标记上std::memory_order_seq_cst的原子操作不仅满足释放-获取顺序的要求(一个线程中 store-release 之前的写入操作在另一个 load-acquire 之后都可见),而且为所有如此标记的原子操作建立了唯一的全局统一修改顺序(single total modification order)。 正式地说,在不考虑std::atomic_thread_fence的情况下,对于每个 lo...
以保证读到的值是最新的, 此处和std::memory_order::memory_order_acquire是等价的....
int data; void producer() { std::string* p = new std::string("Hello"); data = 42; ptr.store(p, std::memory_order_release); } void consumer() { std::string* p2; while (!(p2 = ptr.load(std::memory_order_acquire))) ; assert(*p2 == "Hello"); // never fires assert(data...
memory_order 保证的是可见性的顺序，而不是可见性
通常情况下,std::atomic_flag 被用作简单的互斥锁,而不是用来存储信息。 使用std::atomic_flag 进行原子锁操作: #include <iostream> #include <atomic> #include <thread> std::atomic_flag flag = ATOMIC_FLAG_INIT; void func(int id) { while (flag.test_and_set(std::memory_order_acquire)) { /...
order一定是std::memory_order_relaxed,,,std::memory_order_consume,,,std::memory_order_acquire或std::memory_order_seq_cst否则,行为是未定义的。 参数 order - memory order constraints to enforce 返回值 原子变量的当前值。 例外 noexcept规格: ...
obj->load(order) 参数 obj - pointer to the atomic object to modify order - the memory synchronization ordering for this operation: only std::memory_order_relaxed, std::memory_order_consume, std::memory_order_acquire and std::memory_order_seq_cst are permitted....
DTS_E_BITASK_CANNOT_ACQUIRE_CONNECTION Field DTS_E_BITASK_CANNOT_RETRIEVE_COLUMN_INFO Field DTS_E_BITASK_CANNOT_RETRIEVE_TABLES Field DTS_E_BITASK_CANNOTRETAINCONNINTRANSACTION Field DTS_E_BITASK_DATA_FILE_NOT_SPECIFIED Field DTS_E_BITASK_DESTINATION_TABLE_NOT_SPECIFIED Field DTS_E_BITASK_ER...
DTS_E_BITASK_CANNOT_ACQUIRE_CONNECTION DTS_E_BITASK_CANNOT_RETRIEVE_COLUMN_INFO DTS_E_BITASK_CANNOT_RETRIEVE_TABLES DTS_E_BITASK_CANNOTRETAINCONNINTRANSACTION DTS_E_BITASK_DATA_FILE_NOT_SPECIFIED DTS_E_BITASK_DESTINATION_TABLE_NOT_SPECIFIED DTS_E_BITASK_ERROR_IN_DB_OPERATION DTS_E_BITASK...
DTS_E_BITASK_CANNOT_ACQUIRE_CONNECTION Field DTS_E_BITASK_CANNOT_RETRIEVE_COLUMN_INFO Field DTS_E_BITASK_CANNOT_RETRIEVE_TABLES Field DTS_E_BITASK_CANNOTRETAINCONNINTRANSACTION Field DTS_E_BITASK_DATA_FILE_NOT_SPECIFIED Field DTS_E_BITASK_DESTINATION_TABLE_NOT_SPECIFIED Field DTS_E_BITASK_ER...