这种全局序列一致性带来更多的同步成本，因此在性能上memory_order_acq_rel通常优于memory_order_seq_cst...
y.store(true,std::memory_order_seq_cst)TH3:WHILE !x.load(std::memory_order_seq_cst)IF y.l...
、memory_order_acq_rel（结合acquire和release效果）以及memory_order_seq_cst（提供顺序一致性的最严格...
memory_order_acquire:All writes in other threads that release the same atomic variable are visible in the current thread 初步理解为memory_order_consume会比memory_order_acquire少一些强制依赖关系,或者理解为memory_order_acquire的效果是释放操作后有内存栅设置。 gcc的解释更清晰一些: __ATOMIC_RELAXED No ...
typedef enum memory_order { memory_order_relaxed, memory_order_consume, memory_order_acquire, memory_order_release, memory_order_acq_rel, memory_order_seq_cst, } memory_order; 备注 展开表 memory_order_relaxed 不需要的排序。 memory_order_consume 加载操作,执行内存位置的使用操作。 memory_order...
memory_order_acq_rel 带此内存定序的读修改写操作既是获得操作又是释放操作。当前线程的读或写内存不能被重排到此存储之前或之后。所有释放同一原子变量的线程的写入可见于修改之前,而且修改可见于其他获得同一原子变量的线程。 memory_order_seq_cst 有此内存定序的加载操作进行获得操作,存储操作进行释放操作,而读...
namespacestd {typedefenummemory_order{memory_order_relaxed, memory_order_consume, memory_order_acquire, memory_order_release, memory_order_acq_rel, memory_order_seq_cst } memory_order; 其对应着以下三类的memory order(内存顺序模型) memory_order_seq_cst:顺序一致性模型,这个是默认提供的最强的一致性...
memory_order::acq_rel The operation acts as both an acquire and a release. Read and write operations cannot be re-ordered around the operation, and preceding writes must be made visible as previously described formemory_order::release.
Which can be one of std::memory_order_relaxed, std::memory_order_acquire, std::memory_order_release, std::memory_order_acq_rel, std::memory_order_consume or std::memory_order_seq_cst load: this is read operation on an atomic type. store: this is a write operation on an atomic type...
{ m_lock_word.exchange(false,std::memory_order_acq_rel); if (m_waiters.load()) { signal(); } } They are inspired by respectively "Option A" and "Option B" in https://stackoverflow.com/questions/60053973/how-to-achieve-a-storeload-barrier-in-c11 so you can read the whole "proof...