I/O handler for datagram (UDP) sockets. More...

#include <IOHandlerDatagram.h>

Inheritance diagram for Hypertable::IOHandlerDatagram:

Collaboration diagram for Hypertable::IOHandlerDatagram:

Public Member Functions
	IOHandlerDatagram (int sd, const DispatchHandlerPtr &dhp, Reactor::Priority rp)
	Constructor. More...

virtual	~IOHandlerDatagram ()
	Destructor. More...

int	send_message (const InetAddr &addr, CommBufPtr &cbp)
	Sends a message. More...

int	flush_send_queue ()
	Flushes send queue. More...

bool	handle_event (struct pollfd *event, ClockT::time_point arrival_time) override
	Handle `poll()` interface events. More...

int	handle_write_readiness ()
	Handles write readiness. More...

Public Member Functions inherited from Hypertable::IOHandler
	IOHandler (int sd, const DispatchHandlerPtr &dhp, Reactor::Priority rp=Reactor::Priority::NORMAL)
	Constructor. More...

	IOHandler (int sd)
	Constructor. More...

virtual	~IOHandler ()
	Destructor. More...

void	deliver_event (EventPtr &event, DispatchHandler *dh=0)
	Convenience method for delivering event to application. More...

int	start_polling (int mode=PollEvent::READ)
	Start polling on the handler with the poll interest specified in `mode`. More...

int	add_poll_interest (int mode)
	Adds the poll interest specified in `mode` to the polling interface for this handler. More...

int	remove_poll_interest (int mode)
	Removes the poll interest specified in `mode` to the polling interface for this handler. More...

int	reset_poll_interest ()
	Resets poll interest by adding m_poll_interest to the polling interface for this handler. More...

InetAddr	get_address ()
	Gets the handler socket address. More...

InetAddr	get_local_address ()
	Get local socket address for connection. More...

void	set_proxy (const String &proxy)
	Sets the proxy name for this connection. More...

const String &	get_proxy ()
	Gets the proxy name for this connection. More...

int	get_sd ()
	Gets the socket descriptor for this connection. More...

void	get_reactor (ReactorPtr &reactor)
	Get the reactor that this handler is assigned to. More...

void	display_event (struct pollfd *event)
	Display polling event from `poll()` interface to stderr. More...

Public Attributes
	ImplementMe

Private Types
typedef std::pair< struct sockaddr_in, CommBufPtr >	SendRec
	Send queue message record. More...

Private Attributes
uint8_t *	m_message
	Message receive buffer. More...

std::list< SendRec >	m_send_queue
	Send queue. More...

Additional Inherited Members
Protected Member Functions inherited from Hypertable::IOHandler
bool	test_and_set_error (int32_t error)
	Sets m_error to `error` if it has not already been set. More...

int32_t	get_error ()
	Returns first error code encountered by handler. More...

InetAddr	get_alias ()
	Get alias address for this connection. More...

void	set_alias (const InetAddr &alias)
	Set alias address for this connection. More...

void	increment_reference_count ()
	Increment reference count. More...

void	decrement_reference_count ()
	Decrement reference count. More...

size_t	reference_count ()
	Return reference count. More...

void	decomission ()
	Decomission handler. More...

bool	is_decomissioned ()
	Checks to see if handler is decomissioned. More...

virtual void	disconnect ()
	Disconnect connection. More...

short	poll_events (int mode)
	Return `poll()` interface events corresponding to the normalized polling interest in `mode`. More...

void	stop_polling ()
	Stops polling by removing socket from polling interface. More...

Protected Attributes inherited from Hypertable::IOHandler
std::mutex	m_mutex
	Mutex for serializing concurrent access More...

size_t	m_reference_count
	Reference count. More...

uint32_t	m_free_flag
	Free flag (for testing) More...

int32_t	m_error
	Error code. More...

String	m_proxy
	Proxy name for this connection. More...

InetAddr	m_addr
	Handler socket address. More...

InetAddr	m_local_addr
	Local address of connection. More...

InetAddr	m_alias
	Address alias for connection. More...

int	m_sd
	Socket descriptor. More...

DispatchHandlerPtr	m_dispatch_handler
	Default dispatch hander for connection. More...

