SteamDispatcher Class Reference

#include "steam/control/steam-dispatcher.hpp"

Description

Guard to manage processing commands to operate on the session.

A static application facility, actually backing and implementing the »session subsystem«. Embedded within the implementation of this class is the »session loop thread« to perform any session mutation commands and to activate the Builder, which translates the session contents into a render nodes network. Also embedded herein is the implementation of steam::control::SessionCommandService

Warning

destroying this object while isRunning() will terminate the Application unconditionally.

Definition at line 77 of file steam-dispatcher.hpp.

Static Public Attributes
static lib::Depend< SteamDispatcher >	instance
	storage for Singleton access

Public Member Functions
bool	start (Subsys::SigTerm)
	starting the SteamDispatcher means to start the session subsystem.
bool	isRunning ()
	whether the »session subsystem« is operational.
void	requestStop () noexcept
	signal to the loop thread that it needs to terminate.
void	activate ()
	activate processing of enqueued session commands.
void	deactivate ()
	halt further processing of session commands
void	awaitDeactivation ()
	block until the dispatcher has actually reached disabled state.
void	clear ()
	discard any commands waiting in the dispatcher queue
bool	empty () const

Friends
class	lib::DependencyFactory< SteamDispatcher >

Private Member Functions
void	endRunningLoopState ()
	~SteamDispatcher ()
	SteamDispatcher ()

Private Attributes
unique_ptr< DispatcherLoop >	runningLoop_
bool	active_ {false}

Additional Inherited Members
Static Public Member Functions inherited from Sync< CONF >
static Monitor &	getMonitor (Sync const *forThis)

Constructor & Destructor Documentation

~SteamDispatcher()

~SteamDispatcher ( )

private

Definition at line 341 of file steam-dispatcher.cpp.

SteamDispatcher()

SteamDispatcher ( )

private

Definition at line 340 of file steam-dispatcher.cpp.

Member Function Documentation

start()

bool start

(

Subsys::SigTerm

termNotification

)

starting the SteamDispatcher means to start the session subsystem.

Returns

false when starting failed since it is already running...

Remarks

this function implements the start operation for the »session subsystem«. More specifically, this operation starts a new thread to perform the session loop, which means to perform commands and trigger the builder. It might block temporarily for synchronisation with this new thread and while opening the SessionCommand facade.

Definition at line 352 of file steam-dispatcher.cpp.

References SteamDispatcher::active_, SteamDispatcher::endRunningLoopState(), and SteamDispatcher::runningLoop_.

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isRunning()

bool isRunning

(

)

whether the »session subsystem« is operational.

Returns

true if the session loop thread has been fully started and is not (yet) completely terminated.

Definition at line 398 of file steam-dispatcher.cpp.

References SteamDispatcher::runningLoop_.

requestStop()

void requestStop ( )

noexcept

signal to the loop thread that it needs to terminate.

Note

the immediate consequence is to close SessionCommandService

Definition at line 409 of file steam-dispatcher.cpp.

References ERROR_LOG_AND_IGNORE, and SteamDispatcher::runningLoop_.

activate()

void activate

(

)

activate processing of enqueued session commands.

Remarks

command processing serves as public external interface to the session. This call is used by the session lifecycle (SessManagerImpl) when the session is brought up; any other invocation runs danger to mess up the session lifecycle state and process commands on a deconfigured session. In case the dispatcher loop is not actually running, the activation state is stored and applied accordingly later, when the loop is fired up.

Definition at line 430 of file steam-dispatcher.cpp.

References SteamDispatcher::active_, and SteamDispatcher::runningLoop_.

deactivate()

void deactivate

(

)

halt further processing of session commands

Note

the processing itself runs in a separate thread, thus any currently ongoing command or builder execution will be completed prior to this setting to take effect. If the intention is to halt processing because the session is about to dismantled, it is mandatory to awaitDeactivation()

Definition at line 446 of file steam-dispatcher.cpp.

References SteamDispatcher::active_, and SteamDispatcher::runningLoop_.

awaitDeactivation()

void awaitDeactivation

(

)

block until the dispatcher has actually reached disabled state.

Warning

beware of invoking this function from within the session thread, since the waiting relies on the very lock also used to coordinate command processing and builder runs within that thread.

Exceptions

error::Fatal

when a deadlock due to such a recursive call can be detected

Definition at line 462 of file steam-dispatcher.cpp.

References SteamDispatcher::runningLoop_.

clear()

void clear

(

)

discard any commands waiting in the dispatcher queue

Definition at line 472 of file steam-dispatcher.cpp.

References SteamDispatcher::empty(), and SteamDispatcher::runningLoop_.

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empty()

bool empty

(

)

const

Definition at line 485 of file steam-dispatcher.cpp.

References SteamDispatcher::runningLoop_.

Referenced by SteamDispatcher::clear().

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endRunningLoopState()

void endRunningLoopState ( )

private

clean-up when leaving the session loop thread. This function is hooked up in to the termination callback, and is in fact the only one to delete the loop PImpl. We take the (outer) lock on SteamDispatcher to ensure no one commits anything to the DispatcherLoop object while being deleted. The call itself, while technically originating from within DispatcherLoop::runSessionThread(), relies solely on stack based context data and is a tail call.

Definition at line 380 of file steam-dispatcher.cpp.

References SteamDispatcher::runningLoop_.

Referenced by SteamDispatcher::start().

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Member Data Documentation

runningLoop_

unique_ptr<DispatcherLoop> runningLoop_

private

Definition at line 80 of file steam-dispatcher.hpp.

Referenced by SteamDispatcher::activate(), SteamDispatcher::awaitDeactivation(), SteamDispatcher::clear(), SteamDispatcher::deactivate(), SteamDispatcher::empty(), SteamDispatcher::endRunningLoopState(), SteamDispatcher::isRunning(), SteamDispatcher::requestStop(), and SteamDispatcher::start().

active_

bool active_ {false}

private

Definition at line 81 of file steam-dispatcher.hpp.

Referenced by SteamDispatcher::activate(), SteamDispatcher::deactivate(), and SteamDispatcher::start().

instance

lib::Depend< SteamDispatcher > instance

static

storage for Singleton access

Definition at line 84 of file steam-dispatcher.hpp.

Referenced by CommandUse2_test::check_DispatcherInvocation(), SessionSubsystem::checkRunningState(), SessionCommandFunction_test::perform_massivelyParallel(), SessionSubsystem::start(), SessionCommandFunction_test::startDispatcher(), SessionCommandFunction_test::stopDispatcher(), and SessionSubsystem::triggerShutdown().

Friends And Related Symbol Documentation

lib::DependencyFactory< SteamDispatcher >

friend class lib::DependencyFactory< SteamDispatcher >

friend

Definition at line 101 of file steam-dispatcher.hpp.

Inheritance diagram for SteamDispatcher:

Collaboration diagram for SteamDispatcher:

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

• steam-dispatcher.hpp
• steam-dispatcher.cpp