Main processor for the Event System. More...

#include <I_EventProcessor.h>

Collaboration diagram for EventProcessor:

Public Member Functions
Event *	spawn_thread (Continuation cont, const char thr_name, size_t stacksize=0)
	Spawn an additional thread for calling back the continuation.
EventType	spawn_event_threads (int n_threads, const char *et_name, size_t stacksize)
	Spawns a group of threads for an event type.
Event *	schedule_imm (Continuation c, EventType event_type=ET_CALL, int callback_event=EVENT_IMMEDIATE, void cookie=NULL)
	Schedules the continuation on a specific EThread to receive an event at the given timeout.
Event *	schedule_imm_signal (Continuation c, EventType event_type=ET_CALL, int callback_event=EVENT_IMMEDIATE, void cookie=NULL)
Event *	schedule_at (Continuation c, ink_hrtime atimeout_at, EventType event_type=ET_CALL, int callback_event=EVENT_INTERVAL, void cookie=NULL)
	Schedules the continuation on a specific thread group to receive an event at the given timeout.
Event *	schedule_in (Continuation c, ink_hrtime atimeout_in, EventType event_type=ET_CALL, int callback_event=EVENT_INTERVAL, void cookie=NULL)
	Schedules the continuation on a specific thread group to receive an event after the specified timeout elapses.
Event *	schedule_every (Continuation c, ink_hrtime aperiod, EventType event_type=ET_CALL, int callback_event=EVENT_INTERVAL, void cookie=NULL)
	Schedules the continuation on a specific thread group to receive an event periodically.
Event *	reschedule_imm (Event *e, int callback_event=EVENT_IMMEDIATE)
Event *	reschedule_at (Event *e, ink_hrtime atimeout_at, int callback_event=EVENT_INTERVAL)
Event *	reschedule_in (Event *e, ink_hrtime atimeout_in, int callback_event=EVENT_INTERVAL)
Event *	reschedule_every (Event *e, ink_hrtime aperiod, int callback_event=EVENT_INTERVAL)
	EventProcessor ()
int	start (int n_net_threads, size_t stacksize=DEFAULT_STACKSIZE)
	Initializes the EventProcessor and its associated threads.
virtual void	shutdown ()
	Stop the EventProcessor.
off_t	allocate (int size)
	Allocates size bytes on the event threads.
Event *	schedule (Event *e, EventType etype, bool fast_signal=false)
EThread *	assign_thread (EventType etype)
Data Fields
EThread *	all_ethreads [MAX_EVENT_THREADS]
	An array of pointers to all of the EThreads handled by the EventProcessor.
EThread *	eventthread [MAX_EVENT_TYPES][MAX_THREADS_IN_EACH_TYPE]
	An array of pointers, organized by thread group, to all of the EThreads handled by the EventProcessor.
unsigned int	next_thread_for_type [MAX_EVENT_TYPES]
int	n_threads_for_type [MAX_EVENT_TYPES]
int	n_ethreads
	Total number of threads controlled by this EventProcessor.
int	n_thread_groups
	Total number of thread groups created so far.
EThread *	all_dthreads [MAX_EVENT_THREADS]
int	n_dthreads
volatile int	thread_data_used

Detailed Description

Main processor for the Event System.

The EventProcessor is the core component of the Event System. Once started, it is responsible for creating and managing groups of threads that execute user-defined tasks asynchronously at a given time or periodically.

The EventProcessor provides a set of scheduling functions through which you can specify continuations to be called back by one of its threads. These function calls do not block. Instead they return an Event object and schedule the callback to the continuation passed in at a later or specific time, as soon as possible or at certain intervals.

Singleton model:

Every executable that imports and statically links against the EventSystem library is provided with a global instance of the EventProcessor called eventProcessor. Therefore, it is not necessary to create instances of the EventProcessor class because it was designed as a singleton. It is important to note that none of its functions are reentrant.

Thread Groups (Event types):

When the EventProcessor is started, the first group of threads is spawned and it is assigned the special id ET_CALL. Depending on the complexity of the state machine or protocol, you may be interested in creating additional threads and the EventProcessor gives you the ability to create a single thread or an entire group of threads. In the former case, you call spawn_thread and the thread is independent of the thread groups and it exists as long as your continuation handle executes and there are events to process. In the latter, you call spawn_event_theads which creates a new thread group and you get an id or event type with wich you must keep for use later on when scheduling continuations on that group.

