Calling close on a UnixSocket with a pending read waits for the read to time out on Linux

[charleskorn]

If you create a UnixSocket, set a read timeout and then:

• call read() on one thread
• wait a bit and then call close() on another thread

...the behaviour is different on OS X and Linux.

On OS X, the read is cancelled as soon as close() is called and so close() returns immediately. On Linux, the read blocks until the read timeout is reached, and then close() returns.

This makes interrupting read operations impossible, and is the root cause of square/okhttp#4233.

I have created a test case that fails on Linux (but passes on OS X) in charleskorn@b0981ae.

[charleskorn]

I don't know much about sockets programming, but reading https://www.systutorials.com/docs/linux/man/2-close/ suggests that calling shutdown on the socket before calling close is the correct behaviour. Calling shutdownInput() and shutdownOutput() in AbstractNativeSocketChannel.implCloseSelectableChannel() fixes this.

[headius]

@charleskorn Can you propose a PR to fix this?

[charleskorn]

Done - #68.

[selckin]

This also fixes an issue with docker-maven-plugin for me see fabric8io/docker-maven-plugin#552