service_lifecycle.rb in contrast-agent-4.14.0

- old
+ new

@@ -11,10 +11,14 @@
       module ServiceLifecycle
         include Contrast::Components::Logger::InstanceMethods
 
         private
 
+        # Attempt to start up a local process with SpeedRacer. This will ensure the process isn't just a zombie and is
+        # a real functioning process.
+        #
+        # @return [Boolean] Did the SpeedRacer process start?
         def attempt_local_service_startup
           zombie_check
           service_starter_thread.join(5)
           is_service_started = Contrast::Utils::OS.running?
           if is_service_started
@@ -23,34 +27,40 @@
             logger.error('The bundled service could not be started. The agent will not function properly.')
           end
           is_service_started
         end
 
-        # check if there's a zombie service that exists, and wait on it if so. currently, this only happens when trying
-        # to initialize speedracer
+        # Check if there's a zombie service that exists, and wait on it if so. Currently, this only happens when trying
+        # to initialize SpeedRacer. If there is a zombie, we'll wait until the zombie completes.
         def zombie_check
           zombie_pid_list = Contrast::Utils::OS.zombie_pids
           zombie_pid_list.each do |pid|
             Process.wait(pid.to_i)
           rescue Errno::ECHILD => _e
             # Sometimes the zombie process dies between us finding it and killing it
           end
         end
 
+        # Determine the options used to set up the SpeedRacer process. Specifically, this handles if we need to adjust
+        # where the process needs to log.
+        #
+        # @return [Hash] options used to spawn the SpeedRacer process
         def determine_startup_options
           return { out: :out, err: :out } if ::Contrast::CONTRAST_SERVICE.logger_path == 'STDOUT'
           return { out: :err, err: :err } if ::Contrast::CONTRAST_SERVICE.logger_path == 'STDERR'
 
           { out: File::NULL, err: File::NULL }
         end
 
-        # This is a separate method so we can overwrite it globally in specs
+        # Create a new process for the SpeedRacer. This is a separate method so we can overwrite it globally in specs.
         def spawn_service
           options = determine_startup_options
           logger.debug('Spawning service')
           spawn 'contrast_service', options
         end
 
+        # Create a thread to start the SpeedRacer, making calls to spawn until one starts successfully. As soon as the
+        # SpeedRacer process starts, this thread terminates.
         def service_starter_thread
           Contrast::Agent::Thread.new do
             # Always check to see if it already started
             unless Contrast::Utils::OS.running?
               # Spawn the service process