Added fixed gateway script [Nicholas Seckar]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1721 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 119 insertions, 177 deletions

diff --git a/railties/bin/listener b/railties/bin/listener
index 493ac9dca4..421c453f23 100644
--- a/railties/bin/listener
+++ b/railties/bin/listener
@@ -1,103 +1,86 @@
-require "drb"
-ENV["RAILS_ENV"] = 'production'
-require "#{File.dirname(__FILE__)}/../config/environment.rb"
+#!/usr/local/bin/ruby
+
+require 'stringio'
+require 'fileutils'
 require 'fcgi_handler'
-require 'rbconfig'
 
-VERBOSE = false
+def message(s)
+  $stderr.puts "listener: #{s}" if ENV && ENV["DEBUG_GATEWAY"]
+end
+
+class RemoteCGI < CGI
+  attr_accessor :stdinput, :stdoutput, :env_table
+  def initialize(env_table, input = nil, output = nil)
+    self.env_table = env_table
+    self.stdinput = input || StringIO.new
+    self.stdoutput = output || StringIO.new
+    super()
+  end
+
+  def out(stream) # Ignore the requested output stream
+    super(stdoutput)
+  end
+end
 
 class Listener
   include DRbUndumped
-  attr_accessor :tracker
-  
-  def initialize(timeout = nil)
-    @timeout = timeout
+
+  def initialize(timeout, socket_path)
+    @socket = File.expand_path(socket_path)
     @mutex = Mutex.new
     @active = false
-    
+    @timeout = timeout
+
     @handler = RailsFCGIHandler.new
     @handler.extend DRbUndumped
-    @output = FakeOut.new
-    $stdout = @output
-  end
-  
-  def inform_up(tracker_uri)
-    return unless tracker_uri
-    tracker = DRbObject.new_with_uri(tracker_uri)
-    tracker.register_listener self
-    @tracker = tracker
-  end
-  def inform_down
-    @tracker.remove_listener(self) if @tracker
-  end
 
-  def run(on_uri, tracker_uri)
-    on_uri ||= "drbunix:"
-    DRb.start_service(on_uri, self) # Start a server for us
-    inform_up tracker_uri
-    @handler.process!(self)
-  end
-  
-  def die!
-    inform_down
-    Kernel.exit 0
-  end 
-  
-  def process(input)
-    $stderr.puts "listener: received request -- obtaining lock" if VERBOSE 
-    @mutex.synchronize do
-      @active = true
-      
-      $stderr.puts "listener: obtained -- swaping stdin" if VERBOSE
-      $stdin = input
-      cgi = CGI.new
-      
-      $stderr.puts "listener: yielding to FCGI handler..." if VERBOSE
-      @cgi_block.call cgi
-      $stderr.puts "listener: handler finished, releasing control" if VERBOSE
-      
-      return @output.read!
-    end
+    message 'opening socket'
+    DRb.start_service("drbunix:#{@socket}", self)
+
+    message 'entering process loop'
+    @handler.process! self
   end
-  
-  def each_cgi(&block)
-    @cgi_block = block
+
+  def each_cgi(&cgi_block)
+    @cgi_block = cgi_block
+    message 'entering idle loop'
     loop do
-      @timeout ? sleep(@timeout) : sleep
+      sleep @timeout rescue nil
       die! unless @active
       @active = false
     end
   end
-end
 
-class FakeOut < Struct.new(:contents)
-  def initialize
-    super("")
-  end
-  def write(str)
-    contents << str
+  def process(env, input)
+    message 'received request'
+    @mutex.synchronize do
+      @active = true
+
+      message 'creating input stream'
+      input_stream = StringIO.new(input)
+      message 'building CGI instance'
+      cgi = RemoteCGI.new(eval(env), input_stream)
+
+      message 'yielding to fcgi handler'
+      @cgi_block.call cgi
+      message 'yield finished -- sending output'
+
+      cgi.stdoutput.seek(0)
+      output = cgi.stdoutput.read
+
+      return output
+    end
   end
-  def read!
-    c = contents
-    self.contents = ''
-    return c
+
+  def die!
+    message 'shutting down'
+    DRb.stop_service
+    FileUtils.rm_f @socket
+    Kernel.exit 0
   end
 end
 
