131 lines
2.6 KiB
C++
Executable File
131 lines
2.6 KiB
C++
Executable File
#ifndef _ATOMIC_INT_APPLE_H
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#define _ATOMIC_INT_APPLE_H
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#include <libkern/OSAtomic.h>
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//http://developer.apple.com/library/mac/#documentation/Darwin/Reference/KernelIOKitFramework/OSAtomic_h/index.html
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namespace mt{
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class atomicInt
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{
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private:
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volatile int _q_value;
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public:
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atomicInt()
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{
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_q_value = 0;
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}
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atomicInt( int value )
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{
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_q_value = value;
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}
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// atomic API
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/**
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Reads the current value of this QAtomicInt and then adds valueToAdd
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to the current value, returning the original value.
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Unfortunately, MacOSX does not provide with fetch-and-add functions,
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only add-and-fetch. Therefore, we have to simulate them.
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Implementation based on SDL:
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//http://lists.libsdl.org/pipermail/commits-libsdl.org/2011-January/003568.html
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*/
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inline int fetchAndAddAcquire( int valueToAdd )
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{
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//T *originalValue = currentValue;
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//currentValue += valueToAdd;
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//return originalValue;
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int originalValue;
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do {
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originalValue = _q_value;
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} while (!OSAtomicCompareAndSwap32Barrier(originalValue, originalValue+valueToAdd, &_q_value));
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return originalValue;
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}
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/**
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Atomically increments the value of this atomicInt.
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Returns true if the new value is non-zero, false otherwise.*/
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inline bool ref()
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{
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return OSAtomicIncrement32Barrier(&_q_value) != 0;
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}
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/*
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Atomically decrements the value of this QAtomicInt.
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Returns true if the new value is non-zero, false otherwise.*/
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inline bool deref()
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{
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return OSAtomicDecrement32Barrier(&_q_value) != 0;
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}
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/*
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If the current _q_value of this QAtomicInt is the expectedValue,
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the test-and-set functions assign the newValue to this QAtomicInt
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and return true. If the values are not the same, this function
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does nothing and returns false.
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*/
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inline bool testAndSetOrdered(int expectedValue, int newValue)
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{
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//if (currentValue == expectedValue) {
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// currentValue = newValue;
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// return true;
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// }
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//return false;
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return OSAtomicCompareAndSwap32Barrier(expectedValue, newValue, &_q_value);
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}
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// Non-atomic API
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inline bool operator==(int value) const
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{
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return _q_value == value;
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}
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inline bool operator!=(int value) const
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{
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return _q_value != value;
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}
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inline bool operator!() const
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{
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return _q_value == 0;
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}
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inline operator int() const
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{
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return _q_value;
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}
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inline atomicInt &operator=(int value)
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{
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_q_value = value;
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return *this;
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}
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inline bool operator>(int value) const
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{
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return _q_value > value;
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}
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inline bool operator<(int value) const
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{
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return _q_value < value;
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}
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};
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}//namespace
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#endif
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