Manages reactor (polling thread) state including poll interest, request cache, and timers. More...

#include <Reactor.h>

Collaboration diagram for Hypertable::Reactor:

Public Types
enum	Priority { Priority::HIGH = 0, Priority::NORMAL }
	Enumeration for reactor priority. More...

Public Member Functions
	Reactor ()
	Constructor. More...

	~Reactor ()
	Destructor. More...

void	add_request (uint32_t id, IOHandler handler, DispatchHandler dh, ClockT::time_point expire)
	Adds a request to request cache and adjusts poll timeout if necessary. More...

bool	remove_request (uint32_t id, DispatchHandler *&handler)
	Removes request associated with `id` More...

void	cancel_requests (IOHandler *handler, int32_t error=Error::COMM_BROKEN_CONNECTION)
	Cancels outstanding requests associated with `handler` More...

void	add_timer (ExpireTimer &timer)
	Adds a timer. More...

void	cancel_timer (const DispatchHandlerPtr &handler)
	Cancels timers associated with `handler`. More...

void	schedule_removal (IOHandler *handler)
	Schedules `handler` for removal. More...

void	get_removed_handlers (std::set< IOHandler * > &dst)
	Returns set of I/O handlers scheduled for removal. More...

void	handle_timeouts (PollTimeout &next_timeout)
	Processes request timeouts and timers. More...

int	add_poll_interest (int sd, short events, IOHandler *handler)
	Add poll interest for socket (POSIX `poll` only). More...

int	remove_poll_interest (int sd)
	Remove poll interest for socket (POSIX `poll` only). More...

int	modify_poll_interest (int sd, short events)
	Modify poll interest for socket (POSIX `poll` only). More...

void	fetch_poll_array (std::vector< struct pollfd > &fdarray, std::vector< IOHandler * > &handlers)
	Fetches poll state vectors (POSIX `poll` only). More...

int	poll_loop_interrupt ()
	Forces polling interface wait call to return. More...

int	poll_loop_continue ()
	Reset state after call to poll_loop_interrupt. More...

int	interrupt_sd ()
	Returns interrupt socket. More...

Protected Types
typedef std::priority_queue < ExpireTimer, std::vector < ExpireTimer >, LtTimerHeap >	TimerHeap
	Priority queue for timers. More...

Protected Attributes
std::mutex	m_mutex
	Mutex to protect members. More...

std::mutex	m_polldata_mutex
	Mutex to protect m_polldata member. More...

RequestCache	m_request_cache
	Request cache. More...

TimerHeap	m_timer_heap
	ExpireTimer heap. More...

int	m_interrupt_sd
	Interrupt socket. More...

bool	m_interrupt_in_progress
	Set to true if poll loop interrupt in progress. More...

std::vector< PollDescriptorT >	m_polldata
	Vector of poll descriptor state structures for use with POSIX `poll()`. More...

ClockT::time_point	m_next_wakeup
	Next polling interface wait timeout (absolute) More...

std::set< IOHandler * >	m_removed_handlers
	Set of IOHandler objects scheduled for removal. More...

Friends
class	ReactorFactory

Detailed Description

Manages reactor (polling thread) state including poll interest, request cache, and timers.

Definition at line 66 of file Reactor.h.

Member Typedef Documentation

typedef std::priority_queue<ExpireTimer, std::vector<ExpireTimer>, LtTimerHeap> Hypertable::Reactor::TimerHeap

protected

Priority queue for timers.

Definition at line 272 of file Reactor.h.

Constructor & Destructor Documentation

Reactor::Reactor ( )

Constructor.

Initializes polling interface and creates interrupt socket. If ReactorFactory::use_poll is set to true, then the reactor will use the POSIX poll() interface, otherwise epoll is used on Linux, kqueue on OSX and FreeBSD, and port_associate on Solaris. For polling mechanisms that do not provide an interface for breaking out of the poll wait, a UDP socket m_interrupt_sd is created (and connected to itself) and added to the poll set.

