#include <HappyConnOpener.h>

Inheritance diagram for HappyConnOpener:

Collaboration diagram for HappyConnOpener:

[legend]

Classes
class	Attempt
	a connection opening attempt in progress (or falsy) More...

class	CbDialer
	AsyncCall dialer for our callback. Gives us access to callback Answer. More...

Public Types
typedef HappyConnOpenerAnswer	Answer

typedef CbcPointer< AsyncJob >	Pointer

Public Member Functions
	HappyConnOpener (const ResolvedPeersPointer &, const AsyncCall::Pointer &, HttpRequestPointer &, const time_t aFwdStart, int tries, const AccessLogEntryPointer &al)

virtual	~HappyConnOpener () override

void	allowPersistent (bool permitted)
	configures reuse of old connections More...

void	setRetriable (bool retriable)
	configures whether the request may be retried later if things go wrong More...

void	setHost (const char *)
	configures the origin server domain name More...

void	noteCandidatesChange ()
	reacts to changes in the destinations list More...

void	noteGavePrimeItsChance ()
	reacts to expired happy_eyeballs_connect_timeout More...

void	noteSpareAllowance ()
	reacts to satisfying happy_eyeballs_connect_gap and happy_eyeballs_connect_limit More...

bool	canBeCalled (AsyncCall &call) const
	whether we can be called More...

void	callStart (AsyncCall &call)

virtual void	callEnd ()
	called right after the called job method More...

virtual void	callException (const std::exception &e)
	called when the job throws during an async call More...

void	handleStopRequest ()
	process external request to terminate now (i.e. during this async call) More...

virtual void *	toCbdata ()=0

Static Public Member Functions
static void	Start (const Pointer &job)

Public Attributes
HappyAbsoluteTime	primeStart = 0
	the start of the first connection attempt for the currentPeer More...

const InstanceId< AsyncJob >	id
	job identifier More...

Protected Member Functions
void	deleteThis (const char *aReason)

void	mustStop (const char *aReason)

bool	done () const
	the job is destroyed in callEnd() when done() More...

Protected Attributes
const char *	stopReason
	reason for forcing done() to be true More...

const char *	typeName
	kid (leaf) class name, for debugging More...

AsyncCall::Pointer	inCall
	the asynchronous call being handled, if any More...

bool	started_ = false
	Start() has finished successfully. More...

bool	swanSang_ = false
	swanSong() was called More...

Private Member Functions
	CBDATA_CHILD (HappyConnOpener)

virtual void	start () override
	called by AsyncStart; do not call directly More...

virtual bool	doneAll () const override
	whether positive goal has been reached More...

virtual void	swanSong () override

virtual const char *	status () const override
	internal cleanup; do not call directly More...

void	maybeOpenAnotherPrimeConnection ()
	starts a prime connection attempt if possible or does nothing otherwise More...

void	maybeGivePrimeItsChance ()

void	stopGivingPrimeItsChance ()
	called when the prime attempt has used up its chance for a solo victory More...

void	stopWaitingForSpareAllowance ()
	called when the spare attempt should no longer obey spare connection limits More...

void	maybeOpenSpareConnection ()
	if possible, starts a spare connection attempt More...

void	startConnecting (Attempt &, PeerConnectionPointer &)
	starts opening (or reusing) a connection to the given destination More...

void	openFreshConnection (Attempt &, PeerConnectionPointer &)

bool	reuseOldConnection (PeerConnectionPointer &)

void	notePrimeConnectDone (const CommConnectCbParams &)
	Comm::ConnOpener callback for the prime connection attempt. More...

void	noteSpareConnectDone (const CommConnectCbParams &)
	Comm::ConnOpener callback for the spare connection attempt. More...

void	handleConnOpenerAnswer (Attempt &, const CommConnectCbParams &, const char *connDescription)
	prime/spare-agnostic processing of a Comm::ConnOpener result More...

void	checkForNewConnection ()

void	updateSpareWaitAfterPrimeFailure ()
	reacts to a prime attempt failure More...

void	cancelSpareWait (const char *reason)
	stops waiting for the right conditions to open a spare connection More...

bool	ranOutOfTimeOrAttempts () const
	Check for maximum connection tries and forwarding time restrictions. More...

ErrorState *	makeError (const err_type type) const

Answer *	futureAnswer (const PeerConnectionPointer &)

void	sendSuccess (const PeerConnectionPointer &conn, bool reused, const char *connKind)
	send a successful result to the initiator (if it still needs an answer) More...

void	sendFailure ()
	inform the initiator about our failure to connect (if needed) More...

void	cancelAttempt (Attempt &, const char *reason)
	cancels the in-progress attempt, making its path a future candidate More...

