I'm not sure I understand your question. Sockets in FIN_WAIT_2 have been closed at the application level. This often happens as a consequence of an IO::Handle object (or an instance of a subclass) being DESTROYed.

Please clarify:

• What do you expect an application to do with a closed socket?
• How do you expect an application to call methods on a DESTROYed IO::Handle object?
• What kernel syscalls do you expect to work with closed file descriptors?

Thank you.