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#ifndef INCLUDED_SAL_INTERNAL_ONCE_H
#define INCLUDED_SAL_INTERNAL_ONCE_H

/** sal_once_type
 *  (platform dependent)
 */

#if defined(SAL_UNX) || defined(SAL_OS2)

#include <pthread.h>

typedef pthread_once_t sal_once_type;

#define SAL_ONCE_INIT PTHREAD_ONCE_INIT
#define SAL_ONCE(once, init) pthread_once((once), (init))

#elif defined(SAL_W32)

#define WIN32_LEAN_AND_MEAN
#pragma warning(push,1) /* disable warnings within system headers */
#include <windows.h>
#pragma warning(pop)

typedef struct sal_once_st sal_once_type;
struct sal_once_st
{
	LONG volatile m_done;
	LONG volatile m_lock;
};

#define SAL_ONCE_INIT { 0, 0 }
#define SAL_ONCE(once, init) \
{ \
	sal_once_type * control = (once); \
	if (!(control->m_done)) \
	{ \
		while (InterlockedExchange(&(control->m_lock), 1) == 1) Sleep(0); \
		if (!(control->m_done)) \
		{ \
			void (*init_routine)(void) = (init); \
			(*init_routine)(); \
			control->m_done = 1; \
		} \
		InterlockedExchange(&(control->m_lock), 0); \
	} \
}

#else
#error Unknown platform
#endif /* SAL_UNX | SAL_W32 */

#endif /* INCLUDED_SAL_INTERNAL_ONCE_H */