Private Attributes
const time_t	fwdStart
	requestor start time More...

AsyncCall::Pointer	callback_
	handler to be called on connection completion. More...

ResolvedPeersPointer	destinations
	Candidate paths. Shared with the initiator. May not be finalized yet. More...

Attempt	prime
	current connection opening attempt on the prime track (if any) More...

Attempt	spare
	current connection opening attempt on the spare track (if any) More...

Comm::ConnectionPointer	currentPeer

HappySpareWait	spareWaiting
	preconditions for an attempt to open a spare connection More...

AccessLogEntryPointer	ale
	transaction details More...

ErrorState *	lastError = nullptr
	last problem details (or nil) More...

PeerConnectionPointer	lastFailedConnection
	nil if none has failed More...

bool	ignoreSpareRestrictions = false
	whether spare connection attempts disregard happy_eyeballs_* settings More...

bool	gotSpareAllowance = false
	whether we have received a permission to open a spare while spares are limited More...

bool	allowPconn_ = true
	whether persistent connections are allowed More...

bool	retriable_ = true
	whether we are opening connections for a request that may be resent More...

const char *	host_ = nullptr
	origin server domain name (or equivalent) More...

HttpRequestPointer	cause
	the request that needs a to-server connection More...

int	n_tries
	number of connection opening attempts, including those in the requestor More...

const char *	ranOutOfTimeOrAttemptsEarlier_ = nullptr
	Reason to ran out of time or attempts. More...

Friends
class	HappyOrderEnforcer

std::ostream &	operator<< (std::ostream &, const Attempt &)
	HappyConnOpener::Attempt printer for debugging. More...

Detailed Description

A TCP connection opening algorithm based on Happy Eyeballs (RFC 8305). Maintains two concurrent connection opening tracks: prime and spare. Shares ResolvedPeers list with the job initiator.

Definition at line 102 of file HappyConnOpener.h.

Member Typedef Documentation

◆ Answer

typedef HappyConnOpenerAnswer HappyConnOpener::Answer

Definition at line 106 of file HappyConnOpener.h.

◆ Pointer

typedef CbcPointer<AsyncJob> AsyncJob::Pointer

inherited

Definition at line 34 of file AsyncJob.h.

Constructor & Destructor Documentation

◆ HappyConnOpener()

HappyConnOpener::HappyConnOpener	(	const ResolvedPeersPointer &	dests,
		const AsyncCall::Pointer &	aCall,
		HttpRequestPointer &	request,
		const time_t	aFwdStart,
		int	tries,
		const AccessLogEntryPointer &	al
	)

Definition at line 329 of file HappyConnOpener.cc.

References assert, callback_, destinations, and AsyncCall::getDialer().

◆ ~HappyConnOpener()

HappyConnOpener::~HappyConnOpener ( )

overridevirtual

Definition at line 344 of file HappyConnOpener.cc.

References host_, lastError, and safe_free.

Member Function Documentation

◆ allowPersistent()

void HappyConnOpener::allowPersistent ( bool permitted )

inline

Definition at line 135 of file HappyConnOpener.h.

References allowPconn_.

◆ callEnd()

void AsyncJob::callEnd ( )

virtualinherited

called right after the called job method

Reimplemented in Adaptation::Icap::Xaction.

Definition at line 137 of file AsyncJob.cc.

References assert, AsyncCall::debugLevel, debugs, AsyncCall::debugSection, AsyncJob::done(), HERE(), AsyncJob::inCall, NULL, AsyncJob::started_, AsyncJob::status(), AsyncJob::swanSang_, AsyncJob::swanSong(), and AsyncJob::typeName.

Referenced by Adaptation::Icap::Xaction::callEnd(), and AsyncJob::deleteThis().

◆ callException()

void AsyncJob::callException ( const std::exception & e )

virtualinherited

Reimplemented in ClientHttpRequest, Ftp::Server, Ipc::Inquirer, Ipc::Forwarder, Adaptation::Icap::Xaction, Adaptation::Icap::ServiceRep, Adaptation::Icap::ModXact, and ConnStateData.

Definition at line 128 of file AsyncJob.cc.

References cbdataReferenceValid(), debugs, Must, AsyncJob::mustStop(), and CbdataParent::toCbdata().

Referenced by ConnStateData::callException(), Adaptation::Icap::Xaction::callException(), Ipc::Forwarder::callException(), Ipc::Inquirer::callException(), and Ftp::Server::callException().

