std::atomic_load, std::atomic_load_explicit

 

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线程 thread (C++11) jthread (C++20) stop_token (C++20) stop_source (C++20) stop_callback (C++20) hardware_destructive_interference_sizehardware_constructive_interference_size (C++17)(C++17) this_thread 命名空间 get_id (C++11) yield (C++11) sleep_for (C++11) sleep_until (C++11) 原子类型 atomic (C++11) atomic_ref (C++20) atomic_flag (C++11) 原子类型的初始化 atomic_init (C++11)(C++20 中弃用) ATOMIC_VAR_INIT (C++11)(C++20 中弃用) ATOMIC_FLAG_INIT (C++11) 原子操作的自由函数 atomic_storeatomic_store_explicit (C++11)(C++11) atomic_loadatomic_load_explicit (C++11)(C++11) atomic_exchangeatomic_exchange_explicit (C++11)(C++11) atomic_compare_exchange_weakatomic_compare_exchange_weak_explicitatomic_compare_exchange_strongatomic_compare_exchange_strong_explicit (C++11)(C++11)(C++11)(C++11) atomic_fetch_addatomic_fetch_add_explicit (C++11)(C++11) atomic_fetch_subatomic_fetch_sub_explicit (C++11)(C++11) atomic_fetch_andatomic_fetch_and_explicit (C++11)(C++11) atomic_fetch_oratomic_fetch_or_explicit (C++11)(C++11) atomic_fetch_xoratomic_fetch_xor_explicit (C++11)(C++11) atomic_is_lock_free (C++11) atomic_waitatomic_wait_explicit (C++20)(C++20) atomic_notify_one (C++20) atomic_notify_all (C++20)

原子标志的自由函数 atomic_flag_test_and_setatomic_flag_test_and_set_explicit (C++11)(C++11) atomic_flag_clearatomic_flag_clear_explicit (C++11)(C++11) atomic_flag_testatomic_flag_test_explicit (C++20)(C++20) atomic_flag_waitatomic_flag_wait_explicit (C++20)(C++20) atomic_flag_notify_one (C++20) atomic_flag_notify_all (C++20) 内存序 memory_order (C++11) kill_dependency (C++11) atomic_thread_fence (C++11) atomic_signal_fence (C++11) 互斥 mutex (C++11) recursive_mutex (C++11) shared_mutex (C++17) timed_mutex (C++11) recursive_timed_mutex (C++11) shared_timed_mutex (C++14) 通用锁管理 lock_guard (C++11) scoped_lock (C++17) unique_lock (C++11) shared_lock (C++14) defer_lock_ttry_to_lock_tadopt_lock_t (C++11)(C++11)(C++11) lock (C++11) try_lock (C++11) defer_locktry_to_lockadopt_lock (C++11)(C++11)(C++11) once_flag (C++11) call_once (C++11) 条件变量 condition_variable (C++11) condition_variable_any (C++11) notify_all_at_thread_exit (C++11) cv_status (C++11) 信号量 counting_semaphorebinary_semaphore (C++20)(C++20) 闩与屏障 latch (C++20) barrier (C++20) future promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11) launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

 

在标头 <atomic> 定义
template< class T > T atomic_load( const std::atomic<T>* obj ) noexcept;	(1)	(C++11 起)
template< class T > T atomic_load( const volatile std::atomic<T>* obj ) noexcept;	(2)	(C++11 起)
template< class T > T atomic_load_explicit( const std::atomic<T>* obj,                         std::memory_order order ) noexcept;	(3)	(C++11 起)
template< class T > T atomic_load_explicit( const volatile std::atomic<T>* obj,                         std::memory_order order ) noexcept;	(4)	(C++11 起)

1,2) 如同用 obj->load() 原子地获得 obj 指向的值。

3,4) 如同用 obj->load(order) 原子地获得 obj 所指向的值。

如果 order 是 std::memory_order_release 和 std::memory_order_acq_rel 之一，那么行为未定义。

参数

obj	-	指向要加载的原子对象的指针
order	-	内存同步顺序

返回值

obj 指向的原子对象所保有的值。

参阅

load	原子地获得原子对象的值 (std::atomic<T> 的公开成员函数)
atomic_storeatomic_store_explicit (C++11)(C++11)	原子地以非原子实参替换原子对象的值 (函数模板)
memory_order (C++11)	为给定的原子操作定义内存顺序约束 (枚举)

std::atomic_load(std::shared_ptr) std::atomic_load_explicit(std::shared_ptr) (C++20 中弃用)

为 std::shared_ptr 特化原子操作 (函数模板)