I have some simple asynchronous processing that my app needs to do, and I wanted something a bit lighter weight than any of the gems or plugins I've run across that handle background processing. I decided to roll my own, with the added benefit that I get to use native threads rather than green threads since I'm using JRuby.
I'm unsure how to handle exceptions in the background thread. I'd like to pass it to Rails' exception handling mechanism so that it is dealt with in the same way as exceptions that occur during the normal request-response cycle (except for rendering the 500 page, of course). Since I've got the exception notifier plugin installed, this would email me, as well as log the exception to the log file.
Is there a way to let Rails handle the exception, where whatever exception handling I have in my rails app would get used for exceptions in the background thread?
In case it helps, I've included the code for my background thread below.
Thanks, Myron
class UserSubmissionProcessor SLEEP_TIME = 30 unless defined? SLEEP_TIME @@semaphore = Mutex.new @@singleton_thread = nil unless defined? @@singleton_thread
def self.start_processor_if_necessary @@semaphore.synchronize do if @@singleton_thread.nil? @@singleton_thread = Thread.new {UserSubmissionProcessor.process} end end end
private
def self.process while true begin user_submission = UserSubmission.find(:first, :conditions => {:processing_completed => nil}, :order => 'created_at')
if user_submission user_submission.process else sleep SLEEP_TIME end rescue Exception => ex #TODO: how to I propagate exceptions to rails' exception- handling mechanism? end end end end