/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

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 3 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, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
#ifndef hsThread_Defined
#define hsThread_Defined

#include "hsTypes.h"

typedef UInt32 hsMilliseconds;


#if HS_BUILD_FOR_MAC
    #include <Multiprocessing.h>
#elif HS_BUILD_FOR_WIN32
    #include "hsWindows.h"
#elif HS_BUILD_FOR_UNIX
    #include <pthread.h>
    #include <semaphore.h>
    //  We can't wait with a timeout with semas
    #define USE_SEMA
    // Linux kernel 2.4 w/ NTPL threading patch and O(1) scheduler
    // seems to have a problem in it's cond_t implementation that
    // causes a hang under heavy load. This is a workaround that
    // uses select() and pipes.
//  #define PSEUDO_EVENT
#endif

class hsThread 
{
public:
#if HS_BUILD_FOR_MAC
    typedef MPTaskId ThreadId;
#elif HS_BUILD_FOR_WIN32
    typedef DWORD ThreadId;
#elif HS_BUILD_FOR_UNIX
    typedef pthread_t ThreadId;
#endif
private:
    hsBool      fQuit;
    UInt32      fStackSize;
#if HS_BUILD_FOR_MAC
    ThreadId    fTaskId;
    MPQueueId   fNotifyQ;
#elif HS_BUILD_FOR_WIN32
    ThreadId    fThreadId;
    HANDLE      fThreadH;
    HANDLE      fQuitSemaH;
#elif HS_BUILD_FOR_UNIX
    ThreadId    fPThread;
    hsBool      fIsValid;
    pthread_mutex_t fMutex;
#endif
protected:
    hsBool      GetQuit() const { return hsBool(fQuit); }
    void        SetQuit(hsBool value) { fQuit = value; }
public:
    hsThread(UInt32 stackSize = 0);
    virtual     ~hsThread();    // calls Stop()
#if HS_BUILD_FOR_MAC
    ThreadId        GetThreadId() { return fTaskId; }
#error "Mac is Depricated"
#elif HS_BUILD_FOR_WIN32
    ThreadId        GetThreadId() { return fThreadId; }
    static ThreadId GetMyThreadId() { return GetCurrentThreadId(); }
#elif HS_BUILD_FOR_UNIX
    ThreadId            GetThreadId() { return fPThread; }
    static ThreadId     GetMyThreadId() { return pthread_self(); }
    pthread_mutex_t* GetStartupMutex() { return &fMutex;  }
#endif
                
    virtual hsError Run() = 0;      // override this to do your work
    virtual void    Start();        // initializes stuff and calls your Run() method
    virtual void    Stop();     // sets fQuit = true and the waits for the thread to stop
                
    //  Static functions
    static void*    Alloc(size_t size); // does not call operator::new(), may return nil
    static void Free(void* p);      // does not call operator::delete()
    static void ThreadYield();
                
#if HS_BUILD_FOR_WIN32
    DWORD           WinRun();
#endif
};

//////////////////////////////////////////////////////////////////////////////

class hsMutex {
#if HS_BUILD_FOR_MAC
    MPCriticalRegionId  fCriticalRegion;
#elif HS_BUILD_FOR_WIN32
    HANDLE  fMutexH;
#elif HS_BUILD_FOR_UNIX
    pthread_mutex_t fPMutex;
#endif
public:
    hsMutex();
    virtual ~hsMutex();
    
    void        Lock();
    hsBool      TryLock();
    void        Unlock();
};

class hsTempMutexLock {
    hsMutex*    fMutex;
public:
    hsTempMutexLock(hsMutex* mutex) : fMutex(mutex)
    {
        fMutex->Lock();
    }
    hsTempMutexLock(hsMutex& mutex) : fMutex(&mutex)
    {
        fMutex->Lock();
    }
    ~hsTempMutexLock()
    {
        fMutex->Unlock();
    }
};