◆ callStart()

void AsyncJob::callStart ( AsyncCall & call )

inherited

called just before the called method

Definition at line 115 of file AsyncJob.cc.

References cbdataReferenceValid(), AsyncCall::debugLevel, debugs, AsyncCall::debugSection, AsyncJob::inCall, Must, AsyncJob::status(), CbdataParent::toCbdata(), and AsyncJob::typeName.

◆ canBeCalled()

bool AsyncJob::canBeCalled ( AsyncCall & call ) const

inherited

Definition at line 102 of file AsyncJob.cc.

References AsyncCall::cancel(), debugs, HERE(), AsyncJob::inCall, and NULL.

◆ cancelAttempt()

void HappyConnOpener::cancelAttempt	(	Attempt &	attempt,
		const char *	reason
	)

private

Definition at line 497 of file HappyConnOpener.cc.

References HappyConnOpener::Attempt::cancel(), destinations, Must, HappyConnOpener::Attempt::path, and ResolvedPeers::reinstatePath().

Referenced by swanSong().

◆ cancelSpareWait()

void HappyConnOpener::cancelSpareWait ( const char * reason )

private

Definition at line 678 of file HappyConnOpener.cc.

References HappySpareWait::clear(), debugs, HappySpareWait::forSpareAllowance, Must, spareWaiting, stopGivingPrimeItsChance(), stopWaitingForSpareAllowance(), and HappySpareWait::toGivePrimeItsChance.

Referenced by checkForNewConnection(), swanSong(), and updateSpareWaitAfterPrimeFailure().

◆ CBDATA_CHILD()

HappyConnOpener::CBDATA_CHILD ( HappyConnOpener )

private

◆ checkForNewConnection()

void HappyConnOpener::checkForNewConnection ( )

private

Called when an external event changes initiator interest, destinations, prime, spare, or spareWaiting. Leaves HappyConnOpener in one of these (mutually exclusive beyond the exceptional state #0) "stable" states:

0. Exceptional termination: done()

Processing a single peer: currentPeer 1.1. Connecting: prime || spare 1.2. Waiting for spare gap and/or paths: !prime && !spare
Waiting for a new peer: destinations->empty() && !destinations->destinationsFinalized && !currentPeer
Finished: destinations->empty() && destinations->destinationsFinalized && !currentPeer

Definition at line 703 of file HappyConnOpener.cc.

References cancelSpareWait(), current_dtime, currentPeer, debugs, destinations, ResolvedPeers::destinationsFinalized, AsyncJob::done(), doneAll(), ResolvedPeers::doneWithPeer(), ResolvedPeers::doneWithSpares(), ResolvedPeers::empty(), ResolvedPeers::extractFront(), HappySpareWait::forNewPeer, gotSpareAllowance, ignoreSpareRestrictions, maybeGivePrimeItsChance(), maybeOpenAnotherPrimeConnection(), maybeOpenSpareConnection(), Must, prime, primeStart, ranOutOfTimeOrAttempts(), spare, spareWaiting, and startConnecting().

Referenced by handleConnOpenerAnswer(), noteCandidatesChange(), noteGavePrimeItsChance(), and start().

◆ deleteThis()

void AsyncJob::deleteThis ( const char * aReason )

protectedinherited

Definition at line 50 of file AsyncJob.cc.

References asyncCall(), AsyncJob::callEnd(), debugs, AsyncJob::inCall, JobMemFun(), Must, NULL, AsyncJob::stopReason, and AsyncJob::typeName.

Referenced by ConnStateData::connStateClosed().

◆ done()

bool AsyncJob::done ( ) const

protectedinherited

Definition at line 91 of file AsyncJob.cc.

References AsyncJob::doneAll(), NULL, and AsyncJob::stopReason.

Referenced by AsyncJob::callEnd(), checkForNewConnection(), and Downloader::downloadFinished().

◆ doneAll()

bool HappyConnOpener::doneAll ( ) const

overrideprivatevirtual

Reimplemented from AsyncJob.

Definition at line 366 of file HappyConnOpener.cc.

References callback_, AsyncCall::canceled(), destinations, ResolvedPeers::destinationsFinalized, ResolvedPeers::empty(), prime, ranOutOfTimeOrAttempts(), and spare.

Referenced by checkForNewConnection().

◆ futureAnswer()

HappyConnOpener::Answer * HappyConnOpener::futureAnswer ( const PeerConnectionPointer & conn )

private

Returns: pre-filled Answer if the initiator needs an answer (or nil)

Definition at line 470 of file HappyConnOpener.cc.

References assert, callback_, AsyncCall::canceled(), conn, AsyncCall::getDialer(), and n_tries.

