What are the similarities between the Java memory model and the C++11 memory model?

The Java memory model was an important influence on the C++11 memory model, and was where we pulled the terms happens-before and synchronizes-with from. However, the C++11 memory model offers much more fine-grained control over memory ordering than the Java memory model.

Java volatile variables are equivalent to C++11 std::atomic<> variables, if you use std::memory_order_acquire memory ordering for reads, std::memory_order_release ordering for writes, and std::memory_order_acq_rel ordering for RMW operations.

There is no equivalent in Java to std::memory_order_relaxed, or std::memory_order_seq_cst.