//////////////////////////////////////////////////////////////////////////////

class hsSemaphore {
#if HS_BUILD_FOR_MAC
    MPSemaphoreId   fSemaId;
#elif HS_BUILD_FOR_WIN32
    HANDLE  fSemaH;
#elif HS_BUILD_FOR_UNIX
#ifdef USE_SEMA
    sem_t   fPSema;
#else
    pthread_mutex_t fPMutex;
    pthread_cond_t  fPCond;
    Int32       fCounter;
#endif
#endif
public:
#ifdef HS_BUILD_FOR_WIN32
    hsSemaphore(int initialValue=0, const char *name=nil);
#else
    hsSemaphore(int initialValue=0);
#endif
    ~hsSemaphore();
    
    hsBool      Wait(hsMilliseconds timeToWait = kPosInfinity32);
    void        Signal();
};

//////////////////////////////////////////////////////////////////////////////
#if !HS_BUILD_FOR_MAC
class hsEvent
{
#if HS_BUILD_FOR_UNIX
#ifndef PSEUDO_EVENT
    pthread_mutex_t fMutex;
    pthread_cond_t  fCond;
    hsBool  fTriggered;
#else
    enum { kRead, kWrite };
    int     fFds[2];
    hsMutex fWaitLock;
    hsMutex fSignalLock;
#endif // PSEUDO_EVENT
#elif HS_BUILD_FOR_WIN32
    HANDLE fEvent;
#endif
public:
    hsEvent();
    ~hsEvent();

    hsBool  Wait(hsMilliseconds timeToWait = kPosInfinity32);
    void        Signal();
};
#endif  // HS_BUILD_FOR_MAC

//////////////////////////////////////////////////////////////////////////////
#if !HS_BUILD_FOR_MAC
class hsSleep
{
public:
#if HS_BUILD_FOR_UNIX
    static void Sleep(UInt32 millis);

#elif HS_BUILD_FOR_WIN32
    static void Sleep(UInt32 millis) { ::Sleep(millis); }

#endif
};
#endif  // HS_BUILD_FOR_MAC


//////////////////////////////////////////////////////////////////////////////
// Allows multiple readers, locks out readers for writing.

class hsReaderWriterLock
{
public:
    struct Callback
    {
        virtual void OnLockingForRead( hsReaderWriterLock * lock ) {}
        virtual void OnLockedForRead( hsReaderWriterLock * lock ) {}
        virtual void OnUnlockingForRead( hsReaderWriterLock * lock ) {}
        virtual void OnUnlockedForRead( hsReaderWriterLock * lock ) {}
        virtual void OnLockingForWrite( hsReaderWriterLock * lock ) {}
        virtual void OnLockedForWrite( hsReaderWriterLock * lock ) {}
        virtual void OnUnlockingForWrite( hsReaderWriterLock * lock ) {}
        virtual void OnUnlockedForWrite( hsReaderWriterLock * lock ) {}
    };
    hsReaderWriterLock( const char * name="<unnamed>", Callback * cb=nil );
    ~hsReaderWriterLock();
    void LockForReading();
    void UnlockForReading();
    void LockForWriting();
    void UnlockForWriting();
    const char * GetName() const { return fName; }

private:
    int     fReaderCount;
    hsMutex fReaderCountLock;
    hsMutex fReaderLock;
    hsSemaphore fWriterSema;
    Callback *  fCallback;
    char *  fName;
};

class hsLockForReading
{
    hsReaderWriterLock * fLock;
public:
    hsLockForReading( hsReaderWriterLock & lock ): fLock( &lock )
    {
        fLock->LockForReading();
    }
    hsLockForReading( hsReaderWriterLock * lock ): fLock( lock )
    {
        fLock->LockForReading();
    }
    ~hsLockForReading()
    {
        fLock->UnlockForReading();
    }
};

class hsLockForWriting
{
    hsReaderWriterLock * fLock;
public:
    hsLockForWriting( hsReaderWriterLock & lock ): fLock( &lock )
    {
        fLock->LockForWriting();
    }
    hsLockForWriting( hsReaderWriterLock * lock ): fLock( lock )
    {
        fLock->LockForWriting();
    }
    ~hsLockForWriting()
    {
        fLock->UnlockForWriting();
    }
};

#endif