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/****************************************************************************
**
** Copyright (C) 2008-2012 NVIDIA Corporation.
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt 3D Studio.
**
** $QT_BEGIN_LICENSE:GPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "foundation/Qt3DSAllocatorCallback.h"
#include "foundation/Qt3DSContainers.h"
namespace qt3ds {
namespace foundation {
/**
* Allocator that allocates slabs of a certain size and objects then
* get allocated from those slabs. This allocator is designed to reset,
* meaning every frame you can call reset and the objects get freed but
* not destructed. This allocator does not call destructors!!
*/
template <QT3DSU32 alignmentInBytes = 4, QT3DSU32 slabSize = 8192>
struct SFastAllocator : NVAllocatorCallback
{
ForwardingAllocator m_Allocator;
nvvector<QT3DSU8 *> m_Slabs;
QT3DSU32 m_Offset;
enum {
SlabSize = slabSize,
};
static size_t getSlabSize() { return slabSize; }
SFastAllocator(NVAllocatorCallback &alloc, const char *memName)
: m_Allocator(alloc, memName)
, m_Slabs(alloc, "SFastAllocator::m_Slabs")
, m_Offset(0)
{
}
~SFastAllocator()
{
for (QT3DSU32 idx = 0, end = m_Slabs.size(); idx < end; ++idx)
m_Allocator.deallocate(m_Slabs[idx]);
m_Slabs.clear();
m_Offset = 0;
}
void *allocate(size_t inSize, const char *inFile, int inLine, int inFlags = 0)
{
(void)inFlags;
if (inSize > slabSize) {
QT3DS_ASSERT(false);
return NULL;
}
QT3DSU32 misalign = m_Offset % alignmentInBytes;
if (misalign)
m_Offset = m_Offset + (alignmentInBytes - misalign);
QT3DSU32 currentSlab = m_Offset / slabSize;
QT3DSU32 slabOffset = m_Offset % slabSize;
QT3DSU32 amountLeftInSlab = slabSize - slabOffset;
if (inSize > amountLeftInSlab) {
++currentSlab;
slabOffset = 0;
m_Offset = currentSlab * slabSize;
}
while (currentSlab >= m_Slabs.size()) {
m_Slabs.push_back((QT3DSU8 *)m_Allocator.allocate(slabSize, inFile, inLine));
}
QT3DSU8 *data = m_Slabs[currentSlab] + slabOffset;
// This would indicate the underlying allocator isn't handing back aligned memory.
QT3DS_ASSERT(reinterpret_cast<size_t>(data) % alignmentInBytes == 0);
m_Offset += (QT3DSU32)inSize;
return data;
}
void *allocate(size_t size, const char * /*typeName*/, const char *filename, int line,
int flags = 0) override
{
return allocate(size, filename, line, flags);
}
void *allocate(size_t size, const char * /*typeName*/, const char *filename, int line,
size_t alignment, size_t /*alignmentOffset*/) override
{
QT3DS_ASSERT(alignment == alignmentInBytes);
if (alignment == alignmentInBytes)
return allocate(size, filename, line);
return NULL;
}
// only reset works with deallocation
void deallocate(void *) override {}
void reset() { m_Offset = 0; }
};
}
}
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