Access Queues in 2 threads

I know queues are not thread safe, we should use mailboxes when accessing queues in multiple threads. But if I only push in one thread and pop in another thread, is it safe to use queues ?

In reply to SatyaG:

Multiple threads modifying the same variable, regardless of its type, is never a safe operation.

I don’t think any current tools supporting SystemVerilog have a problem using a queue with multiple threads, but there are some people dabbling in multi-core simulation that might have a problem if the SV threads were split into different CPU cores.