/****************************************************************************
**
** Copyright (C) 2011 Digia Plc
** All rights reserved.
** For any questions to Digia, please use contact form at http://qt.digia.com
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE$
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the 
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  
**
** If you have questions regarding the use of this file, please use
** contact form at http://qt.digia.com
** $QT_END_LICENSE$
** 
** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
**
****************************************************************************/

#ifndef QATOMIC_SH_H
#define QATOMIC_SH_H

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

#define Q_ATOMIC_INT_REFERENCE_COUNTING_IS_NOT_NATIVE

inline bool QBasicAtomicInt::isReferenceCountingNative()
{ return false; }
inline bool QBasicAtomicInt::isReferenceCountingWaitFree()
{ return false; }

#define Q_ATOMIC_INT_TEST_AND_SET_IS_NOT_NATIVE

inline bool QBasicAtomicInt::isTestAndSetNative()
{ return false; }
inline bool QBasicAtomicInt::isTestAndSetWaitFree()
{ return false; }

#define Q_ATOMIC_INT_FETCH_AND_STORE_IS_NOT_NATIVE

inline bool QBasicAtomicInt::isFetchAndStoreNative()
{ return false; }
inline bool QBasicAtomicInt::isFetchAndStoreWaitFree()
{ return false; }

#define Q_ATOMIC_INT_FETCH_AND_ADD_IS_NOT_NATIVE

inline bool QBasicAtomicInt::isFetchAndAddNative()
{ return false; }
inline bool QBasicAtomicInt::isFetchAndAddWaitFree()
{ return false; }

#define Q_ATOMIC_POINTER_TEST_AND_SET_IS_NOT_NATIVE

template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::isTestAndSetNative()
{ return false; }
template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::isTestAndSetWaitFree()
{ return false; }

#define Q_ATOMIC_POINTER_FETCH_AND_STORE_IS_NOT_NATIVE

template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::isFetchAndStoreNative()
{ return false; }
template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::isFetchAndStoreWaitFree()
{ return false; }

#define Q_ATOMIC_POINTER_FETCH_AND_ADD_IS_NOT_NATIVE

template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::isFetchAndAddNative()
{ return false; }
template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::isFetchAndAddWaitFree()
{ return false; }

extern Q_CORE_EXPORT volatile char qt_atomic_lock;
Q_CORE_EXPORT void qt_atomic_yield(int *count);

inline int qt_atomic_tasb(volatile char *ptr)
{
    register int ret;
    asm volatile("tas.b @%2\n"
                 "movt  %0"
                 : "=&r"(ret), "=m"(*ptr)
                 : "r"(ptr)
                 : "cc", "memory");
    return ret;
}

// Reference counting

inline bool QBasicAtomicInt::ref()
{
    int count = 0;
    while (qt_atomic_tasb(&qt_atomic_lock) == 0)
        qt_atomic_yield(&count);
    int originalValue = _q_value++;
    qt_atomic_lock = 0;
    return originalValue != -1;
}

inline bool QBasicAtomicInt::deref()
{
    int count = 0;
    while (qt_atomic_tasb(&qt_atomic_lock) == 0)
        qt_atomic_yield(&count);
    int originalValue = _q_value--;
    qt_atomic_lock = 0;
    return originalValue != 1;
}

// Test and set for integers

inline bool QBasicAtomicInt::testAndSetOrdered(int expectedValue, int newValue)
{
    bool returnValue = false;
    int count = 0;
    while (qt_atomic_tasb(&qt_atomic_lock) == 0)
        qt_atomic_yield(&count);
    if (_q_value == expectedValue) {
        _q_value = newValue;
        returnValue = true;
    }
    qt_atomic_lock = 0;
    return returnValue;
}

inline bool QBasicAtomicInt::testAndSetRelaxed(int expectedValue, int newValue)
{
    return testAndSetOrdered(expectedValue, newValue);
}

inline bool QBasicAtomicInt::testAndSetAcquire(int expectedValue, int newValue)
{
    return testAndSetOrdered(expectedValue, newValue);
}

inline bool QBasicAtomicInt::testAndSetRelease(int expectedValue, int newValue)
{
    return testAndSetOrdered(expectedValue, newValue);
}

