Hello Rubyists,

I have a program that opens a TCPSocket, connects it to a server, and
then creates a thread which loops until the socket closes, reading from
the socket and processing the data read. It calls IO.select() to wait
until there is data available to read. Meanwhile, another thread can
close the socket in certain circumstances. If the first thread is in
IO.select() when the socket is closed, the result is unpredictable -
sometimes the select() returns and sometimes it blocks. I'm not sure of
the circumstances that cause it to block or not - it seems random.

So, is there some way to make it reliably unblock? Or is there something
that the second thread can do to cause the select() to return (set a
flag on the socket before closing it, or something)?

This is with Ruby 2.0.0 p247 on Centos 5 Linux if that's significant.

Thanks in advance for any suggestions.
    Graham

On 15/07/2013 18:32, Robert Klemme wrote:
>     from
>     close the socket in certain circumstances. If the first thread is in
>     So, is there some way to make it reliably unblock? Or is there
>
> Kind regards
>
> robert
>
> --
> remember.guy do |as, often| as.you_can - without end
> http://blog.rubybestpractices.com/
Thanks for replying, Robert.

I had actually simplified a bit what I told you about my use case -
there was a reason for using select(). But you're right - I changed the
program to use a blocking read instead, and it now works. I suspect
there's some bug in select(), but I'm not sure how to reproduce it. Yes,
a timeout would probably work, but not very elegant.

Thank for your help,
    Graham