The following logic creates a UDP socket that is used to interrupt epoll_wait so that it can reset its timeout value

Definition at line 63 of file Reactor.cc.

Hypertable::Reactor::~Reactor ( )

inline

Destructor.

Definition at line 92 of file Reactor.h.

Member Function Documentation

int Reactor::add_poll_interest	(	int	sd,
		short	events,
		IOHandler *	handler
	)

Add poll interest for socket (POSIX poll only).

This method is only called when ReactorFactory::use_poll is set to true. It modifies m_polldata accordingly and then calls poll_loop_interrupt. If an error is encountered, then the poll interest is removed by clearing the m_polldata entry for sd.

Parameters

sd	Socket descriptor for which to add poll interest
events	Bitmask of poll events (see POSIX `poll()`)
handler	Pointer to I/O handler associated with socket

Returns: Error code returned by poll_loop_interrupt

Definition at line 383 of file Reactor.cc.

void Hypertable::Reactor::add_request	(	uint32_t	id,
		IOHandler *	handler,
		DispatchHandler *	dh,
		ClockT::time_point	expire
	)

inline

Adds a request to request cache and adjusts poll timeout if necessary.

Parameters

id	Request ID
handler	I/O handler with which request is associated
dh	Application dispatch handler for response MESSAGE events
expire	Absolute expiration time

Definition at line 102 of file Reactor.h.

void Hypertable::Reactor::add_timer ( ExpireTimer & timer )

inline

Adds a timer.

Pushes timer onto m_timer_heap and interrupts the polling loop so that the poll timeout can be adjusted if necessary.

Parameters

timer Reference to ExpireTimer object

Definition at line 135 of file Reactor.h.

void Hypertable::Reactor::cancel_requests	(	IOHandler *	handler,
		int32_t	error = `Error::COMM_BROKEN_CONNECTION`
	)

inline

Cancels outstanding requests associated with handler

Parameters

handler	I/O handler for which outstanding requests are to be cancelled
error	Error code to deliver with ERROR events

Definition at line 125 of file Reactor.h.

void Hypertable::Reactor::cancel_timer ( const DispatchHandlerPtr & handler )

inline

Cancels timers associated with handler.

Parameters

handler Dispatch handler for which associated timers are to be cancelled

Definition at line 145 of file Reactor.h.

void Reactor::fetch_poll_array	(	std::vector< struct pollfd > &	fdarray,
		std::vector< IOHandler * > &	handlers
	)

Fetches poll state vectors (POSIX poll only).

Parameters

fdarray	Vector of `pollfd` structures to be passed into `poll()`
handlers	Vector of corresponding I/O handlers

Definition at line 444 of file Reactor.cc.

void Hypertable::Reactor::get_removed_handlers ( std::set< IOHandler * > & dst )

inline

Returns set of I/O handlers scheduled for removal.

This is a one shot method adds the handlers that have been added to m_removed_handlers and then clears the m_removed_handlers set.

Parameters

dst	reference to set filled in with removed handlers

Definition at line 186 of file Reactor.h.

void Reactor::handle_timeouts ( PollTimeout & next_timeout )

Processes request timeouts and timers.

This method removes timed out requests from the request cache, delivering ERROR events (with error == Error::REQUEST_TIMEOUT) via each request's dispatch handler. It also processes expired timers by removing them from m_timer_heap and delivering a TIMEOUT event via the timer handler if it exsists.

Parameters

next_timeout Set to next earliest timeout of active requests and timers

Deliver timer events

Definition at line 170 of file Reactor.cc.

int Hypertable::Reactor::interrupt_sd ( )

inline

Returns interrupt socket.

Returns: Interrupt socket

Definition at line 265 of file Reactor.h.

int Reactor::modify_poll_interest	(	int	sd,
		short	events
	)

Modify poll interest for socket (POSIX poll only).

