Data structure for mapping socket addresses to I/O handlers. More...

#include <HandlerMap.h>

Collaboration diagram for Hypertable::HandlerMap:

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

void	insert_handler (IOHandlerAccept *handler)
	Inserts an accept handler. More...

void	insert_handler (IOHandlerData *handler, bool checkout=false)
	Inserts a data (TCP) handler. More...

void	insert_handler (IOHandlerDatagram *handler)
	Inserts a datagram (UDP) handler. More...

void	insert_handler (IOHandlerRaw *handler)
	Inserts a raw handler. More...

int	checkout_handler (const CommAddress &addr, IOHandlerAccept **handler)
	Checks out accept I/O handler associated with `addr`. More...

int	checkout_handler (const CommAddress &addr, IOHandlerData **handler)
	Checks out data (TCP) I/O handler associated with `addr`. More...

int	checkout_handler (const CommAddress &addr, IOHandlerDatagram **handler)
	Checks out datagram (UDP) I/O handler associated with `addr`. More...

int	checkout_handler (const CommAddress &addr, IOHandlerRaw **handler)
	Checks out raw I/O handler associated with `addr`. More...

int	contains_data_handler (const CommAddress &addr)
	Checks to see if `addr` is contained in map. More...

void	decrement_reference_count (IOHandler *handler)
	Decrements the reference count of `handler`. More...

int	set_alias (const InetAddr &addr, const InetAddr &alias)
	Sets an alias address for an existing TCP address in map. More...

int	remove_handler (IOHandler *handler)
	Removes `handler` from map. More...

void	decomission_handler_unlocked (IOHandler *handler)
	Decomissions `handler`. More...

void	decomission_handler (IOHandler *handler)
	Decomissions `handler` with m_mutex locked. More...

void	decomission_all ()
	Decomissions all handlers. More...

bool	destroy_ok (IOHandler *handler)
	Determines if `handler` can be destoryed. More...

bool	translate_proxy_address (const CommAddress &proxy_addr, InetAddr *addr)
	Translates `proxy_addr` to its corresponding IPV4 address. More...

void	purge_handler (IOHandler *handler)
	Purges (removes) `handler`. More...

void	wait_for_empty ()
	Waits for map to become empty. More...

int	add_proxy (const String &proxy, const String &hostname, const InetAddr &addr)
	Adds or updates proxy information. More...

int	remove_proxy (const String &proxy)
	Removes a proxy name from the proxy map. More...

void	get_proxy_map (ProxyMapT &proxy_map)
	Returns the proxy map. More...

void	update_proxy_map (const char *message, size_t message_len)
	Updates the proxy map with a proxy map update message received from the proxy master. More...

int32_t	propagate_proxy_map (IOHandlerData *handler)
	Sends the current proxy map over connection identified by `handler`. More...

bool	wait_for_proxy_map (Timer &timer)
	Waits for proxy map to get updated from a proxy map update message received from the master. More...

Private Member Functions
int	propagate_proxy_map (ProxyMapT &mappings)
	Propagates proxy map information in `mappings` to all active data (TCP) connections. More...

int	translate_address (const CommAddress &addr, InetAddr *inet_addr)
	Translates `addr` to an InetAddr (IP address). More...

int	remove_handler_unlocked (IOHandler *handler)
	Removes `handler` from map without locking m_mutex. More...

IOHandlerAccept *	lookup_accept_handler (const InetAddr &addr)
	Finds accept I/O handler associated with `addr`. More...

IOHandlerData *	lookup_data_handler (const InetAddr &addr)
	Finds data (TCP) I/O handler associated with `addr`. More...

IOHandlerDatagram *	lookup_datagram_handler (const InetAddr &addr)
	Finds datagram I/O handler associated with `addr`. More...

IOHandlerRaw *	lookup_raw_handler (const InetAddr &addr)
	Finds raw I/O handler associated with `addr`. More...

Private Attributes
std::mutex	m_mutex
	Mutex for serializing concurrent access More...

std::condition_variable	m_cond
	Condition variable for signalling empty map. More...

std::condition_variable	m_cond_proxy
	Condition variable for signalling proxy map load. More...

SockAddrMap< IOHandlerAccept * >	m_accept_handler_map
	Accept map (InetAddr-to-IOHandlerAccept) More...

SockAddrMap< IOHandlerData * >	m_data_handler_map
	Data (TCP) map (InetAddr-to-IOHandlerData) More...