Callback event codes:

UNIX: For all of the scheduling functions, the callback_event parameter is not used. On a callback, the event code passed in to the continuation handler is always EVENT_IMMEDIATE.

NT: The value of the event code passed in to the continuation handler is the value provided in the callback_event parameter.

Event allocation policy:

Events are allocated and deallocated by the EventProcessor. A state machine may access the returned, non-recurring event until it is cancelled or the callback from the event is complete. For recurring events, the Event may be accessed until it is cancelled. Once the event is complete or cancelled, it's the eventProcessor's responsibility to deallocate it.

Definition at line 100 of file I_EventProcessor.h.

Constructor & Destructor Documentation

TS_INLINE EventProcessor::EventProcessor ( )

Definition at line 32 of file P_UnixEventProcessor.h.

References all_dthreads, all_ethreads, n_threads_for_type, and next_thread_for_type.

Member Function Documentation

TS_INLINE off_t EventProcessor::allocate ( int size )

Allocates size bytes on the event threads.

This function is thread safe.

Parameters:

size

bytes to be allocated.

Definition at line 45 of file P_UnixEventProcessor.h.

References INK_ALIGN, PER_THREAD_DATA, start(), and thread_data_used.

Referenced by RecAllocateRawStatBlock(), UDPNetProcessorInternal::start(), and UnixNetProcessor::start().

TS_INLINE EThread * EventProcessor::assign_thread ( EventType etype )

Definition at line 62 of file P_UnixEventProcessor.h.

References eventthread, ink_assert, MAX_EVENT_TYPES, n_threads_for_type, and next_thread_for_type.

Referenced by UDPConnection::bindToThread(), NetAccept::init_accept(), and schedule().

Event* EventProcessor::reschedule_at	(	Event *	e,
		ink_hrtime	atimeout_at,
		int	callback_event = `EVENT_INTERVAL`
	)

Event* EventProcessor::reschedule_every	(	Event *	e,
		ink_hrtime	aperiod,
		int	callback_event = `EVENT_INTERVAL`
	)

Event* EventProcessor::reschedule_imm	(	Event *	e,
		int	callback_event = `EVENT_IMMEDIATE`
	)

Event* EventProcessor::reschedule_in	(	Event *	e,
		ink_hrtime	atimeout_in,
		int	callback_event = `EVENT_INTERVAL`
	)

TS_INLINE Event * EventProcessor::schedule	(	Event *	e,
		EventType	etype,
		bool	fast_signal = `false`
	)

Definition at line 75 of file P_UnixEventProcessor.h.

References assign_thread(), Action::continuation, ProtectedQueue::enqueue(), Event::ethread, EThread::EventQueueExternal, ink_assert, MAX_EVENT_TYPES, Thread::mutex, Action::mutex, and Continuation::mutex.

Referenced by schedule_at(), schedule_every(), schedule_imm(), schedule_imm_signal(), schedule_in(), and EThread::schedule_local().

TS_INLINE Event * EventProcessor::schedule_at	(	Continuation *	c,
		ink_hrtime	atimeout_at,
		EventType	event_type = `ET_CALL`,
		int	callback_event = `EVENT_INTERVAL`,
		void *	cookie = `NULL`
	)

Schedules the continuation on a specific thread group to receive an event at the given timeout.

Requests the EventProcessor to schedule the callback to the continuation 'c' at the time specified in 'atimeout_at'. The callback is handled by a thread in the specified thread group (event_type).

Parameters:

	c	Continuation to be called back at the time specified in 'atimeout_at'.
	atimeout_at	Time value at which to callback.
	event_type	thread group id (or event type) specifying the group of threads on which to schedule the callback.
	callback_event	code to be passed back to the continuation's handler. See the Remarks section.
	cookie	user-defined value or pointer to be passed back in the Event's object cookie field.

Returns:: reference to an Event object representing the scheduling of this callback.

Definition at line 117 of file P_UnixEventProcessor.h.

References Event::callback_event, Event::cookie, eventAllocator, Event::init(), ink_assert, MAX_EVENT_TYPES, and schedule().

TS_INLINE Event * EventProcessor::schedule_every	(	Continuation *	c,
		ink_hrtime	aperiod,
		EventType	event_type = `ET_CALL`,
		int	callback_event = `EVENT_INTERVAL`,
		void *	cookie = `NULL`
	)

Schedules the continuation on a specific thread group to receive an event periodically.

