wxutil.h

用DirectX制作高级动画-[Advanced.Animation.with.DirectX]

//------------------------------------------------------------------------------
// File: WXUtil.h
//
// Desc: DirectShow base classes - defines helper classes and functions for
//       building multimedia filters.
//
// Copyright (c) 1992-2002 Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------------------------


#ifndef __WXUTIL__
#define __WXUTIL__

// eliminate spurious "statement has no effect" warnings.
#pragma warning(disable: 4705)

// wrapper for whatever critical section we have
class CCritSec {

    // make copy constructor and assignment operator inaccessible

    CCritSec(const CCritSec &refCritSec);
    CCritSec &operator=(const CCritSec &refCritSec);

    CRITICAL_SECTION m_CritSec;

#ifdef DEBUG
public:
    DWORD   m_currentOwner;
    DWORD   m_lockCount;
    BOOL    m_fTrace;        // Trace this one
public:
    CCritSec();
    ~CCritSec();
    void Lock();
    void Unlock();
#else

public:
    CCritSec() {
        InitializeCriticalSection(&m_CritSec);
    };

    ~CCritSec() {
        DeleteCriticalSection(&m_CritSec);
    };

    void Lock() {
        EnterCriticalSection(&m_CritSec);
    };

    void Unlock() {
        LeaveCriticalSection(&m_CritSec);
    };
#endif
};

//
// To make deadlocks easier to track it is useful to insert in the
// code an assertion that says whether we own a critical section or
// not.  We make the routines that do the checking globals to avoid
// having different numbers of member functions in the debug and
// retail class implementations of CCritSec.  In addition we provide
// a routine that allows usage of specific critical sections to be
// traced.  This is NOT on by default - there are far too many.
//

#ifdef DEBUG
    BOOL WINAPI CritCheckIn(CCritSec * pcCrit);
    BOOL WINAPI CritCheckIn(const CCritSec * pcCrit);
    BOOL WINAPI CritCheckOut(CCritSec * pcCrit);
    BOOL WINAPI CritCheckOut(const CCritSec * pcCrit);
    void WINAPI DbgLockTrace(CCritSec * pcCrit, BOOL fTrace);
#else
    #define CritCheckIn(x) TRUE
    #define CritCheckOut(x) TRUE
    #define DbgLockTrace(pc, fT)
#endif


// locks a critical section, and unlocks it automatically
// when the lock goes out of scope
class CAutoLock {

    // make copy constructor and assignment operator inaccessible

    CAutoLock(const CAutoLock &refAutoLock);
    CAutoLock &operator=(const CAutoLock &refAutoLock);

protected:
    CCritSec * m_pLock;

public:
    CAutoLock(CCritSec * plock)
    {
        m_pLock = plock;
        m_pLock->Lock();
    };

    ~CAutoLock() {
        m_pLock->Unlock();
    };
};



// wrapper for event objects
class CAMEvent
{

    // make copy constructor and assignment operator inaccessible

    CAMEvent(const CAMEvent &refEvent);
    CAMEvent &operator=(const CAMEvent &refEvent);

protected:
    HANDLE m_hEvent;
public:
    CAMEvent(BOOL fManualReset = FALSE);
    ~CAMEvent();

    // Cast to HANDLE - we don't support this as an lvalue
    operator HANDLE () const { return m_hEvent; };

    void Set() {EXECUTE_ASSERT(SetEvent(m_hEvent));};
    BOOL Wait(DWORD dwTimeout = INFINITE) {
	return (WaitForSingleObject(m_hEvent, dwTimeout) == WAIT_OBJECT_0);
    };
    void Reset() { ResetEvent(m_hEvent); };
    BOOL Check() { return Wait(0); };
};


// wrapper for event objects that do message processing
// This adds ONE method to the CAMEvent object to allow sent
// messages to be processed while waiting

class CAMMsgEvent : public CAMEvent
{

public:

