How to use the Arena

[Lin-Mao]

I am new to AMReX and I am going to write some test cases of Arena. So what should I do to get started with this API? Do any guys have a available examples or posts about it? Thanks so much for your help!!!

[WeiqunZhang]

What aspects of Arena do you want to test? Arena's interface is mainly just

virtual void* alloc (std::size_t sz);
virtual void free (void* pt)

[Lin-Mao]

AMReX users typically do not call alloc directly.

What did you actually mean by saying this? Is that to say there are high level APIs to encapsulate the CArena::alloc, and users just need to call high level APIs?
In addition, thank you for your demo code, it helps me a lot!

[WeiqunZhang]

Right, it's like C++ users are encouraged to use std::vector, instead of new.

[Lin-Mao]

Got it. In this way, could you please tell me one or more APIs encapsulate CArena::alloc, and one or more code examples in amrex-tutorials for the corresponding APIs? I would appreciate it.

[WeiqunZhang]

The constructor of MultiFab will eventually call alloc. Almost every tutorial uses it.

[Lin-Mao]

Got it. Thanks so much for your help. I think I have some ideas of what to do next.