SockAddrMap< IOHandlerDatagram * >	m_datagram_handler_map
	Datagram (UDP) map (InetAddr-to-IOHandlerDatagram) More...

SockAddrMap< IOHandlerRaw * >	m_raw_handler_map
	Raw map (InetAddr-to-IOHandlerRaw) More...

std::set< IOHandler * >	m_decomissioned_handlers
	Decomissioned handler set. More...

ProxyMap	m_proxy_map
	Proxy map. More...

bool	m_proxies_loaded
	Flag indicating if proxy map has been loaded. More...

Detailed Description

Data structure for mapping socket addresses to I/O handlers.

An I/O handler is associated with each socket connection and is used to handle polling events on the socket descriptor. Examples incude writing a message to the socket, reading a message from the socket, or completing a connection request. This class maintains three maps, one for TCP socket connections, UDP socket connections, and one for accept sockets. The Comm methods use this map to locate the I/O handler for a given address.

Definition at line 69 of file HandlerMap.h.

Constructor & Destructor Documentation

Hypertable::HandlerMap::HandlerMap ( )

inline

Constructor.

Definition at line 74 of file HandlerMap.h.

Member Function Documentation

int HandlerMap::add_proxy	(	const String &	proxy,
		const String &	hostname,
		const InetAddr &	addr
	)

Adds or updates proxy information.

This method adds or updates proxy information in m_proxy_map. For the data handler to which addr refers, it updates its proxy name via a call to IOHandler::set_proxy and then calls propagate_proxy_map with the newly added/updated proxy information to update all active data connections with the new proxy information.

Note: This method should only be called by the proxy master.

Parameters

proxy	Proxy name of new/updated mapping
hostname	Hostname of new/updated mapping
addr	InetAddr of new/updated mapping

Returns: Error::OK on success, or one of the errors returned by propagate_proxy_map

Definition at line 299 of file HandlerMap.cc.

int HandlerMap::checkout_handler	(	const CommAddress &	addr,
		IOHandlerAccept **	handler
	)

Checks out accept I/O handler associated with addr.

Looks up addr in accept map. If an entry is found, then its reference count is incremented and it is returned in handler.

Parameters

addr	Connection address
handler	Address of handler pointer returned

Returns: Error::OK on success, or Error::COMM_NOT_CONNECTED if no mapping found for addr.

Definition at line 70 of file HandlerMap.cc.

int HandlerMap::checkout_handler	(	const CommAddress &	addr,
		IOHandlerData **	handler
	)

Checks out data (TCP) I/O handler associated with addr.

First translates addr to socket address and then looks up translated address in data map. If an entry is found, then its reference count is incremented and it is returned in handler.

Parameters

addr	Connection address
handler	Address of handler pointer returned

Returns: Error::OK on success, Error::COMM_INVALID_PROXY if addr is of type CommAddress::PROXY and no translation exists, or Error::COMM_NOT_CONNECTED if no mapping found for translated address.

Definition at line 85 of file HandlerMap.cc.

int HandlerMap::checkout_handler	(	const CommAddress &	addr,
		IOHandlerDatagram **	handler
	)

Checks out datagram (UDP) I/O handler associated with addr.

Looks up addr in datagram map. If an entry is found, then its reference count is incremented and it is returned in handler.

Parameters

addr	Connection address
handler	Address of handler pointer returned

Returns: Error::OK on success, or Error::COMM_NOT_CONNECTED if no mapping found for addr.

Definition at line 104 of file HandlerMap.cc.

int HandlerMap::checkout_handler	(	const CommAddress &	addr,
		IOHandlerRaw **	handler
	)

Checks out raw I/O handler associated with addr.

Looks up addr in raw map. If an entry is found, then its reference count is incremented and it is returned in handler.

Parameters

addr	Connection address
handler	Address of handler pointer returned

Returns: Error::OK on success, or Error::COMM_NOT_CONNECTED if no mapping found for addr.

Definition at line 118 of file HandlerMap.cc.

int HandlerMap::contains_data_handler ( const CommAddress & addr )

Checks to see if addr is contained in map.

First translates addr to socket address and then looks up translated address in data map.

Parameters

addr	Connection address

Returns: Error::OK if found, Error::COMM_INVALID_PROXY if addr is of type CommAddress::PROXY and no translation exists, or Error::COMM_NOT_CONNECTED if no mapping found for translated address.

