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//=============================================================================
// MuseScore
// Music Composition & Notation
//
// Copyright (C) 2002-2011 Werner Schweer
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2
// as published by the Free Software Foundation and appearing in
// the file LICENCE.GPL
//=============================================================================
#ifndef __FIFO_H__
#define __FIFO_H__
#include <atomic>
namespace Ms {
//---------------------------------------------------------
// FifoBase
// - works only for one reader/writer
// - reader writes ridx
// - writer writes widx
// - reader decrements counter
// - writer increments counter
// - counter increment/decrement must be atomic
//---------------------------------------------------------
class FifoBase {
protected:
int ridx; // read index
int widx; // write index
std::atomic<int> counter; // objects in fifo
int maxCount;
void push();
void pop();
public:
FifoBase() { clear(); }
virtual ~FifoBase() {}
void clear();
int count() const { return counter; }
bool isEmpty() const { return counter == 0; }
bool isFull() const { return maxCount == counter; }
};
} // namespace Ms
#endif
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