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✏️ Editing: IlmThreadSemaphore.h

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//
// Copyright (c) 2005-2012, Industrial Light & Magic, a division of Lucas
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#ifndef INCLUDED_ILM_THREAD_SEMAPHORE_H
#define INCLUDED_ILM_THREAD_SEMAPHORE_H

//-----------------------------------------------------------------------------
//
//	class Semaphore -- a wrapper class for
//	system-dependent counting semaphores
//
//-----------------------------------------------------------------------------

#include "IlmBaseConfig.h"
#include "IlmThreadExport.h"
#include "IlmThreadNamespace.h"

#if defined _WIN32 || defined _WIN64
    #ifdef NOMINMAX
        #undef NOMINMAX
    #endif
    #define NOMINMAX
    #include <windows.h>
#elif HAVE_PTHREAD && !HAVE_POSIX_SEMAPHORES
    #include <pthread.h>
#elif HAVE_PTHREAD && HAVE_POSIX_SEMAPHORES
    #include <semaphore.h>
#endif

ILMTHREAD_INTERNAL_NAMESPACE_HEADER_ENTER

class ILMTHREAD_EXPORT Semaphore
{
  public:

Semaphore (unsigned int value = 0);
    virtual ~Semaphore();

void	wait();
    bool	tryWait();
    void	post();
    int		value() const;

private:

#if defined _WIN32 || defined _WIN64

mutable HANDLE _semaphore;

#elif HAVE_PTHREAD && !HAVE_POSIX_SEMAPHORES

//
	// If the platform has Posix threads but no semapohores,
	// then we implement them ourselves using condition variables
	//

struct sema_t
	{
	    unsigned int count;
	    unsigned long numWaiting;
	    pthread_mutex_t mutex;
	    pthread_cond_t nonZero;
	};

mutable sema_t _semaphore;

#elif HAVE_PTHREAD && HAVE_POSIX_SEMAPHORES

mutable sem_t _semaphore;

#endif

void operator = (const Semaphore& s);	// not implemented
    Semaphore (const Semaphore& s);		// not implemented
};

ILMTHREAD_INTERNAL_NAMESPACE_HEADER_EXIT

#endif // INCLUDED_ILM_THREAD_SEMAPHORE_H

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