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/* Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009 Dean Beeler, Jerome Fisher
* Copyright (C) 2011-2022 Dean Beeler, Jerome Fisher, Sergey V. Mikayev
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef MT32EMU_MIDI_EVENT_QUEUE_H
#define MT32EMU_MIDI_EVENT_QUEUE_H
#include "globals.h"
#include "Types.h"
namespace MT32Emu {
/**
* Simple queue implementation using a ring buffer to store incoming MIDI event before the synth actually processes it.
* It is intended to:
* - get rid of prerenderer while retaining graceful partial abortion
* - add fair emulation of the MIDI interface delays
* - extend the synth interface with the default implementation of a typical rendering loop.
* THREAD SAFETY:
* It is safe to use either in a single thread environment or when there are only two threads - one performs only reading
* and one performs only writing. More complicated usage requires external synchronisation.
*/
class MidiEventQueue {
public:
class SysexDataStorage;
struct MidiEvent {
const Bit8u *sysexData;
union {
Bit32u sysexLength;
Bit32u shortMessageData;
};
Bit32u timestamp;
};
explicit MidiEventQueue(
// Must be a power of 2
Bit32u ringBufferSize,
Bit32u storageBufferSize
);
~MidiEventQueue();
void reset();
bool pushShortMessage(Bit32u shortMessageData, Bit32u timestamp);
bool pushSysex(const Bit8u *sysexData, Bit32u sysexLength, Bit32u timestamp);
const volatile MidiEvent *peekMidiEvent();
void dropMidiEvent();
inline bool isEmpty() const;
private:
SysexDataStorage &sysexDataStorage;
MidiEvent * const ringBuffer;
const Bit32u ringBufferMask;
volatile Bit32u startPosition;
volatile Bit32u endPosition;
};
} // namespace MT32Emu
#endif // #ifndef MT32EMU_MIDI_EVENT_QUEUE_H
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