GRK/dependencies/physx-4.1/source/foundation/include/PsSync.h

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#ifndef PSFOUNDATION_PSSYNC_H
#define PSFOUNDATION_PSSYNC_H

#include "PsAllocator.h"

namespace physx
{
namespace shdfnd
{
/*!
Implementation notes:
* - Calling set() on an already signaled Sync does not change its state.
* - Calling reset() on an already reset Sync does not change its state.
* - Calling set() on a reset Sync wakes all waiting threads (potential for thread contention).
* - Calling wait() on an already signaled Sync will return true immediately.
* - NOTE: be careful when pulsing an event with set() followed by reset(), because a
*   thread that is not waiting on the event will miss the signal.
*/
class PX_FOUNDATION_API SyncImpl
{
  public:
	static const uint32_t waitForever = 0xffffffff;

	SyncImpl();

	~SyncImpl();

	/** Wait on the object for at most the given number of ms. Returns
	*  true if the object is signaled. Sync::waitForever will block forever
	*  or until the object is signaled.
	*/

	bool wait(uint32_t milliseconds = waitForever);

	/** Signal the synchronization object, waking all threads waiting on it */

	void set();

	/** Reset the synchronization object */

	void reset();

	/**
	Size of this class.
	*/
	static uint32_t getSize();
};

/*!
Implementation notes:
* - Calling set() on an already signaled Sync does not change its state.
* - Calling reset() on an already reset Sync does not change its state.
* - Calling set() on a reset Sync wakes all waiting threads (potential for thread contention).
* - Calling wait() on an already signaled Sync will return true immediately.
* - NOTE: be careful when pulsing an event with set() followed by reset(), because a
*   thread that is not waiting on the event will miss the signal.
*/
template <typename Alloc = ReflectionAllocator<SyncImpl> >
class SyncT : protected Alloc
{
  public:
	static const uint32_t waitForever = SyncImpl::waitForever;

	SyncT(const Alloc& alloc = Alloc()) : Alloc(alloc)
	{
		mImpl = reinterpret_cast<SyncImpl*>(Alloc::allocate(SyncImpl::getSize(), __FILE__, __LINE__));
		PX_PLACEMENT_NEW(mImpl, SyncImpl)();
	}

	~SyncT()
	{
		mImpl->~SyncImpl();
		Alloc::deallocate(mImpl);
	}

	/** Wait on the object for at most the given number of ms. Returns
	*  true if the object is signaled. Sync::waitForever will block forever
	*  or until the object is signaled.
	*/

	bool wait(uint32_t milliseconds = SyncImpl::waitForever)
	{
		return mImpl->wait(milliseconds);
	}

	/** Signal the synchronization object, waking all threads waiting on it */

	void set()
	{
		mImpl->set();
	}

	/** Reset the synchronization object */

	void reset()
	{
		mImpl->reset();
	}

  private:
	class SyncImpl* mImpl;
};

typedef SyncT<> Sync;

} // namespace shdfnd
} // namespace physx

#endif // #ifndef PSFOUNDATION_PSSYNC_H