Requests the EventProcessor to schedule the callback to the continuation 'c' everytime 'aperiod' elapses. The callback is handled by a thread in the specified thread group (event_type).

Parameters:

	c	Continuation to call back everytime 'aperiod' elapses.
	aperiod	duration of the time period between callbacks.
	event_type	thread group id (or event type) specifying the group of threads on which to schedule the callback.
	callback_event	code to be passed back to the continuation's handler. See the Remarks section.
	cookie	user-defined value or pointer to be passed back in the Event's object cookie field.

Returns:: reference to an Event object representing the scheduling of this callback.

Definition at line 140 of file P_UnixEventProcessor.h.

References Event::callback_event, Event::cookie, eventAllocator, Event::init(), ink_assert, ink_get_based_hrtime(), MAX_EVENT_TYPES, and schedule().

Referenced by clusterAPI_init(), cmd_check_internal(), cmd_clear(), UpdateScheduler::Init(), UpdateConfigManager::init(), RamCacheCLFUS::init(), ClusterLoadMonitor::init(), GlobalClusterPeriodicEvent::init(), ClusterAccept::Init(), init_signals2(), init_tracker(), main(), RecProcessStart(), run_RegressionTest(), PluginVC::set_inactivity_timeout(), SSLNetProcessor::start(), ICPProcessor::start(), HostDBProcessor::start(), start_stats_snap(), ClusterHandler::startClusterEvent(), and TSContScheduleEvery().

TS_INLINE Event * EventProcessor::schedule_imm	(	Continuation *	c,
		EventType	event_type = `ET_CALL`,
		int	callback_event = `EVENT_IMMEDIATE`,
		void *	cookie = `NULL`
	)

Schedules the continuation on a specific EThread to receive an event at the given timeout.

Requests the EventProcessor to schedule the callback to the continuation 'c' at the time specified in 'atimeout_at'. The event is assigned to the specified EThread.

Parameters:

	c	Continuation to be called back at the time specified in 'atimeout_at'.
	atimeout_at	time value at which to callback.
	ethread	EThread on which to schedule the event.
	callback_event	code to be passed back to the continuation's handler. See the Remarks section.
	cookie	user-defined value or pointer to be passed back in the Event's object cookie field.

Returns:: reference to an Event object representing the scheduling of this callback.

Definition at line 103 of file P_UnixEventProcessor.h.

References Event::callback_event, Event::cookie, eventAllocator, Event::init(), ink_assert, ink_get_hrtime(), MAX_EVENT_TYPES, and schedule().

Referenced by aio_thread_main(), cacheControlFile_CB(), CacheContinuation::callback_failure(), CacheHostTable::config_callback(), ClusterProcessor::connect(), UnixNetProcessor::connect_re_internal(), ClusterHandler::connectClusterEvent(), CacheContinuation::defer_callback_result(), TransformTerminus::do_io_close(), INKVConnInternal::do_io_close(), TransformTerminus::do_io_read(), INKVConnInternal::do_io_read(), INKVConnInternal::do_io_shutdown(), TransformTerminus::do_io_write(), INKVConnInternal::do_io_write(), CacheTestSM::event_handler(), NetVCTest::finished(), http_pages_callback(), ICPProcessor::ICPQuery(), init_http_update_test(), CacheContinuation::insert_cache_callback_user(), CacheContinuation::insertCallbackEvent(), ConfigUpdateCbTable::invoke(), CacheContinuation::lookupOpenWriteVC(), Http2ConnectionState::main_event_handler(), ICPConfiguration::mgr_icp_config_change_callback(), net_accept(), Cache::open(), RemapProcessor::perform_remap(), ICPPeriodicCont::PeriodicEvent(), TransformTerminus::reenable(), INKVConnInternal::reenable(), register_ShowCache(), register_ShowCacheInternal(), register_ShowNet(), TransformTest::run(), CacheTestSM::run(), LogCollationClientSM::send(), HostDBProcessor::setby_srv(), ClusterAccept::ShutdownDelete(), spdy_cs_create(), UpdateSM::Start(), HostDBProcessor::start(), CacheProcessor::start_internal(), MultiCacheBase::sync_partitions(), TSContSchedule(), TSHttpSchedule(), TSHttpSsnReenable(), TSHttpTxnReenable(), UDPNetProcessorInternal::udp_callback(), UpdateConfigManager::URL_list_update_callout(), and url_rewrite_CB().

