原子类型可以是无锁的,也可以有锁 (c++17)通过静态函数std::atomic::is_always_lock_free 判断 (c++11)通过成员函数 is_lock_free()判断 2)有锁or无锁 性能:无锁操作通常比有锁操作更快,因为它们不需要操作系统级别的同步机制。无锁操作可以直接利用硬件的原子指令,这通常比软件锁更高效。 3)自旋锁与atomic...
首先 您被允许有std::atomic< 很大的且重要的结构>, 所以这样的std::atomic通常不被保证是无锁的(在大多数系统上,尽管很多琐碎的数据类型例如bool,int等都是可以的(笔者:上面源码中的注释)) No other type requires lock-free operations, and hence the atomic_flag type is the minimum hardware-implemented ...
所以这样的std::atomic通常不被保证是无锁的(在大多数系统上,尽管很多琐碎的数据类型例如bool,int等都是可以的(笔者:上面源码中的注释)) No other type requires lock-free operations, and hence the atomic_flag type is the minimum hardware-implemented type needed to conform to this standard. The remainin...
atomic& operator= (const atomic&) volatile = delete; 3)is_lock_free 检查对象是否没有加锁。 4)store 该操作是原子的,memory ordering由sync指定。 void store (T val, memory_order sync = memory_order_seq_cst) volatile noexcept; void store (T val, memory_order sync = memory_order_seq_cst)...
std::atomic_flag Defined in header<atomic> classatomic_flag; (since C++11) std::atomic_flagis an atomic boolean type. Unlike all specializations ofstd::atomic, it is guaranteed to be lock-free. Unlikestd::atomic<bool>,std::atomic_flagdoes not provide load or store operations. ...
atomic_flag From cppreference.com <c |atomic Defined in header<stdatomic.h> structatomic_flag; (since C11) atomic_flagis an atomic boolean type. Unlike other atomic types, it is guaranteed to be lock-free. Unlikeatomic_bool,atomic_flagdoes not provide load or store operations....
std::atomic_flag is an atomic boolean type. Unlike all specializations of std::atomic, it is guaranteed to be lock-free. Unlike std::atomic<bool>, std::atomic_flag does not provide load or store operations. Member functions(constructor) constructs an atomic_flag (public member function) ...
boolis_lock_free()const; voidstore(T, memory_order = memory_order_seq_cst)volatile; voidstore(T, memory_order = memory_order_seq_cst); T load(memory_order = memory_order_seq_cst)constvolatile; T load(memory_order = memory_order_seq_cst)const; operatorT()constvolatile; operatorT()cons...
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::fetch_xor std::atomic::is_always...
Describes an object that atomically sets and clears a bool flag. Operations on atomic flags are always lock-free.复制 struct atomic_flag; MembersPublic Methods展开表 Name Description atomic_flag::clear Method Sets the stored flag to false. atomic_flag::test_and_set Method Sets the stored ...