godot/core/safe_refcount.h

/*************************************************************************/
/*  safe_refcount.h                                                      */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
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#ifndef SAFE_REFCOUNT_H
#define SAFE_REFCOUNT_H

#include "os/mutex.h"
/* x86/x86_64 GCC */

#include "platform_config.h"
#include "typedefs.h"


uint32_t atomic_conditional_increment( register uint32_t * counter );
uint32_t atomic_decrement( register uint32_t * pw );
uint32_t atomic_increment( register uint32_t * pw );



struct SafeRefCount {

  uint32_t count;

public:

	// destroy() is called when weak_count_ drops to zero.

	bool ref() {  //true on success

		return atomic_conditional_increment( &count ) != 0;
	}

	uint32_t refval() {  //true on success

		return atomic_conditional_increment( &count );
	}

	bool unref() { // true if must be disposed of

		if( atomic_decrement ( &count ) == 0 ) {
			return true;
		}

		return false;
	}

	uint32_t get() const { // nothrow

		return count;
	}

	void init(uint32_t p_value=1) {

		count=p_value;
	}

};



#endif