Read/select not blocking on SSL socket?

Ruby
1

I’m working on an SSL client/server application using persistent TLSv1
connections. I’m having some issues with my server and what I think
should be a blocking read or select.

I’m basically doing this where @io is an OpenSSL::SSL::SSLSocket:

until @data.length == READ_SIZE do
tmp = @io.read(READ_SIZE - @data.length)
if tmp.nil?
IO.select [@io]
else
@data << tmp
end
end

(I did not initially have the select call, but decided to give that a
try.)

I would expect that the read would block (I have not set O_NONBLOCK on
the socket) until there is data to be read. Instead, when there is no
data, every read call returns nil. I thought the select would fix
that, but it returns immediately and the read call again returns nil.

Am I misunderstanding how this should work? Would the fact that it’s
an SSL connection cause the issue?

I’m using 1.8.4 on Linux.

Thanks for any insights you can offer.

Jeremy

2

On Aug 30, 3:20 pm, “[email protected]” [email protected] wrote:

else
that, but it returns immediately and the read call again returns nil.

Am I misunderstanding how this should work? Would the fact that it’s
an SSL connection cause the issue?

I’m using 1.8.4 on Linux.

Thanks for any insights you can offer.

Jeremy

I have an update to my initial question. I replaced my read calls with
sysread. With one client who sends to this server, the read or sysread
blocks as expected. With the other, the read always returns nil and
sysread always throws EOFError exceptions when I think it should
block. I catch EOFError and sysread again, but instead of blocking, it
throws EOFError again. And again. Etc.

Is this the correct behavior if they are keeping the client end of the
connection open (the working client – the one where the read blocks
– seems be keeping the connection open) or should the read be
blocking?

At this point, I’m beginning to think my only option will be to sleep
and then check the connection for data in a loop.

Jeremy

3

On Aug 30, 1:20 pm, “[email protected]” [email protected] wrote:

I’m working on an SSL client/server application using persistent TLSv1
connections. I’m having some issues with my server and what I think
should be a blocking read or select.

I also understood Ruby io.read to be blocking.

I’m using 1.8.4 on Linux.

Thanks for any insights you can offer.

Jeremy

Maybe I’m not the best person to be giving advice, but I don’t think
your do/end is a legal Ruby construction.

I was under the impression you would use do/end like the following

sock.each_line do |line|
puts line
end

Notice the nifty | | thingies. This will read each line and then
return.

Chad

4

On Aug 30, 5:58 pm, grocery_stocker [email protected] wrote:

I’m basically doing this where @io is an OpenSSL::SSL::SSLSocket:
(I did not initially have the select call, but decided to give that a
I’m using 1.8.4 on Linux.
sock.each_line do |line|
puts line
end

Notice the nifty | | thingies. This will read each line and then
return.

Chad

Disregard the post. Your do/end is legal. I think I was thinking of
something else when I made the comment.