Definition at line 137 of file HandlerMap.cc.

void HandlerMap::decomission_all ( )

Decomissions all handlers.

This method is called by the ~Comm to decomission all of the handlers in the map.

Note: It doesn't look like the Comm object ever gets deleted and therefore this method never gets called. See issue 1031.

Definition at line 223 of file HandlerMap.cc.

void Hypertable::HandlerMap::decomission_handler ( IOHandler * handler )

inline

Decomissions handler with m_mutex locked.

This method locks m_mutex and calls decomission_handler_unlocked

Parameters

handler Pointer to IOHandler to decomission

Definition at line 217 of file HandlerMap.h.

void HandlerMap::decomission_handler_unlocked ( IOHandler * handler )

Decomissions handler.

Since handler pointers are passed into the polling mechanism and asynchronously referenced by reactor threads, care must be taken to not delete a handler until it has be removed from the polling mechanism. This is accomplished by introducing a two-step removal process. First a handler is decomissioned (by this method) by removing it from the associated map, adding it to the m_decomissioned_handlers set and marking it decomissioned. Once there are no more references to the handler, it may be safely removed. The removal is accomplished via purge_handler which is called by the reactor thread after it has been removed from the polling interface.

Parameters

handler Pointer to IOHandler to decomission

Definition at line 214 of file HandlerMap.cc.

void HandlerMap::decrement_reference_count ( IOHandler * handler )

Decrements the reference count of handler.

The decrementing of a handler's reference count is done by this method with m_mutex locked which avoids a race condition between checking out handlers and purging them.

Parameters

handler Pointer to I/O handler for which to decrement reference count

Definition at line 132 of file HandlerMap.cc.

bool HandlerMap::destroy_ok ( IOHandler * handler )

Determines if handler can be destoryed.

Returns: true if handler is decomissioned and has a reference count of 0.

Definition at line 263 of file HandlerMap.cc.

void HandlerMap::get_proxy_map ( ProxyMapT & proxy_map )

Returns the proxy map.

Parameters

proxy_map reference to returned proxy map

Definition at line 331 of file HandlerMap.cc.

void HandlerMap::insert_handler ( IOHandlerAccept * handler )

Inserts an accept handler.

Uses IOHandler::m_local_addr as the key

Parameters

handler Accept I/O handler to insert

Definition at line 39 of file HandlerMap.cc.

void HandlerMap::insert_handler	(	IOHandlerData *	handler,
		bool	checkout = `false`
	)

Inserts a data (TCP) handler.

Uses IOHandler::m_addr as the key. If program is the proxy master, a proxy map update message with the new mapping is broadcast to all connections.

Parameters

handler	Data (TCP) I/O handler to insert
checkout	Atomically checkout handler

Definition at line 46 of file HandlerMap.cc.

void HandlerMap::insert_handler ( IOHandlerDatagram * handler )

Inserts a datagram (UDP) handler.

Uses IOHandler::m_local_addr as the key.

Parameters

handler Datagram (UDP) I/O handler to insert

Definition at line 55 of file HandlerMap.cc.

void HandlerMap::insert_handler ( IOHandlerRaw * handler )

Inserts a raw handler.

Uses IOHandler::m_addr as the key.

Parameters

handler Raw I/O handler to insert

Definition at line 62 of file HandlerMap.cc.

IOHandlerAccept * HandlerMap::lookup_accept_handler ( const InetAddr & addr )

private

Finds accept I/O handler associated with addr.

This method looks up addr in m_accept_handler_map and returns the handler, if found.

Parameters

addr	Address of accept handler to locate

Returns: Pointer to IOHandlerAccept object associated with addr, or 0 if not found.

Definition at line 439 of file HandlerMap.cc.

IOHandlerData * HandlerMap::lookup_data_handler ( const InetAddr & addr )

private

Finds data (TCP) I/O handler associated with addr.

This method looks up addr in m_data_handler_map and returns the handler, if found.

Parameters

addr	Address of data handler to locate

Returns: Pointer to IOHandlerData object associated with addr, or 0 if not found.

Definition at line 446 of file HandlerMap.cc.

IOHandlerDatagram * HandlerMap::lookup_datagram_handler ( const InetAddr & addr )

private

Finds datagram I/O handler associated with addr.

This method looks up addr in m_datagram_handler_map and returns the handler, if found.

