multiprocess debugging support

Author: denofevil

bin/rdebug-ide

@@ -26,7 +26,8 @@ options = OpenStruct.new(
   'port'        => 1234,
   'stop'        => false,
   'tracing'     => false,
-  'int_handler' => true
+  'int_handler' => true,
+  'dispatcher_port' => -1
 )
 
 opts = OptionParser.new do |opts|
@@ -38,7 +39,10 @@ EOB
   opts.separator ""
   opts.separator "Options:"
   opts.on("-h", "--host HOST", "Host name used for remote debugging") {|host| options.host = host}
-  opts.on("-p", "--port PORT", Integer, "Port used for remote debugging") {|port| options.port = port}
+  opts.on("-p", "--port PORT", Integer, "Port used for remote debugging") {|port| options.port = port}  
+  opts.on("--dispatcher-port PORT", Integer, "Port used for multi-process debugging dispatcher") do |dp| 
+    options.dispatcher_port = dp
+  end  
   opts.on('--stop', 'stop when the script is loaded') {options.stop = true}
   opts.on("-x", "--trace", "turn on line tracing") {options.tracing = true}
   opts.on("-l", "--load-mode", "load mode (experimental)") {options.load_mode = true}
@@ -86,7 +90,19 @@ end
 
 # save script name
 Debugger::PROG_SCRIPT = ARGV.shift
-  
+
+if (options.dispatcher_port != -1)
+  ENV['IDE_PROCESS_DISPATCHER'] = options.dispatcher_port.to_s
+  if RUBY_VERSION < "1.9"
+    require 'ruby-debug-ide/multiprocess'
+  else
+    require_relative '../lib/ruby-debug-ide/multiprocess'
+  end
+
+  old_opts = ENV['RUBYOPT']
+  ENV['RUBYOPT'] = "-r#{File.expand_path(File.dirname(__FILE__))}/../lib/ruby-debug-ide/multiprocess/starter"
+  ENV['RUBYOPT'] += " #{old_opts}" if old_opts
+end
 
 if options.int_handler
   # install interruption handler

lib/ruby-debug-ide.rb

@@ -15,6 +15,7 @@ class << self
     # Prints to the stderr using printf(*args) if debug logging flag (-d) is on.
     def print_debug(*args)
       if Debugger.cli_debug
+        $stderr.printf("#{Process.pid}: ")
         $stderr.printf(*args)
         $stderr.printf("\n")
         $stderr.flush
@@ -76,7 +77,8 @@ def at_return(file, line)
   class << self
 
     attr_accessor :event_processor, :cli_debug, :xml_debug
-    attr_reader :control_thread
+    attr_accessor :control_thread
+    attr_reader :interface
 
     #
     # Interrupts the current thread
@@ -104,7 +106,7 @@ def start_server(host = nil, port = 1234)
       start_control(host, port)
     end
 
-    def debug_program(options)
+    def prepare_debugger(options)
       start_server(options.host, options.port)
 
       raise "Control thread did not start (#{@control_thread}}" unless @control_thread && @control_thread.alive?
@@ -116,7 +118,11 @@ def debug_program(options)
       @mutex.synchronize do
         @proceed.wait(@mutex)
       end
-      
+    end
+
+    def debug_program(options)
+      prepare_debugger(options)
+
       abs_prog_script = File.expand_path(Debugger::PROG_SCRIPT)
       bt = debug_load(abs_prog_script, options.stop, options.load_mode)
       if bt && !bt.is_a?(SystemExit)
@@ -143,13 +149,18 @@ def start_control(host, port)
           $stderr.printf "Fast Debugger (ruby-debug-ide #{IDE_VERSION}, ruby-debug-base #{VERSION}) listens on #{host}:#{port}\n"
           server = TCPServer.new(host, port)
           while (session = server.accept)
+            $stderr.puts "Connected from #{session.addr[2]}" if Debugger.cli_debug
+            dispatcher = ENV['IDE_PROCESS_DISPATCHER']
+            if (dispatcher)
+              ENV['IDE_PROCESS_DISPATCHER'] = "#{session.addr[2]}:#{dispatcher}" unless dispatcher.include?(":")
+            end  
             begin
-              interface = RemoteInterface.new(session)
+              @interface = RemoteInterface.new(session)
               @event_processor = EventProcessor.new(interface)
               IdeControlCommandProcessor.new(interface).process_commands
             rescue StandardError, ScriptError => ex
               bt = ex.backtrace
-              $stderr.printf "Exception in DebugThread loop: #{ex.message}\nBacktrace:\n#{bt ? bt.join("\n  from: ") : "<none>"}\n"
+              $stderr.printf "#{Process.pid}: Exception in DebugThread loop: #{ex.message}\nBacktrace:\n#{bt ? bt.join("\n  from: ") : "<none>"}\n"
               exit 1
             end
           end

