How to perform atomic operations on Linux that work on x86, arm, GCC and icc?

Question

Every Modern OS provides today some atomic operations:

• Windows has Interlocked* API
• FreeBSD has

Answer 1

Darn. I was going to suggest the GCC primitives, then you said they were off limits. :-)

In that case, I would do an #ifdef for each architecture/compiler combination you care about and code up the inline asm. And maybe check for __GNUC__ or some similar macro and use the GCC primitives if they are available, because it feels so much more right to use those. :-)

You are going to have a lot of duplication and it might be difficult to verify correctness, but this seems to be the way a lot of projects do this, and I've had good results with it.

Some gotchas that have bit me in the past: when using GCC, don't forget "asm volatile" and clobbers for "memory" and "cc", etc.