CWE-ou-minkata/Sources/Plasma/CoreLib/hsThread.h

/*==LICENSE==*

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

#include "HeadSpin.h"

typedef uint32_t hsMilliseconds;

#ifdef 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_WIN32
    typedef uint32_t ThreadId;
#elif HS_BUILD_FOR_UNIX
    typedef pthread_t ThreadId;
#endif
private:
    bool        fQuit;
    uint32_t    fStackSize;
#if HS_BUILD_FOR_WIN32
    ThreadId    fThreadId;
    HANDLE      fThreadH;
    HANDLE      fQuitSemaH;
#elif HS_BUILD_FOR_UNIX
    ThreadId    fPThread;
    bool        fIsValid;
    pthread_mutex_t fMutex;
#endif
protected:
    bool        GetQuit() const { return fQuit; }
    void        SetQuit(bool value) { fQuit = value; }
public:
    hsThread(uint32_t stackSize = 0);
    virtual     ~hsThread();    // calls Stop()
#if HS_BUILD_FOR_WIN32
    ThreadId        GetThreadId() { return fThreadId; }
    static ThreadId GetMyThreadId();
#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();
};

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

class hsMutex {
#if HS_BUILD_FOR_WIN32
    HANDLE  fMutexH;
#elif HS_BUILD_FOR_UNIX
    pthread_mutex_t fPMutex;
#endif
public:
    hsMutex();
    virtual ~hsMutex();

#ifdef HS_BUILD_FOR_WIN32
    HANDLE GetHandle() const { return fMutexH; }
#endif

    void        Lock();
    bool        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_WIN32
    HANDLE  fSemaH;
#elif HS_BUILD_FOR_UNIX
#ifdef USE_SEMA
    sem_t*  fPSema;
    bool    fNamed;
#else
    pthread_mutex_t fPMutex;
    pthread_cond_t  fPCond;
    int32_t       fCounter;
#endif
#endif
public:
    hsSemaphore(int initialValue=0, const char* name=nil);
    ~hsSemaphore();

#ifdef HS_BUILD_FOR_WIN32
    HANDLE GetHandle() const { return fSemaH; }
#endif

    bool        TryWait();
    bool        Wait(hsMilliseconds timeToWait = kPosInfinity32);
    void        Signal();
};

//////////////////////////////////////////////////////////////////////////////
class hsEvent
{
#if HS_BUILD_FOR_UNIX
#ifndef PSEUDO_EVENT
    pthread_mutex_t fMutex;
    pthread_cond_t  fCond;
    bool  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();

#ifdef HS_BUILD_FOR_WIN32
    HANDLE GetHandle() const { return fEvent; }
#endif

    bool  Wait(hsMilliseconds timeToWait = kPosInfinity32);
    void  Signal();
};

//////////////////////////////////////////////////////////////////////////////
class hsSleep
{
public:
    static void Sleep(uint32_t millis);
};

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