Referenced by sendFailure(), and sendSuccess().

◆ handleConnOpenerAnswer()

void HappyConnOpener::handleConnOpenerAnswer	(	Attempt &	attempt,
		const CommConnectCbParams &	params,
		const char *	connDescription
	)

private

◆ handleStopRequest()

void AsyncJob::handleStopRequest ( )

inlineinherited

Definition at line 71 of file AsyncJob.h.

References AsyncJob::mustStop().

◆ makeError()

ErrorState * HappyConnOpener::makeError ( const err_type type ) const

private

Create "503 Service Unavailable" or "504 Gateway Timeout" error depending on whether this is a validation request. RFC 7234 section 5.2.2 says that we MUST reply with "504 Gateway Timeout" if validation fails and cached reply has proxy-revalidate, must-revalidate or s-maxage Cache-Control directive.

Definition at line 461 of file HappyConnOpener.cc.

References ale, cause, HttpRequest::flags, RefCount< C >::getRaw(), RequestFlags::needValidation, Http::scGatewayTimeout, Http::scServiceUnavailable, and type.

Referenced by handleConnOpenerAnswer(), and sendFailure().

◆ maybeGivePrimeItsChance()

void HappyConnOpener::maybeGivePrimeItsChance ( )

private

starts waiting for a spare permission (if spare connections may be possible) or does nothing (otherwise)

Definition at line 811 of file HappyConnOpener.cc.

References Config, SquidConfig::connect_limit, currentPeer, debugs, destinations, ResolvedPeers::doneWithSpares(), HappyOrderEnforcer::enqueue(), HappySpareWait::forNewPeer, HappySpareWait::forPrimesToFail, SquidConfig::happyEyeballs, Must, prime, PrimeChanceGiver::readyNow(), spare, spareWaiting, ThePrimeChanceGiver, and HappySpareWait::toGivePrimeItsChance.

Referenced by checkForNewConnection().

◆ maybeOpenAnotherPrimeConnection()

void HappyConnOpener::maybeOpenAnotherPrimeConnection ( )

private

Definition at line 800 of file HappyConnOpener.cc.

References currentPeer, destinations, ResolvedPeers::extractPrime(), Must, prime, and startConnecting().

Referenced by checkForNewConnection().

◆ maybeOpenSpareConnection()

void HappyConnOpener::maybeOpenSpareConnection ( )

private

Definition at line 842 of file HappyConnOpener.cc.

References currentPeer, destinations, HappyOrderEnforcer::enqueue(), ResolvedPeers::extractSpare(), HappySpareWait::forSpareAllowance, gotSpareAllowance, ResolvedPeers::haveSpare(), ignoreSpareRestrictions, SpareAllowanceGiver::jobGotInstantAllowance(), Must, ranOutOfTimeOrAttempts(), SpareAllowanceGiver::readyNow(), spare, spareWaiting, startConnecting(), and TheSpareAllowanceGiver.

Referenced by checkForNewConnection().

◆ mustStop()

void AsyncJob::mustStop ( const char * aReason )

protectedinherited

◆ noteCandidatesChange()

void HappyConnOpener::noteCandidatesChange ( )

Definition at line 521 of file HappyConnOpener.cc.

References checkForNewConnection(), destinations, and ResolvedPeers::notificationPending.

◆ noteGavePrimeItsChance()

void HappyConnOpener::noteGavePrimeItsChance ( )

Definition at line 773 of file HappyConnOpener.cc.

References checkForNewConnection(), HappySpareWait::clear(), Must, spareWaiting, and HappySpareWait::toGivePrimeItsChance.

◆ notePrimeConnectDone()

void HappyConnOpener::notePrimeConnectDone ( const CommConnectCbParams & params )

private

Definition at line 587 of file HappyConnOpener.cc.

References handleConnOpenerAnswer(), and prime.

◆ noteSpareAllowance()

void HappyConnOpener::noteSpareAllowance ( )

Definition at line 781 of file HappyConnOpener.cc.

References HappySpareWait::clear(), currentPeer, destinations, ResolvedPeers::extractSpare(), HappySpareWait::forSpareAllowance, gotSpareAllowance, SpareAllowanceGiver::jobDroppedAllowance(), Must, ranOutOfTimeOrAttempts(), spare, spareWaiting, startConnecting(), and TheSpareAllowanceGiver.

◆ noteSpareConnectDone()

void HappyConnOpener::noteSpareConnectDone ( const CommConnectCbParams & params )

private

Definition at line 594 of file HappyConnOpener.cc.

