Fixed issue #1183 - Repetitive json error on production log.

lib/sessions.rb

@@ -214,9 +214,10 @@ returns
     return false if !data
     path = "#{@path}/#{client_id}"
     data[:meta][:last_ping] = Time.now.utc.to_i
-    content = data.to_json
     File.open("#{path}/session", 'wb' ) { |file|
-      file.write content
+      file.flock(File::LOCK_EX)
+      file.write data.to_json
+      file.flock(File::LOCK_UN)
     }
     true
   end
@@ -261,7 +262,7 @@ returns
     end
     begin
       File.open(session_file, 'rb') { |file|
-        file.flock(File::LOCK_EX)
+        file.flock(File::LOCK_SH)
         all = file.read
         file.flock(File::LOCK_UN)
         data_json = JSON.parse(all)
@@ -432,14 +433,15 @@ returns
   end
 
   def self.queue_file_read(path, filename)
-    file_old = "#{path}#{filename}"
-    file_new = "#{path}a-#{filename}"
-    FileUtils.mv(file_old, file_new)
+    location = "#{path}#{filename}"
     message = ''
-    File.open(file_new, 'rb') { |file|
+    File.open(location, 'rb') { |file|
+      file.flock(File::LOCK_EX)
       message = file.read
+      file.flock(File::LOCK_UN)
     }
-    File.delete(file_new)
+    File.delete(location)
+    return if message.blank?
     begin
       return JSON.parse(message)
     rescue => e
@@ -466,13 +468,15 @@ remove all session and spool messages
     msg = JSON.generate(data)
     path = "#{@path}/spool/"
     FileUtils.mkpath path
-    file_path = "#{path}/#{Time.now.utc.to_f}-#{rand(99_999)}"
-    File.open(file_path, 'wb') { |file|
     data = {
       msg: msg,
       timestamp: Time.now.utc.to_i,
     }
+    file_path = "#{path}/#{Time.now.utc.to_f}-#{rand(99_999)}"
+    File.open(file_path, 'wb') { |file|
+      file.flock(File::LOCK_EX)
       file.write data.to_json
+      file.flock(File::LOCK_UN)
     }
   end
 
@@ -491,7 +495,9 @@ remove all session and spool messages
       filename = "#{path}/#{entry}"
       next if !File.exist?(filename)
       File.open(filename, 'rb') { |file|
+        file.flock(File::LOCK_SH)
         message = file.read
+        file.flock(File::LOCK_UN)
         begin
           spool = JSON.parse(message)
           message_parsed = JSON.parse(spool['msg'])

script/websocket-server.rb

@@ -237,11 +237,10 @@ EventMachine.run {
       next if client[:disconnect]
       log 'debug', 'checking for data...', client_id
       begin
-        queue = Sessions.queue( client_id )
-        if queue && queue[0]
+        queue = Sessions.queue(client_id)
+        next if queue.blank?
         log 'notice', 'send data to client', client_id
         websocket_send(client_id, queue)
-        end
       rescue => e
 
         log 'error', 'problem:' + e.inspect, client_id