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 86 of file steam-dispatcher.hpp.

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

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

Friends
class	lib::DependencyFactory< SteamDispatcher >

Private Member Functions
void	endRunningLoopState ()

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

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

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 361 of file steam-dispatcher.cpp.

References SteamDispatcher::endRunningLoopState().

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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 407 of file steam-dispatcher.cpp.

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 418 of file steam-dispatcher.cpp.

References ERROR_LOG_AND_IGNORE.

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 439 of file steam-dispatcher.cpp.

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 455 of file steam-dispatcher.cpp.

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 471 of file steam-dispatcher.cpp.

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 389 of file steam-dispatcher.cpp.

Referenced by SteamDispatcher::start().

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

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