Describe the Different Types of Memory Ordering in C++11

Different Types of Memory Ordering in C++11

C++11 introduced various types of memory ordering to help control the interaction between threads and memory.

Memory ordering defines how reads and writes to shared variables are executed in a multithreaded environment. The different types include:

• memory_order_relaxed – No synchronization between threads.
• memory_order_acquire – Prevents memory operations from being reordered before the acquire.
• memory_order_release – Ensures memory operations before release are completed.
• memory_order_seq_cst – Strongest ordering, guarantees sequential consistency.

Example of using memory_order_acquire:

atomic x(0);
int y = x.load(memory_order_acquire);

Understanding memory ordering helps avoid subtle bugs in concurrent code.