+which simply reads the counter value currently visible to the calling thread.
+The read is atomic in that the return value is guaranteed to be one of the
+values initialized or modified with the interface operations if a proper
+implicit or explicit memory barrier is used after possible runtime
+initialization by any other thread and the value is modified only with the
+interface operations. atomic_read does not guarantee that the runtime
+initialization by any other thread is visible yet, so the user of the
+interface must take care of that with a proper implicit or explicit memory
+barrier.
+
+*** WARNING: atomic_read() and atomic_set() DO NOT IMPLY BARRIERS! ***
+
+Some architectures may choose to use the volatile keyword, barriers, or inline
+assembly to guarantee some degree of immediacy for atomic_read() and
+atomic_set(). This is not uniformly guaranteed, and may change in the future,
+so all users of atomic_t should treat atomic_read() and atomic_set() as simple
+C statements that may be reordered or optimized away entirely by the compiler
+or processor, and explicitly invoke the appropriate compiler and/or memory
+barrier for each use case. Failure to do so will result in code that may
+suddenly break when used with different architectures or compiler
+optimizations, or even changes in unrelated code which changes how the
+compiler optimizes the section accessing atomic_t variables.
+
+*** YOU HAVE BEEN WARNED! ***
+
+Now, we move onto the atomic operation interfaces typically implemented with
+the help of assembly code.