ReactorPtr	m_reactor
	Reactor to which this handler is assigned. More...

int	m_poll_interest
	Current polling interest. More...

bool	m_decomissioned
	Decomissioned flag. More...

bool m_socket_internally_created	true
	Socket was internally created and should be closed on destroy. More...

Detailed Description

I/O handler for datagram (UDP) sockets.

Definition at line 50 of file IOHandlerDatagram.h.

Member Typedef Documentation

typedef std::pair<struct sockaddr_in, CommBufPtr> Hypertable::IOHandlerDatagram::SendRec

private

Send queue message record.

Definition at line 197 of file IOHandlerDatagram.h.

Constructor & Destructor Documentation

Hypertable::IOHandlerDatagram::IOHandlerDatagram	(	int	sd,
		const DispatchHandlerPtr &	dhp,
		Reactor::Priority	rp
	)

inline

Constructor.

This method initializes the handler by allocating a receive buffer and copying the locally bound address to m_addr.

Parameters

sd	Socket descriptor bound to an address
dhp	Default dispatch handler

Definition at line 59 of file IOHandlerDatagram.h.

virtual Hypertable::IOHandlerDatagram::~IOHandlerDatagram ( )

inlinevirtual

Destructor.

Definition at line 66 of file IOHandlerDatagram.h.

Member Function Documentation

int IOHandlerDatagram::flush_send_queue ( )

Flushes send queue.

This method tries to write all messages on the send queue. If a write succeeds, but writes fewer bytes than requested, that implies the send buffer is full. The send queue holds a list of CommBuf objects (and associated destination addresses) that contain next write pointers that are updated by this method and allow it to pick up where it left off in the event of a short write.

Returns: Error::OK on success, or Error::COMM_SEND_ERROR on send error

Definition at line 383 of file IOHandlerDatagram.cc.

bool IOHandlerDatagram::handle_event	(	struct pollfd *	event,
		ClockT::time_point	arrival_time
	)

overridevirtual

Handle poll() interface events.

This method is called by its reactor thread to handle I/O events. It handles POLLOUT events with a call to handle_write_readiness. If handle_write_readiness returns true the handler is disconnected with a call to handle_disconnect() and true is returned. POLLIN events are handled in a loop by reading messages off the socket in their entirety with a call to recvfrom. The message buffer is 65536 bytes in size and therefore this method can only handle messages of that size or less. Messages are delivered to the application by creating an Event object, initializing it with the message header and arrival_time, and delivering it with the default dispatch handler. POLLERR and errors are handled by decomissioning the handler and delivering an Event::ERROR event to the application.

Warning: This method assumes messages are less than 65535 bytes

Parameters

event	Pointer to `pollfd` structure describing event
arrival_time	Time of event arrival

Returns: false on success, true if error encountered and handler was decomissioned

Implements Hypertable::IOHandler.

Definition at line 56 of file IOHandlerDatagram.cc.

int IOHandlerDatagram::handle_write_readiness ( )

Handles write readiness.

This method handles write readiness by flushing the send queue with a call to flush_send_queue and then removes write interest from the polling interface for this handler if the send queue becomes empty.

Returns: Error::OK on success, or Error::COMM_SEND_ERROR on send error

Definition at line 327 of file IOHandlerDatagram.cc.

int IOHandlerDatagram::send_message	(	const InetAddr &	addr,
		CommBufPtr &	cbp
	)

Sends a message.

This method pushes the message pointed to by cbp onto the send queue, flushes the send queue with a call to flush_send_queue, and then updates polling interest depending on the state of the send queue.

Parameters

addr	Remote address to send message to
cbp	Pointer to message to send

Returns: Error::OK on success, or Error::COMM_SEND_ERROR on send error

Definition at line 349 of file IOHandlerDatagram.cc.

Member Data Documentation

Hypertable::IOHandlerDatagram::ImplementMe

Definition at line 183 of file IOHandlerDatagram.h.

uint8_t* Hypertable::IOHandlerDatagram::m_message

private

Message receive buffer.

Definition at line 200 of file IOHandlerDatagram.h.

std::list<SendRec> Hypertable::IOHandlerDatagram::m_send_queue

private

Send queue.

Definition at line 203 of file IOHandlerDatagram.h.

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

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

Public Member Functions

Public Attributes

Private Types

Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation