What are shared by multi threads in the same process?

Question

I found that each thread still has its own registers. Also has its own stack, but other threads can read and write the stack memory.

My questions, what are shared by the multi threads in the same process?

What I can imagine is

1) address space of the process; 2) stack, register; 3) variables

Can any body elaborate it and add more?

Answer 1

All threads have access to anything within the process.

1. Open file handles
2. Environment variables
3. Memory mappings
4. User credentials
5. Command line arguments