References gotSpareAllowance, handleConnOpenerAnswer(), SpareAllowanceGiver::jobUsedAllowance(), spare, and TheSpareAllowanceGiver.

◆ openFreshConnection()

void HappyConnOpener::openFreshConnection	(	Attempt &	attempt,
		PeerConnectionPointer &	dest
	)

private

opens a fresh connection to the given destination must be called via startConnecting()

Definition at line 562 of file HappyConnOpener.cc.

References asyncCall(), HappyConnOpener::Attempt::callbackMethod, HappyConnOpener::Attempt::callbackMethodName, cause, Comm::Connection::cloneProfile(), conn, Comm::Connection::connectTimeout(), HappyConnOpener::Attempt::connWait, fwdStart, GetMarkingsToServer(), RefCount< C >::getRaw(), host_, n_tries, HappyConnOpener::Attempt::path, and JobWait< Job >::start().

Referenced by startConnecting().

◆ ranOutOfTimeOrAttempts()

bool HappyConnOpener::ranOutOfTimeOrAttempts ( ) const

private

Definition at line 877 of file HappyConnOpener.cc.

References Config, debugs, SquidConfig::forward_max_tries, FwdState::ForwardTimeout(), fwdStart, n_tries, and ranOutOfTimeOrAttemptsEarlier_.

Referenced by checkForNewConnection(), doneAll(), maybeOpenSpareConnection(), and noteSpareAllowance().

◆ reuseOldConnection()

bool HappyConnOpener::reuseOldConnection ( PeerConnectionPointer & dest )

private

reuses a persistent connection to the given destination (if possible)

Returns: true if and only if reuse was possible must be called via startConnecting()

Definition at line 545 of file HappyConnOpener.cc.

References allowPconn_, assert, PeerConnectionPointer::finalize(), fwdPconnPool, host_, n_tries, PconnPool::pop(), retriable_, and sendSuccess().

Referenced by startConnecting().

◆ sendFailure()

void HappyConnOpener::sendFailure ( )

private

Definition at line 506 of file HappyConnOpener.cc.

References assert, callback_, debugs, ERR_GATEWAY_FAILURE, futureAnswer(), lastError, lastFailedConnection, makeError(), and ScheduleCallHere.

Referenced by swanSong().

◆ sendSuccess()

void HappyConnOpener::sendSuccess	(	const PeerConnectionPointer &	conn,
		bool	reused,
		const char *	connKind
	)

private

Definition at line 484 of file HappyConnOpener.cc.

References assert, callback_, conn, debugs, futureAnswer(), and ScheduleCallHere.

Referenced by handleConnOpenerAnswer(), and reuseOldConnection().

◆ setHost()

void HappyConnOpener::setHost ( const char * h )

Definition at line 351 of file HappyConnOpener.cc.

References host_, safe_free, and xstrdup.

◆ setRetriable()

void HappyConnOpener::setRetriable ( bool retriable )

inline

Definition at line 138 of file HappyConnOpener.h.

References retriable_.

◆ start()

void HappyConnOpener::start ( )

overrideprivatevirtual

Reimplemented from AsyncJob.

Definition at line 359 of file HappyConnOpener.cc.

References checkForNewConnection(), destinations, and ResolvedPeers::notificationPending.

◆ Start()

void AsyncJob::Start ( const Pointer & job )

staticinherited

Promises to start the configured job (eventually). The job is deemed to be running asynchronously beyond this point, so the caller should only access the job object via AsyncCalls rather than directly.

swanSong() is only called for jobs for which this method has returned successfully (i.e. without throwing).

Definition at line 24 of file AsyncJob.cc.

References CallJobHere, AsyncJob::start(), and AsyncJob::started_.

Referenced by Ftp::Server::AcceptCtrlConnection(), clientListenerConnectionOpened(), Ipc::Coordinator::handleCacheMgrRequest(), Ipc::Coordinator::handleSnmpRequest(), httpAccept(), httpsAccept(), httpStart(), idnsInitVC(), Ftp::Gateway::listenForDataChannel(), Ftp::Server::listenForDataConnection(), Log::TcpLogger::Open(), peerProbeConnect(), Mgr::FunAction::respond(), Mgr::InfoAction::respond(), Ipc::SendMessage(), Mgr::Inquirer::sendResponse(), snmpConstructReponse(), SquidMain(), CacheManager::start(), Adaptation::AccessCheck::Start(), Rock::Rebuild::Start(), JobWaitBase::start_(), BodyPipe::startAutoConsumptionIfNeeded(), Ftp::StartGateway(), Ftp::StartRelay(), PeerPoolMgrsRr::syncConfig(), and Rock::SwapDir::updateHeaders().