Parameters

addr	Address of datagram handler to locate

Returns: Pointer to IOHandlerDatagram object associated with addr, or 0 if not found.

Definition at line 453 of file HandlerMap.cc.

IOHandlerRaw * HandlerMap::lookup_raw_handler ( const InetAddr & addr )

private

Finds raw I/O handler associated with addr.

This method looks up addr in m_raw_handler_map and returns the handler, if found.

Parameters

addr	Address of raw handler to locate

Returns: Pointer to IOHandlerRaw object associated with addr, or nullptr if not found.

Definition at line 460 of file HandlerMap.cc.

int32_t HandlerMap::propagate_proxy_map ( IOHandlerData * handler )

Sends the current proxy map over connection identified by handler.

This method must only be called by the proxy master, otherwise it will assert.

Parameters

handler Connection over which to send proxy map

Returns: Same set of error codes returned by IOHandlerData::send_message

Definition at line 365 of file HandlerMap.cc.

int HandlerMap::propagate_proxy_map ( ProxyMapT & mappings )

private

Propagates proxy map information in mappings to all active data (TCP) connections.

This method creates a proxy map update message from the mappings in mappings. The update message is just a list of mapping entries in the following format:

<proxy> '\t' <hostname> '\t' <addr> '\n'

Then the proxy map update message is sent via each of the handlers in the data (TCP) handler map. If an error is encountered on a handler when trying to send the proxy map, it will be decomissioned.

Parameters

mappings Proxy map information to propagate.

Returns: Error::OK if proxy map update message was successfully sent across all data handlers, otherwise one of the error codes returned by IOHandlerData::send_message

Definition at line 383 of file HandlerMap.cc.

void HandlerMap::purge_handler ( IOHandler * handler )

Purges (removes) handler.

This method removes handler from the m_decomissioned_handlers set, signals m_cond if m_decomissioned_handlers becomes empty, calls hander->disconnect(), and then deletes the handler. This method must only be called from a reactor thread after the handler has been removed from the polling interface and destroy_ok returns true for the handler.

Parameters

handler Handler to purge

Definition at line 286 of file HandlerMap.cc.

int HandlerMap::remove_handler ( IOHandler * handler )

Removes handler from map.

This method removes handler from the data, datagram, or accept map, depending on the type of handler. If handler refers to a data handler, then its alias address entry is also removed from the data map.

Parameters

handler IOHandler to remove

Returns: Error::OK on success, or Error::COMM_NOT_CONNECTED if handler is not found in any of the maps.

Definition at line 209 of file HandlerMap.cc.

int HandlerMap::remove_handler_unlocked ( IOHandler * handler )

private

Removes handler from map without locking m_mutex.

This method removes handler from the data, datagram, or accept map, depending on the type of handler. If handler refers to a data handler, then its alias address entry is also removed from the data map.

Parameters

handler IOHandler to remove

Returns: Error::OK on success, or Error::COMM_NOT_CONNECTED if handler is not found in any of the maps.

Definition at line 168 of file HandlerMap.cc.

int HandlerMap::remove_proxy ( const String & proxy )

Removes a proxy name from the proxy map.

This method removes proxy from m_proxy_map and then calls propagate_proxy_map to propagate the removed mapping information to all connections.

Note: This method should only be called by the proxy master.

Parameters

proxy Proxy name to remove

Returns: Error::OK if proxy not found in proxy map or if it was successfully removed, or one of the errors returned by propagate_proxy_map

Definition at line 314 of file HandlerMap.cc.

int HandlerMap::set_alias	(	const InetAddr &	addr,
		const InetAddr &	alias
	)

Sets an alias address for an existing TCP address in map.

RangeServers listen on a well-known port defined by the Hypertable.RangeServer.Port configuration property (default = 15865). However, RangeServers connect to the master using an ephemeral port due to a bind conflict with its listen socket. So that the Master can refer to the RangeServer using the well-known port, an alias address can be registered and subsequently used to reference the connection. This method adds an entry to the data (TCP) map for alias which references the IOHandlerData object previously registered under addr.

Parameters

addr	Address of previously registered data handler
alias	Alias address to add

Returns: Error::OK on success, or Error::COMM_CONFLICTING_ADDRESS if alias is already in the data map, or Error::COMM_NOT_CONNECTED if addr is not found in the data map.

Definition at line 152 of file HandlerMap.cc.

int HandlerMap::translate_address	(	const CommAddress &	addr,
		InetAddr *	inet_addr
	)

private

Translates addr to an InetAddr (IP address).