TS_INLINE Event * EventProcessor::schedule_imm_signal	(	Continuation *	c,
		EventType	event_type = `ET_CALL`,
		int	callback_event = `EVENT_IMMEDIATE`,
		void *	cookie = `NULL`
	)

Definition at line 89 of file P_UnixEventProcessor.h.

References Event::callback_event, Event::cookie, eventAllocator, Event::init(), ink_assert, ink_get_hrtime(), MAX_EVENT_TYPES, and schedule().

Referenced by Vol::aggWrite(), aio_thread_main(), ClusterAccept::ClusterAcceptMachine(), NetAccept::do_blocking_accept(), ClusterProcessor::internal_invoke_remote(), and ClusterState::IOComplete().

TS_INLINE Event * EventProcessor::schedule_in	(	Continuation *	c,
		ink_hrtime	atimeout_in,
		EventType	event_type = `ET_CALL`,
		int	callback_event = `EVENT_INTERVAL`,
		void *	cookie = `NULL`
	)

Schedules the continuation on a specific thread group to receive an event after the specified timeout elapses.

Requests the EventProcessor to schedule the callback to the continuation 'c' after the time specified in 'atimeout_in' elapses. The callback is handled by a thread in the specified thread group (event_type).

Parameters:

	c	Continuation to call back aftert the timeout elapses.
	atimeout_in	amount of time after which to callback.
	event_type	Thread group id (or event type) specifying the group of threads on which to schedule the callback.
	callback_event	code to be passed back to the continuation's handler. See the Remarks section.
	cookie	user-defined value or pointer to be passed back in the Event's object cookie field.

Returns:: reference to an Event object representing the scheduling of this callback.

Definition at line 129 of file P_UnixEventProcessor.h.

References Event::callback_event, Event::cookie, eventAllocator, Event::init(), ink_assert, ink_get_based_hrtime(), MAX_EVENT_TYPES, and schedule().

Referenced by Vol::aggWriteDone(), cache_op_result_ClusterFunction(), UpdateScheduler::ChildExitEventHandler(), PrefetchConfigCont::conf_update_handler(), Congestion_CongestionDB(), Congestion_FailHistory(), ClusterProcessor::connect(), ClusterHandler::connectClusterEvent(), Vol::dir_init_done(), dir_sync_init(), CacheContinuation::disposeOfDataBuffer(), HostDBContinuation::dnsPendingEvent(), HttpSM::do_http_server_open(), CacheContinuation::do_op(), CacheContinuation::do_remote_lookup(), ConfigUpdateCallback::event_handler(), RecursiveHttpGet::ExitEventHandler(), FetchSM::ext_destroy(), free_ClusterMachine(), free_configuration(), get_congest_entry(), get_congest_list(), HttpPagesHandler::handle_callback(), HttpPagesHandler::handle_smdetails(), HttpPagesHandler::handle_smlist(), UpdateSM::HandleSMEvent(), http_config_cb(), ICPConfiguration::icp_config_change_callback(), ICPPeerReadCont::ICPPeerReadEvent(), ICPRequestCont::ICPRequestEvent(), ClusterVConnectionCache::init(), ink_aio_start(), HttpUpdateSM::kill_this_async_hook(), CacheSync::mainEvent(), new_Deleter(), new_Derefer(), new_FreeCaller(), new_Freer(), CacheDisk::openDone(), prefetch_config_cb(), ClusterHandler::protoZombieEvent(), reloadCacheControl(), CacheContinuation::remove_and_delete(), RegressionSM::run(), run_AutoStop(), RegressionSM::run_in(), Cache::scan(), CacheVC::scanObject(), CacheVC::scanVol(), PluginVC::set_active_timeout(), ClusterHandler::startClusterEvent(), PluginVCCore::state_send_accept(), PluginVCCore::state_send_accept_failed(), TSContSchedule(), TSHttpSchedule(), and ClusterHandler::zombify().

void EventProcessor::shutdown ( ) [virtual]

Stop the EventProcessor.

Attempts to stop the EventProcessor and all of the threads in each of the thread groups.

Reimplemented from Processor.

Definition at line 165 of file UnixEventProcessor.cc.

EventType EventProcessor::spawn_event_threads	(	int	n_threads,
		const char *	et_name,
		size_t	stacksize
	)

Spawns a group of threads for an event type.

