poll(timeout = nil)public
Remove the head of the queue.
If timeout is not given, remove and return the head the queue if the number of available elements is strictly greater than the number of threads currently waiting (that is, don’t jump ahead in line). Otherwise, return nil.
If timeout is given, block if it there is no element available, waiting up to timeout seconds for an element to become available.
ConnectionTimeoutError if timeout is given and no element
becomes available after timeout seconds,
# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 133 def poll(timeout = nil) synchronize do if timeout no_wait_poll || wait_poll(timeout) else no_wait_poll end end end