c++ Programming Glossary: memory_order_relaxed

http://stackoverflow.com/questions/12346487/what-do-each-memory-order-mean

The below is wrong so don't try to learn from it memory_order_relaxed Does not sync but is not ignored when order is done from another.. consistency across all threads. The opposite approach is memory_order_relaxed . This model allows for much less synchronization by removing..

Does the semantics of `std::memory_order_acquire` requires processor instructions on x86/x86_64?

http://stackoverflow.com/questions/18576986/does-the-semantics-of-stdmemory-order-acquire-requires-processor-instruction

pipeline and assembler's code always corresponds to std memory_order_relaxed and these restrictions are necessary only for the optimization.. for store MSVS2012 x86_64 std atomic int a a.store 0 std memory_order_relaxed 000000013F931A0D mov dword ptr a 0 a.store 1 std memory_order_release.. Disassembler GCC 4.8.1 x86_64 GDB load 20 temp a.load std memory_order_relaxed 21 temp a.load std memory_order_acquire 22 temp a.load std memory_order_seq_cst..

Why GCC does not use LOAD(without fence) and STORE+SFENCE for std::memory_order_seq_cst?

http://stackoverflow.com/questions/19047327/why-gcc-does-not-use-loadwithout-fence-and-storesfence-for-stdmemory-order

void rel movl 0 a rip int temp 0 a.store temp std memory_order_relaxed With respect to the atomic variable a seq and rel are both ordered..

Double-Checked Lock Singleton in C++11

http://stackoverflow.com/questions/6086912/double-checked-lock-singleton-in-c11

m_instance ... static Tp instance if m_instance.load std memory_order_relaxed std lock_guard std mutex lock m_mutex if m_instance.load std.. i std memory_order_release return m_instance.load std memory_order_relaxed Is the std memory_model_acquire of the load operation superfluous.. both load and store operations by switching them to std memory_order_relaxed In that case is the acquire release semantic of std mutex enough..

C++11 introduced a standardized memory model. What does it mean? And how is it going to affect C++ programming?

http://stackoverflow.com/questions/6319146/c11-introduced-a-standardized-memory-model-what-does-it-mean-and-how-is-it-g

this Global atomic int x y Thread 1 Thread 2 x.store 17 memory_order_relaxed cout y.load memory_order_relaxed y.store 37 memory_order_relaxed.. 1 Thread 2 x.store 17 memory_order_relaxed cout y.load memory_order_relaxed y.store 37 memory_order_relaxed cout x.load memory_order_relaxed.. cout y.load memory_order_relaxed y.store 37 memory_order_relaxed cout x.load memory_order_relaxed endl The more modern the CPU..

Memory model ordering and visibility?

http://stackoverflow.com/questions/7461484/memory-model-ordering-and-visibility

then a.load memory_order_acquire is equivalent to a.load memory_order_relaxed followed by atomic_thread_fence memory_order_acquire . Similarly.. memory_order_release before a call to a.store x memory_order_relaxed . memory_order_consume is a special case of memory_order_acquire.. it would act as a release fence for a subsequent a.store x memory_order_relaxed . 3 Fences and atomic operations do not work like mutexes. You..

How to use std::atomic efficiently

http://stackoverflow.com/questions/8749038/how-to-use-stdatomic-efficiently

about ordering constraints on your atomic object then use memory_order_relaxed on what would otherwise be the non atomic operations. However..

Concurrency: Atomic and volatile in C++11 memory model

http://stackoverflow.com/questions/8819095/concurrency-atomic-and-volatile-in-c11-memory-model

2 writes. If you use other memory orderings such as std memory_order_relaxed or std memory_order_acquire then the constraints are relaxed..