lib/ruby-debug-ide/event_processor.rb

@@ -53,7 +53,7 @@ def line_event(context, file, line)
          @last_breakpoint = nil
        end
        raise "DebuggerThread are not supposed to be traced (#{context.thread})" if context.thread.is_a?(Debugger::DebugThread)
-       @printer.print_debug("Stopping Thread %s", context.thread.to_s)
+       @printer.print_debug("Stopping Thread %s (%s)", context.thread.to_s, Process.pid.to_s)
        @printer.print_debug("Threads equal: %s", Thread.current == context.thread)
        IdeCommandProcessor.new(@interface).process_commands
        InspectCommand.clear_references

lib/ruby-debug-ide/interface.rb

@@ -23,6 +23,7 @@ class LocalInterface < Interface
 
   class RemoteInterface < Interface # :nodoc:
     attr_accessor :command_queue
+    attr_accessor :socket
 
     def initialize(socket)
       @socket = socket

lib/ruby-debug-ide/multiprocess.rb

@@ -0,0 +1,7 @@
+if RUBY_VERSION < "1.9"
+  require 'ruby-debug-ide/multiprocess/pre_child'
+  require 'ruby-debug-ide/multiprocess/monkey'
+else
+  require_relative 'multiprocess/pre_child'
+  require_relative 'multiprocess/monkey'
+end

lib/ruby-debug-ide/multiprocess/monkey.rb

@@ -0,0 +1,45 @@
+module Debugger
+  module MultiProcess
+    def self.create_mp_fork
+      %Q{
+        alias pre_debugger_fork fork
+    
+        def fork(*args)
+          if block_given?
+            return pre_debugger_fork{Debugger::MultiProcess::pre_child; yield}
+          end
+          result = pre_debugger_fork
+          Debugger::MultiProcess::pre_child unless result
+          result
+        end
+      }
+    end
+
+    def self.create_mp_exec
+      %Q{
+        alias pre_debugger_exec exec
+    
+        def exec(*args)
+          Debugger.interface.close
+          pre_debugger_exec(*args)
+        end
+      }
+    end
+  end
+end
+
+module Kernel
+  class << self
+    module_eval Debugger::MultiProcess.create_mp_fork
+    module_eval Debugger::MultiProcess.create_mp_exec
+  end
+  module_eval Debugger::MultiProcess.create_mp_fork
+  module_eval Debugger::MultiProcess.create_mp_exec
+end
+
+module Process
+  class << self
+    module_eval Debugger::MultiProcess.create_mp_fork
+    module_eval Debugger::MultiProcess.create_mp_exec
+  end
+end

lib/ruby-debug-ide/multiprocess/pre_child.rb

@@ -0,0 +1,71 @@
+module Debugger
+  module MultiProcess
+    class << self
+      def pre_child
+
+        require "socket"
+        require "ostruct"
+        
+        host = '127.0.0.1'
+        port = find_free_port(host)
+      
+        options = OpenStruct.new(
+            'frame_bind'  => false,
+            'host'        => host,
+            'load_mode'   => false,
+            'port'        => port,
+            'stop'        => false,
+            'tracing'     => false,
+            'int_handler' => true
+        )
+      
+        acceptor_host, acceptor_port = ENV['IDE_PROCESS_DISPATCHER'].split(":")
+        acceptor_host, acceptor_port = '127.0.0.1', acceptor_host unless acceptor_port
+  
+        connected = false
+        3.times do |i|
+          begin
+            s = TCPSocket.open(acceptor_host, acceptor_port)
+            s.print(port)
+            s.close
+            connected = true
+            start_debugger(options)
+            return
+          rescue => bt
+            $stderr.puts "#{Process.pid}: connection failed(#{i+1})"
+            $stderr.puts "Exception: #{bt}"
+            $stderr.puts bt.backtrace.map { |l| "\t#{l}" }.join("\n")
+            sleep 0.3
+          end unless connected
+        end
+      end
+      
+      def start_debugger(options)
+        if Debugger.started?
+          #we're in forked child, only need to restart control thread
+          Debugger.control_thread = nil
+          Debugger.start_control(options.host, options.port)
+        end
+  
+        if options.int_handler
+          # install interruption handler
+          trap('INT') { Debugger.interrupt_last }
+        end
+      
+        # set options
+        Debugger.keep_frame_binding = options.frame_bind
+        Debugger.tracing = options.tracing      
+        
+        Debugger.prepare_debugger(options)
+      end
+  
+  
+      def find_free_port(host)
+        server = TCPServer.open(host, 0)
+        port   = server.addr[1]
+        server.close
+        port
+      end
+    end
+  end
+end

lib/ruby-debug-ide/multiprocess/starter.rb

@@ -0,0 +1,6 @@
+if ENV['IDE_PROCESS_DISPATCHER']
+  require 'rubygems'
+  require 'ruby-debug-ide'
+  require 'ruby-debug-ide/multiprocess'
+  Debugger::MultiProcess::pre_child
+end

lib/ruby-debug-ide/version.rb

@@ -1,3 +1,3 @@
 module Debugger
-  IDE_VERSION='0.4.17.beta9'
+  IDE_VERSION='0.4.17.beta10'
 end