If addr is of type CommAddress::PROXY, then the m_proxy_map is consulted to translate the proxy name to an IP address, otherwise if addr is of type CommAddress::INET, the IP address held in addr is copied to inet_addr.

Parameters

addr	Address to translate
inet_addr	Pointer to valid InetAddr object to hold translated address

Returns: Error::OK on success, Error::COMM_INVALID_PROXY if addr is of type CommAddress::PROXY and no mapping is found.

Definition at line 424 of file HandlerMap.cc.

bool HandlerMap::translate_proxy_address	(	const CommAddress &	proxy_addr,
		InetAddr *	addr
	)

Translates proxy_addr to its corresponding IPV4 address.

This method fetches the mapping for proxy_addr from m_proxy_map and returns the associated IPV4 address in addr. If addr is NULL, then no translation occurs but the return value can be checked to see if the proxy name contains a mapping.

Parameters

proxy_addr	Reference to proxy address
addr	Pointer to return IPV4 address

Returns: true if mapping found, false otherwise

Definition at line 270 of file HandlerMap.cc.

void HandlerMap::update_proxy_map	(	const char *	message,
		size_t	message_len
	)

Updates the proxy map with a proxy map update message received from the proxy master.

Calls ProxyMap::update_mappings with message to update the proxy map. If any of the proxy names have changed, the corresponding data handlers are updated with a call to IOHandler::set_proxy. For each mapping in message that has the hostname set to –DELETED–, the associated data handler is decomissioned. After the proxy map has been successfuly updated, the m_proxies_loaded flag is set to true and the m_cond_proxy condition variable is signalled.

Parameters

message	Pointer to proxy map update message
message_len	Length of proxy map update message

Definition at line 336 of file HandlerMap.cc.

void HandlerMap::wait_for_empty ( )

Waits for map to become empty.

This method assumes that all of the handlers in the map have been decomissioned. It waits for the m_decomissioned_handlers set to become empty, waiting on m_cond until it does.

Definition at line 281 of file HandlerMap.cc.

bool HandlerMap::wait_for_proxy_map ( Timer & timer )

Waits for proxy map to get updated from a proxy map update message received from the master.

This method waits on m_cond_proxy for m_proxies_loaded to become true or timer expires.

Parameters

timer Deadline timer

Returns: true if proxy map was loaded, false if timer expired before proxy map was loaded.

Definition at line 374 of file HandlerMap.cc.

Member Data Documentation

SockAddrMap<IOHandlerAccept *> Hypertable::HandlerMap::m_accept_handler_map

private

Accept map (InetAddr-to-IOHandlerAccept)

Definition at line 415 of file HandlerMap.h.

std::condition_variable Hypertable::HandlerMap::m_cond

private

Condition variable for signalling empty map.

Definition at line 409 of file HandlerMap.h.

std::condition_variable Hypertable::HandlerMap::m_cond_proxy

private

Condition variable for signalling proxy map load.

Definition at line 412 of file HandlerMap.h.

SockAddrMap<IOHandlerData *> Hypertable::HandlerMap::m_data_handler_map

private

Data (TCP) map (InetAddr-to-IOHandlerData)

Definition at line 418 of file HandlerMap.h.

SockAddrMap<IOHandlerDatagram *> Hypertable::HandlerMap::m_datagram_handler_map

private

Datagram (UDP) map (InetAddr-to-IOHandlerDatagram)

Definition at line 421 of file HandlerMap.h.

std::set<IOHandler *> Hypertable::HandlerMap::m_decomissioned_handlers

private

Decomissioned handler set.

Definition at line 427 of file HandlerMap.h.

std::mutex Hypertable::HandlerMap::m_mutex

private

Mutex for serializing concurrent access

Definition at line 406 of file HandlerMap.h.

bool Hypertable::HandlerMap::m_proxies_loaded

private

Flag indicating if proxy map has been loaded.

Definition at line 433 of file HandlerMap.h.

ProxyMap Hypertable::HandlerMap::m_proxy_map

private

Proxy map.

Definition at line 430 of file HandlerMap.h.

SockAddrMap<IOHandlerRaw *> Hypertable::HandlerMap::m_raw_handler_map

private

Raw map (InetAddr-to-IOHandlerRaw)

Definition at line 424 of file HandlerMap.h.

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

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

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation