Mark both client and server as not worker safe

This is due to IO#select not being threadsafe in JRuby

Fixes #13

Author: andrewvc

CHANGELOG.md

@@ -1,5 +1,6 @@
+## 2.0.3
+  - Declare plugin as not worker safe for both server and client mode. (IO#select is not threadsafe)
 ## 2.0.0
- - Plugins were updated to follow the new shutdown semantic, this mainly allows Logstash to instruct input plugins to terminate gracefully, 
+ - Plugins were updated to follow the new shutdown semantic, this mainly allows Logstash to instruct input plugins to terminate gracefully,
    instead of using Thread.raise on the plugins' threads. Ref: https://github.com/elastic/logstash/pull/3895
  - Dependency on logstash-core update to 2.0
-

lib/logstash/outputs/tcp.rb

@@ -38,6 +38,9 @@ class LogStash::Outputs::Tcp < LogStash::Outputs::Base
   # event will be written as a single line.
   config :message_format, :validate => :string, :deprecated => true
 
+  # respond_to? check needed for backwards compatibility with < 2.2 Logstashes
+  declare_workers_not_supported! if self.respond_to?(:workers_not_supported!)
+
   class Client
     public
     def initialize(socket, logger)
@@ -69,9 +72,10 @@ def write(msg)
   def register
     require "socket"
     require "stud/try"
-    if server?
-      workers_not_supported
 
+    workers_not_supported
+
+    if server?
       @logger.info("Starting tcp output listener", :address => "#{@host}:#{@port}")
       @server_socket = TCPServer.new(@host, @port)
       @client_threads = []

logstash-output-tcp.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
   s.name            = 'logstash-output-tcp'
-  s.version         = '2.0.2'
+  s.version         = '2.0.3'
   s.licenses        = ['Apache License (2.0)']
   s.summary         = "Write events over a TCP socket."
   s.description     = "This gem is a logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/plugin install gemname. This gem is not a stand-alone program"
@@ -27,4 +27,3 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'logstash-devutils'
 end
-