EventMachine::Defer + Weird issue

[Ken Ghosh]

I been Using EventMachine for quite a while a know and I really found it
great as It Manage show much more me that i didn't have to worry for
anything.But recently I just found this weird issue which i just fail to
understand

Here what is just telling

I have Eventmachine loop Which look like this

EventMachine::run {
EventMachine::add_periodic_timer(10)
do
EventMachine::defer(@operation_block,@callback_block)
end }

here my operation block look like(Code below use of amqp using carrot
gem)

@operation_block = Proc.new { begin
puts "Initiating the queue"
@carrot ||= Carrot.newhost => localhost)
@queue ||= @carrot.queue("my_queue")
puts "The Queue is Poping the message"

if @queue.pop

[MY LOGIC HERE]
$input_to_callback = "SUCCESS" ## IF LOGIC GET
EVALUATED WITHOUT ERROR ELSE WILL SET TO FAIL
else
$input_to_callback = "NOTHING TO PROCESSES"
end
rescue
puts e
retry!
end
$input_to_callback

}

Here my callback block look like

@callback_block = Proc.new {|operation_block_output|
if operation_block_output == "SUCCESS"
puts "YAHOOOOOOOOO SUCCESS"
elsif operation_block_output == "NOTHING TO PROCESSES"
puts "BOO Nothing to processes"
else
puts "FAIL ALARM"
end
}


Now Here come the Trouble
The Code Though Work the way it should until something bad happen
Here what i meant

Now suppose I running this Above Code

I have a queue set name "my_queue" or it will create one if it doesn't
exists the queue is initially empty

here the output that I get on console

Initiating the queue

The Queue is Poping the Message

BOO Nothing to processes

As I message built the output Change in console accordingly based

Now the trouble

If I momentarily shutdown my AMQP server Here the output(to show what
i meant)

Initiating the queue

Broken Pipe => Error That Caught in
begin rescue block in operation block

Now Start AMQP Server

The Code just never seem move ahead from line where it currently got
error
that means I never Seem to print the line

The Queue is Poping the message

not only the current defer for which is retry happened but also the
new defer operation block that get initiated after the Timer time just
elapsed
i.e means of the subsequent call to operation block
never seem to move ahead and do processing and always print the
following
output only

Initiating the queue

Just never seem to move ahead(stuck) and do Processing that it meant
to i.e fetch the message from the queue do the processing accordingly
and all the other stuff(as the AMQP server is running now)




Thanks