// Fetch and store for integers

inline int QBasicAtomicInt::fetchAndStoreOrdered(int newValue)
{
    int count = 0;
    while (qt_atomic_tasb(&qt_atomic_lock) == 0)
        qt_atomic_yield(&count);
    int originalValue = _q_value;
    _q_value = newValue;
    qt_atomic_lock = 0;
    return originalValue;
}

inline int QBasicAtomicInt::fetchAndStoreRelaxed(int newValue)
{
    return fetchAndStoreOrdered(newValue);
}

inline int QBasicAtomicInt::fetchAndStoreAcquire(int newValue)
{
    return fetchAndStoreOrdered(newValue);
}

inline int QBasicAtomicInt::fetchAndStoreRelease(int newValue)
{
    return fetchAndStoreOrdered(newValue);
}

// Fetch and add for integers

inline int QBasicAtomicInt::fetchAndAddOrdered(int valueToAdd)
{
    int count = 0;
    while (qt_atomic_tasb(&qt_atomic_lock) == 0)
        qt_atomic_yield(&count);
    int originalValue = _q_value;
    _q_value += valueToAdd;
    qt_atomic_lock = 0;
    return originalValue;
}

inline int QBasicAtomicInt::fetchAndAddRelaxed(int valueToAdd)
{
    return fetchAndAddOrdered(valueToAdd);
}

inline int QBasicAtomicInt::fetchAndAddAcquire(int valueToAdd)
{
    return fetchAndAddOrdered(valueToAdd);
}

inline int QBasicAtomicInt::fetchAndAddRelease(int valueToAdd)
{
    return fetchAndAddOrdered(valueToAdd);
}

// Test and set for pointers

template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::testAndSetOrdered(T *expectedValue, T *newValue)
{
    bool returnValue = false;
    int count = 0;
    while (qt_atomic_tasb(&qt_atomic_lock) == 0)
        qt_atomic_yield(&count);
    if (_q_value == expectedValue) {
        _q_value = newValue;
        returnValue = true;
    }
    qt_atomic_lock = 0;
    return returnValue;
}

template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::testAndSetRelaxed(T *expectedValue, T *newValue)
{
    return testAndSetOrdered(expectedValue, newValue);
}

template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::testAndSetAcquire(T *expectedValue, T *newValue)
{
    return testAndSetOrdered(expectedValue, newValue);
}

template <typename T>
Q_INLINE_TEMPLATE bool QBasicAtomicPointer<T>::testAndSetRelease(T *expectedValue, T *newValue)
{
    return testAndSetOrdered(expectedValue, newValue);
}

// Fetch and store for pointers

template <typename T>
Q_INLINE_TEMPLATE T *QBasicAtomicPointer<T>::fetchAndStoreOrdered(T *newValue)
{
    int count = 0;
    while (qt_atomic_tasb(&qt_atomic_lock) == 0)
        qt_atomic_yield(&count);
    T *originalValue = _q_value;
    _q_value = newValue;
    qt_atomic_lock = 0;
    return originalValue;
}

template <typename T>
Q_INLINE_TEMPLATE T *QBasicAtomicPointer<T>::fetchAndStoreRelaxed(T *newValue)
{
    return fetchAndStoreOrdered(newValue);
}

template <typename T>
Q_INLINE_TEMPLATE T *QBasicAtomicPointer<T>::fetchAndStoreAcquire(T *newValue)
{
    return fetchAndStoreOrdered(newValue);
}

template <typename T>
Q_INLINE_TEMPLATE T *QBasicAtomicPointer<T>::fetchAndStoreRelease(T *newValue)
{
    return fetchAndStoreOrdered(newValue);
}

// Fetch and add for pointers

template <typename T>
Q_INLINE_TEMPLATE T *QBasicAtomicPointer<T>::fetchAndAddOrdered(qptrdiff valueToAdd)
{
    int count = 0;
    while (qt_atomic_tasb(&qt_atomic_lock) == 0)
        qt_atomic_yield(&count);
    T *originalValue = (_q_value);
    _q_value += valueToAdd;
    qt_atomic_lock = 0;
    return originalValue;
}

template <typename T>
Q_INLINE_TEMPLATE T *QBasicAtomicPointer<T>::fetchAndAddRelaxed(qptrdiff valueToAdd)
{
    return fetchAndAddOrdered(valueToAdd);
}

template <typename T>
Q_INLINE_TEMPLATE T *QBasicAtomicPointer<T>::fetchAndAddAcquire(qptrdiff valueToAdd)
{
    return fetchAndAddOrdered(valueToAdd);
}

template <typename T>
Q_INLINE_TEMPLATE T *QBasicAtomicPointer<T>::fetchAndAddRelease(qptrdiff valueToAdd)
{
    return fetchAndAddOrdered(valueToAdd);
}

QT_END_NAMESPACE

QT_END_HEADER

#endif // QATOMIC_SH_H
