[ruby-core:31687] Re: IO#gets hangs on socket

Roger Pack wrote:
> basically if two ruby sockets connect, and one ruby one socket does
> 
> io.write "line"
> io.close
> 
> and the other does
> 
> io2.gets # this line here hangs *forever* even though the socket has
> been closed.
> 
> Is this expected? A bug?

How are those two sockets connected?  Because if both sides have a
bidirectional connection then each side is open for reading and
writing.  If one side closes the connection then the other side still
has a connection open for writing.  In which case the reader gets will
wait for input from the still open writer.  Here is a picture.  (And
hopefully you are using a traditional fixed width font or the picture
will be munged.)

  reader \___ socket ___/ reader
  writer /              \ writer

That is an assumption of course since you didn't show how the sockets
were connected but I expect that is what is happening.  Closing one
side only is still leaving the writer on the other side open for
writing.  The reader there will then wait for EOF.  In order to avoid
that the reader side would need to close the write side of the
socket.  Then the still open reader can detect EOF when the writer on
the other side of the socket closes the last write connection.

Bob