This method is only called when ReactorFactory::use_poll is set to true. It modifies m_polldata accordingly and then calls poll_loop_interrupt.

Parameters

sd	Socket descriptor for which to add poll interest
events	Bitmask of poll events (see POSIX `poll()`)

Returns: Error code returned by poll_loop_interrupt

Definition at line 433 of file Reactor.cc.

int Reactor::poll_loop_continue ( )

Reset state after call to poll_loop_interrupt.

After calling poll_loop_interrupt and handling the interrupt, this method should be called to reset back to normal polling state.

Returns: Error::OK on success, or Error code on failure

Definition at line 331 of file Reactor.cc.

int Reactor::poll_loop_interrupt ( )

Forces polling interface wait call to return.

Returns: Error::OK on success, or Error code on failure

Definition at line 255 of file Reactor.cc.

int Reactor::remove_poll_interest ( int sd )

Remove poll interest for socket (POSIX poll only).

This method is only called when ReactorFactory::use_poll is set to true. It modifies m_polldata accordingly and then calls poll_loop_interrupt.

Parameters

sd	Socket descriptor for which to modify poll interest

Returns: Error code returned by poll_loop_interrupt

Definition at line 412 of file Reactor.cc.

bool Hypertable::Reactor::remove_request	(	uint32_t	id,
		DispatchHandler *&	handler
	)

inline

Removes request associated with id

Parameters

id	Request ID
handler	Removed dispatch handler

Returns: true if request removed, false otherwise

Definition at line 115 of file Reactor.h.

void Hypertable::Reactor::schedule_removal ( IOHandler * handler )

inline

Schedules handler for removal.

This method schedules an I/O handler for removal. It should be called only when the handler has been decomissioned in the HandlerMap and when there are no outstanding references to the handler. The handler is added to the m_removed_handlers set and a timer is set for 200 milliseconds in the future so that the ReactorRunner will wake up and complete the removal by removing it completely from the HandlerMap and delivering a DISCONNECT event if it is for a TCP socket.

Parameters

handler I/O handler to schedule for removal

Definition at line 171 of file Reactor.h.

Friends And Related Function Documentation

friend class ReactorFactory

friend

Definition at line 68 of file Reactor.h.

Member Data Documentation

bool Hypertable::Reactor::m_interrupt_in_progress

protected

Set to true if poll loop interrupt in progress.

Definition at line 281 of file Reactor.h.

int Hypertable::Reactor::m_interrupt_sd

protected

Interrupt socket.

Definition at line 278 of file Reactor.h.

std::mutex Hypertable::Reactor::m_mutex

protected

Mutex to protect members.

Definition at line 274 of file Reactor.h.

ClockT::time_point Hypertable::Reactor::m_next_wakeup

protected

Next polling interface wait timeout (absolute)

Definition at line 288 of file Reactor.h.

std::vector<PollDescriptorT> Hypertable::Reactor::m_polldata

protected

Vector of poll descriptor state structures for use with POSIX poll().

Definition at line 285 of file Reactor.h.

std::mutex Hypertable::Reactor::m_polldata_mutex

protected

Mutex to protect m_polldata member.

Definition at line 275 of file Reactor.h.

std::set<IOHandler *> Hypertable::Reactor::m_removed_handlers

protected

Set of IOHandler objects scheduled for removal.

Definition at line 291 of file Reactor.h.

RequestCache Hypertable::Reactor::m_request_cache

protected

Request cache.

Definition at line 276 of file Reactor.h.

TimerHeap Hypertable::Reactor::m_timer_heap

protected

ExpireTimer heap.

Definition at line 277 of file Reactor.h.

The documentation for this class was generated from the following files:

/home/doug/src/hypertable/src/cc/AsyncComm/Reactor.h
/home/doug/src/hypertable/src/cc/AsyncComm/Reactor.cc

Public Types

Public Member Functions

Protected Types

Protected Attributes

Friends

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation