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Document QAtomic testAndSet

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[ChangeLog][QtCore][QAtomic] Documented new overloads of testAndSet()
that were originally added for 5.3.

Fixes: QTBUG-103008
Change-Id: I96c7b5828dc284651e6514389f405d7670d6784b
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
(cherry picked from commit b62c3a85452aecf4f6c863645db34857b05d5ebf)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
This commit is contained in:
Jaishree Vyas 2022-08-08 21:36:40 +02:00 committed by Qt Cherry-pick Bot
parent ee349ffba0
commit b627f51978
2 changed files with 87 additions and 0 deletions
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82
src/corelib/thread/qatomic.cpp
View File

@ -397,14 +397,21 @@
Atomic test-and-set.
\note If you use this function in a loop, consider using the overload with the
additional \c{T &currentValue} argument instead, which avoids the extra load() on
failure.
If the current value of this QAtomicInteger is the \a expectedValue,
the test-and-set functions assign the \a newValue to this
QAtomicInteger and return true. If the values are \e not the same,
this function does nothing and returns \c false.
//![memory-order-relaxed]
This function uses \e relaxed \l {QAtomicInteger#Memory
ordering}{memory ordering} semantics, leaving the compiler and
processor to freely reorder memory accesses.
//![memory-order-relaxed]
*/
/*!
@ -412,15 +419,21 @@
Atomic test-and-set.
\note If you use this function in a loop, consider using the overload with the
additional \c{T &currentValue} argument instead, which avoids the extra load() on
failure.
If the current value of this QAtomicInteger is the \a expectedValue,
the test-and-set functions assign the \a newValue to this
QAtomicInteger and return true. If the values are \e not the same,
this function does nothing and returns \c false.
//![memory-order-acquire]
This function uses \e acquire \l {QAtomicInteger#Memory
ordering}{memory ordering} semantics, which ensures that memory
access following the atomic operation (in program order) may not
be re-ordered before the atomic operation.
//![memory-order-acquire]
*/
/*!
@ -428,15 +441,21 @@
Atomic test-and-set.
\note If you use this function in a loop, consider using the overload with the
additional \c{T &currentValue} argument instead, which avoids the extra load() on
failure.
If the current value of this QAtomicInteger is the \a expectedValue,
the test-and-set functions assign the \a newValue to this
QAtomicInteger and return true. If the values are \e not the same,
this function does nothing and returns \c false.
//![memory-order-release]
This function uses \e release \l {QAtomicInteger#Memory
ordering}{memory ordering} semantics, which ensures that memory
access before the atomic operation (in program order) may not be
re-ordered after the atomic operation.
//![memory-order-release]
*/
/*!
@ -444,15 +463,78 @@
Atomic test-and-set.
\note If you use this function in a loop, consider using the overload with the
additional \c{T &currentValue} argument instead, which avoids the extra load() on
failure.
If the current value of this QAtomicInteger is the \a expectedValue,
the test-and-set functions assign the \a newValue to this
QAtomicInteger and return true. If the values are \e not the same,
this function does nothing and returns \c false.
//![memory-order-ordered]
This function uses \e ordered \l {QAtomicInteger#Memory
ordering}{memory ordering} semantics, which ensures that memory
access before and after the atomic operation (in program order)
may not be re-ordered.
//![memory-order-ordered]
*/
/*!
\fn template <typename T> bool QAtomicInteger<T>::testAndSetRelaxed(T expectedValue, T newValue, T &currentValue)
\since 5.3
Atomic test-and-set.
If the current value of this QAtomicInteger is the \a expectedValue, the
test-and-set functions assign the \a newValue to this QAtomicInteger and
return \c true. If the values are \e not the same, the functions load the
current value of this QAtomicInteger into \a currentValue and return \c false.
\include qatomic.cpp memory-order-relaxed
*/
/*!
\fn template <typename T> bool QAtomicInteger<T>::testAndSetAcquire(T expectedValue, T newValue, T &currentValue)
\since 5.3
Atomic test-and-set.
If the current value of this QAtomicInteger is the \a expectedValue, the
test-and-set functions assign the \a newValue to this QAtomicInteger and
return \c true. If the values are \e not the same, the functions load the
current value of this QAtomicInteger into \a currentValue and return \c false.
\include qatomic.cpp memory-order-acquire
*/
/*!
\fn template <typename T> bool QAtomicInteger<T>::testAndSetRelease(T expectedValue, T newValue, T &currentValue)
\since 5.3
Atomic test-and-set.
If the current value of this QAtomicInteger is the \a expectedValue, the
test-and-set functions assign the \a newValue to this QAtomicInteger and
return \c true. If the values are \e not the same, the functions loads the
current value of this QAtomicInteger into \a currentValue and return \c false.
\include qatomic.cpp memory-order-release
*/
/*!
\fn template <typename T> bool QAtomicInteger<T>::testAndSetOrdered(T expectedValue, T newValue, T &currentValue)
\since 5.3
Atomic test-and-set.
If the current value of this QAtomicInteger is the \a expectedValue, the
test-and-set functions assign the \a newValue to this QAtomicInteger and
return \c true. If the values are \e not the same, it loads the current
value of this QAtomicInteger into \a currentValue and return \c false.
\include qatomic.cpp memory-order-ordered
*/
/*!

5
src/corelib/thread/qatomic.h
View File

@ -70,6 +70,11 @@ public:
bool testAndSetRelease(T expectedValue, T newValue);
bool testAndSetOrdered(T expectedValue, T newValue);
bool testAndSetRelaxed(T expectedValue, T newValue, T &currentValue);
bool testAndSetAcquire(T expectedValue, T newValue, T &currentValue);
bool testAndSetRelease(T expectedValue, T newValue, T &currentValue);
bool testAndSetOrdered(T expectedValue, T newValue, T &currentValue);
static constexpr bool isFetchAndStoreNative();
static constexpr bool isFetchAndStoreWaitFree();