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/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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 Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qplatformdefs.h"
#include <stdlib.h>
/*
Define the container allocation functions in a separate file, so that our
users can easily override them.
*/
QT_BEGIN_NAMESPACE
void *qMalloc(size_t size)
{
return ::malloc(size);
}
void qFree(void *ptr)
{
::free(ptr);
}
void *qRealloc(void *ptr, size_t size)
{
return ::realloc(ptr, size);
}
void *qMallocAligned(size_t size, size_t alignment)
{
return qReallocAligned(0, size, 0, alignment);
}
void *qReallocAligned(void *oldptr, size_t newsize, size_t oldsize, size_t alignment)
{
// fake an aligned allocation
Q_UNUSED(oldsize);
void *actualptr = oldptr ? static_cast<void **>(oldptr)[-1] : 0;
if (alignment <= sizeof(void*)) {
// special, fast case
void **newptr = static_cast<void **>(qRealloc(actualptr, newsize + sizeof(void*)));
if (!newptr)
return 0;
if (newptr == actualptr) {
// realloc succeeded without reallocating
return oldptr;
}
*newptr = newptr;
return newptr + 1;
}
// qMalloc returns pointers aligned at least at sizeof(size_t) boundaries
// but usually more (8- or 16-byte boundaries).
// So we overallocate by alignment-sizeof(size_t) bytes, so we're guaranteed to find a
// somewhere within the first alignment-sizeof(size_t) that is properly aligned.
// However, we need to store the actual pointer, so we need to allocate actually size +
// alignment anyway.
void *real = qRealloc(actualptr, newsize + alignment);
if (!real)
return 0;
quintptr faked = reinterpret_cast<quintptr>(real) + alignment;
faked &= ~(alignment - 1);
void **faked_ptr = reinterpret_cast<void **>(faked);
// now save the value of the real pointer at faked-sizeof(void*)
// by construction, alignment > sizeof(void*) and is a power of 2, so
// faked-sizeof(void*) is properly aligned for a pointer
faked_ptr[-1] = real;
return faked_ptr;
}
void qFreeAligned(void *ptr)
{
if (!ptr)
return;
void **ptr2 = static_cast<void **>(ptr);
free(ptr2[-1]);
}
QT_END_NAMESPACE
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