lib/rflow/pid_file.rb in rflow-1.3.0 vs lib/rflow/pid_file.rb in rflow-1.3.1

@@ -1,15 +1,18 @@
 class RFlow
+  # Represents a file on disk that contains RFlow's PID, for process management.
   class PIDFile
     private
     attr_reader :path
 
     public
     def initialize(path)
       @path = path
     end
 
+    # Read the pid file and get the PID from it.
+    # @return [Integer]
     def read
       return nil unless File.exist? path
       contents = File.read(path)
       if contents.empty?
         RFlow.logger.warn "Ignoring empty PID file #{path}"
@@ -17,10 +20,12 @@
       else
         contents.to_i
       end
     end
 
+    # Write a new PID out to the pid file.
+    # @return [Integer] the pid
     def write(pid = $$)
       return unless validate?
 
       RFlow.logger.debug "Writing PID #{pid} to file '#{to_s}'"
       tmp_path = File.join(File.dirname(path), ".#{File.basename(path)}")
@@ -40,31 +45,37 @@
       pid_fp.close
 
       pid
     end
 
+    # Determine if the application is running by checking the running PID and the pidfile.
+    # @return [boolean]
     def running?
       return false unless exist?
       pid = read
       return false unless pid
       Process.kill(0, pid)
       pid
     rescue Errno::ESRCH, Errno::ENOENT
       nil
     end
 
-    # unlinks a PID file at given if it contains the current PID still
+    # Unlinks a PID file if it contains the current PID. Still
     # potentially racy without locking the directory (which is
     # non-portable and may interact badly with other programs), but the
-    # window for hitting the race condition is small
+    # window for hitting the race condition is small.
+    # @return [void]
     def safe_unlink
       (current_process? and unlink) rescue nil
     end
 
+    # Signal the process with the matching PID with a given signal.
+    # @return [void]
     def signal(sig)
       Process.kill(sig, read)
     end
 
+    # @!visibility private
     def to_s
       File.expand_path(path)
     end
 
     private