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+# A way to cleanly handle process forking in Sinatra when using Passenger, aka "sporking some code".
+# This will allow you to properly execute some code asynchronously, which otherwise does not work correctly.
+#
+# Written by Ron Evans
+# More info at http://deadprogrammersociety.com
+#
+# Mostly lifted from the Spawn plugin for Rails (http://github.com/tra/spawn)
+# but with all of the Rails stuff removed.... cause you are using Sinatra. If you are using Rails, Spawn is
+# what you need. If you are using something else besides Sinatra that is Rack-based under Passenger, and you are having trouble with
+# asynch processing, let me know if spork helped you.
+# 
+module Spork
+  # things to close in child process
+  @@resources = []
+  def self.resources
+    @@resources
+  end
+  
+  # set the resource to disconnect from in the child process (when forking)
+  def self.resource_to_close(resource)
+    @@resources << resource
+  end
+
+  # close all the resources added by calls to resource_to_close
+  def self.close_resources
+    @@resources.each do |resource|
+      resource.close if resource && resource.respond_to?(:close) && !resource.closed?
+    end
+    @@resources = []
+  end
+
+  # actually perform the fork... er, spork
+  # valid options are:
+  # :priority => to set the process priority of the child
+  # :logger => a logger object to use from the child
+  # :no_detach => true if you want to keep the child process under the parent control. usually you do NOT want this
+  def self.spork(options={})
+    logger = options[:logger]
+    logger.debug "spork> parent PID = #{Process.pid}" if logger
+    
+    child = fork do
+      begin
+        start = Time.now
+        logger.debug "spork> child PID = #{Process.pid}" if logger
+
+        # set the nice priority if needed
+        Process.setpriority(Process::PRIO_PROCESS, 0, options[:priority]) if options[:priority]
+
+        # disconnect from the rack
+        Spork.close_resources
+
+        # run the block of code that takes so long
+        yield
+
+      rescue => ex
+        #raise ex
+        logger.error "spork> Exception in child[#{Process.pid}] - #{ex.class}: #{ex.message}" if logger
+      ensure
+        logger.info "spork> child[#{Process.pid}] took #{Time.now - start} sec" if logger
+        # this form of exit doesn't call at_exit handlers
+        exit!(0)
+      end
+    end
+
+    # detach from child process (parent may still wait for detached process if they wish)
+    Process.detach(child) unless options[:no_detach]
+
+    return child
+  end
+  
+end
+
+# Patch to work with passenger
+if defined? Passenger::Rack::RequestHandler
+  class Passenger::Rack::RequestHandler
+    alias_method :orig_process_request, :process_request
+    def process_request(env, input, output)
+      Spork.resource_to_close(input)
+      Spork.resource_to_close(output)
+      orig_process_request(env, input, output)
+    end
+  end
+end