    // Allow SEND messages to be processed while waiting
    BOOL WaitMsg(DWORD dwTimeout = INFINITE);
};

// old name supported for the time being
#define CTimeoutEvent CAMEvent

// support for a worker thread

// simple thread class supports creation of worker thread, synchronization
// and communication. Can be derived to simplify parameter passing
class AM_NOVTABLE CAMThread {

    // make copy constructor and assignment operator inaccessible

    CAMThread(const CAMThread &refThread);
    CAMThread &operator=(const CAMThread &refThread);

    CAMEvent m_EventSend;
    CAMEvent m_EventComplete;

    DWORD m_dwParam;
    DWORD m_dwReturnVal;

protected:
    HANDLE m_hThread;

    // thread will run this function on startup
    // must be supplied by derived class
    virtual DWORD ThreadProc() = 0;

public:
    CAMThread();
    virtual ~CAMThread();

    CCritSec m_AccessLock;	// locks access by client threads
    CCritSec m_WorkerLock;	// locks access to shared objects

    // thread initially runs this. param is actually 'this'. function
    // just gets this and calls ThreadProc
    static DWORD WINAPI InitialThreadProc(LPVOID pv);

    // start thread running  - error if already running
    BOOL Create();

    // signal the thread, and block for a response
    //
    DWORD CallWorker(DWORD);

    // accessor thread calls this when done with thread (having told thread
    // to exit)
    void Close() {
        HANDLE hThread = (HANDLE)InterlockedExchangePointer(&m_hThread, 0);
        if (hThread) {
            WaitForSingleObject(hThread, INFINITE);
            CloseHandle(hThread);
        }
    };

    // ThreadExists
    // Return TRUE if the thread exists. FALSE otherwise
    BOOL ThreadExists(void) const
    {
        if (m_hThread == 0) {
            return FALSE;
        } else {
            return TRUE;
        }
    }

    // wait for the next request
    DWORD GetRequest();

    // is there a request?
    BOOL CheckRequest(DWORD * pParam);

    // reply to the request
    void Reply(DWORD);

    // If you want to do WaitForMultipleObjects you'll need to include
    // this handle in your wait list or you won't be responsive
    HANDLE GetRequestHandle() const { return m_EventSend; };

    // Find out what the request was
    DWORD GetRequestParam() const { return m_dwParam; };

    // call CoInitializeEx (COINIT_DISABLE_OLE1DDE) if
    // available. S_FALSE means it's not available.
    static HRESULT CoInitializeHelper();
};


// CQueue
//
// Implements a simple Queue ADT.  The queue contains a finite number of
// objects, access to which is controlled by a semaphore.  The semaphore
// is created with an initial count (N).  Each time an object is added
// a call to WaitForSingleObject is made on the semaphore's handle.  When
// this function returns a slot has been reserved in the queue for the new
// object.  If no slots are available the function blocks until one becomes
// available.  Each time an object is removed from the queue ReleaseSemaphore
// is called on the semaphore's handle, thus freeing a slot in the queue.
// If no objects are present in the queue the function blocks until an
// object has been added.

#define DEFAULT_QUEUESIZE   2

template <class T> class CQueue {
private:
    HANDLE          hSemPut;        // Semaphore controlling queue "putting"
    HANDLE          hSemGet;        // Semaphore controlling queue "getting"
    CRITICAL_SECTION CritSect;      // Thread seriallization
    int             nMax;           // Max objects allowed in queue
    int             iNextPut;       // Array index of next "PutMsg"
    int             iNextGet;       // Array index of next "GetMsg"
    T              *QueueObjects;   // Array of objects (ptr's to void)

    void Initialize(int n) {
        iNextPut = iNextGet = 0;
        nMax = n;
        InitializeCriticalSection(&CritSect);
        hSemPut = CreateSemaphore(NULL, n, n, NULL);
        hSemGet = CreateSemaphore(NULL, 0, n, NULL);
        QueueObjects = new T[n];
    }