workers watch master and graceful shutdown if it dies

README.md

@@ -112,14 +112,18 @@ The pool master responds to the following signals:
 So you should probably use a config file.  After a `HUP`, workers that are no
 longer needed will be gracefully shutdown via `QUIT`.
 
+Other Features
+--------------
+
+Workers will watch the pool master, and gracefully shutdown if the master
+process dies (for whatever reason) before them.
+
 TODO
 -----
 
 * figure out a good way to test this (preferably via cucumber or rspec)
 * clean up the code (I stole most of it from unicorn, and it's still a bit
   bastardized)
-* workers should watch for the pool master, and gracefully die if pool master
-  disapears (normally parent will send QUIT on exit)
 * do appropriate logging (e.g. all to one logfile, each queue to its own
   logfile, or each worker to its own logfile).  Logfile location must be
   configurable.

lib/resque/pool.rb

@@ -1,6 +1,7 @@
 # -*- encoding: utf-8 -*-
 require 'resque'
 require 'resque/pool/logging'
+require 'resque/pool/pooled_worker'
 require 'fcntl'
 require 'yaml'
 
@@ -288,12 +289,10 @@ def spawn_worker!(queues)
 
     def create_worker(queues)
       queues = queues.to_s.split(',')
-      worker = Resque::Worker.new(*queues)
+      worker = PooledWorker.new(*queues)
       worker.verbose = ENV['LOGGING'] || ENV['VERBOSE']
       worker.very_verbose = ENV['VVERBOSE']
       worker
-    rescue Resque::NoQueueError
-      abort "set QUEUE env var, e.g. $ QUEUE=critical,high rake resque:work"
     end
 
     # }}}

lib/resque/pool/pooled_worker.rb

@@ -0,0 +1,65 @@
+class Resque::Pool
+
+  class PooledWorker < ::Resque::Worker
+
+    def initialize(*args)
+      @pool_master_pid = Process.pid
+      super
+    end
+
+    def pool_master_has_gone_away?
+      @pool_master_pid && @pool_master_pid != Process.ppid
+    end
+
+    # this allows us to shutdown
+    def shutdown
+      @shutdown || pool_master_has_gone_away?
+    end
+
+    # this entire method (except for one line) is copied and pasted from
+    # resque-1.9.9.  If shutdown were used as a method (attr_reader) rather
+    # than an instance variable, I wouldn't need to reduplicate this. :-(
+    #
+    # hopefully I can get defunkt to accept my patch for this.
+    # Until it is, the resque-pool gem will depend on an exact version of
+    # resque.
+    def work(interval = 5, &block)
+      $0 = "resque: Starting"
+      startup
+
+      loop do
+        #### THIS IS THE ONLY LINE THAT IS CHANGED
+        break if shutdown
+        #### THAT WAS THE ONLY LINE THAT WAS CHANGED
+
+        if not @paused and job = reserve
+          log "got: #{job.inspect}"
+          run_hook :before_fork
+          working_on job
+
+          if @child = fork
+            rand # Reseeding
+            procline "Forked #{@child} at #{Time.now.to_i}"
+            Process.wait
+          else
+            procline "Processing #{job.queue} since #{Time.now.to_i}"
+            perform(job, &block)
+            exit! unless @cant_fork
+          end
+
+          done_working
+          @child = nil
+        else
+          break if interval.to_i == 0
+          log! "Sleeping for #{interval.to_i}"
+          procline @paused ? "Paused" : "Waiting for #{@queues.join(',')}"
+          sleep interval.to_i
+        end
+      end
+
+    ensure
+      unregister_worker
+    end
+  end
+
+end

resque-pool.gemspec

@@ -16,7 +16,7 @@ Gem::Specification.new do |s|
   s.required_rubygems_version = ">= 1.3.6"
 
   s.add_development_dependency "rspec"
-  s.add_dependency "resque", "~> 1.9.1"
+  s.add_dependency "resque", "=1.9.9"
 
   s.files        = Dir.glob("lib/**/*")
   s.require_path = 'lib'