Updated cron generator for rufus-scheduler, start of central EventMac…

…hine management code

Manifest.txt

@@ -79,6 +79,7 @@ lib/daemon_kit/core_ext/string.rb
 lib/daemon_kit/cron.rb
 lib/daemon_kit/cucumber/world.rb
 lib/daemon_kit/deployment/capistrano.rb
+lib/daemon_kit/em.rb
 lib/daemon_kit/error_handlers/base.rb
 lib/daemon_kit/error_handlers/hoptoad.rb
 lib/daemon_kit/error_handlers/mail.rb

Rakefile

@@ -10,7 +10,8 @@ $hoe = Hoe.new('daemon-kit', DaemonKit::VERSION) do |p|
   p.post_install_message = IO.read( 'PostInstall.txt' ) # TODO remove if post-install message not required
   p.rubyforge_name       = 'kit' # TODO this is default value
   p.extra_deps = [
-                  ['rubigen', '>= 1.5.2']
+                  ['rubigen', '>= 1.5.2'],
+                  ['eventmachine', '>=0.12.8']
                  ]
   p.extra_dev_deps = [
                       ['newgem', ">= #{::Newgem::VERSION}"]

daemon_generators/cron/templates/config/initializers/cron.rb

@@ -1,7 +1,11 @@
 begin
-  require 'rufus-scheduler'
+  require 'rufus/scheduler'
 rescue LoadError => e
   $stderr.puts "Missing rufus-scheduler gem. Please run 'gem install rufus-scheduler'."
   exit 1
 end
 
+if Rufus::Scheduler::VERSION < "2.0.0"
+  $stderr.puts "Requires rufus-scheduler-2.0.0 or later"
+  exit 1
+end

daemon_generators/cron/templates/libexec/daemon.rb

@@ -15,13 +15,17 @@
 # An instance of the scheduler is available through
 # DaemonKit::Cron.scheduler
 
+# To make use of the EventMachine-powered scheduler, uncomment the
+# line below *before* adding any schedules.
+# DaemonKit::EM.run
+
 # Some samples to get you going:
 
 # Will call #regenerate_monthly_report in 3 days from starting up
 #DaemonKit::Cron.scheduler.in("3d") do
 #  regenerate_monthly_report()
 #end
-# 
+#
 #DaemonKit::Cron.scheduler.every "10m10s" do
 #  check_score(favourite_team) # every 10 minutes and 10 seconds
 #end
@@ -35,5 +39,5 @@
   DaemonKit.logger.debug "Scheduled task completed at #{Time.now}"
 end
 
-# Run our 'cron' daeon
+# Run our 'cron' dameon, suspending the current thread
 DaemonKit::Cron.run

lib/daemon_kit.rb

@@ -1,13 +1,15 @@
 # TODO: Strip this out eventually so we can run without rubygems
 require 'rubygems'
 
+require 'eventmachine'
+
 require File.dirname(__FILE__) + '/daemon_kit/core_ext'
 
 $:.unshift( File.dirname(__FILE__).to_absolute_path ) unless
   $:.include?( File.dirname(__FILE__).to_absolute_path )
 
 module DaemonKit
-  VERSION = '0.1.7.6'
+  VERSION = '0.1.7.7'
 
   autoload :Initializer,    'daemon_kit/initializer'
   autoload :Application,    'daemon_kit/application'
@@ -16,6 +18,7 @@ module DaemonKit
   autoload :Safety,         'daemon_kit/safety'
   autoload :PidFile,        'daemon_kit/pid_file'
   autoload :AbstractLogger, 'daemon_kit/abstract_logger'
+  autoload :EM,             'daemon_kit/em'
   autoload :Configurable,   'daemon_kit/core_ext/configurable'
 
   autoload :Cron,   'daemon_kit/cron'

lib/daemon_kit/cron.rb

@@ -1,32 +1,42 @@
 module DaemonKit
-  
+
   # Thin wrapper around rufus-scheduler gem, specifically designed to ease
   # configuration of a scheduler and provide some added simplicity.
+  #
+  # For more information on rufus-scheduler, please visit the RDoc's
+  # at http://rufus.rubyforge.org/rufus-scheduler/
+  #
+  # To use the evented scheduler, call #DaemonKit::EM.run prior to
+  # setting up your first schedule.
   class Cron
 
-    @@instance = nil
+    @instance = nil
 
     attr_reader :scheduler
-    
+
     class << self
-
+
+      # Access to the scheduler instance
       def instance
         @instance ||= new
       end
 
       def scheduler
         instance.scheduler
       end
-      
+
       private :new
 
+      # Once the scheduler has been configured, call #run to block the
+      # current thread and keep the process alive for the scheduled
+      # tasks to run
       def run
         DaemonKit.logger.info "Starting rufus-scheduler"
 
-        begin
+        if instance.is_a?( Rufus::Scheduler::PlainScheduler )
           instance.scheduler.join
-        rescue Interrupt
-          DaemonKit.logger.warn "Scheduler interrupted"
+        else
+          Thread.stop
         end
       end
     end

lib/daemon_kit/em.rb

@@ -0,0 +1,43 @@
+module DaemonKit
+
+  # EventMachine forms a critical part of the daemon-kit toolset, and
+  # especially of daemon process developers.
+  #
+  # This class abstracts away the difficulties of managing multiple
+  # libraries that all utilize the event reactor.
+  class EM
+
+    class << self
+
+      # Start a reactor, just like classical EM.run. If the block is
+      # provided, the method will block and call the provided block
+      # argument inside the running reactor. If the block argument is
+      # not provided the reactor will be started in a separate thread
+      # and the program will continue to run after the method. All the
+      # signal traps are configured to shutdown the reactor when the
+      # daemon exists.
+      def run(&block)
+        if ::EM.reactor_running?
+          DaemonKit.logger.warn "EventMachine reactor already running"
+          block.call if block_given?
+
+        else
+          if block_given?
+            ::EM.run { block.call }
+          else
+            Thread.main[:_dk_reactor] = Thread.new { EM.run {} }
+            DaemonKit.trap( 'INT' ) { DaemonKit::EM.stop  }
+            DaemonKit.trap( 'TERM' ) { DaemonKit::EM.stop }
+          end
+        end
+      end
+
+      # Stop the reactor
+      def stop
+        ::EM.stop_event_loop if ::EM.reactor_running?
+        Thread.main[:_dk_reactor].join
+      end
+    end
+
+  end
+end