Let's notify ide dispatcher after server started to avoid race described in #38

Author: os97673

lib/ruby-debug-ide.rb

@@ -2,7 +2,7 @@
 require 'stringio'
 require "socket"
 require 'thread'
-if (RUBY_VERSION < '2.0' || defined?(JRUBY_VERSION))
+if RUBY_VERSION < '2.0' || defined?(JRUBY_VERSION)
   require 'ruby-debug-base'
 else
   require 'debase'
@@ -59,14 +59,14 @@ def interrupt_last
       end
     end
 
-    def start_server(host = nil, port = 1234)
+    def start_server(host = nil, port = 1234, notify_dispatcher = false)
       return if started?
       start
-      start_control(host, port)
+      start_control(host, port, notify_dispatcher)
     end
 
     def prepare_debugger(options)
-      start_server(options.host, options.port)
+      start_server(options.host, options.port, options.notify_dispatcher)
 
       raise "Control thread did not start (#{@control_thread}}" unless @control_thread && @control_thread.alive?
 
@@ -97,18 +97,20 @@ def run_prog_script
       end
     end
 
-    def start_control(host, port)
+    def start_control(host, port, notify_dispatcher)
       raise "Debugger is not started" unless started?
       return if @control_thread
       @control_thread = DebugThread.new do
         begin
           # 127.0.0.1 seemingly works with all systems and with IPv6 as well.
           # "localhost" and nil have problems on some systems.
           host ||= '127.0.0.1'
-          gem_name = (defined?(JRUBY_VERSION) || RUBY_VERSION < '1.9.0') ? 'ruby-debug-base' :
-                     RUBY_VERSION < '2.0.0' ? 'ruby-debug-base19x' : 'debase'
           server = TCPServer.new(host, port)
+          gem_name = (defined?(JRUBY_VERSION) || RUBY_VERSION < '1.9.0') ? 'ruby-debug-base' :
+              RUBY_VERSION < '2.0.0' ? 'ruby-debug-base19x' : 'debase'
           $stderr.printf "Fast Debugger (ruby-debug-ide #{IDE_VERSION}, #{gem_name} #{VERSION}) listens on #{host}:#{port}\n"
+          notify_dispatcher(port) if notify_dispatcher
+
           while (session = server.accept)
             $stderr.puts "Connected from #{session.peeraddr[2]}" if Debugger.cli_debug
             dispatcher = ENV['IDE_PROCESS_DISPATCHER']
@@ -134,6 +136,30 @@ def start_control(host, port)
       end
     end
 
+    private
+
+    def notify_dispatcher(port)
+      return unless ENV['IDE_PROCESS_DISPATCHER']
+      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
+          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
+
   end
 
   class Exception # :nodoc:

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

@@ -17,36 +17,19 @@ def pre_child
             'stop'        => false,
             'tracing'     => false,
             'int_handler' => true,
-            'cli_debug'   => (ENV['DEBUGGER_CLI_DEBUG'] == 'true')
+            'cli_debug'   => (ENV['DEBUGGER_CLI_DEBUG'] == 'true'),
+            'notify_dispatcher' => 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
+        start_debugger(options)
       end
 
       def start_debugger(options)
         if Debugger.started?
           # we're in forked child, only need to restart control thread
           Debugger.breakpoints.clear
           Debugger.control_thread = nil
-          Debugger.start_control(options.host, options.port)
+          Debugger.start_control(options.host, options.port, options.notify_dispatcher)
         end
 
         if options.int_handler