Spawns the number of event threads passed in (n_threads) creating a thread group and returns the thread group id (or EventType). See the remarks section for Thread Groups.

Returns:: EventType or thread id for the new group of threads.

Definition at line 33 of file UnixEventProcessor.cc.

References all_ethreads, Debug, eventthread, ink_release_assert, MAX_EVENT_THREADS, MAX_EVENT_TYPES, MAX_THREAD_NAME_LENGTH, n_ethreads, n_thread_groups, n_threads_for_type, REGULAR, EThread::set_event_type(), and Thread::start().

Referenced by UDPNetProcessorInternal::start(), TasksProcessor::start(), SSLNetProcessor::start(), RemapProcessor::start(), DNSProcessor::start(), and ClusterProcessor::start().

Event * EventProcessor::spawn_thread	(	Continuation *	cont,
		const char *	thr_name,
		size_t	stacksize = `0`
	)

Spawn an additional thread for calling back the continuation.

Spawns a dedicated thread (EThread) that calls back the continuation passed in as soon as possible.

Parameters:

cont

continuation that the spawn thread will call back immediately.

Returns:: event object representing the start of the thread.

Definition at line 170 of file UnixEventProcessor.cc.

References all_dthreads, Action::continuation, DEDICATED, Event::ethread, eventAllocator, Event::init(), ink_release_assert, MAX_EVENT_THREADS, Thread::mutex, Continuation::mutex, Action::mutex, n_dthreads, and Thread::start().

Referenced by aio_init_fildes(), and NetAccept::init_accept_loop().

int EventProcessor::start	(	int	n_net_threads,
		size_t	stacksize = `DEFAULT_STACKSIZE`
	)			`[virtual]`

Initializes the EventProcessor and its associated threads.

Spawns the specified number of threads, initializes their state information and sets them running. It creates the initial thread group, represented by the event type ET_CALL.

Returns:: 0 if successful, and a negative value otherwise.

Reimplemented from Processor.

Definition at line 69 of file UnixEventProcessor.cc.

References all_ethreads, Thread::cur_time, Debug, ET_CALL, eventthread, global_mutex, ink_get_based_hrtime_internal(), ink_number_of_processors(), ink_release_assert, ink_thread_setspecific(), MAX_EVENT_THREADS, MAX_THREAD_NAME_LENGTH, Thread::mutex, n_ethreads, n_thread_groups, n_threads_for_type, REC_ReadConfigInteger, REGULAR, EThread::set_event_type(), Thread::start(), Thread::thread_data_key, and Warning.

Referenced by allocate(), and main().

Field Documentation

EThread* EventProcessor::all_dthreads[MAX_EVENT_THREADS]

Definition at line 316 of file I_EventProcessor.h.

Referenced by EventProcessor(), raw_stat_clear(), raw_stat_clear_count(), raw_stat_clear_sum(), raw_stat_get_total(), raw_stat_sync_to_global(), and spawn_thread().

EThread* EventProcessor::all_ethreads[MAX_EVENT_THREADS]

An array of pointers to all of the EThreads handled by the EventProcessor.

An array of pointers to all of the EThreads created throughout the existence of the EventProcessor instance.

Definition at line 272 of file I_EventProcessor.h.

Referenced by EventProcessor(), raw_stat_clear(), raw_stat_clear_count(), raw_stat_clear_sum(), raw_stat_get_total(), raw_stat_sync_to_global(), spawn_event_threads(), and start().

EThread* EventProcessor::eventthread[MAX_EVENT_TYPES][MAX_THREADS_IN_EACH_TYPE]

An array of pointers, organized by thread group, to all of the EThreads handled by the EventProcessor.

An array of pointers to all of the EThreads created throughout the existence of the EventProcessor instance. It is a two-dimensional array whose first dimension is the thread group id and the second the EThread pointers for that group.

Definition at line 282 of file I_EventProcessor.h.

Referenced by assign_thread(), NetAccept::init_accept_per_thread(), SSLNetAccept::init_accept_per_thread(), CacheContinuation::is_ClusterThread(), ShowNet::showConnections(), ShowNet::showConnectionsOnThread(), ShowNet::showSingleThread(), ShowNet::showThreads(), spawn_event_threads(), UDPNetProcessorInternal::start(), UnixNetProcessor::start(), start(), DNSProcessor::start(), ClusterProcessor::start(), CacheProcessor::start_internal(), and ClusterHandler::startClusterEvent().