I/O handler for TCP sockets. More...

#include <IOHandlerData.h>

Inheritance diagram for Hypertable::IOHandlerData:

Collaboration diagram for Hypertable::IOHandlerData:

Public Member Functions
	IOHandlerData (int sd, const InetAddr &addr, const DispatchHandlerPtr &dhp, bool connected=false)
	Constructor. More...

virtual	~IOHandlerData ()
	Destructor. More...

void	disconnect () override
	Disconnects handler by delivering Event::DISCONNECT via default dispatch handler. More...

void	reset_incoming_message_state ()
	Resets incoming message buffer state in preparation for next message. More...

void	free_message_buffer ()
	Frees the message buffer (m_message). More...

int	send_message (CommBufPtr &cbp, uint32_t timeout_ms=0, DispatchHandler *disp_handler=nullptr)
	Sends message pointed to by `cbp` over socket associated with this I/O handler. 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...

bool	handle_write_readiness ()
	Handles write readiness by completing connection and flushing send queue. 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 Member Functions
void	handle_message_header (ClockT::time_point arrival_time)
	Processes a message header. More...

void	handle_message_body ()
	Processes a message body. More...

void	handle_disconnect ()
	Decomissions the handler. More...

Private Attributes
bool	m_connected
	Flag indicating if socket connection has been completed. More...

bool	m_got_header {}
	Flag indicating if message header has been completely received. More...

bool	m_message_aligned {}
	Flag indicating if message buffer was allocated with posix_memalign() More...

EventPtr	m_event
	Pointer to Event object holding message to deliver to application. More...

uint8_t	m_message_header [64]
	Message header buffer. More...

uint8_t *	m_message_header_ptr {}
	Pointer to next write position in m_message_header. More...

size_t	m_message_header_remaining
	Amount of header remaining to be read. More...

uint8_t *	m_message {}
	Poiner to message payload buffer. More...

uint8_t *	m_message_ptr {}
	Pointer to next write position in m_message. More...

size_t	m_message_remaining {}
	Amount of message payload remaining to be read. More...

std::list< CommBufPtr >	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...

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 TCP sockets.

Definition at line 51 of file IOHandlerData.h.

Constructor & Destructor Documentation

Hypertable::IOHandlerData::IOHandlerData	(	int	sd,
		const InetAddr &	addr,
		const DispatchHandlerPtr &	dhp,
		bool	connected = `false`
	)

inline

Constructor.

Parameters

sd	Socket descriptor
addr	Address of remote end of connection
dhp	Default dispatch handler for connection
connected	Initial connection state for handler

Definition at line 61 of file IOHandlerData.h.

virtual Hypertable::IOHandlerData::~IOHandlerData ( )

inlinevirtual

Destructor.

Definition at line 70 of file IOHandlerData.h.

Member Function Documentation

void Hypertable::IOHandlerData::disconnect ( )

inlineoverridevirtual

Disconnects handler by delivering Event::DISCONNECT via default dispatch handler.

Reimplemented from Hypertable::IOHandler.

Definition at line 75 of file IOHandlerData.h.

int Hypertable::IOHandlerData::flush_send_queue ( )

Flushes send queue.

When messages are sent, they are first added to a send queue (m_send_queue) and then the messages in the send queue are written over the socket by calling this method. This method attempts to write all of the messages in the queue and stops under the following conditions:

Send queue becomes empty
A write results in EAGAIN (socket buffer is full)
An error is encountered during a write The send queue holds a list of CommBuf objects 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 EAGAIN.
Returns
Error::OK on success or EAGAIN, or Error::COMM_BROKEN_CONNECTION if a write error was encountered.

void Hypertable::IOHandlerData::free_message_buffer ( )

inline

Frees the message buffer (m_message).

If m_message was allocated with posix_memalign(), as indicated by m_message_aligned, the free() function is used to deallocate the memory. Otherwise, the buffer is deallocated with delete []

Definition at line 97 of file IOHandlerData.h.

void IOHandlerData::handle_disconnect ( )

private

Decomissions the handler.

Definition at line 641 of file IOHandlerData.cc.

bool IOHandlerData::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 by reading message data off the socket. First the message header is read and decoded with handle_message_header and then the message payload is read and delivered to the application with handle_message_body. If a read error is encountered, m_error is set to the approprate error code (if not already set) and the handler is disconnected with a call to handle_disconnect and true is returned. EOF, POLLERR events, and POLLHUP events are handled by disconnecting the handler with a call to handle_disconnect and true is returned. arrival_time is passed into handle_message_header to be delivered to the applicaiton via the Event object.

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 113 of file IOHandlerData.cc.

void IOHandlerData::handle_message_body ( )

private

Processes a message body.

