Ichthyostega
1b970cd943
This subsystem as such can be considered as implemented now, while several details still wait to be filled in.
113 lines
4 KiB
C++
113 lines
4 KiB
C++
/*
|
|
PROC-DISPATCHER.hpp - Proc-Layer command dispatch and execution
|
|
|
|
Copyright (C) Lumiera.org
|
|
2009, Hermann Vosseler <Ichthyostega@web.de>
|
|
|
|
This program is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU General Public License as
|
|
published by the Free Software Foundation; either version 2 of
|
|
the License, or (at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
|
|
*/
|
|
|
|
|
|
/** @file proc-dispatcher.hpp
|
|
** Dispatch and execute mutation operations on the High-level model.
|
|
** The ProcDispatcher is the application facility to back and support working
|
|
** on the Session. While the session itself is just a data structure, _operating_
|
|
** the session means to process commands changing that data structure and it means
|
|
** to evaluate the _session model_ and _build_ a render nodes network in accordance
|
|
** to that model's meaning. This _operation aspect_ of the session thus has a lifecycle
|
|
** and this is what we call the "session subsystem" within the application. When this is
|
|
** running, the SessionCommand facade is opened, accepting commands to work on the session.
|
|
** Such commands are passed through a dispatch queue to ensure consistent session state
|
|
** and to force strictly sequential processing of commands. Moreover, the ProcDispatcher's
|
|
** responsibility is to care for triggering the Builder after any changes induced by those
|
|
** commands. The Builder is guaranteed to run _eventually_, yet with some leeway.
|
|
**
|
|
** Talking of state, independent of the lifecycle running state, the ProcDispatcher can be
|
|
** _activated or deactivated_. In active state, commands are dequeued and processed, while
|
|
** in inactive state commands are just accepted and queued, assuming the SessionCommand
|
|
** interface is currently opened. This activation state is controlled by the session
|
|
** datastructure itself, more precisely the SessionManager. A session can be stored,
|
|
** closed, reset and loaded with existing content from persistent storage, and only
|
|
** when the data structure is complete and consistent, processing can be enabled.
|
|
**
|
|
** @see Command
|
|
** @see Session
|
|
** @see proc-dispatcher.cpp for details of operational semantics
|
|
**
|
|
*/
|
|
|
|
|
|
|
|
#ifndef PROC_CONTROL_PROC_DISPATCHER_H
|
|
#define PROC_CONTROL_PROC_DISPATCHER_H
|
|
|
|
#include "common/subsys.hpp"
|
|
#include "lib/depend.hpp"
|
|
#include "lib/sync.hpp"
|
|
|
|
#include <memory>
|
|
|
|
|
|
|
|
namespace proc {
|
|
namespace control {
|
|
|
|
using std::unique_ptr;
|
|
using lumiera::Subsys;
|
|
|
|
|
|
class DispatcherLoop;
|
|
|
|
|
|
/**
|
|
* Guard to manage processing commands working 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 operate the Builder, which translates the session
|
|
* contents into a render nodes network. Also embedded herein is
|
|
* the implementation of proc::control::SessionCommandService
|
|
*/
|
|
class ProcDispatcher
|
|
: public lib::Sync<>
|
|
{
|
|
unique_ptr<DispatcherLoop> runningLoop_;
|
|
bool active_{false};
|
|
|
|
|
|
public:
|
|
static lib::Depend<ProcDispatcher> instance;
|
|
|
|
bool start (Subsys::SigTerm);
|
|
bool isRunning();
|
|
void requestStop() noexcept;
|
|
|
|
void activate();
|
|
void deactivate();
|
|
void awaitDeactivation();
|
|
void clear();
|
|
|
|
bool empty() const ;
|
|
|
|
private:
|
|
void endRunningLoopState();
|
|
};
|
|
|
|
|
|
|
|
|
|
}} // namespace proc::control
|
|
#endif /*PROC_CONTROL_PROC_DISPATCHER_H*/
|