#include <helper.h>

Inheritance diagram for helper:

Collaboration diagram for helper:

[legend]

Classes
struct	_stats

Public Member Functions
void *	operator new (size_t size)

void	operator delete (void *address)

void *	toCbdata () noexcept

	helper (const char *name)

	~helper ()

Helper::Xaction *	nextRequest ()

bool	trySubmit (const char buf, HLPCB callback, void *data)
	If possible, submit request. Otherwise, either kill Squid or return false. More...

void	submitRequest (Helper::Xaction *r)

void	packStatsInto (Packable p, const char label=nullptr) const
	Dump some stats about the helper state to a Packable object. More...

bool	willOverload () const

void	handleKilledServer (HelperServerBase *srv, bool &needsNewServers)

Public Attributes
wordlist *	cmdline

dlink_list	servers

std::queue< Helper::Xaction * >	queue

const char *	id_name

Helper::ChildConfig	childs
	Configuration settings for number running. More...

int	ipc_type

Ip::Address	addr

unsigned int	droppedRequests
	requests not sent during helper overload More...

time_t	overloadStart
	when the helper became overloaded (zero if it is not) More...

time_t	last_queue_warn

time_t	last_restart

time_t	timeout
	Requests timeout. More...

bool	retryTimedOut
	Whether the timed-out requests must retried. More...

bool	retryBrokenHelper
	Whether the requests must retried on BH replies. More...

SBuf	onTimedOutResponse
	The response to use when helper response timedout. More...

char	eom
	The char which marks the end of (response) message, normally ' '. More...

struct helper::_stats	stats

Protected Member Functions
bool	queueFull () const
	whether queuing an additional request would overload the helper More...

bool	overloaded () const

void	syncQueueStats ()
	synchronizes queue-dependent measurements with the current queue state More...

bool	prepSubmit ()

void	submit (const char buf, HLPCB callback, void *data)
	dispatches or enqueues a helper requests; does not enforce queue limits More...

Static Private Attributes
static cbdata_type	CBDATA_helper = CBDATA_UNKNOWN

Friends
void	helperSubmit (helper hlp, const char buf, HLPCB callback, void data)

Detailed Description

Managers a set of individual helper processes with a common queue of requests.

With respect to load, a helper goes through these states (roughly): idle: no processes are working on requests (and no requests are queued); normal: some, but not all processes are working (and no requests are queued); busy: all processes are working (and some requests are possibly queued); overloaded: a busy helper with more than queue-size requests in the queue.

A busy helper queues new requests and issues a WARNING every 10 minutes or so. An overloaded helper either drops new requests or keeps queuing them, depending on whether the caller can handle dropped requests (trySubmit vs helperSubmit APIs). If an overloaded helper has been overloaded for 3+ minutes, an attempt to use it results in on-persistent-overload action, which may kill worker.

Definition at line 63 of file helper.h.

Constructor & Destructor Documentation

◆ helper()

helper::helper ( const char * name )

inline

Parameters

name	admin-visible helper category (with this process lifetime)

Definition at line 69 of file helper.h.

References stats.

◆ ~helper()

void const char HLPCB void uint64_t STUB helper::~helper ( )

Definition at line 823 of file helper.cc.

References DBG_CRITICAL, debugs, id_name, queue, helper::_stats::queue_size, and stats.

Member Function Documentation

◆ handleKilledServer()

void helper::handleKilledServer	(	HelperServerBase *	srv,
		bool &	needsNewServers
	)

Updates interall statistics and start new helper server processes after an unexpected server exit

Parameters

needsNewServers true if new servers must started, false otherwise

Definition at line 833 of file helper.cc.

References assert, childs, DBG_CRITICAL, DBG_IMPORTANT, debugs, fatalf(), HelperServerBase::flags, id_name, HelperServerBase::index, last_restart, Helper::ChildConfig::n_active, Helper::ChildConfig::n_max, Helper::ChildConfig::n_startup, Helper::ChildConfig::needNew(), HelperServerBase::replies, HelperServerBase::_helper_flags::shutdown, squid_curtime, and HelperServerBase::stats.

Referenced by helper_server::HelperServerClosed(), and helper_stateful_server::HelperServerClosed().

◆ nextRequest()

Helper::Xaction * helper::nextRequest ( )

Returns: next request in the queue, or nil.

Definition at line 1261 of file helper.cc.

References queue, helper::_stats::queue_size, and stats.

Referenced by helperKickQueue(), and helperStatefulKickQueue().

◆ operator delete()

void helper::operator delete ( void * address )

inline

Definition at line 65 of file helper.h.

◆ operator new()

void * helper::operator new ( size_t size )

inline

Definition at line 65 of file helper.h.

◆ overloaded()

bool helper::overloaded ( ) const

protected

Definition at line 486 of file helper.cc.

References childs, helper::_stats::queue_size, Helper::ChildConfig::queue_size, and stats.

Referenced by prepSubmit(), and syncQueueStats().

◆ packStatsInto()

void helper::packStatsInto	(	Packable *	p,
		const char *	label = `nullptr`
	)		const

Definition at line 677 of file helper.cc.

References HelperServerBase::answer_time, Packable::append(), Packable::appendf(), assert, helper::_stats::avg_svc_time, Helper::Request::buf, childs, HelperServerBase::_helper_flags::closing, cmdline, current_time, HelperServerBase::dispatch_time, Helper::Request::dispatch_time, Comm::Connection::fd, HelperServerBase::flags, dlink_list::head, HelperServerBase::index, int, wordlist::key, Helper::ChildConfig::n_active, Helper::ChildConfig::n_max, Helper::ChildConfig::n_running, dlink_node::next, HelperServerBase::pending, HelperServerBase::pid, Helper::Request::placeholder, PRIu64, helper::_stats::queue_size, Format::QuoteMimeBlob(), HelperServerBase::readPipe, helper::_stats::replies, HelperServerBase::replies, Helper::Xaction::request, helper::_stats::requests, HelperServerBase::requests, HelperServerBase::reserved(), HelperServerBase::roffset, servers, HelperServerBase::_helper_flags::shutdown, stats, HelperServerBase::stats, helper::_stats::timedout, HelperServerBase::timedout, tvSubMsec(), HelperServerBase::uses, InstanceId< Class, ValueType >::value, and HelperServerBase::_helper_flags::writing.

Referenced by authenticateBasicStats(), authenticateDigestStats(), authenticateNegotiateStats(), authenticateNTLMStats(), redirectStats(), and storeIdStats().

◆ prepSubmit()

bool helper::prepSubmit ( )

protected

prepares the helper for request submission returns true if and only if the submission should proceed may kill Squid if the helper remains overloaded for too long

Definition at line 519 of file helper.cc.

References Helper::ChildConfig::actDie, childs, DBG_IMPORTANT, debugs, droppedRequests, fatalf(), id_name, Helper::ChildConfig::onPersistentOverload, overloaded(), overloadStart, squid_curtime, and syncQueueStats().