0mq_poll_gremlins.rb

require '0mq'
require 'pry'

address = 'tcp://127.0.0.1:10000'

pull = ZMQ::Socket.new ZMQ::PULL
pull.bind address

# Push a message after a delay.
Thread.new do
  push = ZMQ::Socket.new ZMQ::PUSH
  push.connect address
  sleep 3
  
  push.send_string 'test'
  sleep 0.1 # Intermittent exception if this is removed.
end

# Check if pull has any data (it doesn't yet).
# (Non-blocking demonstration.)
result = ZMQ::Poll.poll_nonblock pull
puts "No data available yet." if result.empty?

# Do a blocking poll until the pull socket has data.
ZMQ::Poll.poll pull do |socket, event|
  puts socket.recv_string
end