler::check_n_wait_for_non_empty_queue() thd Thread RETURN VALUE FALSE Did not wait - LOCK_scheduler_data still locked. TRUE Waited - LOCK_scheduler_data unlocked. NOTE The caller should have locked LOCK_scheduler_data! */ bool Event_scheduler::check_n_wait_for_non_empty_queue(THD *thd) { bool slept= FALSE; DBUG_ENTER("Event_scheduler::check_n_wait_for_non_empty_queue"); DBUG_PRINT("enter", ("q.elements=%lu state=%s", event_queue->events_count_no_lock(), states_names[state])); if (!event_queue->events_count_no_lock()) thd->enter_cond(&cond_vars[COND_new_work], LOCK_scheduler_data, "Empty queue, sleeping"); /* Wait in a loop protecting against catching spurious signals */ while (!event_queue->events_count_no_lock() && state == RUNNING) { slept= TRUE; DBUG_PRINT("info", ("Entering condition because of empty queue")); cond_wait(COND_new_work, LOCK_scheduler_data); DBUG_PRINT("info", ("Manager woke up. Hope we have events now. state=%d", state)); /* exit_cond does implicit mutex_UNLOCK, we needed it locked if 1. we loop again 2. end the current loop and start doing calculations */ } if (slept) thd->exit_cond(""); DBUG_PRINT("exit", ("q.elements=%lu state=%s thd->killed=%d", event_queue->events_count_no_lock(), states_names[state], thd->killed)); DBUG_RETURN(slept); } /* Returns the current state of the scheduler SYNOPSIS Event_scheduler::get_state() */ enum Event_scheduler::enum_state Event_scheduler::get_state() { enum Event_scheduler::enum_state ret; DBUG_ENTER("Event_scheduler::get_state"); /* lock_data & unlock_data are not static */ pthread_mutex_lock(singleton->LOCK_scheduler_data); ret= singleton->state; pthread_mutex_unlock(singleton->LOCK_scheduler_data); DBUG_RETURN(ret); } /* Returns whether the scheduler was initialized. SYNOPSIS Event_scheduler::initialized() RETURN VALUE FALSE Was not initialized so far TRUE Was initialized */ bool Event_scheduler::initialized() { DBUG_ENTER("Event_scheduler::initialized"); DBUG_RETURN(Event_scheduler::get_state() != UNINITIALIZED); } /* Dumps some data about the internal status of the scheduler. SYNOPSIS Event_scheduler::dump_internal_status() thd THD RETURN VALUE 0 OK 1 Error */ int Event_scheduler::dump_internal_status(THD *thd) { DBUG_ENTER("dump_internal_status"); #ifndef DBUG_OFF CHARSET_INFO *scs= system_charset_info; Protocol *protocol= thd->protocol; List<Item> field_list; int ret; char tmp_buff[5*STRING_BUFFER_USUAL_SIZE]; char int_buff[STRING_BUFFER_USUAL_SIZE]; String tmp_string(tmp_buff, sizeof(tmp_buff), scs); String int_string(int_buff, sizeof(int_buff), scs); tmp_string.length(0); int_string.length(0); field_list.push_back(new Item_empty_string("Name", 20)); field_list.push_back(new Item_empty_string("Value",20)); if (protocol->send_fields(&field_list, Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF)) DBUG_RETURN(1); protocol->prepare_for_resend(); protocol->store(STRING_WITH_LEN("state"), scs); protocol->store(states_names[singleton->state].str, states_names[singleton->state].length, scs); ret= protocol->write(); /* If not initialized - don't show anything else. get_instance() will otherwise implicitly initialize it. We don't want that. */ if (singleton->state >= INITIALIZED) { /* last locked at*/ /* The first thing to do, or get_instance() will overwrite the values. mutex_last_locked_at_line / mutex_last_unlocked_at_line */ protocol->prepare_for_resend(); protocol->store(STRING_WITH_LEN("last locked at"), scs); tmp_string.length(scs->cset->snprintf(scs, (char*) tmp_string.ptr(), tmp_string.alloced_length(), "%s::%d", singleton->mutex_last_locked_in_func, singleton->mutex_last_locked_at_line)); protocol->store(&tmp_string); ret= protocol->write(); /* last unlocked at*/ protocol->prepare_for_resend(); protocol->store(STRING_WITH_LEN("last unlocked at"), scs); tmp_string.length(scs->cset->snprintf(scs, (char*) tmp_string.ptr(), tmp_string.alloced_length(), "%s::%d", singleton->mutex_last_unlocked_in_func, singleton->mutex_last_unlocked_at_line)); protocol->store(&tmp_string); ret= protocol->write(); /* waiting on */ protocol->prepare_for_resend(); protocol->store(STRING_WITH_LEN("waiting on condition"), scs); tmp_string.length(scs->cset-> snprintf(scs, (char*) tmp_string.ptr(), tmp_string.alloced_length(), "%s", (singleton->cond_waiting_on != COND_NONE) ? cond_vars_names[singleton->cond_waiting_on]: "NONE")); protocol->store(&tmp_string); ret= protocol->write(); Event_scheduler *scheduler= get_instance(); /* workers_count */ protocol->prepare_for_resend(); protocol->store(STRING_WITH_LEN("workers_count"), scs); int_string.set((longlong) scheduler->workers_count(), scs); protocol->store(&int_string); ret= protocol->write(); /* queue.elements */ protocol->prepare_for_resend(); protocol->store(STRING_WITH_LEN("queue.elements"), scs); int_string.set((longlong) scheduler->event_queue->events_count_no_lock(), scs); protocol->store(&int_string); ret= protocol->write(); /* scheduler_data_locked */ protocol->prepare_for_resend(); protocol->store(STRING_WITH_LEN("scheduler data locked"), scs); int_string.set((longlong) scheduler->mutex_scheduler_data_locked, scs); protocol->store(&int_string); ret= protocol->write(); } send_eof(thd); #endif DBUG_RETURN(0); } /* Wrapper for pthread_mutex_lock SYNOPSIS Event_scheduler::lock_data() mutex Mutex to lock line The line number on which the lock is done RETURN VALUE Error code of pthread_mutex_lock() */ void Event_scheduler::lock_data(const char *func, uint line) { DBUG_ENTER("Event_scheduler::lock_mutex"); DBUG_PRINT("enter", ("mutex_lock=%p func=%s line=%u", &LOCK_scheduler_data, func, line)); pthread_mutex_lock(LOCK_scheduler_data); mutex_last_locked_in_func= func; mutex_last_locked_at_line= line; mutex_scheduler_data_locked= TRUE; DBUG_VOID_RETURN; } /* Wrapper for pthread_mutex_unlock SYNOPSIS Event_scheduler::unlock_data() mutex Mutex to unlock line The line number on which the unlock is done */ void Event_scheduler::unlock_data(const char *func, uint line) { DBUG_ENTER("Event_scheduler::UNLOCK_mutex"); DBUG_PRINT("enter", ("mutex_unlock=%p func=%s line=%u", LOCK_scheduler_data, func, line)); mutex_last_unlocked_at_line= line; mutex_scheduler_data_locked= FALSE; mutex_last_unlocked_in_func= func; pthread_mutex_unlock(LOCK_scheduler_data); DBUG_VOID_RETURN; } /* Wrapper for pthread_cond_wait SYNOPSIS Event_scheduler::cond_wait() cond Conditional to wait for mutex Mutex of the conditional RETURN VALUE Error code of pthread_cond_wait() */ int Event_scheduler::cond_wait(int cond, pthread_mutex_t *mutex) { int ret; DBUG_ENTER("Event_scheduler::cond_wait"); DBUG_PRINT("enter", ("cond=%s mutex=%p", cond_vars_names[cond], mutex)); ret= pthread_cond_wait(&cond_vars[cond_waiting_on=cond], mutex); cond_waiting_on= COND_NONE; DBUG_RETURN(ret); } /* Signals the main scheduler thread that the queue has changed its state. SYNOPSIS Event_scheduler::queue_changed() */ void Event_scheduler::queue_changed() { DBUG_ENTER("Event_scheduler::queue_changed"); DBUG_PRINT("info", ("Sending COND_new_work")); pthread_cond_signal(&cond_vars[COND_new_work]); DBUG_VOID_RETURN; } /* Inits mutexes. SYNOPSIS Event_scheduler::init_mutexes() */ void Event_scheduler::init_mutexes() { pthread_mutex_init(singleton->LOCK_scheduler_data, MY_MUTEX_INIT_FAST); } /* Destroys mutexes. SYNOPSIS Event_queue::destroy_mutexes() */ void Event_scheduler::destroy_mutexes() { pthread_mutex_destroy(singleton->LOCK_scheduler_data); }