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

@@ -1,3 +1,6 @@
+## 3.2.0
+  - Declare plugin as not worker safe for both server and client mode. (IO#select is not threadsafe)
+
 ## 3.1.0
   - breaking,config: Remove deprecated config `message_format`
 
@@ -14,7 +17,6 @@
  - New dependency requirements for logstash-core for the 5.0 release
 
 ## 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

@@ -30,6 +30,8 @@ class LogStash::Outputs::Tcp < LogStash::Outputs::Base
   # `client` connects to a server.
   config :mode, :validate => ["server", "client"], :default => "client"
 
+  declare_workers_not_supported!
+
   class Client
     public
     def initialize(socket, logger)
@@ -61,9 +63,10 @@ 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         = '3.1.0'
+  s.version         = '3.2.0'
   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/logstash-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
-