-if ARGV.shift == 'start-listeners'
-  tracker = ARGV.shift
-  number = (ARGV.shift || '1').to_i
-  exit(0) if number.zero?
-  
-  if number > 1
-    fork do
-      exec(
-        File.join(Config::CONFIG['bin_dir'], Config::CONFIG['RUBY_SO_NAME']), 
-        __FILE__, 'start-listeners', tracker, (number - 1).to_s
-      )
-    end
-  end
-  
-  l = Listener.new(90)
-  l.run(nil, tracker)
-end
\ No newline at end of file
+socket_path = ARGV.shift
+timeout = (ARGV.shift || 90).to_i
+
+Listener.new(timeout, socket_path)
\ No newline at end of file
diff --git a/railties/bin/tracker b/railties/bin/tracker
index 17fce67e54..859c9fa0e0 100644
--- a/railties/bin/tracker
+++ b/railties/bin/tracker
@@ -1,110 +1,69 @@
-require "drb"
-require "rbconfig"
+#!/usr/local/bin/ruby
 
-VERBOSE = false
+require 'drb'
+require 'thread'
+
+def message(s)
+  $stderr.puts "tracker: #{s}" if ENV && ENV["DEBUG_GATEWAY"]
+end
 
 class Tracker
   include DRbUndumped
-  
-  def initialize(timeout = 90, uri = nil)
-    @timeout = timeout
-    @waiting = []
-    @working = []
-    
-    @waiting_mutex = Mutex.new
-    
-    DRb.start_service(uri, self)
-    @uri = DRb.uri
-  end
-  def run
-    start_listener 3
-    sleep 3
-    
-    background
-  end
-  
-  def register_listener(listener)
-    @waiting.push listener
-    nil
-  end
-  def remove_listener(listener)
-    @waiting.delete listener
-    @working.delete listener
-    nil
+
+  def initialize(instances, socket_path)
+    @instances = instances
+    @socket = File.expand_path(socket_path)
+    @active = false
+
+    @listeners = []
+    @instances.times { @listeners << Mutex.new }
+
+    message "using #{@listeners.length} listeners"
+    message "opening socket at #{@socket}"
+
+    @service = DRb.start_service("drbunix://#{@socket}", self)
   end
-  
+
   def with_listener
-    listener = @waiting.shift
-    unless listener
-      start_listener(2) unless @waiting.length + @working.length > 6
-      @waiting_mutex.synchronize do
-	10.times do
-          sleep 0.5
-          listener = @waiting.shift
-          break if listener
-        end
-        unless listener
-          ($stderr.puts "Dropping request due to lack of listeners!!!" unless listener) if VERBOSE
-          return
-        end
+    message "listener requested"
+
+    mutex = has_lock = index = nil
+    3.times do 
+      @listeners.each_with_index do |mutex, index|
+        has_lock = mutex.try_lock
+        break if has_lock
       end
+      break if has_lock
+      sleep 0.05
     end
-    
-    @working << listener
-    yield listener
-  ensure
-    if listener
-      @working.delete listener
-      @waiting << listener
-    end
-  end
-  
-  def background
-    loop do
-      @timeout ? sleep(@timeout) : sleep
-      unless @processed
-        $stderr.puts "Idle for #{@timeout} -- shutting down tracker." if VERBOSE
-        Kernel.exit 0 
+
+    if has_lock
+      message "obtained listener #{index}"
+      @active = true
+      begin yield index
+      ensure
+        mutex.unlock
+        message "released listener #{index}"
       end
-      @processed = false
+    else
+      message "dropping request because no listeners are available!"
     end
   end
-    
-  def process(input)
-    output = nil
-    $stderr.puts "tracker: received request.. obtaining listener" if VERBOSE
-    with_listener do |listener|
-      $stderr.puts "tracker: obtained -- forwarding request to listener.." if VERBOSE
-      @processed = true
-      output = listener.process(input)
-      $stderr.puts "tracker: listener released control." if VERBOSE
-    end
-    return output
-  end
-  
-  def start_listener(n = 1)
-    tracker_uri = @uri
-    listener_path = File.join(File.dirname(__FILE__), 'listener')
-    fork do
-      exec(
-        File.join(Config::CONFIG['bin_dir'], Config::CONFIG['RUBY_SO_NAME']), 
-        listener_path, 'start-listeners', tracker_uri, n.to_s
-      )
+
+  def background(check_interval = nil)
+    if check_interval
+      loop do
+        sleep check_interval
+        message "Idle for #{check_interval}, shutting down" unless @active
+        @active = false
+        Kernel.exit 0
+      end
+    else DRb.thread.join
     end
   end
-  
-  def ping
-    true
-  end
 end
 
-if ARGV.first == "start"
-  tracker = Tracker.new(90, ARGV[1])
-  socket = (/druby:([^?]*)\?/ =~ ARGV[1]) ? $1 : nil
-  require 'fileutils' if socket
-
-  begin tracker.run
-  ensure 
-    FileUtils.rm_f(socket) if socket
-  end
-end
+socket_path = ARGV.shift
+instances = ARGV.shift.to_i
+t = Tracker.new(instances, socket_path)
+t.background(ARGV.first ? ARGV.shift.to_i : 90)
\ No newline at end of file