scummvm/backends/platform/psp/powerman.h
2011-05-12 01:16:22 +02:00

133 lines
4.6 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#ifndef POWERMAN_H
#define POWERMAN_H
#include "backends/platform/psp/thread.h"
#include "common/singleton.h"
#include "common/list.h"
/*
* Implement this class (interface) if you want to use PowerManager's suspend callback functionality
*
*/
class Suspendable {
public:
virtual ~Suspendable() {}
virtual int suspend() = 0;
virtual int resume() = 0;
};
/******************************************************************************************************
*
* This class will call a Suspendable when the PSP goes to suspend/resumes. It also provides the ability to block
* a thread when the PSP is going to suspend/suspending, and to wake it up when the PSP is resumed.
* This ability is very useful for managing the PSPIoStream class, but may be found useful by other classes as well.
*
*******************************************************************************************************/
class PowerManager: public Common::Singleton<PowerManager> {
public:
int blockOnSuspend(); /* block if suspending */
bool beginCriticalSection(); /* Use a critical section to block (if suspend was already pressed) */
void endCriticalSection(); /* and to prevent the PSP from suspending in a particular section */
bool registerForSuspend(Suspendable *item); /* register to be called to suspend/resume */
bool unregisterForSuspend(Suspendable *item); /* remove from suspend/resume list */
void suspend(); /* callback to have all items in list suspend */
void resume(); /* callback to have all items in list resume */
// Functions for pausing the engine
void pollPauseEngine(); /* Poll whether the engine should be paused */
enum {
Error = -1,
NotBlocked = 0,
Blocked = 1
};
enum PauseState {
UNPAUSED = 0,
PAUSING,
PAUSED
};
private:
friend class Common::Singleton<PowerManager>;
PowerManager();
~PowerManager();
Common::List<Suspendable *> _suspendList; // list to register in
volatile bool _pauseFlag; // For pausing, which is before suspending
volatile bool _pauseFlagOld; // Save the last state of the flag while polling
volatile PauseState _pauseClientState; // Pause state of the target
volatile bool _suspendFlag; // protected variable
PspMutex _flagMutex; // mutex to access access flag
PspMutex _listMutex; // mutex to access Suspendable list
PspCondition _threadSleep; // signal to synchronize accessing threads
PspCondition _pmSleep; // signal to wake up the PM from a critical section
volatile int _criticalCounter; // Counter of how many threads are in a critical section
int _error; // error code - PM can't talk to us. For debugging
volatile int _PMStatus; // What the PM is doing. for debugging
// States for PM to be in (used for debugging)
enum PMState {
kInitDone = 1,
kDestroyPM = 2,
kWaitForClientPause = 3,
kWaitForClientToFinishPausing = 4,
kGettingFlagMutexSuspend = 5,
kGotFlagMutexSuspend = 6,
kWaitCritSectionSuspend = 7,
kDoneWaitingCritSectionSuspend = 8,
kGettingListMutexSuspend = 9,
kIteratingListSuspend = 10,
kDoneIteratingListSuspend = 11,
kDoneSuspend = 12,
kDonePowerUnlock,
kBeginResume,
kCheckingPauseFlag,
kGettingListMutexResume,
kIteratingListResume,
kDoneIteratingListResume,
kGettingFlagMutexResume,
kGotFlagMutexResume,
kSignalSuspendedThreadsResume,
kDoneSignallingSuspendedThreadsResume,
kDoneResume
};
volatile int _listCounter; /* How many people are in the list - just for debugging */
void debugPM(); /* print info about the PM */
public:
int getPMStatus() const { return _PMStatus; }
};
// For easy access
#define PowerMan PowerManager::instance()
#endif /* POWERMAN_H */