首先参考：std::atomic<T>::compare_exchange_weak, std::atomic<T>::compare_exchange_strong When ...
在C++中，`std::atomic::compare_exchange`函数的选择主要基于业务需求和数据对象的特性。选择`strong`版本的比较与交换操作，通常意味着在比较不匹配时不需要循环，这是更优的选择，除非数据类型`T`的表示可能包含填充位、陷阱位或提供相同值的不同对象表示（如浮点数的NaN）。在这些情况下，弱比较与交...
std::atomic_exchange,std::atomic_exchange_explicit C++ Concurrency support library Defined in header<atomic> template<classT> T atomic_exchange(std::atomic<T>*obj, typenamestd::atomic<T>::value_typedesired)noexcept; (1)(since C++11)
Atomic operations libraryATOMIC_FLAG_INITATOMIC_VAR_INITATOMIC_xxx_LOCK_FREEstd::atomicstd::atomic::atomicstd::atomic::compare_exchange_strongstd::atomic::compare_exchange_weakstd::atomic::exchangestd::atomic::fetch_addstd::atomic::fetch_andstd::atomic::fetch_orstd::atomic::fetch_substd::atomi...
Something likehttps://en.cppreference.com/w/cpp/atomic/atomic_exchange If at return of such function the value of the counter already increased it is not a problem, but it is important that the load and store of the counter value happen atomically ...
ATOMIC_xxx_LOCK_FREE std::atomic std::atomic::atomic std::atomic::compare_exchange_strong std::atomic::compare_exchange_weak std::atomic::exchange std::atomic::fetch_add std::atomic::fetch_and std::atomic::fetch_or std::atomic::fetch_sub ...
std::atomic_exchange, std::atomic_exchange_explicit std::atomic std::atomic_flag std::atomic_ref std::atomic_compare_exchange_weak, std::atomic_compare_exchange_strong, std::atomic_compare_exchange_weak_explicit, std::atomic_compare_exchange_strong_explicit std::atomic_fetch_add, std::atomic_...
atomic::fetch_xor atomic::operator&=atomic::operator|=atomic::operator^= T exchange(T desired,std::memory_orderorder= std::memory_order_seq_cst)noexcept; (1)(since C++11) T exchange(T desired,std::memory_orderorder= std::memory_order_seq_cst)volatilenoexcept; ...
template< class T > T exchange( volatile std::atomic<T>* obj, T desired ); 其中,obj参数指向需要替换值的atomic对象,desired参数为期望替换成的值。如果替换成功,则返回原来的值。 整个操作是原子的(原子读-修改-写操作):从读取(要返回)值的那一刻到此函数修改值的那一刻,该值不受其他线程的影响。
演示std::compare_exchange_strong 如何要么更改原子对象的值,要么将变量用于比较。 本节未完成原因:强 CAS 的更实际用法会更好,例如在 Concurrency in Action 使用它的地方 运行此代码#include <atomic> #include <iostream>std::atomic<int> ai;int