This method is called when a message has been completely received (header + payload). It first checks to see if the message is a proxy update message and if so, it updates its proxy map with a call to HandlerMap::update_proxy_map and returns. Otherwise if it is a response message and the CommHeader::FLAGS_BIT_IGNORE_RESPONSE bit is not set in the header flags, the corresponding dispatch handler is removed form request queue and the message is delivered to the applicaton using that handler. Otherwise, the message is delivered to the application using the default dispatch handler. After the message has been delivered, the message receive state is reset with a call to reset_incoming_message_state.

Definition at line 603 of file IOHandlerData.cc.

void IOHandlerData::handle_message_header ( ClockT::time_point arrival_time )

private

Processes a message header.

This method is called when the fixed length portion of a header has been completely received. It first checks to see if there is a variable portion of the header that has not yet been read, if so, it adjusts m_message_header_remaining and returns. If the header has been completely received, it allocates a new Event object and sets m_event pointing to it. It initializes the event object with the message header and arrival_time. It then allocates the message payload buffer (m_message), initialzes the payload buffer pointers, and sets m_got_header to true.

Definition at line 566 of file IOHandlerData.cc.

bool IOHandlerData::handle_write_readiness ( )

Handles write readiness by completing connection and flushing send queue.

When a data handler is created after a call to connect it is in the disconnected state. Once the socket becomes ready for writing, the connection request can be completed. This method handles the completion of the connection when the handler is in the disconnected state by doing the following:

Sets the socket send and receive buffer to 4*32768 bytes
Reads the local socket address and initializes m_local_addr
Sets m_connected to true
If proxy master, propagate proxy map over newly established connection.
Delivers Event::CONNECTION_ESTABLISHED event via the default dispatch handler After completion has been handled (if needed) then this method flushes the send queue with a call to flush_send_queue.
Returns
false on success, true if error encountered

Definition at line 645 of file IOHandlerData.cc.

void Hypertable::IOHandlerData::reset_incoming_message_state ( )

inline

Resets incoming message buffer state in preparation for next message.

Definition at line 82 of file IOHandlerData.h.

int IOHandlerData::send_message	(	CommBufPtr &	cbp,
		uint32_t	timeout_ms = `0`,
		DispatchHandler *	disp_handler = `nullptr`
	)

Sends message pointed to by cbp over socket associated with this I/O handler.

If the message being sent is a request message (has the CommHeader::FLAGS_BIT_REQUEST set) and disp_handler is not 0, then an entry is added to the reactor's request cache so that disp_handler will be called to handle the response or receive a TIMEOUT event if the response is not received within timeout_ms milliseconds.

Parameters

cbp	Reference to CommBufPtr pointing to message to send
timeout_ms	Millisecond timeout used for request messages
disp_handler	Dispatch handler used for request messages

Returns: Error::OK on success, Error::COMM_NOT_CONNECTED if handler has been decomissioned, or Error::COMM_BROKEN_CONNECTION if a write error was encountered.

Definition at line 738 of file IOHandlerData.cc.

Member Data Documentation

Hypertable::IOHandlerData::ImplementMe

Definition at line 242 of file IOHandlerData.h.

bool Hypertable::IOHandlerData::m_connected

private

Flag indicating if socket connection has been completed.

Definition at line 299 of file IOHandlerData.h.

EventPtr Hypertable::IOHandlerData::m_event

private

Pointer to Event object holding message to deliver to application.

Definition at line 308 of file IOHandlerData.h.

bool Hypertable::IOHandlerData::m_got_header {}

private

Flag indicating if message header has been completely received.

Definition at line 302 of file IOHandlerData.h.

uint8_t* Hypertable::IOHandlerData::m_message {}

private

Poiner to message payload buffer.

Definition at line 320 of file IOHandlerData.h.

bool Hypertable::IOHandlerData::m_message_aligned {}

private

Flag indicating if message buffer was allocated with posix_memalign()

Definition at line 305 of file IOHandlerData.h.

uint8_t Hypertable::IOHandlerData::m_message_header[64]

private

Message header buffer.

Definition at line 311 of file IOHandlerData.h.

uint8_t* Hypertable::IOHandlerData::m_message_header_ptr {}

private

Pointer to next write position in m_message_header.

Definition at line 314 of file IOHandlerData.h.

size_t Hypertable::IOHandlerData::m_message_header_remaining

private

Amount of header remaining to be read.

Definition at line 317 of file IOHandlerData.h.

uint8_t* Hypertable::IOHandlerData::m_message_ptr {}

private

Pointer to next write position in m_message.

Definition at line 323 of file IOHandlerData.h.

size_t Hypertable::IOHandlerData::m_message_remaining {}

private

Amount of message payload remaining to be read.

Definition at line 326 of file IOHandlerData.h.

std::list<CommBufPtr> Hypertable::IOHandlerData::m_send_queue

private

Send queue.

Definition at line 329 of file IOHandlerData.h.

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

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

Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation