virtual_oss: Clean up pthread on exit

[christos]

Summary

To do that we also need to cache the thread pointers so that we can use
them later in destroy_threads(). Also add error checking on pthread
functions whose return values we care about.

Sponsored by: The FreeBSD Foundation

[christos]

Full diff.

[markj]

virtual_main.c

2680

I don't see much benefit to explicitly freeing memory right before the process exits.

[christos]

virtual_main.c

2680

I'm aware the OS will clean up resources anyway, but isn't it better to make sure we clean up on our part?

[markj]

virtual_main.c

2680

The only reason it might be better to clean up is to future-proof it, in case this code is copied into a library for instance. But in that case the change is incomplete, since presumably we'd need to clean up in the error cases as well.

[christos]

Remove atomic_destroy().

[christos]

Committed: https://github.com/freebsd/virtual_oss/commit/fcf3d0e7d1e3b351975f444606ba30d1e5106fbf