/************************************************************************************

Filename    :   Util_Watchdog.h
Content     :   Deadlock reaction
Created     :   June 27, 2013
Authors     :   Kevin Jenkins, Chris Taylor

Copyright   :   Copyright 2014 Oculus VR, LLC All Rights reserved.

Licensed under the Oculus VR Rift SDK License Version 3.2 (the "License"); 
you may not use the Oculus VR Rift SDK except in compliance with the License, 
which is provided at the time of installation or download, or which 
otherwise accompanies this software in either electronic or hard copy form.

You may obtain a copy of the License at

http://www.oculusvr.com/licenses/LICENSE-3.2 

Unless required by applicable law or agreed to in writing, the Oculus VR SDK 
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

*************************************************************************************/

#ifndef OVR_Util_Watchdog_h
#define OVR_Util_Watchdog_h

#include "Kernel/OVR_Timer.h"
#include "Kernel/OVR_Atomic.h"
#include "Kernel/OVR_Allocator.h"
#include "Kernel/OVR_String.h"
#include "Kernel/OVR_System.h"
#include "Kernel/OVR_Threads.h"

namespace OVR { namespace Util {


//-----------------------------------------------------------------------------
// WatchDog

class WatchDog : public NewOverrideBase
{
    friend class WatchDogObserver;

public:
    WatchDog(const String& threadName);
    ~WatchDog();

    void Disable();
    void Enable();

    void Feed(int threshold);

protected:
	// Use 32 bit int so assignment and comparison is atomic
	AtomicInt<uint32_t> WhenLastFedMilliseconds;
    AtomicInt<int>      ThreshholdMilliseconds;

    String              ThreadName;
    bool                Listed;
};


//-----------------------------------------------------------------------------
// WatchDogObserver

class WatchDogObserver : public Thread, public SystemSingletonBase<WatchDogObserver>
{
    OVR_DECLARE_SINGLETON(WatchDogObserver);
    virtual void OnThreadDestroy();

    friend class WatchDog;

public:
    // Uses the exception logger to write deadlock reports
    void EnableReporting(const String organization = String(),
                         const String application = String());

    // Disables deadlock reports
    void DisableReporting();

protected:
    Lock ListLock;
    Array< WatchDog* > DogList;

    static const int WakeupInterval = 1000; // milliseconds between checks
    Event TerminationEvent;

    // Used in deadlock reporting.
    bool IsReporting;

    // On Windows, deadlock logs are stored in %AppData%\OrganizationName\ApplicationName\.
    // See ExceptionHandler::ReportDeadlock() for how these are used.
    String ApplicationName;
    String OrganizationName;

protected:
    virtual int Run();

    void Add(WatchDog* dog);
    void Remove(WatchDog* dog);

public:
    static bool IsExitingOnDeadlock();
    static void SetExitingOnDeadlock(bool enabled);
};


}} // namespace OVR::Util

#endif // OVR_Util_Watchdog_h